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View Full Version : New ViperXZ HD, help motor tuning etc



ClintonH
01-01-2014, 06:15 PM
Finally had time to build my ViperXZ Hd 30X48. Great kit only missing a set of 8 bolts for the 8080 extrusions but other than that went together fairly quickly. But after getting it up and running ran into some issues with motor tuning, here's where I'm at if there's anyone willing to give advise. :)

It has the fallowing ball screws, Z - 1605 Y - 1610 X - 2010, I bought the motor kit from George It is this one
Germany Free SHIP 3Axis NEMA 23 270oz 3A 4wire Motor Driver DQ542MA CNC Engrave | eBay (http://www.ebay.com/itm/Germany-Free-Ship-3Axis-Nema-23-270oz-3A-4wire-motor-DRIVER-DQ542MA-CNC-engrave-/131082680605?pt=LH_DefaultDomain_0&hash=item1e8522f91d)

The drivers are set at 16 microsteps and 2.36 RMS-3.31 peak amps. I'm using Linuxcnc with the fallowing settings, units are MM
X + Y axis
Steps per rev - 200 Driver Steps - 16 lead screw pitch - 10 Max velocity - 800 Max accel - 400

Z axis

lead screw pitch - 5 max velocity - 600 Max Accel - 300

Does that all look correct? I can't hardly feel the steppers getting warm after a 30 min air test run and a first cut that took approx 15min. I set the Max Velocity and Accel way up to 6000 and 1000 etc but didn't seem to make much difference in anything besides jog mode and nothing ever stalled out or stopped. Anything I should change or try?

Also wanted to ask if anyone could tell me about wiring up the proximity sensors? I have 3 installed, one on the Z one on the y bearing block and one on the X crossmember. They are the same as these ones.
Proximity Switch with LED Indication (http://www.cnc4you.co.uk/index.php?route=product/product&product_id=233)
They take 6-36 volts to power them I have a 7.5 volt power brick, other than that I'm not sure exactly how they should be wired. Do I need a resistor? Would be great if anyone could help with that. :)

If I have missed any information or need to post any of the diagrams I am trying to fallow I will asap.

Thanks for taking a look.
Clinton

BanduraMaker
01-02-2014, 12:57 AM
If your driver is a 16x micro step, your steps/rev should be 200 x 16 = 3200

ClintonH
01-02-2014, 01:21 AM
Yep that's what I have them set for, cutting dimensions are spot on. More curious about the Acceleration and velocity settings. As well as how to wire these proximity switches in, not sure about the resistor value or if it needs one etc. Thanks. :)

BanduraMaker
01-02-2014, 01:49 AM
What are the units for max accel and max velocity?

ClintonH
01-02-2014, 01:53 AM
Max Velocity is mm/sec and Acceleration is mm/sec 2

BanduraMaker
01-02-2014, 10:12 AM
Something is a little hinkey here because:

800 mm/sec = 1860ipm - That's blazingly fast. Your steppers would also have to spin at 4800rpm to do that which is pretty much impossible.

800mm/min = 31ipm - that's horribly slow

With the setup you have, I would imagine you should be able to run max velocity at somewhere between 300 and 500ipm so 7,620mm/min or more.

Your accel looks rather low as well. It's possible that your accel is so low that you never move long enough to get close to your target speed.

ClintonH
01-02-2014, 10:51 AM
Something is a little hinkey here because:

800 mm/sec = 1860ipm - That's blazingly fast. Your steppers would also have to spin at 4800rpm to do that which is pretty much impossible.

800mm/min = 31ipm - that's horribly slow

With the setup you have, I would imagine you should be able to run max velocity at somewhere between 300 and 500ipm so 7,620mm/min or more.

Your accel looks rather low as well. It's possible that your accel is so low that you never move long enough to get close to your target speed.

Yes this is why I was having problems understanding what the settings should be. I tried to raise the values up to match mm/min and it didn't really change much, went a bit faster but not much. It moves no problems just about half the speed I've seen from all the Vids George has posted.

Here is what the settings screen looks like for the axis config, this is not my settings just a image I found on the net that shows the mm/s settings. Thanks for the reply and the help BTW. :)

216682

BanduraMaker
01-02-2014, 11:08 AM
Try Setting your max velocity to about 130 mm/s and your acceleration to about 800 mm/s^2 and see what happens.

ClintonH
01-02-2014, 04:17 PM
I tried those values and it didn't seem to make a difference. I searched around on the web to see if I could find any info and on the LinuxCNC forum I found one of the mods there said to set the Steps to 1600 rather than 3200. Recalibrated all axis so it's correct and now it's super fast with those settings you posted. :) Thanks you very much for the help.