Walk away from a machine?

[Geof]

Originally Posted by millbastard our shop only ever deals with 6061 aluminum and most of our programs have run enough times (or high enough quantities) that most errors end up coming from dull tooling deciding to pop or...well the most common human error

Don't be too confident. We have a VF0 that ran for six years without any problems machining 6061. One day doing a job that had been done thousands of times with a 1 hr cycle time it did not pick up a tool correctly, rammed the partially gripped tool into the work so it wedged sideways in the taper and proceeded to try burn the pull stud away against the inside of the spindle taper halfway up. It only took about 5 or 6 seconds before someone got to the red button but that was too late.

Needless to say the runout in that spindle now exceeds the manufacturers specs.

[millbastard]

weve definatly had our fair share of 'unknown errors' we run an eleven machine mill department, all haas machines ranging from 1997 model vf-1's vf-2ss vf-3 with rotary and our newest is an MDC 500, unfortunatly some of our employees think that they are smarter than newton and decide to make changes which once in a while turn into fried bearings in spindles or smoked boards...my favorite (just this last week) one of our button pushers decided the lights were dirty and sprayed them down with his coolant hose, needless to say haas will be out tomorrow to fix the 'ground fault error'

[tim clay]

you know the best thing about cnc is that it will follow the same path over and over and over until it is told to change, after watching the machine run a couple of parts and you know it does that part fine without crashing, than yea i wouldn't feel bad leaving it while it ran. Just don't forget it.


thanks Tim Clay

Originally Posted by skydivebase We just purchased a VF1 and are machining loads of aluminum parts. Each part takes about 20min and there's a bunch of tool changes. Because this is our first machine and none of us have worked in a machine shop with cnc equipment, we a bit short on common procedures. Do you leave a machine and come back to reload? I bet there's more than one answer here and I'm ready to learn something, Thanks J

[code]

Walk away?

You have ran the program and machined a good part (actually 100 parts). That indicates you are satisfied with the program, and the quality of the parts coming off the machine - no mention of any problems with dimensions, finish, flushing chips away from the part, or coolant being misdirected. Also, you apparently have had no tool changing problems.

So, these are some things to check, or consider, before walking away:

1. Is the coolant tank full?
2. Is the path from your office to the machine clear and uncluttered?
3. Can you listen to the machine from your office and therefore be warned if something sounds wrong?
4. Are the cutting tools in good condition?
5. After replacing a tool, stay with the machine during that tools' first use - tool pickup, use, and replacement back into the tool drum.
6. If there are other personnel around, let them know that the machine is not being watched.
7. As each part comes off the machine, look it over for any indications of tool fatigue.
8. Is there a time demand/delivery schedule that keeps you away from the machine?
9. If your other work can be brought near the machine, so much the better.

[ImanCarrot]

3. Can you listen to the machine from your office and therefore be warned if something sounds wrong?

Very wise words. I used one of them baby monitor thingies (can't remember what it's called)- you know the things you put in your baby's bedroom so you can listen to them downstairs. I could then happily carry on my Acad work in the office content that nothing too bad was happening to the machine.

As an aside- you can't cover everything- a few years ago the guys in the lab were extremely amused to see me sprinting into the machine area, punching the E-Stop and pulling all the 3 phase power plugs. The reason? an electrical storm had just started outside- the last time this happened it fried the PMAC board- about £5K damage and a week downtime re- calibrating and setting up the machine.

[serickson]

Originally Posted by HuFlungDung Has anyone invented a radio controlled switch that a person could wire into the EStop or Feedhold circuits? For those times when a person does walk away, sometimes you can hear trouble starting to happen, but you are too far away to stop it in time. A 'personal' EStop would be nice to have.

Several years ago I was with a company that considered using such a remote to control a hydraulic winch system. We were using a national professional hydraulic manufacturer for this system. They assured us that such remotes were available off the shelf, and that they were reliable enough through redundant, encrypted, acknowledged two-way coms, and that they were not succeptable to false triggering.

Steve