Hi,

I have a small problem with crane's claws of Unimog. I built this set recently and I've noticed a problem with them. When I close the claws without any object inside (so they are closed maximally) I can't open them again by th switch and I must touch them and slightly help to open. However sometimes this problem doesn't occur (I don't know why) and also after non-maximal closing (with something inside) it always does properly and I can open them. Do you know something about it?

Mine did the same thing. I thought maybe it was the "teeth" catching on each other. After repeatedly failing to get it to work properly, I finally changed the air cylinder in the claw. Problem solved. I was lucky enough to have an extra one, though.

That's because LEGO pneumatics are really very poor constructions and not implemented well. LAs are much better for this purpose. I've had the same problems as you

I'm off to bed and will read the shitstorm tomorrow

Try to contact LEGO customer service - the first sets had a problem with the small cylinder - it lost a lot of air (the crane boom didn't stay up because of this failure, too). I received a replacement without any problems.

Thank you for advices. I'm going to contact LEGO. I agree that the pneumatic technology is poor and should be improved. Pneumatics could be very interesting when it worked properly.

Edited March 15, 201311 yr by Tommi1983