1" Bore x 1" Stroke Vertical i.c. Engine

[I make chips]

Would that be the one in Buffalo? I'm only 1/2 hr from there and I use Online Metals instead. Also, some great deals on eBay. Even with the shipping, it's still cheaper than the local guy -- by a large margin (>= 50%)

Sorry no. In Wisconsin near Milwaukee.

I met a neat guy that has decent pricing on small lots of metals. Toss him an email with your needs for a quote to see if it's reasonable.
He has a lot more than what is shown on his website.
https://hobbymetalkits.com/

For me it's easy as he's only 15 miles away.

[nickel-city-fab]

Sorry no. In Wisconsin near Milwaukee.

I met a neat guy that has decent pricing on small lots of metals. Toss him an email with your needs for a quote to see if it's reasonable.
He has a lot more than what is shown on his website.
https://hobbymetalkits.com/

For me it's easy as he's only 15 miles away.

Thanks for the tip! I saved that link, will investigate...

[brian Rupnow]

A gearcase is being born--and so far this morning it's been a hard labour. I expect to finish it after I get some lunch!!

[brian Rupnow]

Well!!! That took much more time than I thought it would. The fitting of the gearcase to the crankcase took longer than machining the gearcase. This is the kind of thing where you only get one chance to drill and tap the holes in the correct place in the crankcase, and not have the inside of the gearcase rubbing on one of the gears. My solution to this involves many layers of masking tape around the large gear, to the point where it will just barely fit into the cavity in the gearcase. It doesn't sound like a lot when you say it fast, but it's taken me most of the afternoon to get it to this point. I'm happy with it, but I started this morning at 8:00 and just finished up now at 3:50.

[sid pileski]

Didn’t you just follow the dimensions you designed it to?
Why the guess work with tape and all that?
What are we missing here?

Sid

[brian Rupnow]

I build to my drawings. My drawings are seldom wrong.--And yes, that has risen up and bit my arse before. You can call it a stack up of tolerances, missing a few thou on some dimensions, or the moon not being in conjunction with Aquarius. Most things I build can be fudged a bit here or there to cover up something that's not quite perfect. Sometimes though, I find it's better to use old fashioned tried and true pre-computer methods. Particularly when a few thou out of place means that a gearcase rubs on one of the gears with no good way to correct it.

[brian Rupnow]

Okay---I did build something today. Not a complex critter by any means, but now the engine has an exhaust system.

[brian Rupnow]

I'm going to make a fan to cool my engine. I wanted to buy a pre made fan, but couldn't find one I liked on the internet, and the local hobby shop doesn't have anything close to what I want. Jason made his own cooling fan, and he did it very well. He posted pictures of two different fans he had made on one of the forums, and I'm impressed. I have one piece of 0.050" thick mild steel here (Which I think started life as an inspection hatch cover on an electrical box.) I designed and printed out a 10 blade fan 1.75" diameter, and glued it to the steel. Tomorrow I will drill the 3mm center hole and cut it out using my rotary table and then cut the slots between each blade on my bandsaw. The bandsaw blade cuts a 1/16" kerf and I don't have any files that thin except for a couple of ignition point files to clean up the cuts with after they are sawn. I will let you know what happens.----Brian

[nickel-city-fab]

Dang, why didn't I think of that.... was going to suggest an old computer fan, painted to match. But this is much better. Maybe it'll be easier to file/sand the edges after they are twisted into position? And the overall photos are cool -- its a good-looking engine!

[brian Rupnow]

Today's rattlesnake roundup starts with an ignition cam. Probably one of the easiest parts on the entire engine to make. The dual set screws keep the engine from getting "out of time" if the cam slips on the crankshaft.

[brian Rupnow]

It's a tricky little dance, and it goes like this----There is a round plate up against the side of the crank-case which is bolted in place with flat head screws from inside the crankcase. It doesn't move. Then there is a separate plate which the ignitions points mount to, and it is a sliding fit over the previously mentioned plate, and it has a handle (not shown) that can rotate it around the previously mentioned plate to adjust timing while the engine is running, and lock it in place. The ignition cam sets on the crankshaft and is locked in place. It's a lot to figure out if you haven't seen this before, but it does allow for "dynamic" timing.

[Sparky_NY]

Can you explain why your ignition cam profile is so different than normally seen? Considering the spark happens as the points open, you cam keeps the points open more most of the rotation and the coil only gets to charge back up during that small flat area before the next opening and spark. Most lobes I have seen more resemble atypical valve can lobe shape.where the points are closed the majority of the rotation.

I am guessing that as slow as these engines run it does not make much difference, dwell angles probably don't matter much.

[brian Rupnow]

I have a really scrofulous old drill press vice, that works for holding just about anything. Clamped to the corner of my desk, it makes a good filing jig to hold the fan in place while I file and deburr inside the slots. My ignition points file which you can see in the foreground is a perfect fit into the slots cut by the bandsaw blade. Next step will be to soak the fan in some boiling water to get the paper pattern off.

[J Tiers]

Can you explain why your ignition cam profile is so different than normally seen? Considering the spark happens as the points open, you cam keeps the points open more most of the rotation and the coil only gets to charge back up during that small flat area before the next opening and spark. Most lobes I have seen more resemble atypical valve can lobe shape.where the points are closed the majority of the rotation.

I am guessing that as slow as these engines run it does not make much difference, dwell angles probably don't matter much.

Dwell angle doe not have to be huge. All it takes is to get the needed current flowing in the coil, storing the spark energy. Longer than that is just a waste, overheating the coil.

With electronic ignition, even that is not needed. Just the signal to trip the SCR and blast the coil with a pulse.

[brian Rupnow]

Well, for a first time ever fan experience, that wasn't too bad. If I had it to do again, I would use 1/16" plate instead of the 0.050" that I used, but that is what I had. I silver soldered a hub onto the one side, and right now it's setting in a jar of pickling salts to get some of the flux off, and hopefully some of the rust. Tomorrow I will figure out just how I'm going to attach the 3 mm shaft, and probably give the fan some primer paint to fill the rust pits. Sorry about the blurry picture. I'll put up a better pic when it's finished.