Elmer no 5

I have decided to attempt an engine based on Elmer's No 5, I say based as the detail will be own design.
I do not have gear making equipment in my workshop and inspired by a build over on HMEM I decided to try making the gears by drilling holes.
Sizes and spacing were done on the basis it looks about right, you just need the 2:1 ratio and careful measurement, I have chosen 12/24 teeth.

The external gear was completed by putting it back in the cut off square and then inserting 12 x 6mm dia slugs and soft soldering them in. I was worried the strength might not be enough for subsequent clean up machining but it was quite OK. The gears fit together nicely though there is still a bit of solder to file away.

I then went on and made a couple of main bearing stands and will do the crankshaft next.

Andrew

Amazing, I'd never have thought of drilling holes as a method and they look to have come out great. I did once make some bevel gears by setting a HSS tool on its side, setting the topslide at an angle and manually taking off a tiny bit at a time, rotating the workpiece using a detent - it took forever and isn't something I'd countenance doing again!

That engine is such a cool design! Good thinking on the gear, I like it.

Did you drill the holes using a rotary table, or by x-y movements on a mill?  Either way, excellent work! 

Nice work! I too have been wanting to make the geared engine. I just had not come up with a method of making the internal toothed gear.

Eric

That was really clever ! Nice job

Thanks for the comments.
The holes were drilled on a rotary table, I have a BCA Mk111 jig borer which is perfect for this sort of work but the machine is a bit light for general milling work and it is my only mill.
Elmer gives dire warnings about making the internal gear PCD x 2 of the pinion otherwise lock ups will occur and this method is probably not as precise as gear cutting so we will see. Back of my mind is build some adjustment possibilities for the centres.

Andrew