home made press hydraulic press question (wont hold billet for twisting)

C

CTrelichunter

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Jul 11, 2020
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i built a forge press from red beard ops videos on you tube its a beast with squashing hot steel no problems there when i did some twist damascus the other day i put my billet in jaws of presswhen i went to twist my press piston started moving up it had no down pressure? is this normal? is there a way to fix this so i can use in the future otherwise ill use a vice any help would be appreciated Mark
 
Well, I've been waiting for somebody with real knowledge to respond. I checked my Coal Iron 9 ton press (now 14 tons) and it holds a billet solid. I pressed on a 1/4" flat bar, moved control lever to center position and the flat bar was solid clamped. Almost like the hydraulic fluid was back flowing. I don't know, but it doesn't seem to be normal.
 
Ken H> said:
Well, I've been waiting for somebody with real knowledge to respond. I checked my Coal Iron 9 ton press (now 14 tons) and it holds a billet solid. I pressed on a 1/4" flat bar, moved control lever to center position and the flat bar was solid clamped. Almost like the hydraulic fluid was back flowing. I don't know, but it doesn't seem to be normal.
Click to expand...
thanks
 
Ok, also try moving the ram but hand, when it's in the up position. With the motor on and off.

Your getting some fluid seeping back through your system, or you've got some air in your lines.

Basically there's really only a couple of options. One, it's bleeding back through the pump, or two it's bleeding through your valves. Or air.

You've checked for external leaks fastidiously right?
 
Hey Mark

If your piston goes up because of the force you put (during the twisting) it might be caused by few things (hard to say, because I don't see the press- please, upload some picture so I could see it):
- if you operate the press with a hand lever and you don't have any additional components of control system the issue can be in Hydraulic Directional Control Valve- it can be damaged
- A.McPherson A.McPherson point one of the option- the air in the system- during first run did you go up and down with the piston all the way few times? this is the way you can remove the air from the system.. if the construction of your press limited the piston movement range you will not get all air out from the system.

also I have a few questions:
- did you use the press in max pressure? Usually, the control valve limiter is set to 160Bar. When the cylinder reach the 160Bar the control valve direct the oil back to the tank and the pressure gauge tip stay on the 160Bar possition (it's about 2200PSI I think). If you set the control leaver to natural position the pressure should stay on 160Bar- this is how the system should work.
- if you didn't use the press with max pressure - try to check it on cold steel- it's less ungenerous.

To use press as a vise you need to leave the piston/cylinder under the pressure (in natural position). I don't recommend to turn off the press/motor cause when pump does not running the pressure on the cylinder drop (it's natural and normal).

hope it help you somehow
-David (from Dark Blade Knives)
 
It is most likely the control valve type. If it is a spring loaded log splitter valve it is in the bypass mode when not being pushes up or down. There isn't any force to the ram in that mode.
A bungee cord, locking arm, or other retainer to hold the handle down would keep pressure on the ram. It must be removed to use as a normal press.
 
A.McPherson said:
Ok, also try moving the ram but hand, when it's in the up position. With the motor on and off.

Your getting some fluid seeping back through your system, or you've got some air in your lines.

Basically there's really only a couple of options. One, it's bleeding back through the pump, or two it's bleeding through your valves. Or air.

You've checked for external leaks fastidiously right?
Click to expand...
12345678910 said:
That's how it works.

You can change valves, but it's not worth
Click to expand...

David Baranowsky said:
Hey Mark

If your piston goes up because of the force you put (during the twisting) it might be caused by few things (hard to say, because I don't see the press- please, upload some picture so I could see it):
- if you operate the press with a hand lever and you don't have any additional components of control system the issue can be in Hydraulic Directional Control Valve- it can be damaged
- A.McPherson A.McPherson point one of the option- the air in the system- during first run did you go up and down with the piston all the way few times? this is the way you can remove the air from the system.. if the construction of your press limited the piston movement range you will not get all air out from the system.

also I have a few questions:
- did you use the press in max pressure? Usually, the control valve limiter is set to 160Bar. When the cylinder reach the 160Bar the control valve direct the oil back to the tank and the pressure gauge tip stay on the 160Bar possition (it's about 2200PSI I think). If you set the control leaver to natural position the pressure should stay on 160Bar- this is how the system should work.
- if you didn't use the press with max pressure - try to check it on cold steel- it's less ungenerous.

To use press as a vise you need to leave the piston/cylinder under the pressure (in natural position). I don't recommend to turn off the press/motor cause when pump does not running the pressure on the cylinder drop (it's natural and normal).

hope it help you somehow
-David (from Dark Blade Knives)
Click to expand...
 
thanks very much i just tried to post pics but didnt work im i did get all the air out of system ill just use my vice in the future
 
In my restoration build I used the same control valve that I had purchased from Prince back in 2006... still working great! This is the one I linked to in the video... I think it's the same one with a spring center. Is this the one you bought?

 
J. Keeton said:
In my restoration build I used the same control valve that I had purchased from Prince back in 2006... still working great! This is the one I linked to in the video... I think it's the same one with a spring center. Is this the one you bought?

Click to expand...
Yes james its me Mark Anderson i emailed you about this its a prince RD 25-75
 
For reference, this is what the guts of the RD-2500 series looks like:



-------------

You were saying that you are getting pressing power if I remember right? Have you messed with the relief adjusting screw at all? This screw sets the max psi your press will operate at. It's the governor. I don't think this is your issue... but maybe it's backed all the way out?
 
This was my valve before I cleaned it up and painted it.

I'm pretty sure it's the same one as above... but now hearing your issues... I'm not as sure:

 
J. Keeton said:
For reference, this is what the guts of the RD-2500 series looks like:



-------------

You were saying that you are getting pressing power if I remember right? Have you messed with the relief adjusting screw at all? This screw sets the max psi your press will operate at. It's the governor. I don't think this is your issue... but maybe it's backed all the way out?
Click to expand...
I adjusted it a little bit when i first installed it bit not alot
 
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