Cutting Issue

[jwa1156]

I have a problem that I and the support team have been attempting to run down.
I have a file that will not cur correctly
I am attempting to cut some simple holes for a bit storage.
In the VCarvePro the dement ions are correct.

I zero the Z Axes and then test the zeroing by doing a MZ0
works great, have even move the spindle around the table and
did the MZ0 bit right on the material.
Then I load the part file and hit GO
the movement in the x&y are correct, the Zis 0.501 shallow.
After the file is finished the bit goes to X&Y 00 and the safe Z is
now 0.73 or more,
when I do a MZ0 the bit move down and the software shows that the Z is at 00
but it is actually 0.501 above the material

any ideas?

Thanks

[gc3]

post both the crv and sbp files...

[zeykr]

Some possibilities:
Loose pinion on Z axis or binding on z axis. Moving z to high and hitting stop or hitting the thumbscrew that holds the dust collector.

[jwa1156]

Ken
Thanks for the idea, I have watched and the Spindle never reaches the top of he Z Axes to cause it to lose position, My DC seems to have a lot of free movement, I do have a pipe clamp very loosely on the spindle frame in the slots provided, but is not tight has about .5in clearance on all side.
Gene here are the CRV and SPB files
Thanks for any help, has been very frustrating, I am sure it is asimple thing I have missed or set by mistake, but to new at this to know
a they say You Don't Know what you Don't know
Thanks to all

[zeykr]

Check for loose pinion on the Z motor shaft.

[scottp55]

Jerry, Of course I immediately thought you may have drawn it referencing to spoilboard and then zeroed to material as I did that yesterday:)
But file looks good. Are other files running correctly? Any chance settings (offset in particular) may have been changed or corrupted? Maybe try a UR if other files are affected?
Hope support gets it straightened out.

[jerry_stanek]

Remove the set screw on the Z pinion and see if there is a second one below it. On mine they have 2 sets screws that are one on top of the other and if you try to tighten the pinion it doesn't get tight.

[bill.young]

What kind of bit are you using.? If it's not an "End Cutting" bit and is plunging straight into the piece, it will lose steps most of the time...it's trying to push a blunt end through the material.

Ramping into the work helps a lot if that's the problem, or replacing the bit with one that has cutting edges on the bottom.

Bill

[twelchPTM]

I had a similar problem but the Z was off by an inch, somehow the setting had gotten changed to alpha even though my machine is a standard, reloading the setting fixed it...

[jwa1156]

Thanks for all the ideas
As in most cases it is a little thing
Frank and Nate with Shop Bot were great
Finally after doing some back and forth, and measuring the
drilled depth, which were getting shallower with hole
which mean the Z was being changed
Nate suggested looking at the plunge rare.
Since I am so new, I had been just using the default setting
It seems that setting is to aggressive for my desktop
Changed the setting from 1.0 to 0.5, Nate suggested 0.75 but I
wanted to give the machine lots of room, may teak it up a little
each use until it screws up and then will know the limit

Again

Thanks for all the help

[scottp55]

Jerry, Was that with all bits? Just wondering in case I ever run across it. I use higher than 1.4 for some cuts, but ramping is slowing down the actual cut in those. I've seen TJ run at 5,5 for 3D in one of his classes(but 3D is different)!
The few people I correspond with run 1IPS Z on a regular basis and so do I depending on the bit/wood/cut.
Glad you got it worked out. I ran .5 Z for 6 months on everything to start:)