Presumably the next gen collet tightening/un-tightening tool [when rolled out] will potentially help as well.
I assume it is general knowledge that best-practices include placing a bit – I guess the one required in first tool path to be run – in the collet during warm-up cycle [and move spindle towards center of table to avoid accidental human contact]. Or at least it used to be considered best practice?
Thats something I didn’t know. However since the machine had been in use right before I got on it, I didn’t do the warmup cycle.
i guess its to warm up bit at same time so when placed in it doesn’t expand or contract or whatever. Not sure how much sens it actual makes as if you have 2 or more tool paths to run, i.e. more than one bit to use, the 2nd will be colder no matter what, and in fact the spindle head probably noticeably hotter. But that’s what I was told to do once upon a time…
You need to dive in and do some cutting! Ideally, everything goes perfectly. On the other hand, you get to learn something and then can help another based on that experience! I’ve learned a lot during the years I owned and ran a Multicam … not all of it from doing things right the first, or third, time!
Edit add: I’d be happy to help if we can align schedules.
I’ve had stepper miss a beat as well, but very rarely. They are typically exceptional counters! Most of the time that I wanted to blame the stepper, I later discovered I had done something to restrict the spindle and mechanically exceeded the stepper motor torque or had let the drive belt teeth wear. Most folks have no idea that the Z axis depends on a simple and amazingly skinny timing belt to do all that work.
It’s amazing what they can do with steppers on 3D printers at least to avoid missing steps. Controllers like the TMC2130 can detect if the stepper is approaching a stall out and detect a “crash” (on 3D printers, these are typically nowhere near as violent of an event 
).
I’m guessing it’s much harder use that approach on a machine that has spindle load like a router or mill. It would probably fire off too many false positives to make it viable to use.
The industry has routers with feedback loops, typically with servos instead of steppers, but feedback none the less. We just don’t happen have one of those!
From the manual…
Operators should insert a tool into the spindle prior to warmup.
That’s it regarding tools and warmup. No explanation.
I guess the best explanation is, because the manufacturer says so.
Yeah, my friend has a couple of CNC routers and they’re both servos. He was shocked ours was a stepper, but I’m sure it’s much less expensive that way.
What I understand to be the issue is proper loading on the bearings. Apparently, without the nut & collet weight (and you should never install a collet without a bit) you don’t have a proper loading on the shaft bearings. Those puppies are darned expensive to replace.
I don’t want to wear out my welcome with Nick Silva since he’s offered to cut a new wrench design for the Multicam … but if any of you dear readers have an opportunity to suggest this project get a bit closer to the top of his “to do” list, you’d be a hero!
Once we have a working wrench that’s better than that exasperating crown wrench, we’ll work toward a torque wrench for the spindle.
I know. I have wasted so much time worrying, and have nothing to show for it! I have recently watched all the videos again (several times), and I think I have it down. Will let you know if i need help though. Thanks!!!
Tommy, I think you may have clicked the wrong post for the “solution”. If that can be changed, please redirect to the discussion about bit slipping during multiple paths. Any reader that only looks at part of the posts could be pretty puzzled by how the spindle warm up protocol could cause a cut to be too deep. Thanks, Bert
Nick likes BBQ. Just saying…