Jerky project cylinder action

[bigdeano]

Yarg,
I think you've done an amazing job on your drilling rig. As problems go this is a very small one. You had it almost fixed I think when you put the 1/16 restrictor in the line. If the engine hadn't stalled it probably would have worked.

If you decide to buy a flow control valve take a look at ebay auction 300867377287

 

[yarg]

Thank you very much. Some friends really like it and I am hoping it works well too but with 2 ft of snow on the ground and temps in the teens, this will be some time I made my own restrictor from a coupling with a hex drive plug ground to allow It to go to the middle of the coupling. All I had was a 1/16 bit and I saw some on a hydraulic site with 1/32 inch orifice. It takes a week to get anything here so I improvised a bit. I could tell it helped but just too big a hole. The fittings were only 3 bucks but shipping was 12? I chose the needle valve hoping to be able to dial the right speed.

Can not wait for the parts!

 

[bigdeano]

yarg,

I thought of a way to simplify this. Since you're using the needle valve to control the ram speed, all you need is a pressure relief valve set at maybe 600 psi in the line from the motor valves to the ram valve. It will take much of the load off the engine when you're raising the ram. No proportional valve is needed. All the excess flow ends up in the tank anyway, this would just be simpler and cheaper.

If your engine doesn't labor too much while raising the mast, you don't even need this additional valve.

 

[yarg]

Bigdeano,

In reality, tat is the result of my plan.

Needle valve and a low oreasur relief cartridge in the ram spool. This cartidge will do this very thing but when neither valve is working there will be no back pressure to speak if os the engine can just idle.
Hope I have this right?
Gray

 

[bigdeano]

I thought you were going to put the 1000 psi relief cartridge in the motor valve. Sounds like you have a good plan.

 

[yarg]

I thought you were going to put the 1000 psi relief cartridge in the motor valve. Sounds like you have a good plan.

Yes, I am putting the cartridge into the ram spool valve. Any time I actuate this valve the max pressure will flow to the ram and the excess will flow though the relief and to the tank.

The motor spool is upstream of the ram spool and thus can have the 1500 psi the motors are rated at. The power pack I have will produce enough for either motor to have full power and about 25% extra if needed if I run both for any reason at once.

I did come up with one more question while reading a thread on a float valve:

I have a float spool on the motor valve. I got this configuration so that if I was running the chain hoist motor in the down travel mode, I could put it in float and allow the wieght of the drill head and pipe to travle freely for drilling force. I have tried the float possition and it does not do this??? What am I missing here?

Gray

 

[J_J]

In float mode, all ports are common.

You will have no force, as all fluid goes to tank.

Think what happens with float on a loader, the bucket just follows the contour of the ground.

With enough weight on the motor drive, it might try and make a pump out of the motor.

 

[yarg]

JJ,

That is what I thought would happen but the head is 200 pounds and this is not enough to move the motor? It puts about 200 inch pounds of rotational force on the motor by my calculations. Maybe it needs to work in a bit or needs a bit more wieght?
I have a Kubota L48 and nderstand the float function but thought that it would not take much force to overcome the friction---I may be wrong.

Gray

 

[bigdeano]

The hyd motors I have were very hard to turn when new. You could try pulling down on the head to add more weight. I seem to remember that some float valves only open one work port to the tank port, so like a blade it can float up but not down. Not sure about this though. If you can't get it to move you could try reversing the hoses.

 

[yarg]

You know, I thought it might just be a friction thing. Being brand new, those motors are not broke in if that even happens?
My float in the tractor does both up and down but the static pressure is likely higher than on these motors.
I will try a load on the head to see if I can move it then I should know what to expect?

I do not really need this feature but it would be nice to have.
I am thinking it will work
No parts today? Getting antious!

Update: just got back from my shop and I checked if the float woukd work with additional weight. It does but the motor sounds like a bucket of bolts when you lever the head to move in float ( engine off). Sounds like it has to break in to smooth out and react under lesser load?
Gray