[4Rm0D]

Hi guys, I'm working at a shop where we are using a Mighty Comet CNC with a Mitsubishi Meldas M520 controller.

When we try to do a tool change of 2 tools or less it works fine. Unless the rapid override is set to less than 100. It also doesn't work if you do a change greater than 2 tools apart.

Eg: T1 to T2 works fine
T1 to T2 works fine

All else fails.

What it does when it fails is also confusing.

Its a rotary tool changer and if it fails what it does it does is after completing the tool change normally the changer rotates back to the original tools location and tries to put the new tool back in and the two tools collide. We then have to reboot the machine.

Eg:

- Current tool is T1.
- Request T5 using T5 M06 or M06 T5
- Z axis goes to zero and the tool changer extends to pikup the tool
- machine releases the tool and z axis raises to clear the changer as it rotates
- tool change rotates to tool 5
- z axis lowers and the machine locks tool 5 in place
- tool changer retracts

up to this point everything is normal, then it does something weird...

- the tool changer rotates back to T1
- the tool changer extends to pickup the tool from the spindle
- tools 1 and 5 collide

at this point the only way to correct this is to reboot the controller. when it comes back on its still at tool 1.

Any info you guys can provide is greatly appreciated.

[A1CNC]

I have a mighty comet 500p withthe meldas 520.

I know you can register any pocket to hold any tool. I saw that somewhere in the manual. I would guess you might need to clear the tool register and start over. Not the length/ diameter registers.

I haven't used mine that way so you are going to have to read it in the manual.

[4Rm0D]

any idea why that would cause it to malfunction when the rapid override is changed from 100 to 50 or 25?

[onthebumper]

I worked on a mighty with a 500 control a long time ago that was doing something very similar. My memory is foggy but I believe there was a problem with the clamping mechanism for the tool on the spindle. I think it was air actuated and there was a leak in the air so the clamping mechanism would very slowly release and the switch for clamp confirmation was no longer being made which confused the control. I think we ended up replacing some worn O rings.

[InlandPT]

Its been about 5 years here....so I'm grabbing at a thread and wondering if you ever figured out the problem with the Meldas 520 tool changing issue on you mighty comet. I recently purchased one and it is having the sane issue with the changer....sometimes it works....then sometimes is goes back to another station and crashes. Any advice you guys can give would be most. I have not looked into the o-ring fix suggestion above....I will look into that as well as quickly as possible.