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Author Topic: z axis gaining height with vcarve toolpath's only  (Read 6623 times)

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Re: z axis gaining height with vcarve toolpath's only
« Reply #10 on: December 29, 2013, 09:36:26 PM »
40 on velocity and 4 on acceleration. I dropped them down to 10 vel and .5 on accelerate and everything in between.

Offline Hood

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Re: z axis gaining height with vcarve toolpath's only
« Reply #11 on: December 30, 2013, 05:15:38 AM »
Is your cutter moving in the collet?
Have you shut down Mach and then run the driver test? If so what does it look like?
What kernel are you running?
What is the frequency and Time in Int on Diagnostics page showing?
Attach your xml and I will look through that.

Hood
Re: z axis gaining height with vcarve toolpath's only
« Reply #12 on: December 30, 2013, 07:43:59 AM »
I will check all of this and get this information. I am at work now so it may be tommorow before I can get this checked out. Thanks.
Re: z axis gaining height with vcarve toolpath's only
« Reply #13 on: December 30, 2013, 04:05:04 PM »
The bit hasnt moved in the collet. Ran the driver test and it said system excellent. Pulse frequency read 24999. Time in Int=4.4 to 4.9, it fluctuates some. CPU speed= 2793.0000. PWM base = 5

Offline Hood

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Re: z axis gaining height with vcarve toolpath's only
« Reply #14 on: December 30, 2013, 04:47:51 PM »
Was the line in driver test smooth or did it have spikes?

Your xml looks fine but your steps per unit seem small, what setup do you have, ie any microstepping, what pitch screws? any reduction between motor and screw?

You could try Sherline mode.

Hood
Re: z axis gaining height with vcarve toolpath's only
« Reply #15 on: December 30, 2013, 05:26:17 PM »
Just a thought.
When you save the toolpath, what post processor do you use?
I was just thinking if your Mach 3 native units are set to metric, but you save the toolpath in inch, could that cause this issue?
Are your steps per calculated correctly for the Z ball screw, as you state that the Z has a different pitch/start to the other 2 screws.
I use Vcarve 6, Mach 3 and Probotix boards, drivers and motors and have done a huge amount of engraving without any problem.
Re: z axis gaining height with vcarve toolpath's only
« Reply #16 on: December 30, 2013, 07:19:19 PM »
OK.I got off of work early and had some time to check some things out. I have been running all  3 axes at full step because I felt that I needed the full torque because my table has 69-1/2 inch long Y axis lead screw and the X has a 47 inch long screw. I have been running at full step since I first put this together and everything that I have ran has been fine except when I had time to try some v-carving projects, It always would cut above the wood after a small amount of time. So, I changed the driver board for Z to half step and ran a small v-carve toolpath and it did not miss a step. Worked great. So next I ran a larger v-carve toolpath(33 mins) and once again it worked great. I should have checked this a long time ago but  99 percent of the stuff I ran was just profile toolpaths and they were always perfect. I feel so stupid. Humility is a great way to learn things. Thanks to everyone who took the time to offer their expertise and advice.

Offline ger21

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Re: z axis gaining height with vcarve toolpath's only
« Reply #17 on: December 30, 2013, 08:13:25 PM »
You really should be using 1/8 stepping, as it should give smoother motion.
Gerry

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Re: z axis gaining height with vcarve toolpath's only
« Reply #18 on: December 30, 2013, 09:49:57 PM »
Ok I will certainly run them at 1/8. It doesnt take but a minute or so to change. Thanks again.

Offline Hood

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Re: z axis gaining height with vcarve toolpath's only
« Reply #19 on: December 31, 2013, 03:30:37 AM »
Good you found the problem, I was certainly surprised to see such small pulses per unit for an Imperial setup :)
Hoood