Model Engine Maker

Engines => From Kits/Castings => Topic started by: Jo on June 01, 2019, 08:50:51 AM

Title: 15cc Seal and 30cc Seal Major
Post by: Jo on June 01, 2019, 08:50:51 AM
The design for the 15cc Seal was published in Model Engineer by Edgar Westbury in February 1947. It is typical of the pre-war straight four engine designs with water cooling, side valves and a two-bearing crank. From the first article Edgar suggested that the Seal was going to be the first of a number of four cylinder model engines he intended to publish promising both 15cc and 30cc designs of side and overhead valve arrangements.
Edgar chose to design an engine based around automobile rather than marine practice as it is simpler and lends towards straightforward methods of construction.

(http://listerengine.com/coppermine/albums/userpics/10007/Seal_GA.JPG)

In the UK Castings for this engine are available at a reasonable cost from Hemingway: http://www.hemingwaykits.com/acatalog/The_Seal___Edgar_T_Westbury.html and it makes up into a nice little engine:

(http://listerengine.com/coppermine/albums/userpics/10007/seal_fin5B15D.jpg)

While Edgar promised an engine in the larger 30cc size in 1950 David Braid beat him to publishing providing us with the Seal Major. Hemingway can also provide castings for this engine as well: http://www.hemingwaykits.com/acatalog/Seal_Major.html

dTmVyiUmqpQ
In his original article Westbury described the machining operations for his engine and the same techniques can be employed to build the larger Major, the Major requiring a lathe of greater capacity for the machining operations.


Our casting sets for both of these engines are Orphans  :'( the Seal being further along than the Major. So you can understand the starting point it is probably best we start by investigating their 'features'  :paranoia:

Jo

P.S. About the same time as Westbury published his Seal, Elmer Wall published his 50CC four cylinder Side valve engine the 501.

Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on June 01, 2019, 02:27:31 PM
Nice "new" project(s) Jo. Will you be building both at the same time?

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 01, 2019, 02:34:29 PM
Yes Bill the plan is to build both in tandem:

Status Review: Seal Major

The set of castings for the Seal Major has had less done to it than the Seal so this will be the main focus of this thread, while I am at it I will complete the Seal :)

The set of castings from Hemingway includes: Cylinder Block, Head & Cover, Sump, Bearing Housing, Timing End Plate, Timing Cover, Manifold Body & Cover, Valve Cover and the Carburettor Body. The set I have also includes Bronze connecting rods and the castings necessary to attach the water pump.

(http://listerengine.com/coppermine/albums/userpics/10007/Major_Castings.JPG)

There are two variations of this design one has a Horizontal distributor driven directly off the end of the camshaft:

(http://listerengine.com/coppermine/albums/userpics/10007/Seal_Major_Distributor.JPG)

The other design is for a vertical distributor driven off of some spiral gears which are difficult to cut or acquire and an impeller water pump:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1766.JPG)

 :thinking: So if I want to use those castings for the water pump I will need to cut some spiral gears.


As for the Castings:

I also have a set of timing gears that I cut for this engine when I was making the Kiwi timing gears (Westbury must have had a ready supply of 40DP gears of 20 and 40 teeth). A new set of Japanese bearings have been purchased for the crank to run in and an nice piece of EN8 has been sat there ageing for the crankshaft and there is an off cut of some sort of steel that can be used for the flywheel 

Assuming the crankcase has been bored in line I can't see any obvious problems starting on this engine  :-X

Jo




Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on June 01, 2019, 03:03:18 PM
Hello Jo,

Two nice little engines. I have always promised to build one for myself. Well perhaps one day

The other design is for a vertical distributor driven off of some spiral gears which are difficult to cut or acquire and an impeller water pump:
Jo

HPC Gears should be able to help you with some crossed helical gears. They have a large section in their catalog offering a wide range in both MOD and DP

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 01, 2019, 03:06:59 PM
Thanks Mike, I will look and see if HPC have some suitable gears for the Major.

Status Review - Seal


If you buy the castings from Hemingway for the Seal you get 10 castings: Cylinder Block, Head & Cover, Sump, Bearing Housing, Timing End Plate, Timing Cover, Manifold Body & Cover, Carburettor Body. Our set has a few more: 7 connecting rods  :headscratch: 3 pistons  :facepalm: and more than two sets of the additional castings to fit the water pump.

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1770.JPG)

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1769.JPG)

This engine has had a lot done to it but sadly it has not been finished hopefully we can complete it while the Major is underway.

Lets see what has been done:


Whoever started this engine had gone a long way. I'll have to review the fine measurements of the crank and camshaft at a later stage, in the meantime where to start  :thinking: Maybe a bit of fettling

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on June 01, 2019, 11:41:43 PM
Jo , I have an orphaned Seal 15cc also but not as much done as yours. Are you sure the horizontal distributor ran off the crank? I thought it ran off the camshaft, don't have my plans hand atm to check. Really looking forward to these builds
Mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Dave Otto on June 02, 2019, 12:00:52 AM
Hi Jo

Looking forward to following along with the new project/s!

Dave
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 02, 2019, 07:11:47 AM
Jo , I have an orphaned Seal 15cc also but not as much done as yours. Are you sure the horizontal distributor ran off the crank? I thought it ran off the camshaft, don't have my plans hand atm to check.

 :facepalm: You are right it is driven off the big gear.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: ChuckKey on June 02, 2019, 11:16:25 AM
Older aluminium castings from Hemingway or Kirk's predecessor Woking Precision can be infuriatingly soft and gummy. I found a slow speed, no more than for mild steel, and lubrication with Rocol RTD liquid usually gave a good finish with sharp HSS tools. Paraffin, my usual ally lubricant, was not much help. 'Course, somebody else may find dry, flying carbide works.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 02, 2019, 03:18:03 PM
Thanks ChuckKey, I know Kirk doesn't get his castings heat treated which would cure the gummy/sticky problem. Having had a fettle with the manifold these seem to have aged nicely and I am hopeful that they won't give me problems.

I decided to start by reviewing the manifolds, first the Seal which had its Carb mounted:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1771.JPG)

Clearly it won't fit  :ShakeHead: The answer is going to be to fettle off the bit of carb that has the air bleed in it. Hopefully the plugs will be clear when fitted  :noidea:

Both the Seal and the Major can be built either way round. I don't have this option as the timing plates have already been fitted. And someone has drilled for the water outlet on the Seal:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1773.JPG)

The next feature to think about is the bolts that attach the manifold to the Seal:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1775.JPG)

These are standard headed 7BA screws and there is no space to get the spanner in to tighten them. The options are to use hex bolts with a smaller head, slotted screws or Replace them with studs and nuts but they would have the larger hex again  :noidea:

One of the known issues with this engine is that one of the head threads crosses over one of the manifold threads in the block:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1776.JPG)

It is already drilled and tapped so it looks like it is going to stay there. And looking in the manifold it would be difficult to move the bolt holes without falling into the air gap:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1777.JPG)

This had been gunged together with Blue silicon sealant. Having removed that I found the surfaces were still a bit rough so they have been lapped flat using a piece of wet and dry on the surface plate. The carb on this looks good: the barrel is a nice tight fit and other than that solder tag  :facepalm2: which someone has tried to use as the friction spring its good to go.

 (http://listerengine.com/coppermine/albums/userpics/10007/IMG_1778.JPG)

However, the carb on the Major is a reject:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1779.JPG)

The barrel is a sloppy fit :Doh: the fuel hole in the bottom is not central so who ever made it tried making the hole in the bottom of the barrel larger so it won't suck very well. Thankfully the engine came with a spare carb casting so maybe someone realised that it was no good.

The other feature I found on the major was that someone has drilled both ends of the manifold for the exhaust  :headscratch: So were they intending on having one exhaust going forward and one backwards?

I think I need to get the major block up to the same stage as the Seal first....

Jo


Title: Re: 15cc Seal and 30cc Seal Major
Post by: Alyn Foundry on June 02, 2019, 03:50:08 PM
Be quick Jo.

I noticed Surrus has OD'd on the Snickers tub.... " to the casting cupboard " !!   :)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 02, 2019, 04:12:38 PM
Drawings seem to show that the manifold bosses should have been spot faced flush with the tops of the ribs not recessed so that does not help with the fit of your fixings.

You could make up some bolts with taller heads if you want to keep to the same hex, or some home made flange headed bolts would look good, maybe drop to 8BA hex on those. Failing that what about turning some thick washers and using the fixings you have if they are long enough.

EDIT Thinking about it a bit more the ideal solution would be to reinstate the bosses to the correct height. So recut the counter bores with a slightly larger cutter say 5.0mm or 5.5mm to get a crisp edge and go a bit deeper then Loctite in some new aluminium bosses and finally skim them all down to one height when the Loctite has set. :ThumbsUp:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: ChuckKey on June 02, 2019, 04:18:22 PM
You can get one-size-smaller BA nuts at EKP Supplies (among others).
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 02, 2019, 05:41:12 PM
Be quick Jo.

I noticed Surus has OD'd on the Snickers tub.... " to the casting cupboard " !!   :)

Thanks Graham... So much for us sharing the tub :ShakeHead: While I can remind myself what is in the cupboard I dare not take any  :hellno: He will make my life so difficult.


I am still thinking about the fixings.... you know how much I love my studs  :embarassed: and I was considering giving them  flanged nuts  :-X

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Roger B on June 02, 2019, 07:18:27 PM
Two interesting engines  :) I will be following along :wine1:

I know some of ETW's engines were designed as working engines like the Aero engines and the 1831/Wallaby. Were these also designed to power something or just for display?
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 02, 2019, 07:48:25 PM
Thanks Roger  :)

I know some of ETW's engines were designed as working engines like the Aero engines and the 1831/Wallaby. Were these also designed to power something or just for display?

The intention of the Seal was to provide a multi cylinder engine for a model boat like a motor cruiser or a launch of about 1m length. The Seal Major is for bigger boats  ;)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 04, 2019, 01:09:03 PM
Sorry for the delay in this build my Doctor thought I was a funding opportunity and has been checking I hadn't had a heart attack on Sunday  :paranoia:


Having survived that we are now back to the engine build  :) : The Seal has already been bored and had all its stud holes drilled and tapped. To be able to do this for the Major I decided to first turn up the liners:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1781.JPG)

The drawing shows the main part of the liner at 23.81mm but I have chosen to leave the top 6.35mm at 24mm.

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1783.JPG)

The reason for this is to make it easier to fit the liners into the block. 

As well as turning up the four liners I have turned up a 24mm/26.2mm plug gauge so it can be used to check the top of the liner tunnel in the block:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1782.JPG)

 :thinking: Suppose I should bore those next.

Jo



Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on June 04, 2019, 02:23:24 PM
Couldn't help but laugh at Surus laid out in a sugar coma after emptying the tub of Snickers ice cream. Nonetheless, you are making some nice progress Jo.

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Tennessee Whiskey on June 04, 2019, 07:58:13 PM
Doctors, lawyers, and morticians are three professions I try to avoid at all costs  :old:. Iím still watching BTW.

Big E
Title: Re: 15cc Seal and 30cc Seal Major
Post by: ChuckKey on June 04, 2019, 08:33:50 PM
Two interesting engines  :) I will be following along :wine1:

I know some of ETW's engines were designed as working engines like the Aero engines and the 1831/Wallaby. Were these also designed to power something or just for display?
All Westbury engines were designed to do work.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Mike Bondarczuk on June 05, 2019, 11:02:46 AM
Hi Jo,

Watching, admiring and learning.

Mike  :old:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 05, 2019, 01:16:58 PM
Any reason why they were parted off before boring?

Would boring at the same setting have ensured concentricity and no risk of distorting the liner by holding it's outside.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 05, 2019, 01:53:22 PM
Watching, admiring and learning.

Mike  :old:

Hi Mike, Thanks for following along. How's my old set of Clarkson castings coming on? We haven't seen any progress since  :noidea:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 05, 2019, 01:59:41 PM
Any reason why they were parted off before boring?

Would boring at the same setting have ensured concentricity and no risk of distorting the liner by holding it's outside.

Yes because it saved Cast Iron and as Mr Silky will be using his 5C collets to hold the liner for boring there will be no risk of distortion ;) and as for him not turning concentric  :lolb: He's not a red Devil  :hellno:

Jo

P.S.  Rumour is a Red Devil will be arriving on Sunday  :facepalm: I have to try and get rid of it before anyone sees it  :paranoia:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Bluechip on June 05, 2019, 03:21:33 PM

Jo

P.S.  Rumour is a Red Devil will be arriving on Sunday  :facepalm: I have to try and get rid of it before anyone sees it  :paranoia:


Looks 'water clear' to me .....  :headscratch:  But the second bit's probably right. I doubt anyone else will get a look in ...  :lolb:

Dave
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 05, 2019, 04:20:09 PM
Sounds promising Dave   ;)

Just had a fly past by another Red team the Red arrows: Will have to complain we only got the low flypast this year normally it is the full show when they drop by :disappointed: The Chinook boys make sure they rattle the windows when they do their flybys  ::)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Allen Smithee on June 05, 2019, 04:37:19 PM
They're all heading down to Normandy where there is some sort of commemoration going on.

AS
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 06, 2019, 07:15:33 AM


P.S.  Rumour is a Red Devil will be arriving on Sunday  :facepalm: I have to try and get rid of it before anyone sees it  :paranoia:

Just make sure you have a bucket of water to hand, don't want them to start interbreading ;)

I've only used red (and blue/cream) devils for milling preferring my Green and Yellow dragon for turning though I don't have any zero run out collets for it like you seem to have found, have you got a unicorn too? :LittleDevil:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 06, 2019, 07:25:14 AM
..... have you got a unicorn too? :LittleDevil:

Surus has the castings for one  ::)

Jo

P.S. If any one wants a set they are available here: https://www.ajreeves.com/unicorn/page/1/
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 06, 2019, 04:23:36 PM
I am still a little worried about the idea that one of our suppliers is supplying collets that Jason doesn't trust to run true and close down in such a way as they distort/crush a piece :facepalm: I wonder where he got them from... Maybe there is nothing wrong with the collets and someone was just being ham-fisted when they tighten them but it takes a lot of force to crush a tube   :noidea:


The liners were bored in a 5C collet, if you want to use an ER collet you will need an ER40 to hold these liners. They were first bored to 20.50mm and had a final cut of 0.05mm to provide a fine surface before Smelly hones them for me.

As you can see the finished walls are nice and thick but when we fit them we will not be looking to test the strength of these walls  :hellno: They will be a light press fit  all we have to stop is water leaks


The other little job I managed to get done was the Seal's sump screws. In the drawing these are shown as 7A countersunk screws, which are not easy to come by so I am using M2.5 stainless screws who for our purposes are as good as the same pitch as a 7BA. As expected with such a small deep hole not all of the screws lined up or went in square   :disappointed: A bit of hole realigning with a needle file and in the case shown using a milling cutter to move over the hole - they are all in and no-one is none the wiser  :-X

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 06, 2019, 04:44:37 PM
You missed my point that not even Hardinge Special accuracy collets run with zero runout, bit more runout with their standard ones :) Agree a collet will not distort like say a 3 jaw would.

So you don't have oversize ER32 collets either  ::), they fit my 24mm engines rather well so should be happy holding those liners;D
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Tennessee Whiskey on June 06, 2019, 05:01:37 PM
Other than by the grace of god will anything run perfectly true except a four jaw chuck; which if zero is required; requires the grace of god and the patience of Job :lolb: Just my two pence

Big E
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 06, 2019, 05:11:06 PM
You missed my point that not even Hardinge Special accuracy collets run with zero runout, bit more runout with their standard ones :) Agree a collet will not distort like say a 3 jaw would.

I got your point: you don't trust your collets. Have you been abusing them and trying to hold squares or hexes in round collets  :slap: that would make you worry about uneven forces and causing damage  :paranoia:

Could you explain why having a liner with even 0.5mm run out would make any difference on a straight 4  :noidea:

No I don't have any tools above 20mm so I don't need any over sized ER collets. If I need to go above 5C collet sizes I use Big C's collets.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 06, 2019, 05:56:01 PM
Jo second part of that quote, I agreed with you that if collets were used they should not distort or damage the round liner.

Well as the recess in he piston is 3/8" wide, little end also 3/8" wide and similar for the big end and crank you would have a rather tight engine if one or more of the liners was out by 0.5mm as there is not enough clearance. If there was some play say a 5/16" wide little end which is common on quite a few other engines then you would not have to worry.

I don't tend to use the large ER collets in the lathe as I have a 24mm 5C, but it is handy for workholding on the mill as I have a flange mount ER32 with 4 rather than the more usual 3 mounting holes that fits the Rotary table's 4 slots and is also nice to fix straight to the table as I can't mount my 5C chuck on either. I'll be using it to hold a cylinder end cover when I CNC the matching true eliptical boss for this piston rod gland to fit.

(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/829424.jpg)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 06, 2019, 06:03:20 PM
Well as the recess in he piston is 3/8" wide, little end also 3/8" wide and similar for the big end and crank you would have a rather tight engine if one or more of the liners was out by 0.5mm as there is not enough clearance.

This is the Major not the Seal.. Yes you should not have the top of the con-rod a tight fit in the bottom of the piston or the bottom end a tight fit on the crank :hellno: But it would not make any difference if the 12.7mm wide little end was 1mm narrower  ;)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 06, 2019, 06:28:29 PM

This is the Major not the Seal.. Yes you should not have the top of the con-rod a tight fit in the bottom of the piston or the bottom end a tight fit on the crank :hellno: But it would not make any difference if the 12.7mm wide little end was 1mm narrower  ;)

Jo

So it is, though same applies if any error were along the length of the engine. As you say making the little end a bit narrower will give a bit of float that will take up any slight variations in many parts such as block, crank, etc. without affecting the rods strength with the display running it will get, doubt it would even hurt if it were put to work. You could even go for a nice round metric number such as 12mm wide ;)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Tennessee Whiskey on June 06, 2019, 07:42:59 PM
Iíll let you two keep getting on with each other and Iíll quietly follow along

Eric



Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 09, 2019, 12:10:53 PM
The Seal has been started by someone who didn't have a milling machine as can be seen by the turning mark under the top cover :thinking: More features one of the Seal valve guides/seats has a pit on it  :facepalm: I don't think it will prevent the valve sealing but it is concerning


Its a challenging day: The Red Devil has turned up and is trying to take over bench space  :facepalm2: and if that isn't enough Surus is suffering with withdrawal symptoms :ShakeHead: In the meantime I really should make some progress on the Major  ::)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on June 09, 2019, 12:24:59 PM
More features one of the Seal valve guides/seats has a pit on it  :facepalm: I don't think it will prevent the valve sealing but it is concerning


'Should polish out'. As they say in my local garage :facepalm:

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 09, 2019, 01:46:14 PM
I suppose quite a few of your older orphans may well have been constructed before mills were as common in the home workshop as they are today.

A quick spin with some fine SiC powder and oil should ball all that valve needs unless it was sealing right on the rim in which case a few more mins work will be needed.

You can't tell us about red devils and then not show us :mischief:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 09, 2019, 01:55:05 PM
You can't tell us about red devils and then not show us :mischief:

Its boy racer Red  :facepalm2: I believe I have just doubled its total usage time by checking it cuts. Now I just need to find a new home for it before it thinks it can make itself at home  :paranoia:

Jo

P.S. I will accept castings in exchange for it   :naughty:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on June 09, 2019, 02:52:42 PM
So Red Devil just showed up on your doorstep?? Who was it that said one cannot have too many lathes  :lolb:

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 09, 2019, 03:08:33 PM
Its my (casting collection's) magnetic attraction Bill  :ShakeHead:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 09, 2019, 04:28:14 PM

P.S. I will accept castings in exchange for it   :naughty:

Preferably gold ingots ;)

As you say does not look to have had much use, did it come with other bits like 3 & 4 jaw chucks? Make sure you get it into quarantine as soon as possible.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Bluechip on June 09, 2019, 04:38:37 PM

So Red Devil just showed up on your doorstep??

Bill

Nope. Personally delivered by a Friendly Neighbo(u)rhood Fairy.

AKA  General Purpose Lower Class Subaru Operator of Little or No Consequence.  :(

Dave

PS Did also deliver Posh Slurp & Sticky Wotsits so I was not entirely unwelcome .... err .. I think     :headscratch:  ....

Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 09, 2019, 04:44:41 PM
Thanks Dave, I'll get it sorted and find a new home for it  ;)


As you say does not look to have had much use, did it come with other bits like 3 & 4 jaw chucks?

Someone lost the three jaw ::) but it now has an ER32 collet chuck and set of Imperialious ER 32 collets  :paranoia:  to go with it.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 13, 2019, 04:06:46 PM
Over the last few days I have turned up a set of valve guides out of Phosphor Bronze so I am now in a position to be able to start machining the top of the Seal Major Cylinder  :)

I have just started on the nuts for the Seal Cylinder head/cover and Manifold 30 are needed to be made then another set of 30 for the Major   :toilet_claw: There are so many other interesting things to be doing than nuts :ShakeHead:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: bouch on June 13, 2019, 08:23:44 PM
You can't tell us about red devils and then not show us :mischief:

Its boy racer Red  :facepalm2: I believe I have just doubled its total usage time by checking it cuts. Now I just need to find a new home for it before it thinks it can make itself at home  :paranoia:

Jo

P.S. I will accept castings in exchange for it   :naughty:

I have one of those, similar story as to how I got it.  Works fine for turning, but the tailstock center isn't the same as the headstock center, and as far a I can discern, there's no adjustment.

If you figure out how to get the two centers to match, I'd be interested in know how/what you did.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 13, 2019, 09:31:13 PM
Unsurprisingly I have had no interest yet Bouch :lolb:

I have one of those, similar story as to how I got it.  Works fine for turning, but the tailstock center isn't the same as the headstock center, and as far a I can discern, there's no adjustment.

If you figure out how to get the two centers to match, I'd be interested in know how/what you did.

That sounds about right for a Chinese quality machine  :facepalm2: Possibly the tailstock needs shimming up to get it in line but do I want to spend my time on it and neither did its previous owner :ShakeHead:

At the moment I am considering throwing away the tailstock and fitting a spare Schaublin capstan unit to it so that won't be a problem  :ThumbsUp: I will also trash take off the leadscrew with its engagement :-X mechanism and possibly even the cross slide as it doesn't seem to have much tool clearance, 80mm seems to be the limit but that won't be a problem as a capstan machine as the saddle will be converted to a cut off slide.

But I must try to keep going on the engines and not waste time converting a Chinese machine tool casting set into something actually useful, can you imagine the embarrassment if anyone saw it in my workshop :-[  :paranoia:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 15, 2019, 04:49:52 PM
Update: The Red Devil is still sitting there :lolb:


In the meantime I have been starting on some of the fiddly bits for the engines 1, the head and manifold nuts for the Seal  :Love: These are 7BA shouldered nuts made in 303 Stainless so there is no worry about rust  :ThumbsUp: Which is handy as they have just had a bath in the ultrasonic cleaner to removed the remains of the tapping fluid from the internal threads. I'll need to do a matching set of nuts for the Major..

While on a roll doing small stuff I decided to look again at the valve nuts. The original arrangement was decidedly odd having a 7BA tapped washer so I was not sure how you were supposed to adjust it :headscratch: I intend on working to drawings which means making some out of 6.35mm A/F Steel with shoulders but the original nuts were 8BA threads, my valves have been threaded 7BA.

Looking at the size of the hex and the springs that came with the Seal I realised that the spring were rather too big - in fact they are the same size as came with the Seal Major  :noidea: . Thankfully a very nice man  :embarassed: gave me a box of springs from which I found some 5mm ID springs which look about right.

Now we just need a few more days of rain so I can get some more workshop time  :thinking:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on June 17, 2019, 10:35:19 PM
Jo, Hi! Nice work on the nuts! can you go through the machining process to how you made them please, I have to make a batch for mine and was thinking there will be a lot of to and fro from the lathe to the mill !
thanks
Mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 18, 2019, 04:45:57 PM
Thanks Mark, I'll try to remember to document the ones I make for the Major later in the week  :old: .. I got bored doing them so today I did something more interesting  :naughty:

To find out what the casting was like I decided to start with mounting the sump: The drawing shows 10 mounting holes 4mm diameter  :headscratch: As the engine has BA threads this is a bit odd as it is neither 3BA or 4BA and for 4BA it would be rather slack. I opted to use 5BA mounting screws so drilled 3.2mm. Drilling from the inside to see where the holes were relative to the bosses they were drilled and the other side countersunk to match the screws.

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1821.JPG)

I checked the mounting position of the sump on the crankcase before drilling and tapping those:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1822.JPG)

It is also important to find the centre again as the crankcase is offset:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1823.JPG)

I was worried about how little metal there was just under the lip as I could see the drill breaking through the side and  :facepalm: it did, it broke a screw  :ShakeHead:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1825.JPG)

It fitted ok:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1826.JPG)

following on from that success I decided to do the cylinder head and the top cover. The cylinder head is very difficult to hold and had to be packed round the sparkplug lugs and to play it safe I added a tool maker's jack. Again drilling from the side where you can see the lugs the holes were drilled this time 3.6mm for 4BA clearance. While at it I took the head casting to the same length as the crankcase:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1827.JPG)

The top cover was similar except that it was necessary to face the top of the cylinder head stud nut lugs and I decided to mill the part number off the top of the cover but leave the outline so that it can be used for stamping in some sort of identification:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1828.JPG)

So the two engines are nearly up to the same stage:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1829.JPG)

Now for the exciting bit: :paranoia:

Jo

Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 18, 2019, 05:01:58 PM
Coming along and so much nicer to follow the thread when the photos are in with the text :)

Time to dust of the pantograph  :stickpoke: for a bit of engraving rather than risk damaging the head with a stamp.

Title: Re: 15cc Seal and 30cc Seal Major
Post by: Roger B on June 18, 2019, 06:44:22 PM
Good progress  :praise2:  :praise2:  Is Tigger sitting on Tigs ?
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 18, 2019, 07:57:53 PM
Thanks Guys  :)

Is Tigger sitting on Tigs ?

Yes  ::)

My sister kept buying me Winnie the Pooh thingies including two Tiggers who liked the workshop so much they have moved in around Tgs  :noidea:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on June 18, 2019, 10:53:21 PM
Great progress Jo. That's a lot of holes too!!

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 19, 2019, 04:09:04 PM
As I had the vice set up and all the stud dimensions defined for co-ordinate drilling I decided to drill:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1830.JPG)

and using the UPT tap:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1833.JPG)

The cylinder so that the head alignment could be checked:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1835~0.JPG)

Then realised the Seal one is not aligned:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1836~0.JPG)

So that will need to be sorted out  :facepalm: and couple of pics of Tgs friends attached for Roger. Anyone would think they knew they were being photographed   ::)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Roger B on June 19, 2019, 05:38:45 PM
 :)  :)  :ThumbsUp:  :ThumbsUp:  :wine1:  :wine1:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on June 19, 2019, 10:30:57 PM
The alignment doesn't look that bad Jo. What is the other side like?

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 20, 2019, 11:35:37 AM
I've spent the morning setting up the Seal Major to bore for the liners: having used a ruler against the side of the valve chest I then put a bar through the crank holes to find the valve chest face is not 100% parallel to the crank line  :facepalm:

And the sides of the crankcase are not square to the bottom face either  :ShakeHead: thankfully both the base and the bottoms of the mounting lugs are so the cylinder can be clamped down using that  :) The cylinder has been centred up on the centre line of the crank and the length of the casting.

On fitting the boring head I found that there is a feature  in the drawing  >:( Depending on which drawing you look at (Seal or Major) either the cylinders are on the crankshaft line or they are offset.... Time to have lunch while I check which is right - hopefully it needs an offset as the bore is going to be dangling in mid air if it doesn't  :toilet_claw:

Edit: The Seal Major locates the cylinder bore 4mm offset from the crankshaft. The Seal drawing shows the cylinder in one view on the same line as the crankshaft and another 3.18mm offset. So it looks like the holes in the casting are ok  :ThumbsUp:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 20, 2019, 12:02:27 PM
Just got to hope they put the camshaft holes inline with the crankshaft ones, may be worth checking while you have it set up and that the crank bore is horizontal when the top of the casting is horizontal in the X axis..

Can't see anything on the drawings or articles that I have that would suggest the bores are on ctr line?

Where did you get that precision ground test bar, do I need one too? ;)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 20, 2019, 02:41:04 PM
Can't see anything on the drawings or articles that I have that would suggest the bores are on ctr line?

See the Seal drawing of the cylinder (attached) from above the cylinder bores look to be on the same line as the crankshaft. I think the two bosses are actually supposed to be the water gland mounting.

You only need one of those special bars if you are intending on making a model ploughing engine  ::)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 20, 2019, 03:33:30 PM
I took that as being the width of the oval boss, a measure of your glands may confirm that!

I can see its use for the ploughing engine now as it comes with a ploughed surface :LittleDevil: best get on with that BB1 before it all turns to iron oxide :stickpoke:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 20, 2019, 04:38:17 PM
... best get on with that BB1 before it all turns to iron oxide :stickpoke:

The BB1 is one of the sets of model castings I have already lined up for my retirement  ;D The problem is now that I am retired I still need more time  :facepalm: and castings  :mischief:


The required bore dimensions are just between the standard and into the extended capability of the chosen boring head. So I started by boring all four liner holes to the maximum 22.7mm that was obtainable using the long Swiss boring bar I had chosen for this job - it has to be a long boring bar as it has to do both the head and the bottom of the water jacket. It was a bit fun doing the lower hole as they were not absolutely inline with the top holes so there was a danger of thinking everything was dandy going through the top hole only to crash into the casting at the bottom.

The good news is that all four liner holes are out to 22.7mm and the boring head has had its extender fitted and the boring bar adjusted to just scrape the existing bore so we are ready to go for the morning  :cartwheel: That is if don't indulge in too many  :wine1: while we do a bit of casting fondling this evening  :embarassed:

Jo

P.S. How's the plumbing coming along on your traction engine  ::)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 20, 2019, 04:53:16 PM
I think there is more chance of you getting all your casting sets made up and running than me plumbing up the Fowler :-[

Just can't get enthusiastic about it and even if I did plumb it up and do the other few bits it would just go back into the same corner as I'm not into sitting in a soggy field all day which reminds me why am I going to Guildford :headscratch:
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 20, 2019, 05:18:44 PM
... which reminds me why am I going to Guildford :headscratch:

You are going so that you can inspire young people (and possibly older people ) that there is more to model engineering than playing Choo Choo trains  :stickpoke: and so that you can talk to fellow enthusiasts who build model engines and to admire/discuss the progress on their model engines  8)

We have to support the shows or we will loose them  :'(

Jo

P.S. There is also the free Bacon Buttie on Saturday morning  :P
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Mike Bondarczuk on June 20, 2019, 07:24:29 PM
Hi Jo,

When is the Guildford meeting and is it still at the same location as for the last few years.

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 20, 2019, 07:31:06 PM
Hi Mike,

Same place as normal, first weekend in July (6th & 7th). I'll be there Saturday  ;)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 21, 2019, 11:13:58 AM
So much for being able to start the final boring for the liners - Last night I luckily remembered that I had to hone the liners before fitting them  :old:

Not unexpectedly I found that I did not have a suitable size hone to be able to do this on Smelly  :( so back to the old way of doing it: find a piece of ali bar of a suitable diameter, cut a tapered bore to match my arbour and cut three slots to allow it to expand equally up the arbour. A bit of fine grinding paste some oil and gently move the  liner up and down the hone to smooth the surface.

Equally important is to get all the grinding paste off of the liners - time to try that little ultra sonic cleaner so filled with boiling water and washing up liquid I am trying the liners in that (having first used brake cleaner to get off the worst of the oil/paste.

Edit: I have just removed the liners from the ultrasonic cleaner and was very pleased by just how much extra muck it managed to extract from the liners  ;D

Hopefully after lunch I can do the cylinder boring for the liners  :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on June 21, 2019, 11:22:04 AM
Shame the lathe bed won't fit in the U.S. Cleaner :'(

I would not even treat the green dragon like that
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 21, 2019, 12:28:03 PM
Shame the lathe bed won't fit in the U.S. Cleaner :'(

I would not even treat the green dragon like that

Having seen the quality of the metal that Chinese lathes are made of I totally understand your concerns JB   :facepalm2: But Mr Silky and my other ex-industrial lathes are made of a totally different quality metal than you are used to and they are designed to cope with much more than just a couple of drips of grindy oil  :Lol: A rag soaked in a bit of brake cleaner easily cleans it off, there is no worries about it soaking in ;)


First task is to bore each hole to fit the bottom of the liner, once the top will take the liner the bottom will as well:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1858.JPG)

Then we can look to take out the top that extra 0.2mm for the top step:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1859.JPG)

Last bit is to bore out the top for the collar:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1860.JPG)

Then the liner will push all the way in, but for now I will leave it nearly in its hole:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1861.JPG)

And after a cuppa I will start the next one  :)

Jo



Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 21, 2019, 04:10:58 PM
Another two cuppa's (and some sticky wotsits  :-X ) later and we have four liners fitted:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1862~0.JPG)

I decided to play it safe and try marking the valve guides 20.63mm out from the liners and it is clear they have to go over 24.63mm. We are all set up to repeat the same set of machining tasks job for the valve guides  :wine1:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on June 21, 2019, 10:52:23 PM
Jo, on the basis that no question is stupid if you don't know the answer, (and you may find this stupid but I don't know the answer!), with your ali, or aloominum, hone, I can understand the taper bore and the three slots but are the three slots joined at any point and if so where?  Logic says they are, but the photo seems to show the same slots emerging from both ends of the liner, which would mean three seperate slices of ali up the liner???

Chris
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 22, 2019, 07:35:14 AM
Morning Chris,

In case others have similar questions I will go through the whole honing tool design:

The honing set up consists of two metal arbors that I have cut tapers on, to match a tapered reamer, on the end is a thread which is used to force a mandrel up the taper.

The mandrels are bits of Ali which have been drilled and reamed using said tapered reamer. To enable these mandrels to expand I have cut slots down the side of the Ali, in this case 3 slots: 2 only go part way down the Ali from opposite directions and the third goes all the way through the Ali (on other mandrels I have chosen to cut to depth on all but one slot, the last being taken through I am not sure which is best  :noidea: ). The sharp edges are then cleaned up....

In use the Mandrel is slid onto the Arbor and the nut on the thread is used to adjust the size of the mandrel by forcing it up the taper so that it is fractionally under the size of the bore of the liner. Oil and grinding paste is applied to the outside of the Ali and the liner gently moved up and down with the lathe running slowly. Once the liner moves freely over the mandrel the bore of the liner is checked and if necessary the nut tightened to expand the mandrel further for another hone.

Hopefully that is clear  :) A pic attached of said mandrels and the tapered reamer used.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: ChuckKey on June 22, 2019, 09:14:01 AM
Pedantry Corner: what you have there are laps. Hones are the things with solid blocks of bonded abrasive material.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on June 22, 2019, 10:30:44 AM
Morning Jo,     (gosh, you are up and about early for a retired gentlefolk!)

Many thanks for the detailed explanation and picture - all now very clear, clear as the proverbial mountain stream.  :ThumbsUp:

Chris

I'll retire now back into the background to watch the build and leave you to get back to trading banter with Jason!
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 22, 2019, 01:13:38 PM
Pedantry Corner: what you have there are laps. Hones are the things with solid blocks of bonded abrasive material.

Quiet right  :old:  :old:

gosh, you are up and about early for a retired gentlefolk!
.......I'll retire now back into the background to watch the build and leave you to get back to trading banter with Jason!

One has to make the most of one's remaining time: lying around in bed doesn't produce swarf. I am not sure if I would use the term "banter" for Jason's constant criticisms  :hellno:


I hope to get back in the workshop shortly to do the valve guides  :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on June 22, 2019, 02:25:43 PM
Well, "banter" sounded so much better than "slagging each other off" Jo!!    :LittleDevil:   
But it does make for amusing reading for the rest of us, so please do keep it up!!   :cheers:


Chris
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 25, 2019, 12:28:25 PM
All the valve guide holes have been bored so that the guides are a push fit in their respective holes.

Each hole has been de-swarfed and had Loctite applied before pushing home the guide/liner. These now need to be left for 24 hours before the final finishing cut across the top of the cylinder can be done with the large facing cutter.

In the meantime Mr Silky has been complaining about a lack of attention and is trying to encourage me into doing some studs and he knows how much I like playing with all those nuts I still have to do :facepalm:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Stuart on June 25, 2019, 12:45:32 PM
Well, "banter" sounded so much better than "slagging each other off" Jo!!    :LittleDevil:   
But it does make for amusing reading for the rest of us, so please do keep it up!!   :cheers:


Chris

They sound like a married couple  :Jester: runs for cover under the duvet
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 26, 2019, 04:59:25 PM
A quick wizz down the side so that it is square to the crankshaft line:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1868~0.JPG)

And a couple of skims off the top:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1870~0.JPG)

And the Major block is looking similar to the Seal one:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1871~0.JPG)

 :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Johnmcc69 on June 26, 2019, 05:36:35 PM
 :ThumbsUp:
They look great Jo!

 John
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 26, 2019, 05:53:08 PM
Thanks John  :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on June 26, 2019, 06:36:06 PM
"Lord; Lead us not into temptation"

They are looking so good.  :ThumbsUp: :ThumbsUp:

I would love to find the time to build a Seal Major for myself. One day perhaps.

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on June 27, 2019, 10:24:51 AM
Thanks Mike, one of these days I may come own to visit you and could bring these two down for a visit  ;)


When I acquired my Seal castings from my supplier a bag of little brass mushrooms came with it: These are intended to go on either end of the gudgeon pin as end caps to prevent the gudgeon pin drifting sideways and scoring the liner except, pretty as they are and made to drawing, they are wrong  :( Actually the drawing is wrong and they are correct to the drawing .

Gudgeon pins are easy to make as they are nothing more than a piece of steel turned to length and a hole drilled through the centre. The hole does two things: it lightens the weight of the pin and it provides something to attach those little brass mushrooms with. The drawing mentions hardening the pins but as the pistons are aluminium and the rods ali or bronze I cannot see any need to harden them - if you feel the need then it needs to be done before fitting the end caps.

I am not sure how someone turned those little mushrooms - they strike me as tricky little  :censored: to make. My technique is to turn a piece of suitable sized brass down so that it fits in the hole, drill the all important little hole through the centre of it then part it off over sized. Having turned all 8 in each size they are then stuck into the end of the gudgeon pin for turning.

Now we come to that feature :ShakeHead: in the drawings which means the little bag of mushrooms were made wrong. The 0.8mm dimension is the total height of the brass top not the dimension of the parallel bit, if you make them to drawing the gudgeon pins will be too long to fit in the liner bore  :disappointed: Hence it was necessary to turn that beautifully curved top off on each of them. Personally I use a hand file the curve to match the liner curve rather than using a form tool which is what I think was used to do the originals.

My supplier stressed the importance of getting all of the rotating masses (Piston, gudgeon pin and piston rod) the same so I checked the weight of each of the gudgeon pins and was happy to find that each pin, in each set, weighs the same as the other 3 and that the Seal gudgeon pins weigh exactly 1/2 that of the Major's ones  :thinking:

Piston time  :whoohoo:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on June 27, 2019, 01:58:44 PM
Going back to your lapping method Jo, thinking more about it, I can see it having quite an advantage in that once you have the mandrel and tapered reamer, then all that is to be made is the just a simple turning/drilling/reaming/slitting job on a bit of ali bar.

Up to now I have used Ramon's lapping method (his Lapping Thread from 2013) using a bit of copper plate bent circular and silver soldered to an adjustable rod core; works very well but a bit longer to make, each one is different and needs making entirely, and a bit more expensive maybe in materials.

I mention this as I am making another one now; had I a suitable tapered reamer I might have tried your method!

Nice work on your two orphan engines by the way.

Chris
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on July 01, 2019, 10:01:56 AM
Hi Jo, when you bored the block and fitted the liners did you have an interference fit? If so what was it? I have just bored my seal and machined the liners to have at the moment .0015" , will this be too much?
Thanks
Mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 01, 2019, 12:24:50 PM
Hi Mark,

The liners were made a light push fit and secured with Loctite which also helps seal the water jacket.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Del_61 on July 02, 2019, 02:32:38 PM
Hi there my first post on this website, so be gentle...!

When I did my apprenticeship last century I was told to allow for an interference fit of 0.001" per inch diameter. So Mark, I suspect that 0.0015 is a bit too much of a tight fit for your liner and bore.

Jo's suggestion seems better, but judging the light push fit is the difficult part, no way would you want to end up pressing in a liner and getting half way and it refuses to go in any further....and then very difficult to remove!

Another idea would be to first pop the liners in the freezer for a few hours before attempting to fit them in the bores.

Regards

Del
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 02, 2019, 05:58:08 PM
Thanks Del, as you are newbie would you like to start a post in the introduction area about yourself and your interest in model engines  :)


Things have been slow doing these pistons  :( To start with I have no castings for the Major and only 3 for the Seal:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1875~0.JPG)

These cannot be used as I need 4 pistons of the same weight so all have to be made out of barstock  :Doh:

I have chosen to make the pistons back to back as this makes them easier to hold in the dividing head. Each piston has its outside turned to size and then has the inside turned. I am not sure if the under cut just beyond the gudgeon pin hole is of any benefit but I will do it any way.

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1878.JPG)

The depth was correctly achieved using a slot drill. To get the depth measurement right a 1mm thick rule was used to zero the tailstock dial and then plunged in to provide the depth:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1876.JPG)

The contours inside can then be turned and the undercut achieved using an internal circlip tool:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1877.JPG)

Now the pistons can be mounted and have their gudgeon pin holes drilled and reamed:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1879~0.JPG)

Having turned then bottom up the centre section needed to be milled out to allow for space for the piston rods. On the first Seal one I got the size wrong as I went by the dimensions on the connecting rod end and only when I looked closely at machined piston did I realise that there was a good chance the piston ring groove will break through  :paranoia:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1881.JPG)

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1883.JPG)

The set of pistons are coming on:

(http://listerengine.com/coppermine/albums/userpics/10007/IMG_1882.JPG)

Before going further I decided it was necessary to see if I can make rings of the required size.

Jo





Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on July 02, 2019, 09:56:54 PM
Halfway there on the Pistons for both engines. Nice work. Hope the ring making goes just as smoothly for you.

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 02, 2019, 10:06:13 PM
Thanks Bill  :)

Hope the ring making goes just as smoothly for you.

Its not the making that I am worried about. The Seal ones are 16mm diameter and 1mm square so there is a high probability of breaking them when trying to fit them to the pistons if the heat treatment is not spot on  :paranoia: The Major's ones are not much better 

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Roger B on July 06, 2019, 10:45:00 AM
1mm square is big for a 16mm bore. I think I ended up with 0.8mm deep having broken most of the 1mm ones. 0.5mm was too thin.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 06, 2019, 07:55:27 PM
Thanks Roger  :) I made a point of discussing ring thickness today at the Guildford show and the boys agreed with you 0.7 to 0.8mm thick is probably good  :ThumbsUp:

I was in trouble with Vixen as I failed to take these two engines to the show today   :facepalm2:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 07, 2019, 02:17:02 PM
Piston Rings are done  :)

These are a simple turning exercise: Turn the outside to fit the bore, bore the inside to leave the required ring thickness (1mm for the Major and 0.75mm for the Seal) score the inside with the boring tip then using an old slitting saw blade as a parting off tool slice off the rings.

Finally give the rings a rub on wet and dry paper on each side to clean up the surface. This is not as easy as it sounds  :ShakeHead: It is very easy to end up with a ring that is thinner on one side than the other so it is worth checking with a micrometer. I used a pot chuck to hold the ring while giving it a rub on the paper.

Split the ring by holding the ring in a vice with the score line right on the edge and using a pair of parallel action pliers gently rock the ring until it breaks. I clean up the ends after heat treating.

My version of heat treating is to spring the rings round a bit of steel then hang them in the hearth. The rings are then gently heated and as they take the set they loose their springiness so drop off the bit of steel. These are then allowed to cool at their own pace still surrounded by the heat in the hearth. Once cool the rings can have their ends filed to give the appropriate gap when fitted to the bore.

I checked one ring to make sure it did not want to break when sprung over the Major piston and it survived so now that I have my set of rings it must be time to finish off those pistons.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on July 07, 2019, 02:24:18 PM
Nice work on those rings Jo. Did you make any spares....just in case?

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 07, 2019, 02:25:31 PM
Thanks Bill, there is one spare ring for each engine so I will have to be careful  :paranoia:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on July 07, 2019, 08:03:22 PM
Jo, They look great! The rings Kirk supplies are .8mm thick. How much smaller did you make the pistons for the Seal? I will make mine this week, liners were lapped and fitted yesterday, hope to make the valve cages later today
cheers
Mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 08, 2019, 07:45:43 AM
Is the 0.8mm for the Major or Seal Mark? I did my Seal ones about that size.

How much smaller did you make the pistons for the Seal?

I made mine a rattling good fit  ::) What that means is reasonable fit in the liner but if you put your fingers over top and bottom and shake it too and fro it is free moving in the liner  :) If I had done cast Iron pistons they would have been lapped to fit and would wear in on the first run.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on July 08, 2019, 09:29:14 AM
Jo, .8 for the Seal. Well actually 1/32" in the old language . So do you think .1mm smaller for the Pistons? Or a bit more??

Thanks
Mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 08, 2019, 12:26:44 PM
Nearer to -0.02mm. Test the liner on the piston as you turn it down.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: gadabout on July 08, 2019, 07:59:57 PM
Jo,
thanks, thats not as much as I was thinking!

cheers
mark
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 09, 2019, 11:59:53 AM
All the rings are on the pistons. They are a bit fragile and there was one breakage  :Doh: The biggest challenge was getting the bottom ring on. I chose to put them on in reverse and slide them up the piston by pushing the piston into the bore of the cylinder.

The drawings show the bottom of the liner is chamfered, this is to enable the pistons with their rings to be easily inserted into the liners. Of course this has not been done on either of the engines  :ShakeHead:. It is possible to put the pistons in from above but it is a bit of a challenge so I have decided to add the chamfer, which would have been so easy on the lathe before fitting the liners  :facepalm:

This is going to be done from the bottom which needs a longer boring bar than I have so I have had to make another chamfering bit out of silver steel. I will cheat and do this machining holding the cylinders in a vice. This will require my big heavy vice on the table so time to get the roller skate out.

I probably won't get this finished today as I have other jobs to do  :toilet_claw:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on July 09, 2019, 12:19:10 PM
To put the pistons into liners from the top generally needs either a clamp making up which clamps around the piston compressing the rings into their grooves but not too tightly done up so as to stop the piston being gently pushed through it and into the liner, or, a fixture fitting around the top of the liner with a bore tapering from uncompressed ring diameter down to liner bore diameter, with a short parallel section at liner bore diameter at the bottom, to push the piston and rings through.  Both methods benefit from the use of oil, copious amounts in the case of the second method, which is how we did it on big ships.

I appreciate this is teaching granny to suck eggs stuff to most folk on here but I mention it to others who might not know.   :old:

Chris
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 09, 2019, 12:22:45 PM
Thanks Chris, it is always worth mentioning other methods  :ThumbsUp:

 :thinking: I could make a tapered brass piston fitting jig... rather than doing all the chamfering - it would be much quicker..

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on July 09, 2019, 01:15:19 PM
Can you get the wrist pins in from below? Big ends don't look like they will fit down the bore so you would need to fit the conrods after the pistons if fitting them from above. probably easier to fir rods and pins and then poke the lot in from below.

Personally I like to get all the conrods and crankshaft fitted to see how things turn over before fitting the rings as you can feel for any tight spots which the friction of new rings can hide.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 09, 2019, 04:14:57 PM
The conrods are long enough to poke through from underneath and to fit the gudgeon pin into the piston above the top of the cylinder and then draw it all down onto the crankshaft.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 11, 2019, 11:10:39 AM
I opted to make a couple of tapered guides to enable the pistons to be fitted with their rings into the liners. They are about half the length of the pistons and when you poke the piston through they close up the rings.

But I still broke a ring  :toilet_claw:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on July 11, 2019, 11:42:30 AM
They all look nice and snug. Hope you end up with two pistons up and two down, rather than all in a straight line :Lol:

What type of CI did you use? Continuous cast or centrifugal cast?

cheers

Mike

Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 11, 2019, 11:54:35 AM
Thanks Mike  :)

What type of CI did you use? Continuous cast or centrifugal cast?

I am using some of that very nice centrifugal cast that our supplier acquired in 29mm sticks. He started off with 10s of feet of the stuff but has much less these days  ;)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on July 11, 2019, 12:09:43 PM
Sounds like some very good stuff from your supplier.

I am looking for some 45mm diameter centrifugal cast for the Jupiter. Two compression and one oil control ring per cylinder, that's a lot of rings and CI.

What technique did you use to  trepan out the centre of the bar, so you could reuse the remaining CI for smaller engines?

cheers

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 12, 2019, 11:20:45 AM
Hi Mike, I have tried using various tools but things like hole saws will not let you get very deep. I have a number of specially shaped HSS tools but loose about 10mm on the diameter if I use those  :-\


About this point a set of connection rods would be useful  :thinking: The Seal came with 7 Ali rods, actually 4 match, 2 are suspect and one is totally different  :headscratch: . The Major came with 4 Bronze rods.

The starting point is to put in the big end bolts: The drawing for the major shows 5BA bolts, which we all know are like rocking horse do-dahs to get hold of so I will be using 1/8 Whit cap head screws. The Seal shows 8BA but I only have slot headed screws which is not a good idea .. I wonder if I can get hold of M2.5 Cap heads.

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Bluechip on July 12, 2019, 11:38:35 AM

I wonder if I can get hold of M2.5 Cap heads.

Jo

Ho Yus

https://www.kayfast.co.uk/view-product/SOCKET-CAP-SCREW-DIN-912-HIGH-TENSILE-SELF-COLOUR

Not uncommon actually   :ThumbsUp:

Dave

PS  In fact, I think I might have some ....  :headscratch:  What length are we looking for ??? ... Well, you ... I suppose.  :)

PPS A quick shufti reveals I have M2.5 10mm & M2.5 x 12mm
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Stuart on July 12, 2019, 11:50:58 AM
Another source of small fasteners

http://www.modelfixings.co.uk/index.html


Do small quantityís as well

No affiliation just a satisfied customer

Worth a look for small bearings as well
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 12, 2019, 12:01:39 PM
10mm or 12mm long would be perfect  :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Bluechip on July 12, 2019, 12:31:38 PM
10mm or 12mm long would be perfect  :)

Jo

How many of each ??  When do you want them?

Dave
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 12, 2019, 12:43:43 PM
Thanks Dave,

I need 8 for the Seal rods plus some spares in case the Workshop gnome gets back from the cricket world cup and takes a shine to them  ::)

No great rush but it would be nice to have them to make the rods with  :)

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on July 12, 2019, 12:56:15 PM
Hi Mike, I have tried using various tools but things like hole saws will not let you get very deep. I have a number of specially shaped HSS tools but loose about 10mm on the diameter if I use those 
Jo

That's more or less I have found. I had hoped you would have a method to reliably trepan a couple of inches deep from both ends of a CI bar.

Anyone else have any good ideas?

Cheers

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Bluechip on July 12, 2019, 01:28:38 PM
Thanks Dave,

I need 8 for the Seal rods plus some spares in case the Workshop gnome gets back from the cricket world cup and takes a shine to them  ::)

No great rush but it would be nice to have them to make the rods with  :)

Jo

Rightey-Ho  Sarge ....   I have bagged up [ 20 off]  each of the following:

M2 x 10mm
M2 x 12mm
M2.5 x 10mm
M2.5 x 12mm

Will probably post tomorrow AM

 :ThumbsUp:

Dave


Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 12, 2019, 01:32:38 PM
 :-*
Title: Re: 15cc Seal and 30cc Seal Major
Post by: b.lindsey on July 12, 2019, 01:48:22 PM
Glad to know that the cylinder insertion tool worked well for the most part. That is one task you are probably happy to have behind you now.

Bill
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on July 12, 2019, 03:11:32 PM


That's more or less I have found. I had hoped you would have a method to reliably trepan a couple of inches deep from both ends of a CI bar.

Anyone else have any good ideas?

A bit long winded but you can use a cranked tool to undercut each ring and then part off which leaves the core intact, probably a task for a rear mounted parting tool and the cranked tool in the main toolpost. As the undercut is shallow you don't get a problem of swarf buildup like you would if doing a long length in one go

(https://img.photobucket.com/albums/v156/jasonballamy/Hit%20n%20Miss/Robinson%20X-Type/DSC02644_zpsueii6nu7.jpg)

If you really want to see how it's done have a look at some of this guys videos.

Jvr_9GfVbdU
And how to make the cutter

R--RjyOrrsA
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on July 12, 2019, 05:22:43 PM
Yup, that's the way to do it.

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Johnmcc69 on July 12, 2019, 06:57:33 PM
Now that's some pretty amazing tool making there!

 Just...WOW!!!

 John
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Laurentic on July 12, 2019, 07:11:05 PM

But I still broke a ring  :toilet_claw:

Jo
That's why you need copious amounts of lub oil - dry and they all would have broke I suspect. !!  Fragile animals, piston rings.
Glad it worked

Chris
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Roger B on July 12, 2019, 07:47:21 PM
Hi Mike, I have tried using various tools but things like hole saws will not let you get very deep. I have a number of specially shaped HSS tools but loose about 10mm on the diameter if I use those 
Jo

That's more or less I have found. I had hoped you would have a method to reliably trepan a couple of inches deep from both ends of a CI bar.

Anyone else have any good ideas?

Cheers

Mike

I have had success with some Bosch hole saws in cast iron and aluminium. This may be because my bench drill is the most powerful machine I have. The hole saws are 40mm deep and the pieces I was working on were 78mm long.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 15, 2019, 07:21:17 PM
Following on from the postman delivering the big ends screws for the Seal (Thank you Dave   :) ) each of the rods have been drilled and tapped.

The trick to position the rods in the vice for drilling the bolt holes is to use the centre line of the rod to get it square in a vice then to  balance out the spacing of the bolts to get the same amount of metal around both bolts.


The next trick is to position the slit in the rod so that it is at the right distance from the centre of the small end boss  :thinking:

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 16, 2019, 06:29:17 PM
My supplier. having first sold me the connecting rod castings for the Seal, said "ho I wouldn't bother with them I'd use barstock"   ::)

Starting with the Major's rods the small end is pinned to the jig so that the middle of the small end is under the spindle and then clamped in place. It can then be drilled and reamed. Looking at the positioning of the hole it is not central on either side of the rod but is a balance between the two. I have four usable Major rods ready for the next phase.

However  :Mad: having drilled and reamed the Seal's ones bits started coming away from the castings leaving holes  :toilet_claw: So I will be making the Seal rods out of Bar Stock  :facepalm: maybe tomorrow

Jo
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Craig DeShong on July 17, 2019, 08:23:32 PM
My supplier. having first sold me the connecting rod castings for the Seal, said "ho I wouldn't bother with them I'd use barstock"   ::)

Jo

Well, you can't say he didn't tell you  :LittleDevil:

And... I machined the water pump casting on the Frisco only to find the casting was porous, with water squirting out all over the place.  Fortunately a little gas tank sealant corrected that problem but... I feel your pain.  Bar stock it is.
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 18, 2019, 01:29:07 PM
Thank you Craig   ::) he waited over 12 months after he took my money for the rods before he told me    :slap:


The replacement con rods are going to be made out of some ex fast jet scrap-binium. This is not HE15 but much stronger and machines like BMS and has good bearing properties  :ThumbsUp:

First up machine the Ali to a 20mm wide and 9.5mm thick and start thinking about the measurements  :thinking: I am going to change the spacing of the big end bolts as originally there was only 0.3mm between the bolts and the bearing surface on either side, so the 11.1mm has been increased to 11.7mm.

The machining operations for bar stock is different from a casting as first the bottom end is machined flat, has the two holes drilled and tapped for the M2.5mm thread before using a slitting saw to cut the cap off the rod.  The small end hole has at this stage not been done  :hellno:

Three more for the set...

Jo

P.S. I was told the scrap-binium was good for Mach 3 which is a little faster than I intend on running this engine  ;)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jasonb on July 18, 2019, 04:14:20 PM

P.S. I was told the scrap-binium was good for Mach 3 which is a little faster than I intend on running this engine  ;)

Good for CNC work then ;)
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Vixen on July 18, 2019, 07:41:04 PM
. I was told the scrap-binium was good for Mach 3 which is a little faster than I intend on running this engine  ;)

Good decision Jo;

Conrods made from aircraft grade scrap-binium bar stock have got to be better than aero (chocolate bar) grade castings. Better still; go out and buy the correct grade of bar stock from a reputable metal stockist.

Cheers

Mike
Title: Re: 15cc Seal and 30cc Seal Major
Post by: Jo on July 18, 2019, 08:08:45 PM
Better still; go out and buy the correct grade of bar stock from a reputable metal stockist.

Strange you should mention that I recall on at least three occasions we made fast-jet airframes out of fully certificated metal from a reputable metal stockist only to find that when we did our own metallurgical analysis of it it was not what they claimed it was. The supply of the metal was finally traced back to a far Eastern smelter  >:( . All three aircraft with the offending metal had to be stripped down again and the frames scrapped  :disappointed:


The drawings say bronze which is rather heavier than the supplied Ali castings. What I am using is the same stuff I make my conrods out of for my single cylinder model aero engines  :ThumbsUp:

Jo