Bimba

[Oldmechthings]

An easy quick way to build a lively little engine is by using a pneumatic cylinder. Air cylinders can often be found at flea markets and swap meets, etc. The Surplus Center in Lincoln Nebraska has bushels of them. This engine has a simple spool valve and is connected with plastic tubing. The crankshaft bearings are from roller blade wheels. Skate boards, roller blades, and those little aluminum scooters are all equipped with ball bearings, and the bearings usually outlast the treads on the wheels so they are a good source for little bearings for your engines.

Although the cylinder on this engine is not a Bimba brand, I named it that anyway. The Baby Bimba shown below does have a Bimba cylinder. In fact the factory decal is still on it

It is a real little hummer, with a 1/4" bore by 1/2" stroke. I sort of suspect that is the smallest cylinder that Bimba makes.

 

[cfellows]

Pretty cool. I've bought several different sizes of air cylinders with the idea of using them in a compressed air engine design. I've also used them in a compressor design.

Chuck

 

[AllThumbs]

Are those "pillowblock" bearings anodized?

 

[J. Tranter]

What is a good size cylinder to make one of these? I see alot of these on ebay but I'm not really sure what size to buy.

 

[J. Tranter]

I'll try reposting and see if someone responds.

 

[Kactiguy]

Bimba videos:
[ame]http://www.youtube.com/watch?v=5f7AEkX_JQo&feature=related[/ame]
[ame]http://www.youtube.com/watch?v=M0PUYrp2gv8[/ame]

 

[gary55ford]

How did you figure stroke on air valve to run cyl.?

 

[Oldmechthings]

J Tranter
I'm sorry it took so long to reply, but I do not set at the keyboard all the time. Answer to your question on cylinder size, is whatever size cylinder you can find. The baby Bimba gas a 1/4" bore, the one with the brass cylinder is about 1" diameter, and the Whichway engine on another post is about 1 3/4" diameter. Just find a cylinder and build it into an engine. Make sure your crank throw or travel is slightly less that the cylinder stroke, otherwise it will not run.


gary55ford
I'm not sure I understand your question, but I think you are asking about eccentric offset or valve travel. I just designed valves and made the eccentric to provide the needed travel. The little engine valve travels about 1/16" and the bigger one about 1/8". The nice thing about designing your own, is that you can make it almost anyway you want to.


All Thumbs
The pillow block bearings are aluminum castings that have been spray painted with Krylon.

Birk

 

[cfellows]

Wonder how well the Bimba's would tolerate live steam? Aren't they 100% stainless steel?

Chuck

 

[gary55ford]

Yes you've answered my question about timing thanks.-------I use Bimba cyls. exclusivly at work building machines& thier great, but I don't think they would work with steam because they have a rubber o-ring on the piston and I think it would swell up under steam