Author Topic: Two Cylinder Engine  (Read 23738 times)

Offline Roger B

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Re: Two Cylinder Engine
« Reply #105 on: November 11, 2018, 06:36:43 PM »
I think there are nearly 40 holes  :)
Best regards

Roger

Offline Admiral_dk

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Re: Two Cylinder Engine
« Reply #106 on: November 11, 2018, 08:20:06 PM »
Fantastic progress Roger - you are really moving forward now  :ThumbsUp:

And this is one of the more complicated components.

Offline Art K

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Re: Two Cylinder Engine
« Reply #107 on: November 12, 2018, 03:46:20 AM »
Roger,
Great progress, on a very complicated part. Looking at the drawing under the head in one of the photos. Are you planning to radius the corners to match the cylinder?
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Roger B

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Re: Two Cylinder Engine
« Reply #108 on: November 12, 2018, 08:06:49 PM »
Thank you both  :ThumbsUp:  :ThumbsUp:

Art,  I could radius the sparking plug side but the manifold side would have to remain flat (the ports have to be outside the push rods) I think I will keep to as much of the original design as possible.
Best regards

Roger

Offline Gas_mantle

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Re: Two Cylinder Engine
« Reply #109 on: November 12, 2018, 08:17:57 PM »
Looking great Roger, can't wait to see it running  :)

Offline Art K

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Re: Two Cylinder Engine
« Reply #110 on: November 13, 2018, 05:25:59 AM »
Roger,
Sorry my bad, looking at the blueprint closer I realized it was just the oval shape of the cylinder.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Roger B

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Re: Two Cylinder Engine
« Reply #111 on: November 16, 2018, 05:53:56 PM »
Thank you all for your interest  :ThumbsUp:

I turned some 4.3mm plugs from aluminium rod, pressed them in and filed them flat. The four rockers were then cut from 6mm square silver steel and squared up with the Proxxon micro mill using a 3mm carbide cutter at 8000 rpm and 0.2mm cuts. As this will go as fast as I can turn the handle it didn't take long. The holes for the adjusting screws were drilled 3.2 mm (to be tapped M4) and the pivots were drilled 2.8mm and reamed 3mm. On the single I fitted thin brass bushes but I think silver steel on hardened silver steel should be OK. A quick alignment check on a 3mm rod suggested that the holes were in the right place.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #112 on: November 17, 2018, 04:00:29 PM »
The adjuster screw holes were then aligned on a short length of 1/8" silver steel and the sides were milled using a 3mm end mill 8000rpm and 0.4mm depth of cut. The pivot holes were aligned again on the 3mm silver steel and the bottoms were milled. Next I got out the fixture I used to radius the tips for the vertical engine. I had to make a 3mm to 6mm mandrel to centre the RT using a 6mm filing button Loctited to 3mm silver steel. The radiuses were cut at 8000rpm with 0.2 mm depth of cut. I now need to tap the adjuster holes M4 and do a little fettling. I haven't decided whether to harden the tips or not  :headscratch:
Best regards

Roger

Offline fumopuc

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Re: Two Cylinder Engine
« Reply #113 on: November 17, 2018, 04:04:33 PM »
Hi Roger, nice progress.
Kind Regards
Achim

Online Kim

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Re: Two Cylinder Engine
« Reply #114 on: November 17, 2018, 05:45:10 PM »
Nice looking rocker arms Roger.  Enjoying the show!  :popcorn:
Kim

Offline Roger B

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Re: Two Cylinder Engine
« Reply #115 on: November 17, 2018, 07:34:33 PM »
Thank you both  :ThumbsUp:  It's interesting using the Proxxon micro mill, the process window is a long way from what I am used to. Very high speeds, shallow cuts and feeds as fast as you can turn the the handles  ::)
Best regards

Roger

Offline Art K

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Re: Two Cylinder Engine
« Reply #116 on: November 17, 2018, 08:41:49 PM »
Roger,
That looks like a great way of using fixtures to do multiple steps at a time. Looking good.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline zeeprogrammer

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Re: Two Cylinder Engine
« Reply #117 on: November 17, 2018, 09:48:54 PM »
I haven't said much but I've been following along.

In the last picture with the rotary table...there's a clamp on the left that's using a bolt to lift the end of the clamp.
I hadn't seen that before.

Did you modify the clamp to take that bolt? And if so, what size is it?

I have a small rotary table and clamping has always been an issue. That looks like it could help.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online crueby

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Re: Two Cylinder Engine
« Reply #118 on: November 17, 2018, 09:52:48 PM »
I haven't said much but I've been following along.

In the last picture with the rotary table...there's a clamp on the left that's using a bolt to lift the end of the clamp.
I hadn't seen that before.

Did you modify the clamp to take that bolt? And if so, what size is it?

I have a small rotary table and clamping has always been an issue. That looks like it could help.
Great work Roger!




Zee, I have clamps like that, Sherline has them, fits in spaces where a step block is too wide. Would be easy to make from some flat stock too.

Offline Roger B

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Re: Two Cylinder Engine
« Reply #119 on: November 18, 2018, 09:16:08 AM »
Thank you for your interest  :ThumbsUp:

Carl, I have two sizes of the clamps, both take M6 clamping bolts, the support bolts on the small ones are M4 and on the large ones M6. The small ones came with my RT and the large ones with my EMCO copy milling table, both from RC Machines in Luxembourg.
Best regards

Roger