Lapidaryforum.net
Gadgets, Gizmos, and Dohickeys => Fixing, Modifying and Refurbishing your Lapidary Equipment => Topic started by: AndrewBloxom on January 23, 2021, 05:10:44 PM
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Hi all,
This is my first post so bear with me. I'm excited to be here and looking fwd to learning and also sharing my experiences.
I just rebuilt the hydraulic feed on my GW18. I'm wondering if there is a procedure for refilling the hydraulic system. My carriage is not easy to move at the far left side to start a fresh cut. Starting more In the middle, it will start and move consistently. But when I reset and try open the valve the carriage does not move. If I push it manually I can get it moving but with the reservoir top open I can see it gurgling/ bubbling. I have the fluid above both lines out. Does this indicate an air leak in a fitting?
Let me know if this is not making sense and I can post a link to a video.
Thanks,
Andrew
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I have no idea about the feed on your saw, but welcome sir! Someone here can probably help you out with this.
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Welcome.
Any way to get a brake bleeder / vacuum pump on it? Or did you do that after you rebuilt it? If there was no air in the system after the rebuild, then it must be "suckin' air" somewhere.
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Thanks Bill and Vince. I did not use a bleeder or anything. I moved the carriage far left to start position and opened the valve to pour in fluid to the hydraulic system. Then I cycled it a few time while topping the fluid above the outlines amd getting air out. I used mineral oil so that I could have the same fluid for cutting and hydraulics.
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Here is a link to a video where I show what is happening.
https://drive.google.com/file/d/1kZ9hzIfzu4HED9L1xvZQEarcFM5fAqgY/view?usp=drivesdk (https://drive.google.com/file/d/1kZ9hzIfzu4HED9L1xvZQEarcFM5fAqgY/view?usp=drivesdk)
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Yeah, those are big bubbles. Must be suckin' air somewhere for it to repeat with that much air in there.
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If you have a schematic of the system it would be a lot easier to diagnose.
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Thanks SlabberCabber, let me know if this is useful or more info is required...
(https://i.imgur.com/N5EflHn.jpg)
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There's a lot missing there. If that was all you had, it would not be possible to reverse the piston. There should be a power source and some type of control valve. That valve is really important.
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Can you scroll right to see the whole image? On the right side it shows a needle valve and across the bottom is the line to the gravity fed counterweight
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I see the needle valve, but there has to be something more. Something has to relieve the pressure to reverse. There must also be something to provide pressure. Either an on off for the motor or a bypass valve.
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My knowledge is short on this so I'm hoping some others can chime in here.
My belief is that it acts as a hydraulic damper and not as a powered hydraulic cylinder. The power comes from the counterweight pulling the carriage vise towards the blade. Does the return line from the reservoir to the left side of the cylinder not provide the pathway you reference for reversing the carriage?
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OK I see what you mean now. The only place that could be leaking other than the line fittings is the needle valve. Can you bypass the valve with a piece of tubing to eliminate that possibility?
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Yes, I agree that is a good line of thinking to isolate the valve for troubleshooting.
I was actually just pondering earlier that one possibility is that some of the old leather cup seal that had disintegrated may have lodged itself up in there and caused damaged somehow.
I will follow up once I can make that modification and test it.
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It is designed so that it doesnt move fast from left to right, you can open the needle valve all the way and it will bypass fairly quickly but when it moves from left to right it pushes all the fluid back up into the reservoir.
It is a hydraulic dampening system to keep the saw from cutting too fast, you can regulate speed with the needle valve, it doesnt actually move anything though.
Tony