zeroing after bit change

[twelchPTM]

When starting a new toolpath within a partfile, the software gives you the option to use the keypad to raise the z to allow access to the bit, I normally do this. Then after changing the bit the software gives you the option to move the x and y to a preffered zero point,then the Z axis moves to 1" in regards to the current zero setting. This has not yet caused me a problem yet but I realize if I were changing from a short bit to a long one it could crash into my workpiece:eek:. What can I do to prevent the Z from dropping back to the 1" mark before zeroing?:confused:

[MogulTx]

...Or raising up to 1" if you are doing a very tall set up. I had that trouble once. It was a bother.

[twelchPTM]

I actually messed up, it moves in between the oputunity to raise the z and the oppurtunity to move the x,y. either way it still could cause a problem. Mostly if my bit is real long its because I'm using a collet adapter to hold little 1/8 shank bits and so far I've been able to do all my fine cutting and them switch to larger diamet bits. I found an after market collet for my PC router that would eliminate the legth of the adapter but I would still have an issue where bits are longer then others and could ruin a workpiece or worse damage my machine. I figured I'd see if anyone figured out a way to stop this action before I called tech-support....

[twelchPTM]

I am so freaking great.... I am going to answer my own question, there are three solutions to this problem 1. Plan your partfile so that the longewst bit runs first, 2. Save the toolpath for the longer bit to a seperat partfile and zero before running, 3. "extend the "tail" of the last vector or create a small vector so the bit ends up off the table.

Also I'm sure if it becomes to much of a pain in the but someone will figure out how to crack the post-processor

[garyc]

Thomas...
Should you care to learn editing SBP files, you can edit out the "safe_Z" move from the zeroing file. You may want a replacement tho.... :rolleyes:

In the post you can remove the line that is similar to: " MZ,[ZH]" , but remember that the bit will still be at its retract height. You can also change the "Z home" position inside PartWorks.

Make sure that you test your changes if you make any, as sometimes we make them for one reason and another scenario can result in a crash... or worse.

[adrianm]

Also I'm sure if it becomes to much of a pain in the but someone will figure out how to crack the post-processor

Full instructions on how to edit the Post Processors are on the Partworks help menu.

As far as the bit retraction goes I make sure the safe Z setting in Partworks is set so that it's not right at the top of the movement in relation to the bit length for the job in hand.

[twelchPTM]

so if i understand correctly the problem is caused by the fact that the safe z is set to 1" (on my machine) and if I change that to say 2" or 3" when I am working with longer bits I shouldn't have this problem?
I don't typically work with long bit but the particular adapter I purchased for using 1/8" bit in my PC router is long, I just order some after-market collets though so it wount cause me anymore grief but I am sure it will come up again eventually.
Thanks for all the help guys

[dana_swift]

I have had problems with long bits and inadequate Z to run the zzero routine. What I have done is install a max z prox switch, so the zzero moves up its fixed distance- or hits the prox switch. That way the machine does not fault and lose its setup.

I wish a max z prox switch was standard equipment. It has been wonderful since I added mine.

Another benefit I have received from the max z prox switch, is at the end of a cut I just seek maximum z, not some fixed z. Then I have maximum clearance to change bits, remove parts or whatever.

The max z prox switch is set to trigger about 1/4 inch below the hard stop. I have posted photos already.

D