Slave Axis Tuning Independent of master?

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Slave Axis Tuning Independent of master?

Postby mende200 » Sat Jul 07, 2018 1:18 am

I have an A motor slaved to X, I have noticed that the steps/unit is slightly different on the A axis, it also has different backlash. Whenever I try to save or apply the values that should be used, it automatically autofills the values from the X axis. Am I missing something?

Also, I am using a UC400eth with a G540 gecko drive on a Plasma CNC application. I am having issues assigning the Torch on output pin. When I try to assign the correct output pin (to external relay) it will clear my input and show pin0 port0 upon either applying or saving. What am I doing wrong?!

Thanks in advance,

Brad
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Re: Slave Axis Tuning Independent of master?

Postby cncdrive » Sat Jul 07, 2018 1:36 am

It is not possible to set different steps per units for a master/slave connected axes and it is not possible to set different backlash for a master/slave connected axes. Those parameters have to be the same when the 2 axes are in a master/slave connection.

The software clears the port and pin when you trying to use an incorrect pin number. When you trying to assign an output pin to an input function or an input pin to an output function.
Because that is ofcourse not possible and the software verifies that when you apply the settings it simply zeros the numbers to let you see that your settings are incorrect.
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Re: Slave Axis Tuning Independent of master?

Postby Robertspark » Sat Jul 07, 2018 3:09 am

mende200 wrote:. I am having issues assigning the Torch on output pin. When I try to assign the correct output pin (to external relay) it will clear my input and show pin0 port0 upon either applying or saving. What am I doing wrong?!
Brad



When you type a number into a text box you must press the "enter" key for that value to be accepted, you can then apply and save settings
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Re: Slave Axis Tuning Independent of master?

Postby Robertspark » Sat Jul 07, 2018 3:16 am

viewtopic.php?f=3&t=610&p=4390&hilit=Enter+key#p4390

Look at cncdrive post of 15 July 2017 at 3:45
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Re: Slave Axis Tuning Independent of master?

Postby Robertspark » Sat Jul 07, 2018 3:35 am

With regards to your other thread on backlash here

And continuing my suggestion / thoughts

viewtopic.php?f=4&t=1361

__________________________________________________

If you cannot reduce the backlash to acceptable levels

Why not choose a backlash value half way between your two axis backlash values that way your backlash will be halved .

For simplicity say you have 2mm on X axis and 1mn on X' (a slaved) set the backlash at 1.5 so the error is only + and - 0.5 between the axis

If you set it on 1 or 2 the error between the axis will be + / - 1

Your application is plasma.... How bad is your backlash really.... Is it that apparent in the cut?

Would it be that apparent with a midpoint backlash value?

Sometimes it's worth asking if people are chasing perfection in an imperfect world. I don't know your application or machine (is it commercial, is it a hobby, is the machine hobby built or commercial built etc)

I run a belt setup (with steel wire core) on a hobby machine, but I accept that running 0.3g on acceleration may induce backlash by way of belt tolerance and belt teeth compression over the pulley when the axis velocity changes, dispite my belts being tight, tensioned and spring loaded.

But where I came from was hand cutting with plasma or grinder with a whole load of hand measuring and marking and cleanup... It's also not Lazer but plasma.

I don't know your background but newcomers to CNC tend to chase perfection with backlash settings (plus plasma divots at end of cuts), but like I've posted above it is possible to half the error by choosing a midpoint between axis, but it's best to try to minimise it first before applying backlash compensation
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Re: Slave Axis Tuning Independent of master?

Postby mende200 » Sat Jul 07, 2018 3:02 pm

Thanks for the quick replies.

Concerning the backlash and tuning on the slave. I came from using Mach3, there it was possible to use different tuning parameters and bachlash comp values for the slave axis. Just seemed weird to me I could not do it in UCCNC. Kind of goes with your statement, "chasing perfection in an imperfect world" In the perfect world the slave would have identical parameters, unfortunately that is not always the case.

Concerning the Arc on Pin, I will try again today. My arc relay should be triggered by pin1 port1, strangely if I use pin1 port1 for the anti-dive, it accepts it. Strange it works on anti-dive but not for Arc on?

Thanks again,

Brad
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Re: Slave Axis Tuning Independent of master?

Postby mende200 » Sat Jul 07, 2018 3:16 pm

And just for a little summary on the machine and me.

machine:
5x10' gear rack driven. Commercial use. Using mach3 I could regularly put out +/- 0.002" tolerance cuts on square features, sometimes less.

My background:
I am controls engineer for material, vehicles, and aerospace testing equipment by day, and a fab shop owner/operator by night. :D

Overall I am pleased with the overall architecture and stability UCCNC, far above what i was dealing with on mach3.

Regards,

Brad
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Re: Slave Axis Tuning Independent of master?

Postby Robertspark » Sat Jul 07, 2018 3:23 pm

mende200 wrote:Concerning the Arc on Pin, I will try again today. My arc relay should be triggered by pin1 port1, strangely if I use pin1 port1 for the anti-dive, it accepts it. Strange it works on anti-dive but not for Arc on?


That sounds like a bug, balazs can you advise / test

Mende200 What version of uccnc are you using?

Impressive tollerance.

The THC works loads better with uccnc and the motion is much smoother in my opinion
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Re: Slave Axis Tuning Independent of master?

Postby mende200 » Sat Jul 07, 2018 4:58 pm

Figured it out, just an embarrassing newb mistake.

For some reason I was thinking that the arc on pin in the THC I/O config panel was the output resource for the M03 command. When in fact it is the input. Went into the spindle axis tab and got it assigned properly and working properly in the first 10 mins of starting this morning. All is right with the world now.

I think it was a matter of staring at it too long last night...

Thanks for info on the slave axis and support helping a newb.

Regards,

Brad
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Re: Slave Axis Tuning Independent of master?

Postby Robertspark » Sat Jul 07, 2018 5:20 pm

:D

The user manual within the c:\uccnc\doumentation folder is always kept up-to-date.

The macro manual listed in my signature is also helpful (although I need to update it again as I've missed out a few functions)
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