Hello everybody. I'm a technician in VN factory.
I've got a mechanical problem: Tool drops when I machining with heavy load. Something's wrong? Please help me troubleshooting. My email: dungjuki@yahoo.com.

do the tools drop only when you try to tool change after a heavy load?
a quick check would be to mill with a heavy load, zero return the z axis, then have an m0(optional stop) before the tool change. take the holder out of the machine. if it is sticking in the spindle, you might want to check the drawbar and the spindle liner. if you put the tool back in, it should tool change fine.
i would also check that the spindle orientation is correct after milling and before a tool change.

"you might want to check the drawbar and the spindle liner"?
The worker's worked for 3 hours before the tool drop droped. We disassembed to check the drawbar and the spindle liner and assemble
again many times. We don't have a lot experiences about this probems. I needs for your helps

"you might want to check the drawbar and the spindle liner"?
The worker's worked for 3 hours before the tool drop droped. We disassembed to check the drawbar and the spindle liner and assemble
again many times. We don't have a lot experiences about this probems. I needs for your helps

Check the catchers that hold the pull studs.One might be broken or all of them worn out.
Or it could be the spring washers.Some of them can be broken and the pull much lighter than it should be.
We have had the same problem with one of our Mori Seikis.