[cr4ck3r]

This machine is a MA-400HA.

I can step the APC through manually and change the pallets in MDI with an M60.

The tombstone clamps and all looks good until the program goes to run... then I get the regular pallet unclamped error.

The problem is that the rotating table is not dropping down and clamping. Thus not hitting the proximity switch (which is expected.) I've called service techs and no one has really been any help but before I have one come and take an actual visit I figured I'd try here.

Any ideas why the rotating table will not drop down and clamp? Any help would be greatly appreciated. Right now I'm at a loss and its just sitting here not making any $$.

[supercut]

In all my experience with table clamping problems, the most common is CHIPS built up around or on the switch under the table. Basically what is happning is the table is not at the HOME position for clamping or not reconizing it. Another thing to check is the arm that pushes and pulls the pallets in and out and the slot it fis into. What happens here is chips pack up here and doesn't allow the pallet to go far enough or to far for the CLAMPING position. Air blow everyting out good and try again. I've never had to call service for this. Hope it's this simple. Good Luck!!

Supercut

[cr4ck3r]

We have a smaller pallet changing machine that we have had those same issues with and yes, it is a pretty easy fix.

In this machine it is different though. The tombstones are the only things changed on a pallet change. When a change is done the tombstone comes in and is lowered onto the rotating table. It then clamps there. This all works fine. Then the rotating table is supposed to drop down into postion (which it is not) and when the proximity switch is tripped it too clamps in position. Since the rotating table never moves it is completely sealed off from chips and whatever other elements.

Btw, this is a horizontal mill and the rotating table indexes the tombstone at 1 degree increments. I assume it unclamps and lifts up to disengage the incremental indexing (possible driven by gears underneath) and then when another pallet is loaded it drops back down to engage the indexing..... if that helps you understand anymore... I may have just lost you though because I even started to lose myself

Thanks though.

[cr4ck3r]

Well With no true explanation it is fixed. Indexing the table 180 degrees in MDI mode the rotating table clamped and it worked. The problem couldn't be recreated either. Just thought I'd comment about this in case anyone else ever comes across the problem.

[Shotout]

Well With no true explanation it is fixed. Indexing the table 180 degrees in MDI mode the rotating table clamped and it worked. The problem couldn't be recreated either. Just thought I'd comment about this in case anyone else ever comes across the problem.

Our 500s with OSP 200M controls do it regularly. If you read the pocket manual, if you have it on the control, it will tell you in that situation to index the table to any position as you found by trial and error. I've had to train my more advanced operators on how to do go into the APC screen from manual mode and step through. If they can't restart then they are to go back into that screen, return cycle and then to MDI and enter in the g codes to index. After that to clear the chips from the loading area. What the normal cause is with ours is either chips building up as said by supercut or the dog that trips the limit switch at the loading station is out of whack, which in our case is from operators letting the pallet lock stop a rotating pallet. When it does it again don't reset just hit the APC button and look for errors at the bottom of the screen LS does not exist with some address characters means a sticky limit switch or something similar preventing the control from reading a ready state. One other thing that will happen is if someone uses the tool probe sometimes chips will prevent it from closing completely and that limit switch will prevent it from indexing since it thinks the probe is still up. It still gives an APC Clamping alarm but the error is Tool Probe LS up or something similar. Don't know if you are using a probe to check for tool breakage but if so it could be chips falling under the cover on the side away from the spindle preventing it from completely dropping down. Hope this helps.