Large Monarch question

I have a Large Monarch 613 engine lathe that has a weird problem. I start the motor and all is well, then engage the spindle and it will run fine for about a minute, then slowly start to make headstock noise and then it stalls the spindle. If I disengage the spindle and then re engage, it will run for a about a minute and then stop again. Any ideas? Do these machines need oil pressure to run? Thanks for any ideas.

Do these machines need oil pressure to run?

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Since they are full of hydraulic clutches, I would say they do.

I believe the 613 is the same headstock but with a lighter bed than the 612. If this is correct, then Mr. Oder is right: these machines are hydraulically activated. Even though you have a manual engage lever, hydraulic pressure is used to collaspe a bunch of friction disks together in the headstock to provide the link between the electric motor and the spindle. Pretty much the same principle of an automatic transmission. I haven't played much with the hydraulic manifolds in the back of our 612 but I think one was for the engage/disengage and the other was for the braking action. (The 62 has many more manifolds as it's completely hydraulically driven). If I remember to check while I'm at the shop this weekend, I'll finger through the 612 operators manual and see if I can come up with a few suggestions to your problem.

It might be that you're nothing more than low on hydraulic fluid and you start cavitating the hydraulic motor when you sling/slush a lot of fluid around the headstock. Or, your filter might be clogged. Or, your drain from the headstock to the resevior might be blocked... Lots of small possible easy-fix issues but I will double check on manifold adjustments for you.

Rex

There is a second motor starter for the hydraulic pump, and at least one recent purchaser of such a machine had a problem with his pump intake, in which it would pump air, but not hydraulic fluid.

I did some work on it today, the machine doesn't need hydraulic system to run. The hydraulic system runs the brake and the lube system. I unhooked the wires from the terminal strip going to the hyd. pump and the machine ran fine, so I think hydraulic pressure is going to the brake assy. when it shouldn't be, causing it to drag to a stop. Took brake assy. apart and it looked pretty good. There is a valve on the back of the machine that engages the brake when lever is activated, might be out of adjustment. I'll have to see if Monarch can fax me a procedure on adjusting.

"the machine doesn't need hydraulic system to run"

Interesting... I'll have to study our 612 diagrams and verify how ours operates. Now you got me wondering what I was looking at when I had our headstock open...

I have had that happen to me a few times what I did was run the machine in reverse for a bit an that seamed to make it un jam its self. Might be worth a try.