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View Full Version : How to safely change bits within a cutting file



bbortnick
07-19-2025, 07:46 PM
Hi,
Wondering what the best and safest way to change bits, when your cut file has bit changes.
At the moment, when a bit change is called for, I power-off the VFD (interlock key/wrench is removed), raise the spindle, change the bit/collet, re-zero the Z height and then proceed with the cut.

This leaves the gantry powered on, with the attendant risk of its accidental movement. Hitting the E-stop button makes it safe, but it also crashes the Shopbot3 software and the potential of loosing your x/y position.

Any way around this, or is this the nominal safe procedure?

Thanks for the advice!

scottp55
07-22-2025, 06:59 PM
Back in 2013, we were anticipating teaching learning challenged young adults in our Northcountry, to operate as safe as possible.
After shooting down total containment/klaxons/flashing lights, we asked some of Dad's machinists.
We were looking at Shopbots, and the machinists concerned about the kids, thought the "spindle interlock) the most bank for the buck.

BUT we found out Shopbot didn't offer it for Desktops.
I called Nancy in sales(WONDERFUL LADY), and when she couldn't answer the question, she put me on hold....and the Ted Hall got on the phone for 45 minutes!!!!!
Ted thought it was a good idea for all, so he had Glenn fab up that first spindle interlock for for Nada :)

Also he put limit switches on ALL ends of X/Y and a Z-limit switch!!
Again for nothing :)

That's why we bought an identical Desktop the next January WITH a makercrate.
(Thanks to Bill and TJ!)

Without going whole hog,
the way your are doing it is relatively safe.
To make it a little safer...change your home position to an easy tool change position, where a gantry move will always move away from you.
Also put out garlic cloves to chase away small children who don't listen/inquisitive pets/ and GREMLINS!! :)
Sidle interlock and Z limit all became standard in early 1015

bbortnick
07-22-2025, 09:40 PM
Thanks Scott. I think the current home is 0,0,1". I will try to change that to 0,0,6" which will allow space to change bits and any movement will be away from 0,0.