Brown and Sharpe 618 Micromaster Hydraulic Table Help Please

[Technical Ted]

Yes, I can manually work the gate with zero failure.

I would think this means all the valving, etc., is working correctly, but there is just slop in things??? I think you're on the right track trying to tighten things up. Maybe just some warn linkage... I might try setting things up to move the table back and forth as slow as possible and "help" the gate by hand and see if you can tell/feel or at least get an idea of what might be happening... It's hard to tell when the table is moving back and forth rapidly. You might even find that the problem is better or worse and different speeds which might help you determine what's going on.

Ted

 

[Janderso]

Good ideas, pin #23 has some movement. I can probably tighten that up some to get more rotation.
Works perfect if I help it as you can see.
I have the hydraulics diagram, the filters have been replaced, oil and metering valves.
Based on the lubrication system, if properly maintained this baby would run for decades. Oh wait, 1966 = 53 years old.
I'll check into the drips. There are many drain points as all the oil drains down back into the reservoir.

 

[C-Bag]

I was surprised to see a hydraulic system like that dripping and leaking like that. I understand it all just use to a sealed system were as it's leaking there's your problem. Then containment of fluid in a grinding machine I'm sure it's sealed just odd to me. Not knockin it I've heard only good things of the machines just thinking out loud. Good luck

THIS blows my mind. All the hydraulic's I've ever worked on were sealed systems and they still got dirt and grit in them. It's always interesting to try to reverse engineer what the original engineer was thinking.....but this is a first seeing a purposely dripping hydraulic system! I could see this would simplify plumbing just letting it drip. Very much like the electro pneumatic valves I'm used to where they just vent to atmosphere. It would sure seem like Cadillac is on to it and that you have a restriction in the return drip orifice or that link slop. I would be tempted to change the return ramp making it steeper to more mimic what your finger does to make it work properly. To me the ramp is to shallow and just changing the roller size won't change the ramp engagement.

 

[Janderso]

Interesting, we are thinking along the same lines. I made a larger bumper to force the valve open/closed to it's limit.
When I slow down the table, move the lever to it's full engagement and let go, the table cycles properly every time.
I did it before work this morning. When I get home tonight i'll install it and try it out. If it works, I'll make one out of delrin (sp?)
Another observation. When I first pressure up the table cylinder, it cycles fine for the first few times then it starts jogging on the left side only.

 

[Cadillac]

I know you said you replace the filters but read the last sentence of first paragraph. They call them resistive plugs???

Then on second pick the first paragraph and the next sentence talks of orfices getting gummed up.
Those are what I was meaning.

 

[Janderso]

Excellent!
Thank you Mr. Cadillac man

 

[Janderso]

I installed the larger contact roller, it made no difference.
It appears I have an internal fault with the spool valve or something else going on.
It may be an adjustment on something I am just not aware of.
I used the grinder this morning to grind a piece of scrap low carbon steel.
The finish is great. No wavy texture.
For the near future I think I will just baby sit the auto table feed. Not a big deal.
It's much easier than having a manual grinder.
Thanks for all you help and guidance,
Jeff

 

[Cadillac]

That stinks. Do you have access to a gauge that you can hookup to check the relief valve. I saw in the manual about testing to verify pressures. I think it was 110* for movement and like 25* in nuetral? Everything I’ve read says the control box is pretty stout and most problems are with linkage. I did read there is a oring seal for the table cylinders. If it has a crack in it can cause erratic movements??? Maybe something to check. Good luck.

 

[Janderso]

I do have a pressure gauge but I haven't checked yet.
I wouldn't know what to do if the pressures are out of range so I'm not motivated to do anything about it.
I'm bummed no doubt. I just don't know what to do.

 

[Cadillac]

Checking the pressure will verify the pumps output. Once checked it’ll eliminate or point to the pump. If pressure is where it should be then you could be dealing with to much internal leakage in controls or cylinders.
At least she works and I’m sure you’ll figure it out with some time.
If interested I picked up a bunch of wheel hubs in auction lot. Their right hand thread with washers so they can be used just not left handers. Pm me if interested have a good one