Model Engine Maker

Engines => From Kits/Castings => Topic started by: Jasonb on December 14, 2019, 10:17:28 AM

Title: RMC Type-B Engine Build
Post by: Jasonb on December 14, 2019, 10:17:28 AM
I have liked the look of the engines from RMC designed by Nick Rowland for a long time but they went through a period of being hard to get. About 18 months ago I managed to pick up a Type-A from a collector who was reducing his stash, then earlier this year I saw a link to an e-bay listing where Nick was selling a small batch of the Type-B castings. Unfortunately they were all gone but I decided to e-mail him and luckily some more were available so i snapped one up as they are on my small list of Casting sets that I would like to make.

Nick's Website could probably do with an update but I'll post a link to his various designs for those interested http://rowland24.20megsfree.com/

A couple of weeks later the box arrived and as well as the castings and individual numbered name plate it contained one of the most comprehensive drawing/construction packages you are likely to get together with a CD with several hundred images ranging from some of the original hand drawn sketches, through CAD models to patterns and mould making then machining and finally finished engines. Nick has said it is OK to share a few here, this one gives a good mix of whats on the CD

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/rmc%20making_zpsjltoldnn.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/type%20b%20ren2a_zpsbolpbtax.jpg)

As you can't have quality castings without quality patterns these bode well for good parts. Although Nick does use traditional patterns this one looks to be done with CNC cut PU board.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSCN7323_zpsumdabwzd.jpg)

A rubber mould is then taken

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSCN7342_zpsfhwyyrci.jpg)

Then from that resin copies are cast and mounted onto the boards to go to the foundry

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/a13%20finished%20foundry%20boards_zpspk75szxs.jpg)

You then say the magic words and hand over some cash and come away with a few castings! Jo, best cover Surus' eyes now so he does not get over excited. ;)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/3q%20aug07%20castings_zpsc5rxnmy0.jpg)

Though this is all you get when buying teh quite reasonably priced set of castings, in next post I'll make a start on them and see how that very generous chucking spigot is used to hold the casting for machining :)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20190220_141123_zpshz9pcnvx.jpg)


Title: Re: RMC Type-B Engine Build
Post by: Vixen on December 14, 2019, 12:09:48 PM
Hi Jason,

Well , what can I say?  :censored:   The RMC is certainly different and unlike any engine I have built. It reminds me of a futuristic space ship or perhaps one of those fancy iced cream cakes you see in a confectioners window.

That said, the patterns and the castings look to be extremely well executed. It should be a fun build and an interesting engine to display and run at one of our shows. It should attract a lot of attention.

Mike
Title: Re: RMC Type-B Engine Build
Post by: tghs on December 14, 2019, 12:30:16 PM
I've looked at them as "steam punk gone organic"  a modern take on Victorian embellishment.. it's something is just made to watch running, might as well look cool..
Title: Re: RMC Type-B Engine Build
Post by: Jo on December 14, 2019, 01:57:48 PM
It looks better in the metal than in the photos  ::)

Surus is still of the opinion it looks like a Mr Whippy Ice Cream and unless it comes with nuts he says he will stick with his box of Snickers and more traditional model engine casting sets :pinkelephant:

Jo
Title: Re: RMC Type-B Engine Build
Post by: Roger B on December 14, 2019, 03:35:08 PM
That's a very elegant engine  :)  :)  :) Very much form and function  :ThumbsUp:
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 15, 2019, 04:50:26 PM
Yes Nick's engines have an almost unique look along the Art Nouveau style, the only other engine that I can think of along similar lines is the hot air fan from Myers (http://www.myersengines.com/engines/stove_fan_engine.htm)

I often seem to start an engine by working on the silencer (muffler) and this was no exception, I think it is because they are reasonably simple parts and can be fitted in while the previous engine is being test run or painted.

I started with the half that goes towards the engine first holding by the edge of the flange to true up the chucking spigot, in fact it ran amazingly true maybe a thou or two run out but still needed skimming to remove the draft angle. I then had a parallel surface to hold in the 3-jaw chuck to skim the flange which even though it's not much more than 1/8" think machined easily - no chilled thin sections here.  :)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191102_104658_zpsvxsqdwga.jpg)

The casting was then turned around and held by the flange again, I had added the Sharpie marks when doing the spigot so it could be replaced in the same position. The spigot was cut off and a hole drilled and then bored to a firm fit on some 1/2" steel rod.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191102_105813_zpsuf02vxkt.jpg)

The other half was then skimmed across the flange before reducing the thickness to leave the three bosses full depth which act to space the two halves apart unlike a lot of silencers that have simple turned spacers. I cut until the edge was just breaking through as any more would have risked cutting into the chuck jaws, what little remained was easily files off.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191102_111947_zpszam2gahw.jpg)

The small stub pipe is simply a piece of 1/2" steel drilled out and then cross drilled for some additional holes, I just used a square ER collet block to index the 4 holes with the back of the nut against the vice jaws to locate the block in the X-axis.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191102_132730_zpsmwhyudko.jpg)

All that is left is to drill clearance holes in one half and tap the other, I opted to use BA fixings on this engine rather than UN so in this case 4BA rather than #6-32, the hex head fixings are temporary and I will turn up some fillister heads screws for the finished engine. The pipe is retained with high temp Loctite 648.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_182930_zpssyuhuxvb.jpg)
Title: Re: RMC Type-B Engine Build
Post by: Art K on December 15, 2019, 11:41:07 PM
Jason,
I've seen Nick's stuff at the names show. I do like the steam punk look to them. I will be following along.
Art
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 16, 2019, 11:16:46 AM
Good morning Jason.

As yet you haven't mentioned the engines working principle.

My own assumption is that it's based on the Southall patent,  a two stroke/cycle that doesn't have a charging piston or crankcase transfer arrangement?

Attached is a picture of an early Hardy and Padmore that employs the same principle.

Cheers Graham.
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 16, 2019, 11:23:40 AM
Morning Graham, I was going to come to that when I got to the piston but it is a modified Loyal Cycle.

That's an interesting flywheel/crankshaft arrangement with the single bearing and a flywheel either side or has the far one been added?
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 16, 2019, 12:35:53 PM
Morning Graham, I was going to come to that when I got to the piston but it is a modified Loyal Cycle.

That's an interesting flywheel/crankshaft arrangement with the single bearing and a flywheel either side or has the far one been added?

Ah, thanks, I thought as much.

No, that's the standard engine design. Rather nifty and elegant with the crankpin extended to be the starting handle!

Under that domed casting on the cylinder top is a weighted flap that is blown open as the piston passes the port, exhausting the cylinder.  The remaining down stroke pulls in a fresh charge of gas and air to be compressed for the next cycle.

Cheers Graham.
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 16, 2019, 02:14:00 PM
Here's my own example of the Loyal patent.

A modified " A.L.F. " engine with water cooled hopper and the 1/8" BSP nipple fixed half way down the stroke. A non return valve was fitted to the nipple so that induction could occur directly after the exhaust event.

This engine ran beautifully and would go in either direction depending on a simple change of the ignition timing.

I'll be following with interest Jason, I like IC with a twist.... ;)

Cheers Graham.
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 16, 2019, 03:00:50 PM
Graham, if you like things with a twist then sit down and watch this video all the way through with your afternoon cuppa, it has got plenty of twists 4-stroke, duel stroke, 2-stroke, throttled or governor and a glass cylinder head all in the same engine which is a modified version of the same Type=B.

I do like the look of the fan and may just add one for interest as the bosses are already there on the casting, engine runs quite cool so not really needed.

rz17bBpR0xM
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 16, 2019, 04:44:59 PM
Thanks for the video Jason.

Pretty straightforward until about two thirds the way in. Without a commentary I started to get a bit lost on what was happening.

I don't get the " dual " bit, if the engine fires once per revolution it's a two stroke. I'm assuming we watched a " ported " exhaust followed by a " mechanised " exhaust?

Perhaps someone could explain please?

Cheers Graham.
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 17, 2019, 04:41:04 PM
Hi Jason.

My apologies if I appear to have shifted the focus of your thread topic. Having spent most of my adult life both restoring and researching the early IC engine it's refreshing to see something a little different.

Despite this being the " information " era I can find very little on either the Loyal or Southall patents. It's obvious that they differ because they were both patented. The employment of the " weighted " exhaust valve on the Hardy and Padmore might just be the subtle difference for a patent application? However....

I'll just sit back and enjoy the rest of the journey.

Cheers Graham.
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 17, 2019, 05:00:45 PM
No apologies needed Graham, I can always learn something from your posts and you do tell a good storey so happy for you to chip in whenever you fancy.

Nick has directed me to this page on his website which may go some way to explaining the cycles (about half way down) or it may equally leave you with more questions :-\

http://www.rmccyclestrokes.20megsfree.com/rich_text.html

He also included a nice shot of the spark through the glass cylinder head

J

PS did you get my second e-mail yesterday?
Title: Re: RMC Type-B Engine Build
Post by: Alyn Foundry on December 17, 2019, 06:44:58 PM
Yes Jason, I did receive your email.

It seems I may have something in common with Nick, particularly his grandad....

Taken in 1985 my Spec 401 Lister of 1911 ( foreground ) sporting a Canadian style water hopper, seeing two together here in the UK is a very rare occurrence. Its mate belonged to the Late Mike Stokes of Bridgend.

Happy days....
Title: Re: RMC Type-B Engine Build
Post by: RayW on December 17, 2019, 09:27:41 PM
Hi Graham,
By coincidence the back cover of the February 2020 edition of Stationary  Engine  magazine  features photos of two ball hopper Listers, one a J type and the other an L type, both photographed at the Great Dorset Steam Fair this year.
Title: Re: RMC Type-B Engine Build
Post by: Admiral_dk on December 18, 2019, 07:48:48 PM
Hi Jason

Did you forget to pay PhotoSuckit or are there other reasons why you profile and the rest of the pictures from you are gone ....?....  :embarassed:

Really looking forward to the rest of the build of this very interesting engine  :ThumbsUp: + perhaps some extra explanation on some of the rather special running options on this engine (yes I have read the article) that isn't the most self evident.  :cheers:   :popcorn:

Per
Title: Re: RMC Type-B Engine Build
Post by: Jo on December 18, 2019, 07:51:31 PM
Did you forget to pay PhotoSuckit or are there other reasons why you profile and the rest of the pictures from you are gone ....?....  :embarassed:

 :facepalm:
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 19, 2019, 07:03:28 AM
Says they are working on the site, I only see two missing images rest are coming up OK here and on ME
Title: Re: RMC Type-B Engine Build
Post by: Jo on December 19, 2019, 07:09:42 AM
Only your YouTube link working here :(

Jo
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 19, 2019, 07:14:02 AM
As I said only a couple not showing, Profile was but is not now.

And posted by PB, at least the user knows whats going on unlike some free sites that when they go down nobody knows.
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 21, 2019, 05:07:45 PM
Jo will be pleased to know that PB us back up and running which just means I can get through the construction posts faster and then posts the videos of the engine running  :LittleDevil:
Title: Re: RMC Type-B Engine Build
Post by: Jo on December 21, 2019, 05:25:07 PM
I hope you get a refund for this month  :stir:

Jo
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 22, 2019, 06:59:48 PM
Taking  a break from the castings I thought I would do the conrod next, this was roughed out from a piece of 5/8" steel. To produce the shapely big end I drew it out in Alibre and used that to produce a series of co-ordinates at 0.020" spacing which were cut with an insert parting tool

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_083942_zps2ayionej.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_084012_zps3ra6wl3y.jpg)

The stepped cut was then blended with files until a pleasing shape was produced.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_091540_zpsx7z7lpom.jpg)

As the distance between big and little ends was less than the width of my vice jaws I used a couple of 15-30-60 blocks as packing to hold the rod for drilling and reaming the ends, I also supported the big end with a make shift jack from some clamping nuts and a stud to make sure it did not deflect.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_143711_zpsit7yawan.jpg)

A couple of bronze bearings were turned up and fixed with 648 Loctite and the drilling for the oiler in teh big end carried through the bearing.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_182842_zpsbxeixmpe.jpg)

The carb is a fairly simple turning job with a few decorative beads that was then transfered to a 5C collet block to drill the cross hole for the choke and one half way in at 90deg for the fuel line nipple. I must stop taking such close up shots as it make sthe surface look rough!

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191106_165440_zpsmpqdtklf.jpg)

The choke is just a spindle with a hole for the control lever at the end and then milled away either side to form a butterfly, not much metal left so a jack was used again.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191106_171728_zpsvdvlbjuf.jpg)

The completed carb which looks a lot better from this distance ;) it's just a press fit into the hole in the cylinder side.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_182909_zpsblg1lxyf.jpg)

J

Title: Re: RMC Type-B Engine Build
Post by: Vixen on December 22, 2019, 08:16:43 PM
Taking  a break from the castings I thought I would do the conrod next, this was roughed out from a piece of 5/8" steel. To produce the shapely big end I drew it out in Alibre and used that to produce a series of co-ordinates at 0.020" spacing which were cut with an insert parting tool
J

Jason, You have made a nice elegantly shaped conrod for your Mr Whippy engine.

When i am profiling a smooth curved surface, like your conrod ends, I prefer to use a round nosed (1.0mm radius) insert type MRMN 200 in place of the square ended MGMN 200 insert. Both fit the same parting tool holder. The radiused steps are neater and easier to blend with a file than those cut with the square ended insert.

Both the MRMN 200 and the MGMN 200 will cut sideways as well as plunge cut, provided you do not too ambitious with the depth of cut. I often use them as a normal (but very narrow) turning tool, you can get into very tight places with them.

MIke

Mike
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 22, 2019, 08:38:02 PM
The square steps are a bit easier to workout the coordinates for and I find less likely to be deflected sideways, different for you using the CNC. But the 2mm round tip does usually live in my holder rather than the square one, I use it a lot when making "castings" as it leaves a nice fillet in the internal corners, also good for small conrods etc. That is also what I used to do the 1/4 and half circle concave cuts on the collet end of the carb body and was also using it this weekend to do a steam engine cylinder. Also got a 1mm one for my Nikole holder for really small stuff but often a 0.4mm corner radius insert tip will do.

(https://www.model-engineer.co.uk/sites/7/images/member_albums/44290/847076.jpg).
Title: Re: RMC Type-B Engine Build
Post by: Vixen on December 22, 2019, 08:47:21 PM
The square steps are a bit easier to workout the coordinates for ....................

J

Draw a offset line, 1.0 mm from the curved surface. You can then pick off the coordinates to that line in the same way as before. Just remember to add the 1.mm to your tool zero position.

Mike
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 26, 2019, 06:56:20 PM
I was just able to fit the jaws of the 3-jaw chuck between the spokes and counter weight of the flywheel casting which ran reasonably true and this enabled me to work on both sides and the edge all at once. The curved finished surface extends around about 220 degrees around the rim before stepping in slightly to the rest of the cast surface. I started by just taking off enough from front, back and edge to get a cleaned up ring and then measured the width. Armed with this size I worked out co-ordinates and machined the rim in 20 thou steps before blending these together with graver, files and finally some Emery.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191110_105803_zpsaed4wgzm.jpg)

I also took a light cut to define where the machined surface meets the cast and later blended that in with the Dremel. Hub was also machined and hole drilled and finish bored to a firm push fit on the PGMS that I used for the shaft.

The flywheel was then clamped to the mill table to have the crankpin hole drilled and reamed as well as a slot milled for the governor bracket and a tapped hole to hole said bracket in place. You may also just be able to see the mark on the rim to indicae where the governor pin hole needs to be drilled which was marked with a carbide point held in the mill chuck.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191120_163415_zpsfgzmt7d4.jpg)

This mark made it easier to line things up when it came to drill the pin hole which is also counter bored and threaded so the threaded pin can be turned to alter the governor spring pressure.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191120_183203_zpsid9w2pok.jpg)

The governor weight is made by modifying a 3/8" diameter bronze ball by adding a hole and turning a small shoulder.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191120_185936_zpsp1rpka1h.jpg)

The shoulder is used to locate the ball in the governor bracket while it is soldered in place. In use when running as in hit and miss mode the ball and bracket are thrown out by the force of the rotating flywheel which causes it to move away from the isolated ignition contact so the engine will miss, as things slow back down the bracket will again come into contact with the isolated point and it will hit (fire). governed speed can be adjusted by screwing the long pin in and out which alters the spring tension. To run as a throttler the nut retaining the bracket is simply tightened so it can't move outwards.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSC03890_zps431rnpub.jpg)

J
Title: Re: RMC Type-B Engine Build
Post by: crueby on December 26, 2019, 07:43:02 PM
Beauty of a flywheel, well done!    :popcorn:
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 28, 2019, 08:02:59 PM
Thanks but the credit should go to the designer and pattern maker.

The main bed casting looks quite a challenge at first but each operation is listed out in the build instructions and was actually not too hard to do.

First item is to hold in the 4-jaw by the chucking spigot and turn the small pip on the end flat and drill a ctr hole. I added some balance weights in the form of a couple of vee blocks and a 15-30-60 block taped and wired on which enabled me to run at about 400rpm before the lathe wanted to start dancing down the workshop. Once the tailstock ctr is brought up for additional support the feet can be skimmed flat.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191110_162300_zpsm6mmqcwf.jpg)

The next suggested thing is to bore the cylinder but I could sense a little bit of movement when facing the pip so did not want to do the bore like this, I think is was due to the chucking spigot being slightly larger at the far end so it could not be gripped really firmly. So I flipped the casting around and clamped it to the faceplate so that I could true up the end of the chucking spigot to give me something even to hold.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191113_172608_zps1eyoscke.jpg)

With the bore and cylinder head mating face now machined I brought up the tailstock again and took the slightest skim off the feet to make sure they were true to the completed bore as that would be my ref surface for what followed.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_155831_zpsajvs9zlo.jpg)

One advantage of the imported lathes with their flange mount is that the studs can quickly be removed from the backplate so the chuck can be clamped to the mill table which is how I held the casting to drill the holes for the feet, cylinder head and I also added two holes for 3mm dowel pins front to back as I decided not to use a machining plate and the dowels would help with lining things up.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_165604_zpskfg4ox0o.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_144723_zpsvwac4cc2.jpg)

So with two bits of 3mm drill rod in the holes resting against the side of a tee slot the casting was set up to machine the top of the bearing housing that takes the oval shaped name plate, I added an angle plate against the side to resist the force of the cutter as I did not want to bend or break the casting.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_175011_zpskebmi7c0.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_174956_zpspsrmyjsu.jpg)

While setup like this I also cleaned up the top of the cylinder, the 80mm indexable mill allowing me to get close enough without the quill hitting the overhanging bearing housing.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_184318_zpsuftylxd9.jpg)

The instructions suggest using a 1" CSK to chamfer the top of the cylinder but as I don't have one that big I just managed with a boring head and tool ground at 45degrees.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191115_185732_zpskianufr5.jpg)

To be continued
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on December 28, 2019, 08:11:41 PM
with two drill bits poked into the feet holes resting on parallels the base was clamped to an angle plate, to locate the ctr line of the cylinder I turned up a close fitting plug and touched off each side of that, heights were easy enough touching off the angle plate.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_083028_zpsxzu36ftd.jpg)

The bearing housing could then be drilled and reamed 1/2", I added some aluminium packets at teh bottom to stop any deflection from drilling pressure.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_091204_zpsfuipdjqi.jpg)

The casting was then rotated 90deg and with pins in the dowel holes again lined up to do the exhaust and spark plug contact holes

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_134825_zpsww0em7lz.jpg)

Then rotated 180 degrees to drill and tap for the sparkplug

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_140648_zpst5vosoc1.jpg)

Finally two angle plates were cobbled together so the casting could be held at a suitable angle to drill and tap for a grub screw to retain the exhaust which has to fit between two of the sloping cooling fins.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191116_143743_zpsxjmwcal0.jpg)

just enough done for a trial assembly.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191117_142247_zpsiakpglny.jpg)

Title: Re: RMC Type-B Engine Build
Post by: awake on December 28, 2019, 09:21:33 PM
Wonderful pictures and write up - great illustration of how to go about machining a complex casting!
Title: Re: RMC Type-B Engine Build
Post by: crueby on December 28, 2019, 09:32:32 PM
Great job on the machining - that is quite a shape to figure out how to hold.
 :popcorn:
Title: Re: RMC Type-B Engine Build
Post by: Dave Otto on December 29, 2019, 01:21:53 AM
Nice work Jason!

Dave
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on January 03, 2020, 05:06:35 PM
The drawings include details for a home made spark plug to suit the engine so I had a go at making one, well two actually as the extra can be used in the Type D when I get round to making that.

The body started out being turned on the end of some EN1A bar and then screwcut 1/4 x 32 UNEF as I only have a tap that size. The large picture makes it look rougher than it is.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191122_183633_zpsr83x1cfs.jpg)

Next over to the spin indexer to mill the 5/16 hex

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191123_080803_zpsm6o6odsz.jpg)

A suitable female thread was tapped into the end of a bit of scrap so the body could be held to finish the top end.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191123_083310_zpsfua4bxoq.jpg)

The insulator is a length of 3mm glass tube which cut very easily with a diamond coated disc in the Dremel, I used the slowest speed to avoid heating the glass and then just twisted the glass in my fingers against the disc to chamfer off the sharp edges

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191123_104217_zps9hsp53ad.jpg)

The central electrode is a piece of 0.5mm tig welding electrode and the final part is a small brass cap with a groove to accept the wire clip. The electrode is trimmed to length after assembly.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191124_162021_zpsvusc9iuu.jpg)

The plugs are assembled using Loctite 380 "Black Max" adhesive. I could not get the plugs to work at first and it turned out that the adhesive had insulated the electrode from the brass cap, a quick spot of electrical solder on the end soon cured that problem and the engine ran better than with the standard length Rimfire plug that I had been using for initial testing.

Unlike a conventional plug the spark does not travel from the central electrode to the plug body but to a long screw that enters from the opposite side of the cylinder, plug gap is adjusted by turning this screw and securing with a locknut. At one time Nick did offer a disc of glass that coul dbe fitted to a modified cylinder head so you can tip the engine up when running to watch the spark and ignited fuel.

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Title: Re: RMC Type-B Engine Build
Post by: propforward on January 03, 2020, 05:11:48 PM
That's fantastic. That actually makes me want to clap my hands with excitment. Great fun!
Title: Re: RMC Type-B Engine Build
Post by: gary.a.ayres on January 05, 2020, 12:06:16 AM
Wow...

A most elegant casting - and it's in good hands with you.

 8)
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on January 06, 2020, 07:16:36 PM
I did not take many photos of the adjustable timing bracket. Below is the lever having had a 2BA thread put on the end it was slid out of the chuck to reduce most of it's length to 3/16" leaving a 1/4" collar for the contact.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191102_185829_zpsmdacdpop.jpg)

After cutting off it was held the other way round and a decorative ball turned on the end. The collar is straight forward turning and milling and the brass cotter applies the friction to hold it in position but still allow easy movement to advance and retard the timing. I opted to use Corian as the insulators rather than the suggested materials.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20200102_103300_zpshhberl3o.jpg)

The "hemi" cylinder head was turned from some cast iron and as I don't have the large diameter ball nose cutter suggested I first drilled to depth and then hand cut the shape.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191103_153307_zpsn9z2repd.jpg)

It was then held the other face out in the soft jaws and the outer curve also shaped by hand turning with a flat ended tool.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191103_160452_zpsbjmtvatk.jpg)

Finally over to the mill to drill for the fixings

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191122_165810_zpsnruklrs0.jpg)

The fairly long piston can be turned from the chucking spigot that was cut off of the base casting but I chose to use some 25mm CI bar. After turning and cutting the groove for the quad ring it was held in a collet block to have assorted holes and notches cut which provide the porting for the Loyal cycle.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191123_152952_zps58musjaz.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191123_154112_zpsgvytqhhc.jpg)

The engine is designed to run on a surface vapour fuel tank which is based on a 1/2 pint "Ball" jar, to increase the surface area a felt wick is fixed to the lid and sits down in the fuel. This is held together with a central screw that is drilled for the vapour and has a reduced diameter end for a fuel pipe, here the head of the screw is being slotted.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191106_185651_zpssj2k9fec.jpg)

Some large brass washers are also needed, rather than slicing up good bar stock I had some old 1/8" brass door kick plates that were cut up and milled to thickness followed by drilling the central holes, a step drill saves the risk of a jobber drill snatching in the brass.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191108_171725_zpsrsvavu8v.jpg)

They were then rounded off in the lathe.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191108_173715_zps9q5njmzp.jpg)

This is the finished vapour tank

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20191109_183016_zpsih06h2va.jpg)

And the inside showing the felt wick

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20200102_094458_zpsddn4jcck.jpg)

Final finishing touches are a pulley to go on the other end of the crankshaft turned from the chucking piece

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20200102_094950_zpsi6740axn.jpg)

And the nicely etched nameplate. This also has two recessed pockets in it to hold oil and holes are drilled through this, the bearing housing and bearings to get the oil down to where it is needed.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/20200102_094808_zpsfwgfmbqy.jpg)






Title: Re: RMC Type-B Engine Build
Post by: Jasonb on January 07, 2020, 08:23:26 PM
So with all the parts made it was time for a trial. As I mentioned earlier the homemade plug did not work at first so I used a standard length (too short) Rimfire and I also had a job getting the Viton Quad ring so initially tried a nitrile  one which started to swell with the fuel/oil so I just ran without rings. It would not run that strongly or for long, not helped By the bloke who keeps playing with the carb and ignition timing!

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After a few e-mails from Nick which gave me some pointers things have started to get better, this is it running with the home made plug and a Viton O ring which has got the compression back up. I will bite the bullet and pay the high postage to get a Viton Quad Ring from the US and also want to try one of Nicks buzz coils which should give a stronger spark than the S/S single spark CDI that I am using at the moment.

To start with the engine has the governor weight free to move and is running in Hit & miss mode then tightened up to run with throttle control via carb and ignition timing.

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I'm undecided if I like this paint job or whether I should have stuck with the bare cast iron, this is Rustoleum "cast iron" but it's a bit light in colour and looks "flat" as in lifeless not the opposite to gloss. Skids are apple.

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSC03908_zpssrxlpwnx.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSC03902_zps0fdzmoug.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSC03905_zpsgaamyjnk.jpg)

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/RMC%20Type%20B/DSC03907_zpsgdzbakkn.jpg)

Title: Re: RMC Type-B Engine Build
Post by: Admiral_dk on January 07, 2020, 09:27:00 PM
Looks nice Jason - but I will admit it is a very discreet colour, almost bland .... I do really like the plague (sp?)

Runs fine in the last video - is the last (throttled) bit of that, in four-stroke mode ?

Per
Title: Re: RMC Type-B Engine Build
Post by: crueby on January 07, 2020, 09:49:53 PM
Very nicely done. The shapes really make for a distinctive engine - maybe a close but slightly darker color on the inside corners to pick out the shape, give it more depth? Like shadow lines.
Title: Re: RMC Type-B Engine Build
Post by: gary.a.ayres on January 07, 2020, 10:53:23 PM
To my eye the colour works well - in the photos at least.

A damn handsome engine with an H.R. Giger 'Alien 3' feel to it.   ;)
Title: Re: RMC Type-B Engine Build
Post by: Jasonb on January 08, 2020, 07:34:28 AM
It's effectively a two stroke but there are a few miss fires which make it sound more like a 4-stroke.

Chris that is exactly what I feel it is lacking, I did think of some colour washes to get shadow and maybe a bit of dry brushing for highlights and had also considered a product we can get here called "iron paste" which is a graphite and wax past that you scrub on and then buff so the high spots are brighter - used for cast iron fire surrounds etc. but was worried about both methods being affected by fuel and oil or reacting to fuel proof lacquer
Title: Re: RMC Type-B Engine Build
Post by: Roger B on January 10, 2020, 11:16:16 AM
Excellent  :praise2:  :praise2:

How did you remove the (very well designed) chucking piece, with a bandsaw?

Is the red G clamp some form of quick adjustment design? I haven't seen one like that before  :headscratch: