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Author Topic: Ref All Home & Auto Square Not Working  (Read 3495 times)

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Offline ger21

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Re: Ref All Home & Auto Square Not Working
« Reply #10 on: July 11, 2016, 11:52:42 AM »
You can change the microstepping, but I would NOT recommend it. The Xylotex is very susceptible to resonance issues, and running at lower microstep settings can make it much worse.

I've been using one for many years at 1/8 microstepping and get very repeatable homing with homemade Hall effect switches.

To be honest, in  almost 15 years of doing this, I've never heard anyone recommend reducing microstepping to improve homing accuracy.
« Last Edit: July 11, 2016, 11:54:57 AM by ger21 »
Gerry

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Re: Ref All Home & Auto Square Not Working
« Reply #11 on: July 11, 2016, 12:48:31 PM »
Hi Gerry,

I'm not 100% sure but i believe the setup I have is using 1/16 microstepping. I remember in one of Dave Gatton's video's he mentions that Jeff made some modifications to the newer controllers. In his video i recall some of his settings for the motors and he had 3200 steps.
Mine is set for 6400 steps per the instructions from Jeff @ Xylotex.

Is 1/8 better? Smoother? More accurate? Not necessarily for the gantry issue but general use
Can i change it?

Do you have any recommendations on an accurate switch or method to square up the gantry?

Thanks,
Joe
Re: Ref All Home & Auto Square Not Working
« Reply #12 on: July 11, 2016, 12:51:17 PM »
Hi Gerry,

my fingers are going faster than my mind and i hit send to soon.
Do you have any info on your hall effect sensors?
Are you using Xylotex's BOB?

Thanks again,
Joe

Offline ger21

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Re: Ref All Home & Auto Square Not Working
« Reply #13 on: July 11, 2016, 05:45:50 PM »
I built my sensors based on this thread:

http://www.cnczone.com/forums/open-source-cnc-machine-designs/101878-cnc-forum.html

And yes, I'm using a Xylotex that I bought about 10 years ago.

I don't know if the kits that Jeff is selling now are using the same board or not?
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Ref All Home & Auto Square Not Working
« Reply #14 on: July 11, 2016, 09:45:15 PM »
Gerry,
I wasn't suggesting running with reduced microstepping.  I was simply suggesting that the mechanical linkages be adjusted with a full step holding everything stationary. If the gantry is square at a full step then I think it might tend to stay that way. When my drives power up they always seem to jump to some position. Might be an initial full step? If two drives power up and they had be aligned by microstepping might they not be out when that initial step happens?  As I said just a suggestion, based on lots of people seeming to have an issue when two motors are involved.  Comes up frequently on the 3D printer forums too.
Re: Ref All Home & Auto Square Not Working
« Reply #15 on: July 12, 2016, 09:34:54 AM »
Hi Gary,

The issue you are speaking about is what I believe is causing my problem with the gantry going out of square.
Almost every time I turn the controller on the motors "jump" and lock into position. when I'm trying to manually square the gantry I turn off the controller to turn the screw by hand to adjust the dial indicator. when I turn it back on it jumps anywhere from .001" to .005" in either direction. I seem to spend a lot of time chasing this to dial it in so it's square.
Would going from 1/16 step to 1/8, assuming my Xylotex controller gives me that option, help in anyway with this or make it worse?
Any thoughts or this isuue just an inherent problem with steppers?

Thanks,
Joe
Re: Ref All Home & Auto Square Not Working
« Reply #16 on: July 20, 2016, 01:11:23 PM »
How about optical(opto) sensor type limit switch, will it be better or or at least as well as the said hall effect or inductive type limit switchs?

In my gantry machine, I already installed two pulleys on the axis and mechanical linked them with timing belt to fix the out of squareness problem. The problem is really harassed, if not properly resolved, large current draw and friction force will damage electronic and mechan ical parts...

Thanks