12-30-2013, 09:13 AM
I am excited! For many years I had an idea of an opposed engine along the same lines of what you have came up with and was curious how it would run and what it would output.
12-30-2013, 09:21 AM
It's turning out to be a very cool looking Model Brian,
Your keeping so many things open for viewing and that's what a good working model should have,
Many of us engineer types are hardwired to build things as structurally sound and with the least amount of materials and pieces and machining possible - which is an entirely different juggling act in itself,
And there is no doubt that your unit could be built twice as strong at close to half the weight, but it's not a production unit and its meant for viewing, and with that in mind I say Bravo, well done and it really is a great looking little engine...
It will be neat to see the U-tube vid on this one
12-30-2013, 09:52 AM
Thanks Guys. Its positive comments like that that help to keep me going!!!---Brian
12-30-2013, 09:58 AM
I agree with A.K. Can't wait to see it run!
12-30-2013, 11:58 AM
As promised yesterday, here is the first assembly, consisting of the crankshaft, flywheel, and all but one of the frame components (the plate the cylinders attach to). I set my glasses in the foreground to give a sense of scale on this engine. Its not very big!!! So far, so good. The parts all fit together. (I don't have the crankshaft bushings in place because I haven't made them yet!!!)-----Brian
12-30-2013, 02:22 PM
Okay jwcnc--I have a place to mount the two bits you are making for me!!! I haven't put the snap ring grooves in yet.---Its safer to wait and get everything mounted BEFORE cutting the snap ring grooves. I have also mounted the camshaft. That's enough for me for today.---Brian
Last edited by brian Rupnow; 12-30-2013 at 03:06 PM.
12-30-2013, 04:13 PM
There will definitely be some head scratching involved with making this part!!!
12-31-2013, 03:21 PM
Today I had to go down to my "nut and bolt" store to pick up the 3/8" socket head capscrews that hold the cantilevered pivot shafts and camshaft into the main vertical support plate. While I was there I asked the sales guy if they carried any of the "low head" style of capscrews. He did, and the head on them is roughly 0.180" shorter than the head height on a standard 3/8" shcs. He didn't have any 5/16" shcs in that style, but he did have some 5/16" flat head capscrews. So---I bought them and installed them this afternoon. This allows me to move the flywheel in 0.185" closer to the main support plate. I will have to cut that much off the long hub on the flywheel, but that will still leave me room for a couple of set screws. I like this much better, allowing me to keep the flywheel tucked in tighter to the main vertical support plate.
12-31-2013, 03:34 PM
Those 5/16" flat head capscrews look like what I
used to refer to as Stripper Bolts when purchasing
from an Unbrako distributor.
Edit: I see Unbrako describes these as Shoulder
Screws in their catalog these days.
Edit II: My mistake.
I looked up the thread and saw a previous image
that made clear that what appears to be the
shoulder and thread of a shoulder screw in the
last photo are actually portions of stand-offs
machined by Mr Rupnow.
Last edited by EddyCurr; 12-31-2013 at 03:45 PM.
12-31-2013, 03:45 PM
Eddy--No, the bolts I use are just a standard 3/8"-16 socket head cap screw with an extra low head. The part you see sticking out the far side of the vertical plate is my cantilevered pivot shaft. I know that "shoulder bolts" and stripper bolts" look like what I have shown, but in this case its not the case.