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amazing runner! Well done

Finally managed to get a bit more shed time this weekend. First I solved the centring square stock on the 4-jaw issue. I ended up going for a simple centre-finder as detailed in Sparrey's The Amateur's Lathe book. That really is a treasure trove of great tips! Now I bored as large as I...

Hi, after completing my first engine (Webster) and procrastinating for 6 months, I have finally taken the plunge and decided to build my next engine. After much browsing I decided I would have a go at an aero diesel this time. I remember them so well from when I was a kid (including the sliced...

OK so a *bit* of progress today. After reading a load of articles during the week and trying to get my head around the maths, I ended up going for Gearotic: http://www.gearotic.com. I had a few dead ends with CAD (both Blender and Fusion 360). Gearotic seemed to do the trick. I had a play with...

Legend! thanks for measuring. So 30 on the crankshaft(driving) gear, 60 on the camshaft(driven) gear. Same PA/module. 90deg drive should work. I hope to get tinkering on a prototype gear this weekend.

Hi Andrew, do you know what the skew angle of the driving (crankshaft) and driven (camshaft) gear is on your setup please? I have heard any angle combination works provided that the sum is 90deg for perpendicular screw gears. I heard 60/30 ratio but I haven't found the formula to calculate the...

That's a good approach. Like it. Ill have a look around for a 2-part/sided counter weighted crankhaft design tonight (there must be something on model engine news). Thanks for posting

Hi, managed to spend a bit of time thinking about the build over the weekend (and wrestling with CAD :mad:). Here's where I got to so far Crank and counterweight, piston, sleeve, conrod measured off the OS FS120. The counterweight will be a little bit light as the piston will be heavier so...

Thanks

Hi, thanks for all the helpful replies. I have decided its just too much trouble to try making these helical gears. I'm going to use standard spur gears on this design and have them up front like the Saitos. Doesn't look quite as sleek but I think will increase the chances of success greatly...

Thanks Tony. I think these are above my machining skill level.:oops:

I love that site. Some great resources there. Feeney was on the shortlist.

thanks for this. Ill take a look

hi kadora, good plan but feels like not manufacturing the crankshaft and camshaft myself feels like cheating :)+ they would add £65 to my build.

Yeah that's what I thought. I can't even get my head around how the gears mesh let alone how they happily spin along at 14,000 RPM with a 2:1 reduction. Ill keep doing homework and update this thread on what I find. I think cracking the technique of making them could open the doors to some neat...

Hi Mayfield, no such thing as a stupid comment! A bevel gear would transfer rotation to the vertical. I’m trying to get the camshaft rotating how OS did it perpendicular to the crankshaft. I’m rapidly thinking this is out of the realms of amateur manufacturers.

OK so its one of these I'd need to make (spiral/perpendicular helical gears) to copy the OS design. Ill see if anyone out there has already tried. I found George Britnell's video which will be very helpful in figuring this out although I think that's just a straight Helical gear.

Thanks Cogsy, I'll have a look. Cant even get my head around how they work let alone making them at the moment!

Hi HMEM, I wanted to run something by all you knowledgeable sorts out there. I have just completed a Webster engine and toying with the idea of having a go at designing an amateur workshop-friendly copy of the popular OS FS120 4-stroke glow engine (un-pumped)...