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This is a beta can engine. I'm trying to decide if my crank is right. If my displacer lifts 1.5in, should the balloon also lift that much in retrospect?

If your displacer moves 1 1/2", I think 3/4" would be a place to start, but 1 1/2" seems a big stroke. Is this the stroke recomended in the plan of the motor? Ian S C

Lol, there was no motor plan. I looked at the other engines being built and started to build from scratch under my own assumptions and common knowlage of physics.

The balloons in my models usually only move about 5 - 10 mm total stroke. The displacer usually 28 - 35 mm stroke. These are coke can models.

Insainhouserecords wrote:Lol, there was no motor plan. I looked at the other engines being built and started to build from scratch under my own assumptions and common knowlage of physics.

See you other thread, please.

R

Insainhouserecords wrote:Lol, there was no motor plan. I looked at the other engines being built and started to build from scratch under my own assumptions and common knowlage of physics.

This may be your problem. There is more to these engines than meets the eye. Best to start with a tested and proven existing plan, then move on later to your own designs. There are plenty of Coke can plans on the net.
Here is a good one
https://sites.google.com/site/reukpower ... ing-engine

Yea, that was the first type I tried. Idk what materials the guy used but no glue sticks to balloons and his wire bends aren't descriptive enuf. I guess I really need a diagram or template because looking at what he does and trying to replicate it are two different things.

Insainhouserecords wrote:This is a beta can engine. I'm trying to decide if my crank is right. If my displacer lifts 1.5in, should the balloon also lift that much in retrospect?

Probably not.

Insainhouserecords wrote:This is a beta can engine. I'm trying to decide if my crank is right. If my displacer lifts 1.5in, should the balloon also lift that much in retrospect?

No. That would be stretching the rubber too far.
If the Displacer moves 1.5 inches, the rubber diaphragm needs to move about half an inch.

So your crankshaft should have one offset of 3/4" inch for the displacer and one offset of 1/4 inche for the rubber diaphragm.
The two offsets should be at 90 degrees to each other, so that when the displacer is at the very top, the diaphragm is flat in the middle of its movement.

Thank you for your help everyone!