rcx132
Philip
- Messages
- 2,709
- Location
- London, UK
I'm fitting some Audi axles to my 4x4 buggy. The axles have locking differentials built in which are switched on using a vacuum powered device which pushes a lever. I want to ditch the vacuum device for a pneumatic piston/actuator which would run off a small on-board compressor (most serious 4x4s have these fitted). This would be easier to plumb and control as most 4x4s use compressors to control their diff locks and transfer boxes.
I've found some pneumatic actuators online. But they are really long, example to get the 35mm stroke that I need the actuators come in 100mm length which will never fit in the space I have. I don't see why an actuator needs to be so long to get such a short stroke.
I spoke yesterday to my friend, a fabricator, who thinks its about a days work to make a pair of piston actuators to fit. But he's worried about what to do for piston seals because he's never done actuators before. He also reckons I need some decent seals that will survive dry use (i.e. no lubrication).
So has anyone got experience making actuators so I can pass on some tips?
Or maybe there's a better source of off the shelf actuators that have a better body length to stroke length ratio?
I haven't googled around for piston seals yet, but if anyone knows a source?
http://www.ebay.co.uk/itm/KUHNKE-24...095818?hash=item5d5c55f58a:g:i-oAAOSws65TlvF9
I think the 4x4 on-board compressors run at 70-100 psi. To get desired force out of an actuator it would need to be max 3mm piston, which is impossibly tiny. So I found a small pressure regulator that would take the pressure right down so I can use a bigger piston size without breaking the axle mechanism. This has a double advantage because it means my compressor will use less air so I can run a smaller compressor as well.
I've found some pneumatic actuators online. But they are really long, example to get the 35mm stroke that I need the actuators come in 100mm length which will never fit in the space I have. I don't see why an actuator needs to be so long to get such a short stroke.
I spoke yesterday to my friend, a fabricator, who thinks its about a days work to make a pair of piston actuators to fit. But he's worried about what to do for piston seals because he's never done actuators before. He also reckons I need some decent seals that will survive dry use (i.e. no lubrication).
So has anyone got experience making actuators so I can pass on some tips?
Or maybe there's a better source of off the shelf actuators that have a better body length to stroke length ratio?
I haven't googled around for piston seals yet, but if anyone knows a source?
http://www.ebay.co.uk/itm/KUHNKE-24...095818?hash=item5d5c55f58a:g:i-oAAOSws65TlvF9
I think the 4x4 on-board compressors run at 70-100 psi. To get desired force out of an actuator it would need to be max 3mm piston, which is impossibly tiny. So I found a small pressure regulator that would take the pressure right down so I can use a bigger piston size without breaking the axle mechanism. This has a double advantage because it means my compressor will use less air so I can run a smaller compressor as well.