Author Topic: 15cc Seal and 30cc Seal Major  (Read 9830 times)

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6518
  • Surrey, UK
Re: 15cc Seal and 30cc Seal Major
« Reply #30 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

Online Tennessee Whiskey

  • Full Member
  • *****
  • Posts: 3774
  • Springfield, Tennessee. USA
Re: 15cc Seal and 30cc Seal Major
« Reply #31 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

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 12537
  • Hampshire, england.
Re: 15cc Seal and 30cc Seal Major
« Reply #32 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
Usus est optimum magister

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6518
  • Surrey, UK
Re: 15cc Seal and 30cc Seal Major
« Reply #33 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.


Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 12537
  • Hampshire, england.
Re: 15cc Seal and 30cc Seal Major
« Reply #34 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
Usus est optimum magister

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6518
  • Surrey, UK
Re: 15cc Seal and 30cc Seal Major
« Reply #35 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 ;)

Online Tennessee Whiskey

  • Full Member
  • *****
  • Posts: 3774
  • Springfield, Tennessee. USA
Re: 15cc Seal and 30cc Seal Major
« Reply #36 on: June 06, 2019, 07:42:59 PM »
Iíll let you two keep getting on with each other and Iíll quietly follow along

Eric




Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 12537
  • Hampshire, england.
Re: 15cc Seal and 30cc Seal Major
« Reply #37 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
Usus est optimum magister

Online Vixen

  • Full Member
  • ****
  • Posts: 1222
  • Hampshire UK
Re: 15cc Seal and 30cc Seal Major
« Reply #38 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
It is the journey that matters, not the destination

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6518
  • Surrey, UK
Re: 15cc Seal and 30cc Seal Major
« Reply #39 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:

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 12537
  • Hampshire, england.
Re: 15cc Seal and 30cc Seal Major
« Reply #40 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:
Usus est optimum magister

Online b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13584
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: 15cc Seal and 30cc Seal Major
« Reply #41 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

Online Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 12537
  • Hampshire, england.
Re: 15cc Seal and 30cc Seal Major
« Reply #42 on: June 09, 2019, 03:08:33 PM »
Its my (casting collection's) magnetic attraction Bill  :ShakeHead:

Jo
Usus est optimum magister

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6518
  • Surrey, UK
Re: 15cc Seal and 30cc Seal Major
« Reply #43 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.

Online Bluechip

  • Full Member
  • ****
  • Posts: 797
  • Derbyshire
Re: 15cc Seal and 30cc Seal Major
« Reply #44 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:  ....