PC1800 Front Shovel (1/12)

[steamer]

Speed in hydraulic's can only be changed by two things, pump rpm and volume of oil. The pump is designed to give max cc at the max diameter hose that can be fitted to the pump output.
If you put on small hose it acts like a restriction in the circuit. Also to get max flow every hose from tank to pump to valve and back to tank has to be the same diameter or you'll have the same restriction in the circuit. If the pump is the same as what I think you have the inlet and outlet in 9/16" Dia. =1.767 sq. in. Sizing the hose down to 1/4" .785 brings you down to about 2.25 less volume than the pump can produce = slow cylinders.
I think if you up size all the primary circuit hoses to the proper diameter then you'll able to control it from there with motor rpm.
Hope this helps.
Rob

[DADSGARAGE]

Originally Posted by steamer

Speed in hydraulic's can only be changed by two things, pump rpm and volume of oil. The pump is designed to give max cc at the max diameter hose that can be fitted to the pump output.
If you put on small hose it acts like a restriction in the circuit. Also to get max flow every hose from tank to pump to valve and back to tank has to be the same diameter or you'll have the same restriction in the circuit. If the pump is the same as what I think you have the inlet and outlet in 9/16" Dia. =1.767 sq. in. Sizing the hose down to 1/4" .785 brings you down to about 2.25 less volume than the pump can produce = slow cylinders.
I think if you up size all the primary circuit hoses to the proper diameter then you'll able to control it from there with motor rpm.
Hope this helps.
Rob

Speed in hydraulics can be changed.....but the pump RPM is directly related to the output volume, so short of up sizing a pump the only way to increase volume flow is to increase the pump RPM. The pump I'm using is really much to big for what I'm using it for so I don't need the max output it can produce....you are right about creating an unnecessary restriction due to under sized hoses but the current sized plumbing is actually within the proper sizes for the flow rate, there are oil flow speed charts that can help in getting the proper combination of flow, hoses sizes and the ideal flow of oil in feet/second....suction is the slowest, pressure lines are the fastest and the return is a bit slower than the pressure lines. The ideal oil flow velocity according to the charts is....suction 2-4 ft/sec, return is 10-15 ft/sec and pressure lines are 15-25 ft/sec...this is for full size systems but I would think the same would apply to smaller scale as well. I think the problem I'm dealing with isn't the flow from the pump but more about where its disappearing to....not going to the cylinders...it's either the PRV or valve body not doing what is should .