Compressor - not enough oomph

[GazK]

Hi all.

I've been working for some weeks on building a working train pantograph - I'm happy with the design, which closely mimics the operation of the main UK type. But I'm having trouble getting my compressor to provide enough oomph to raise it - it's quite a large load, given it has to raise the whole pan up at a large mechanical disadvantage (just like the real thing).

I started with a 4 pump compressor, driven by two hard-coupled L motors driving the pumps in 2 groups of 2 through 24/12. Initially it worked, but as time went on it got weaker - which I don't understand - and often would work on the first lift, but on subsequent lifts the pump would audibly "fade" once initial pressure is reached.

I tried a few things; the compressor is now run off a 9V mains supply, to avoid going through batteries. I've now added two more pumps, and I've tried decoupling the two motors. None of those measures improved things.

Here is a video of the current setup: 

 

Can anyone advise what I'm doing wrong?

[dr_spock]

Have you checked for air leaks? 

[Nazgarot]

Remove the lifting-cylinder and test it without a load. It may be the seals in the cylinder as you say it worked the first few times... This seems a bit heavy a load for a single cylinder. I would try doubling it after having checked the cylinder. The sudden drop when the pressure is released is also indicating this. A cylinder in working order should not be able to drop the load that fast except if you designed it to actively lower.

-ED-

Edited December 14, 2019 by Nazgarot

[KevinMD]

What about isolating each air line to a pump (or two) so you’re not trying to lift all cylinders at once?

or just use LAs?