Another hydraulic pump option

[dsdmax]

Originally Posted by RCP57

Be careful of the pneumatic rotary valves. My father in-law machined a valve block for my Volvo that was very close to the rotary style that Princess Auto sells. At 30 bar you could barely turn the valves with pliers. Too much surface area for that kind of pressure.

I was thinking/planning on making rotary valves. Looks like they would be easier to make versus spool valves (i would be concerned about trying to hold the required tolerance on such a narrow shaft... though maybe if i started with a reamed hole and ordered precision ground shafts to start that might not be too bad... im assuming each spool would need some kind of seal, o-ring? but tolerance between the lands would still hve to be good to keep from leaking between the lands. what is the diameter for one of these mini spools? .125 .1875? something bigger?

If memory serves i think the rotary valves your father inlaw made were smaller than a penny...

sorry - thinking out loud what about pressure release valves? are people making those? buying or ignoring that option? i would assume some adjustability would be nice ... i guess i have to learn something about spring pressure as well... at least making those on a lathe is not difficult...

waiting on my motors from robotmarketplace ... once i get those i can start on mounts and drive train... might need to source some bevel or spiral bevel gears (i dont think the spiral bevels will be necessary or worth the additional cost though).