Pneumatic Cylinders Testing

[Milan]

For a project I need a lots of pneumatic cylinders, and I need to know fairly precise how much they can lift/push. So i tested them with compressor and hand pump.

All pneumatic components are brand new, never used.

Results:

Small Cylinder:

Powered by compressor: 435 grams.

Powered by large hand pump: 570 grams

http://youtu.be/0ldaX5JWmEM

Large Cylinder:

Powered by compressor: 1810 grams.

Powered by large hand pump: 2450 grams

http://youtu.be/ByeBRVU_OKE

[Pat-Ard]

Thanks Milan, that's really interesting. The performance with the hand pump is 30% higher. That means only one thing -> we need a better compressor :)

[Rockbrick]

try an RC motor for the compressor - I have never found it too weak for any purpose

[piterx]

i love these kind of experiments!

what if you use water instead of air inside of them?

[Bricktrain]

I have used the large pumps to build compressors for that reason, they work better if you take the spring off when driving them with a motor.

[PhyBuilder]

Very usefull test, thanks. So as a rule of thumb one can say that the large cilinders are aprox. four times as strong as the little ones.

The ideas with the RC-Motor, water and the handpumps as an automated compressor are all usefull tips. Another one could be the parallel use of two or even more small compressors. I thought that Sariel once did that in a huge snow groomer. This because it may maintain the pressure better, and thus perhaps maximize it too.

[Rockbrick]

radial pumps maintain the pressure better....

http://www.brickshelf.com/gallery/kclague/dual-hex-compressor/p9090172.jpg

never seen anything like the citroen hydraulic pump done in lego though -

Edited April 23, 2014 by Rockbrick

[Boxerlego]

i love these kind of experiments!

what if you use water instead of air inside of them?

The metal rod will probably rust. The better option is to use non aromatic mineral oil. It wont hut the lego unless it has perfume it, nor will the mineral oil make the metal rust.

[efferman]

Not probably, it will rust definetely

[aol000xw]

Mineral oil can react with ABS, use silicon oil instead.

[1974]

Hello Milan

Thanx for the vids, great job

I just got a similar weight and could do a test with the old style pneumatics, if anyone is interested?

[Boxerlego]

Mineral oil can react with ABS, use silicon oil instead.

Mineral oil is an inert substance. It probably not going to react with the abs. Here is a video on this.

You could use either one but I want you to consider this, Do you know how much one gallon of silicon oil cost over one gallon mineral oil?

Edited April 23, 2014 by Boxerlego

[Milan]

Hello Milan

Thanx for the vids, great job

I just got a similar weight and could do a test with the old style pneumatics, if anyone is interested?

I am.

[1974]

Ok, then. I'll do the 48 & 64mm with a hand pump. I don't fancy taking the spring off one of my large pumps though ..

What do you think the outcome will be? More or less than 2,5kg (for the 48mm)?? I actually don't know the answer myself ..

[Rockbrick]

mineral oil could react with the rubber seals unless they are made for mineral oil systems (like on bike brakes, citroen hydraulic seals etc...)

[Milan]

If you can, it would be interesting to see how they will behave when powered by both hand pump (unmodified, of course) and compressor with small pump (M motor -> pulley wheel -> 6L pump) . I think those are systems that most people use.

Regarding power, I used brand new components just for the sake of the test.

I guess your 64mm is used. So probably has some imperfections in sealing, thus its outcome would be lower than it should.

For 48mm, if they are in used condition, i guess the situation would be the same.

[1974]

No, I bought a MISB 8680 and have one unopened 1162 left

Edit : The new style pumps does not work with the old pneumatics, so I cannot try with compressor. Well, maybe a buggy motor won't mind driving a pump _with_ spring?

Should have some time saturday to try it out

Edited April 24, 2014 by 1974

[BondemandClausen]

My experience with the compressors, is that the new style 6L compressor, creates a bigger resistance, and heats up, probably because of an internal overload valve inside the compressor. And that the old style 5.5L compressor runs more smoothly. If you have one of the old ones, it would be interesting to see the difference between them. Nice, and useful experiment!

[Milan]

My experience with the compressors, is that the new style 6L compressor, creates a bigger resistance, and heats up, probably because of an internal overload valve inside the compressor. And that the old style 5.5L compressor runs more smoothly. If you have one of the old ones, it would be interesting to see the difference between them. Nice, and useful experiment!

It is more efficient as it uses full range of motion and provides more airflow for the same rpm. I agree that this should be tested with 5.5 pump also.

[JM1971]

i love these kind of experiments!

what if you use water instead of air inside of them?

+1, but no propane, butane or napalm.

[Jullian_pdx]

It would be interesting to see how much more pressure a 9v power supply does with the same test setup.

[aol000xw]

Mineral oil is an inert substance. It probably not going to react with the abs. Here is a video on this.

You could use either one but I want you to consider this, Do you know how much one gallon of silicon oil cost over one gallon mineral oil?

You are right when you said mineral oil I though of synthetic oil. My fault here.

Anyways on this kind of application not a big amount is needed and silicon oil is the perfect oil for everything Lego.

[fasterthanlight]

Hey - sort of off topic - but can anyone tell me the overall length (in studs) that the small cylinder is when extended *and* retracted ??

[izorn]

[Leif]

Milan,

Is there any chance you can measure the pressure as well, using the Lego Gauge?