New air powered engine - WIP

[Tamas Juhasz]

These are good mechanism for operate, but it requires power from the motor, I don't know, if it will be enough to keep working. The main problem is sealing around this (or other) valve mechanism. If won't be sealed well, then there will be air loss. But keep trying, doesn't seems to be impossible.

[piterx]

These are good mechanism for operate, but it requires power from the motor, I don't know, if it will be enough to keep working. The main problem is sealing around this (or other) valve mechanism. If won't be sealed well, then there will be air loss. But keep trying, doesn't seems to be impossible.

yeah...do you have any idea on how to make it with legos? even including drilling some pieces :P

Edited August 28, 2012 by piterx

[Tamas Juhasz]

I don't have any idea yet. Modding or drilling pieces is not so acceptable for me, imho it would be great only with Lego. I think my motor with your sealing could work well(with sealing it could work only with an air tank - I needed the compressor because of the lot of air loss). I think it's not so plausible that a pneumatic piston motor could operate also the valves. One 9V motor for valves isn't so much in a moc which is equipped with this piston motor. You need remote controlled steering and "throttle" if you want to build the engine in a moc. I don't have better idea.

[SNIPE]

If I was you I would just use a lego air pump as the cylinder as it has a chamber that is sealed and you can add an air tank to it without air escaping..

Note that if you have two pumps hooked up in parralel when one is pushed down it will push the other one open, a bit like the cylenders of a car how one goes out and the opposite one goes in.

I had the same problem as you, I was making a supercharger that didn't have a belt, it blew air through a hole in which the outer gear of a differential was span, the gear was very close to the hole, thats why it worked so well, the planet gears inside of the diff worked fine too but it still had too many holes and gaps to make it into a supercharger.

Edited August 28, 2012 by SNIPE

[piterx]

yeah i know modding and drilling pieces is not orthodox...it's the same for me, i don't like it but my problem was:

PF motors don't allow a vehicle to go fast unfortunately...XL motor has nice torque but it doesnt have enough rpm to build a fast vehicle...at the same way a PLE motor requires a big compressor to work...so i was looking for some feather weight engine who could pull a medium vehicle.

lego unfortunately lacks some useful pieces such as valves or stuff like that (probably because it's just a toy and im forgetting it XD) so i need to "cheat" and create from scratch valves...

im aiming to something powerful :D

btw if you havent dismounted it yet id like to see a sealed version of your video, just to understand how much improvement could it bring :)

[Tamas Juhasz]

yeah i know modding and drilling pieces is not orthodox...it's the same for me, i don't like it but my problem was:

PF motors don't allow a vehicle to go fast unfortunately...XL motor has nice torque but it doesnt have enough rpm to build a fast vehicle...at the same way a PLE motor requires a big compressor to work...so i was looking for some feather weight engine who could pull a medium vehicle.

lego unfortunately lacks some useful pieces such as valves or stuff like that (probably because it's just a toy and im forgetting it XD) so i need to "cheat" and create from scratch valves...

im aiming to something powerful :D

btw if you havent dismounted it yet id like to see a sealed version of your video, just to understand how much improvement could it bring :)

If you need a fast vehicle, you need power. It doesn't matter if the motor has high rpm with low torque or low rpm with high torque, only the power(torque*angular velocity) matters. If you have a motor with 60 rpm and 1 Nm torque, the power is ((60*2*3,1415)/60)*1 = 6,28 W.

I think from this piston engine with air operating you couldn't get much power, maximum some percent of a Buggy or XL motor. If you need power to speed, then an RC buggy motor (or PF XL, but the buggy is better) is recommended for you. But if you can run this engine at several thousand rpm, it's possible to have the same power(or even more) as the buggy motor. The torque is little because of the short stroke, you can mostly increase the power with increasing the rpm. But in that case the motor will consume a lot of air, so it would require a compressor or a very big air tank.

I think it will be useful in low rpm with very little air consumption, so you could operate a car with piston LPE, but without wires and pneumatic tubes from compressor.

I'm planning to try out the engine with sealing, now I'm looking for a good string.

[piterx]

eheh yeah mate you're probably right...im not an engineer unfortunately to know these kind of things so my "learning" proceeds by trying :P

anyway even some wool wires could be good...be sure to wet them first so they will get well attached :)

[piterx]

FINALLY! after some days of thinking i came out with this custom, not so orthodox, lego valve :)

hrontos gave me a brilliant solution wich is this one

i had to modify some pieces, i know someone of you doesn't agree with it but you know, lego lacks some pieces :P

if i manage to make my motor work (and i'm really near to get this accomplished) ill send it to lego...who knows, maybe they could produce these pieces so even the purists could build this engine :P

[allanp]

Quite a nifty idea. May I suggest that you hone the valves by spinning them using a fast motor and holding them against the "seat". You may also use some cutting compound but be gentle. The goal is not to wear a groove. just to get a nice air tight seal. I assume you will also drill a hole in the side of the engine block near the bottom so the exhaust air can escape when the piston reaches the bottom. You may also want to use some gastet making compound like hylomar blue. Once the pieces are braced together this should allow you to run some fairly high pressure without any air leaks.

Edited August 31, 2012 by allanp

[piterx]

yeah i need to drill the piston too maybe...last time i was testing the valve it blew up with only 1 bar XD due to the almost perfect sealing of the whole thing lol...but probably the best way of making it should be 2 valves in the same chamber...and i explain why:

lets say we have 2 valves just like that one i posted, when the air gets into the first valve it pulls the piston and then get stuck in the valve chamber and could cause it's blown...

having 2 valves under the same chamber will avoid this problem because when the first valve is closed the second one is opened so air always have a place to pass...im really near to get all of this working :D im so happy lol!

[kcabe1]

is this post over or moved to a new thread?

is this post over or moved on to new thread?