Sterling Diaphragm Engine

[Ian S C]

Trev, You do really have to use steel through out for the crankshaft, and I tend to go up a size for both the main shaft and the crank pins, but you have done well.
I tend to make my shafts from solid, that's even more work.
Ian S C

[Trevor]

Thanks Ian - I must get some steel shafting for the cranks as you suggest, but I do find it hard to work with and there is no way I can make a crank from a solid piece - Your the Guru here Ian and I am overwhelmed with your work. I promise to try and make a better one next though it is going to be a Beam type.
Thank you ever so much for your help on this project. Trev

[James]

Great job Trevor.

All I can say is there is beauty in function.

[Trevor]

Amen! to that James.

[Ian S C]

trev, continue with the methd of construction that you are using now, you are doing well. Ian S C

[thanh-cuibap]

I hate Trevor, Trevor made nice engine , I have painted my engine !!
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[Trevor]

Wow! Thanh. Nice engine with all that paint work. I have to ask you, how did you make the fins with a parting off blade? I have tried many times without not much success. I don't know what I am doing wrong, but the bloody things keep chattering and then snapping the blade. Checked the angle of cutting to the work, but ALAS - Darn!
Gee you have done some nice work on that engine - Does it run for a long time - I did see the video but was only shoprt.
Trevor

[thanh-cuibap]

Hi Trevor !! I make the fins with a parting off blade . I think it's not run for a long time ! because all made of aluminum !!
Photos for you !!
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[Trevor]

Thank you Thanh - I think I see where I may have been wrong and that is the angle of relief. Mine has been very low or flat compared to yours. Excellent info with the pics - Love them.
I will try what you pics show and let you know in a few days. Like your work Thanh

Trevor

[James]

Those fins look cool. Anyone care to explain the function of these fins? I think they look nice on the engine even if its just for aesthetics.

[Ian S C]

James, the fins increase the area exposed to the air to dissipate the heat, same happens on a motor bike, or lawn mower motor.
Trev, when using the parting tool, knock the speed right back on the lathe, use a steady but slow feed(some people use power feed), if the material is aluminium, lubricate it with WD-40, or kerosene/paraffin(UK), cast iron dry, steel I use soluble cutting oil. Don't have the blade extended any more than need be.
Ian S C

[Trevor]

Thanks Ian.I do use dewatering and/or kerosene fluid for aluminium as it is the only thing that works. Got me on the speed though. I was always taught fast with alloys, but this is not necessary so! I have found chattering does stop when going really slow - So your point is taken as gospel to me. Good show mate. Might actually get one made very soon

Trevor

[Ian S C]

The speed mainly depends on the state of the machinery, light lathes don't absorb the vibrations, a heavy industrial machine will manage the high speeds.
One of the main reasons for high speed machining is money, the faster you can make a part the cheaper it is.
I use mainly HSS tooling, and on ally I usually stick to about 600rpm.
Ian S C

[Trevor]

Thanks Ian - Never looked at it that way. We will see how I go next week when I am back from our holiday in the rain.
Trev

[Trevor]

Yep! you were right Ian. The slower the better, I have now set my lathe to 150rpm and it works a wonder on the parting off of the alloy and especially brass. I also listened to Thanh as you may have noticed from his pics that the angle of attack was a lot more acute to what I was using. It also made a difference. Trev