Veeeeery interesting.... so 30 x 150 psi means 4500 psi from your average compressor? I'm guessing it does very low volumes though, and from what I can tell is the equivalent of fitting a pneumatic diaphragm to drive a shock pump.
No, not I. Would only be caught dead in one of those.
The diaphragm chamber is a service brake chamber from a big truck...it's actually 30 in2 effective area (Type 30)... the long stroke chambers(Type 30LS) have a 3" stroke.
Considering they're VERY common, the cost is also VERY low...have seen them online for ~$20-30
Posted: Fri Apr 26, 2013 1:14 am
by jackssmirkingrevenge
Staying with PVC, 150 psi on say a 4" piston is a force of 1885 lbs... hooked up to say a 0.5" head diameter pump, that gives you a maximum pressure potential of OVER 9000 PSI!
Slide valve and QEV to power every stroke...
Posted: Fri Apr 26, 2013 11:08 am
by Gippeto
Safety note...if using a brake chamber, use a service brake chamber...the "double chamber" brake pots contain the parking brake spring, which requires special tools and knowledge to work with...VERY dangerous....as in "crushed rib cage" kind of dangerous.
Priced out a Type 30LS service brake chamber locally @ $40+tax
Posted: Thu May 09, 2013 3:53 pm
by Kilash
I'm guessing this works through hydraulic leverage?
Posted: Thu May 09, 2013 10:02 pm
by Gippeto
Not familiar with your terminology, but I suspect the answer is yes.
Pressure(100psi) acting upon surface area (30 in2) to generate force (3000lbs)...that force acting upon a reduced surface area (1 in2 to generate a higher pressure (3000psi).
This looks like something that could easily be duplicated using two air cylinders of different bores. The one with the larger bore, of course, drives the one with the smaller bore. In fact, that's quite similar to what they seem to have done with an earlier model:
Although I suspect that here, there is a single shaft with duel pistons, one for each size bore.
Posted: Sat May 11, 2013 9:39 am
by wyz2285
Pressure(100psi) acting upon surface area (30 in2) to generate force (3000lbs)...that force acting upon a reduced surface area (1 in2 to generate a higher pressure (3000psi).
Assuming that the input air used to push the strock is then exhausted by the slide valve... for each amount of effective charge, 30 times more air is wasted
Posted: Sat May 11, 2013 2:45 pm
by Gippeto
It takes energy to do work.
The operational cost of such a unit is still very low compared to any alternatives I have available. Even a box of doughnuts for the firehall to get a fill is going to cost more than using this.
That I could use it at home in my garage to keep my tanks full on MY schedule is a huge bonus IMO.
Posted: Sat May 11, 2013 3:06 pm
by wyz2285
I don't have any large size compressor, so use my hill mk3 pump is still easier than pumping a bike pump a couple million times :p
Posted: Thu May 23, 2013 8:32 pm
by Gippeto
Collect some stuff...
Do some work...
A little more...
Bored the brass cylinder liner to final after work...no pic. With a little luck, I'll be testing by next weekend.
