Brian does Ridders flame eater

[sid pileski]

Why Yikes? The heat from an alcohol burner isn't going to melt silver solder.

That much is true, OD

[brian Rupnow]

My three bearings came in today. They cost $23.00 total and have seals on them. I'm not going to rush to take the seals out at least until I am set up to do some comparative tests to see how easily they spin. The key issue is that they fit the crankshaft and con rod pin properly. Tomorrow I will put the counterbores in the bearing supports and maybe build a con rod. I am still a bit undecided what material to use for pistons. Jan Ridders drawings indicate that you can use graphite OR cast iron. Nobody in Barrie sells machinable graphite, and I already have some cast iron left over from other projects. I may go with cast iron and if it don't work I can switch to machinable graphite after the fact.

[vpt]

How about a phenolic piston? Has everything needed t be a piston and machinable.

https://www.nationwideplastics.net/plastics/phenolic/

[brian Rupnow]

Okay--The bearing stands are counterbored and the bearings (complete with seals and full of factory grease) , crankshaft, and flywheel are installed. Time for some comparative testing. This is hillbilly work at its finest. Using an online stop-watch, I gave the flywheel a spin and started then stopped the stopwatch. I repeated this 5 times. The average length of spin comes out to 7.18 seconds from when I flicked the flywheel into motion until all motion stopped. Next step will be to remove the seals, wash out any factory grease, then reassemble and check the "free-wheeling" time again.

[brian Rupnow]

The results are in, and they are incredible. I disassembled everything, pulled the seals out of the bearings, then washed them in laquer thinners and blew them clean with compressed air, then reassembled everything exactly as it had been with the previous test. I did five runs, using the same finger pressure to spin the flywheel (That is the hillbilly element) and the average length of free-wheeling was 2.51 minutes. That means that on average, the bearings without grease will spin 21 times longer than bearings with grease.

[brian Rupnow]

As this assembly continues, I thought I might have an alignment issue with the centerline of the cylinder and the center of the very small ball bearing on the end of the crank throw. So--I made myself a special weapon, and installed it. I was right. The tip of that special weapon should fall directly on the center of the bearing.---It doesn't. Now I have to figure out what I'm going to do about it. I don't want an offset in my connecting rod!!!

[brian Rupnow]

Hahh!!!--It was the old "slot the bolt holes and move the cylinder over a bit" trick that saved the day.-I have to declare now--This was not a fault with my drawings. It was more a testament to accumulated tolerances and my inability to position everything dead nuts accurately when machining. Anyway--We're good now. The point of the new weapon is on center of the small bearing.

[brian Rupnow]

Here's a little trick your mother probably never told you about. When you locate a bearing into a prepared pocket that is "size on size", the bearings lose all ability to "self align" with each other. This can cause binding and make the shaft reluctant to spin freely. If you make the pocket about .001 to .002" oversize, then use a bit of Loctite on the outer race before assembling things, this lets the bearings align with the shaft and with each other. The trick though, is to not get any Loctite down into the balls of the bearing. So---as you see, I use masking tape and a scalpel to make a temporary "shield" on both sides of the bearing to keep Loctite out. Add my Loctite, reassemble everything quickly, tighten the bolts and let it set for 24 hours. The bearings will be perfectly aligned, and you can then safely disassemble things and remove the tape from the exposed side of the bearing. On the other side of the bearing that becomes inaccessible, just leave the tape there. It won't hurt anything.

[J Tiers]

The results are in, and they are incredible. I disassembled everything, pulled the seals out of the bearings, then washed them in laquer thinners and blew them clean with compressed air, then reassembled everything exactly as it had been with the previous test. I did five runs, using the same finger pressure to spin the flywheel (That is the hillbilly element) and the average length of free-wheeling was 2.51 minutes. That means that on average, the bearings without grease will spin 21 times longer than bearings with grease.

What about a light oil? Seems like you will want something in there if only to avoid corrosion.

[brian Rupnow]

I don't know Jerry. I will find out more as I go along. I removed the seals and all the factory grease from the bearings on my Stirling engine and it needed me to add some light oil so it would even run.--Brian

[sasquatch]

Interesting stuff Brian, following along here,,,,,,

[Willy]

Yes even a light coating of oil will leave a viscous drag.
When just a whisper of oil is needed I just mix a drop or two of the chosen oil in a solvent such as gasoline or naphtha at about a 30:1-50:1 ratio, depending on the type and viscosity of the oil.
Simply drop the bearing in and then place on a paper towel to let the aromatics of the solvent evaporate.

[brian Rupnow]

I'm down to the point now where I'm making pieces so small that it should be against the law!!!

[J Tiers]

Yes even a light coating of oil will leave a viscous drag.
When just a whisper of oil is needed I just mix a drop or two of the chosen oil in a solvent such as gasoline or naphtha at about a 30:1-50:1 ratio, depending on the type and viscosity of the oil.
Simply drop the bearing in and then place on a paper towel to let the aromatics of the solvent evaporate.

Super idea... one of those "should be obvious" things that isn't.....

[Lew Hartswick]

My dad (back in the 40s) lubricated grandmother and grandfather type clocks by putting a little flat container of kerosene in the bottom of the case. He said the vapors were enough to keep them lubed.
...lew...