Author Topic: lil brother air cooled.  (Read 4972 times)

Offline Bluechip

  • Full Member
  • ****
  • Posts: 1005
  • Derbyshire
Re: lil brother air cooled.
« Reply #45 on: October 16, 2023, 09:08:19 AM »
E-clip groove ?  With a recess in the collar to stop it coming adrift ??

I assume that's what the pin is for  :thinking:

Never had much joy cross-drilling skinny shafts.

D.

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9420
  • Surrey, UK
Re: lil brother air cooled.
« Reply #46 on: October 16, 2023, 09:09:08 AM »
I've always just held valves and small pins/shafts in the mill vice, located the ctr and very lightly spot drilled before drilling for the pin often 0.8mm for a 1/32" split pin.

These are 0.5mm holes through 1/16" dia done in the vice as above

« Last Edit: October 16, 2023, 09:13:12 AM by Jasonb »

Offline Jo

  • Administrator
  • Full Member
  • *****
  • Posts: 15278
  • Hampshire, england.
Re: lil brother air cooled.
« Reply #47 on: October 16, 2023, 09:31:20 AM »
There are lots of different ways to secure small valves. In this case I would use C shaped clips (washer with a slot filed out)  secured in a small groove in the stem. The last thing you want to try doing is drilling holes through thin valve stems, apart from anything else it weakens them :toilet_claw:

Jo
Enjoyment is more important than achievement.

Offline miss_emma_jade

  • Full Member
  • ****
  • Posts: 31
Re: lil brother air cooled.
« Reply #48 on: October 16, 2023, 10:02:10 AM »
thanks guys. ill spend tomorrow remaking these and see how i go. i got some e clips but i hate them almost as much. imight just drill them with a .06 jewellers burr at work and open them out to 1mm. my mill just doesnt go fast enough to drill a 1mm hole straight . i went to solder the silencer head on the pipe just now and im out of LPG, so im done for tonight. ill upload some better pics tomorrow when i get back on track.
because I always need another project..

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9420
  • Surrey, UK
Re: lil brother air cooled.
« Reply #49 on: October 16, 2023, 10:14:56 AM »
I'm not sure an e-clip will work, as the groove dia would be 2.0mm on the 2.4mm (3/32") valve so very little groove depth for the spring load it would have to take

Even Jo's home made C clip could only have a 0.010" deep groove before it reduces the cross section to less that a 1/32 pin hole would do.

I don't think many of us have high speed spindles, mine tops out at 2000prm and has no problem with the 0.8mm holes yet book speed would be about 5000

Offline ettingtonliam

  • Full Member
  • ****
  • Posts: 128
Re: lil brother air cooled.
« Reply #50 on: October 16, 2023, 08:36:25 PM »
I think I'm going to go and have a cry for you! I can't honestly  see what you did that was wrong.

Offline miss_emma_jade

  • Full Member
  • ****
  • Posts: 31
Re: lil brother air cooled.
« Reply #51 on: October 17, 2023, 06:45:42 AM »
anyway , new valve made, muffler soldered up and assembled, still no cross holes. all the springs and caps made, aand they feel like they might seal eventually. sparkplug made, and soft washer, and its bolted on. flange made for the mixer, and some bits started.
because I always need another project..

Offline miss_emma_jade

  • Full Member
  • ****
  • Posts: 31
Re: lil brother air cooled.
« Reply #52 on: October 18, 2023, 02:15:04 PM »
Well that did the trick. cross drilled them with the faro tool and a carbide burr. pins in. spring seems way too strong for the intake, will reassess that. anyway i gotta get the steam roller put back together this month, so ill get back to it when thats done.

might make some more bits in the mean time too i guess.  lol. now im rolling, i dont like stopping
because I always need another project..

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 3717
  • S°ften - Denmark
Re: lil brother air cooled.
« Reply #53 on: October 18, 2023, 06:34:27 PM »
Great to see that you solved the problem  :ThumbsUp:   :ThumbsUp:

Per       :cheers:

Offline Myrickman

  • Full Member
  • ****
  • Posts: 264
Re: lil brother air cooled.
« Reply #54 on: January 31, 2024, 11:44:40 AM »
Coming along nicely! Wanted to offer a suggestion on the points. I scarfed a set of relay contacts and mounted the insulated one on a piece of plastic tucked underneath the cylinder. This looks a bit less bulky than the print version. I also recessed the spark plug to get the electrodes closer to the combustion chamber. I think Graham pointed this out earlier. Mine uses a single Viton oring for piston sealing.

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal