Lamina flow issues

[weisermouth84]

Ive been working on a lamina flow engin for a few weeks now. I finally got everything put together but Im having diffuculty getting it to run. I am using an airpot actuator but i replaced the glass test tube with a 3/4" x 4" galvenized pipe as it was much easier to connect the actuator and heating chamber. I dont seem to have any air leaks and i seem to have good compression. Im using bearings for all my conections except for the rubber bushing on the piston rod and friction does not seem to be the problem. I feel like i have an issue with my steel wool and/or "hot side" of the engine. Could this be becuase of the pipe im using? Ive also tried several different arrangments of the steel wool. Any ideas would be greatly appreciated.

[Ian S C]

If you used galv pipe, I asume you have a lathe, and have bored the pipe, and honed it till it is as shiney, and as pollished as possible, and the piston fitting so that with the cylinder open, the piston will just slide through under its own weight, it should almost stop if you seal one end. Galv pipe can be a bit of a problem to some, getting a good finish, its fairly soft, and tends to tear the surface, leaving it a bit rough. As far as the tube goes, if it is being used for the hot end, it's proberbly too thick, a mm is thick enough, but you can run into trouble with the weld, the big one of mine in my album has the power cylinder end made from 2" galv water pipe, and as I bored it, the weld let go, so I closed up the gap again, and welded it with the arc welder, The motor, built in 1992 is still going strong with the origional cast iron piston showing no wear, but it did wear out the first crankshaft after running 2000 hrs, and I can't remember how much LPG was used in that first year.
Just a wee note; if you use galv pipe for the hot end, remove the galv were its heated, you don't need the i'll effects of over heated zinc, and remove it from inside, or it will "fluff" up, and block up the works. Ian S C

[weisermouth84]

Thanks Ian
I think i may have conveyed my design wrong. Im only using gal pipe for the heating tube. Im using a graphite piston and a pyrex cylinder for the other end. sorry for the miss com. I found a suitable test tube last night for the heating tube and i can tell there is a drastic improvement in pressure but the dang thing still doesnt seem to want to run. Does the test tube need to be a certian length or diameter. Im using a 4" long and 7/16" ID and have it filled approx 2/3 the way with # 6 fine steel wool. For a while i was thinking it was the fine steel wool; that i may need to move to a more coarse regenerator, but after doing some reading last night im reading of engines using the same steel wool and producing 1200 rpm? Im starting to feel like this is just going to be a lot of trial an error until I get it fine tuned.

[weisermouth84]

Thanks Ian
I think i may have conveyed my design wrong. Im only using gal pipe for the heating tube. Im using a graphite piston and a pyrex cylinder for the other end. sorry for the miss com. I found a suitable test tube last night for the heating tube and i can tell there is a drastic improvement in pressure but the dang thing still doesnt seem to want to run. Does the test tube need to be a certian length or diameter. Im using a 4" long and 7/16" ID and have it filled approx 2/3 the way with # 6 fine steel wool. For a while i was thinking it was the fine steel wool; that i may need to move to a more coarse regenerator, but after doing some reading last night im reading of engines using the same steel wool and producing 1200 rpm? Im starting to feel like this is just going to be a lot of trial an error until I get it fine tuned.

[Ian S C]

You can ignor the bit I wrote about your power end. On my vertion of the motor. the power cylinder and the displacer are the same diameter, the hot end of mine is a bit of stainless tube turned down to about half thickness. I made mine with the steel wool at a foreward possition, with a 3/16" tube through the steel wool, and heating at the end of the cylinder, I don't think it makes much difference. The thing is to not have the hot cylinder too thick, 1 mm is about as thin as you would take mild steel, .25 mmor even less is OK with stainless steel.
One thing I don't understand is the rubber bushing on the piston, that seems like an extra part that's not needed.