PC1800 Front Shovel (1/12)

[Supermario]

Don't feel bad about not seeing the issue sooner KP. Feel happy your still making progress and can move forward with the system you've created.

It's all about accuracy within a range. looking at the valve your using I'm guessing it's rated at probably 3,500 - 4,000psi? Maybe 2,500?
When trying to maintain 275 what's not working properly is the cracking pressure of the relief. It's supposed to hold closed and stay closed and then snap open when opening pressure is reached. When it's turned way down out of that " proper cracking pressure" range it opens slightly and slowly and in essence becomes a flow control and not a pressure relief if you know what I mean.
Question is, how to remedy? I wonder if a lower rated relief valve is available?
I think best thing would be to make your own relief externally or purchase a RC hydraulics type relief? The 4200 relief comes to mind but I know there are much better versions out there that might work ?

[DADSGARAGE]

Originally Posted by Supermario

Don't feel bad about not seeing the issue sooner KP. Feel happy your still making progress and can move forward with the system you've created.

It's all about accuracy within a range. looking at the valve your using I'm guessing it's rated at probably 3,500 - 4,000psi? Maybe 2,500?
When trying to maintain 275 what's not working properly is the cracking pressure of the relief. It's supposed to hold closed and stay closed and then snap open when opening pressure is reached. When it's turned way down out of that " proper cracking pressure" range it opens slightly and slowly and in essence becomes a flow control and not a pressure relief if you know what I mean.
Question is, how to remedy? I wonder if a lower rated relief valve is available?
I think best thing would be to make your own relief externally or purchase a RC hydraulics type relief? The 4200 relief comes to mind but I know there are much better versions out there that might work ?

Can't help but feel a bit like a dumb dumb and really disappointed in myself for missing the obvious problem...... but sometimes when you are trying to trouble shoot a problem you take for granted that one component is working properly.....wrong....I was convinced that the PRV wasn't the issue....not...so off we go on a wild goose chase....lol...the school of hard knocks did however teach me a fair amount more on hydraulics than what I knew at the beginning, so it's all good!!(just wish I wasn't such a slow learner...lol)

The stock PRV setting on the valve body is from 1500-3750 psi. I simply installed a smaller spring, and it worked...or so I thought...lol....you are right about it always bypassing like a flow control never really totally closing or holding pressure!! I will most likely have to make a stand alone PRV before the valve body, would really like a piloted version but can't seem to figure out how to make one, a simple poppet style will have to do. Should I use a ball bearing and seat or a tappered pin and seat...???