Tool changing procedure

[micatkin]

I am curious as to the process of how you switch out bits during a nesting run. At my day job I operate a KOMO mach 1 which has an 8 tool changer so all my bits are touched off. How do you switch bits in the middle of a run and how are the bits touched off?

[richards]

I do it the easy way and have a separate tool path for each cutter. For instance if I've just finished the path for a V-cutter and am now ready for a 3/8-inch spiral cutter, I have the V-cutter tool path file end up at a tool changing location, raise the cutter to a tool changing height and then stop. I change the tools, manually enter the X/Y coordinates for Z-zeroing, press C2 to Z-zero, and then start the file for the 3/8-inch tool.

[garyb]

For simplicity, put a pause in your file, turn off spindle/router, change bit and use a touch off plate to zero the bit.

On the Komo you will find the bits are touched off to the table surface where here you will find most people using touch off plates zero to the material surface.

[micatkin]

Thanks for the info guys. Take it easy

[david_beede]

Michael,
I have a bit changing station where I made a Zeroing jig gizmo. Off the end of the table I have a tool change tray. I had the machine drill a 1/2" hole there and with a Tee nut and locking nut I have a 3/8"bolt with a brass plate soldered to the top. It has a wire soldered to it with an aligator clip that I attach to the zero plate. It could (and probably should) be wired into the shopbot board where the Z zero line goes.
I sometimes zero to the top of the material and sometimes to the bed, but most often I use a modified Z-zero program that allows me to input the material thickness. (Learned input comands from "Bills Corner")
To get everything ready, first I zero a bit to the surface of my material holding jig. then I send the bit to my changing station (in my case its X -2.5 and Y 20)
I send the Z to zero. I then thread the jig bolt up until it just touches the bit (shown by control software light) and lock it in place.
My modified Zero file sets plate thickness to "0" since I'm not using a plate. The input comand lets me fill in the blank for the material thickness. After the bit goes through its usual motion to zero, it moves to the material thickness hieght and it then "ZZ", z zeroes there, and moves up to safe Z of 1 inch.
I've saved this variation as a custom cut file - C9 in my case. I like to use files I call "routines" to call up batches of files for various bit sizes. In between the machine jogs to my changing station and pauses with a prompt telling me what bit to change to, and reminding me to connect the aligator clip. It then calls up C9.
After it zeroes it pauses and reminds me to turn on the router, then calls up the next cut file.
I pretend I'm making this process "fool proof" for a not so sharp employee, but it's really for me. I don't know about you, but I can get pretty punchy running a lot of parts. I love pauses and prompts, like moving the tool out of the way and pausing it and having it tell me to turn the stock over... etc.
I'm hoping to write some articles on using a shopbot for instrument building for the shopbot site, and I'll include some of this with jpegs.
That's my 2 cents worth.
David Beede
www.davidbeede.com (http://www.davidbeede.com)

[paco]

That's pretty much what I do too!... with some variations.

That's about 0.0234853 CAD dollar from me!

8-)