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Author Topic: Problem with index homing  (Read 19644 times)

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Re: Problem with index homing
« Reply #10 on: September 03, 2015, 03:00:53 PM »
I did say 3000 didn't I. My test indicate that the x and y axis are 3k and the z axis is 2 k. It comes out to 500 pulses per mm if my calculations are correct. It seems odd to me that the encoders would be different but the gearing on the z axis is different as well. The z axis is geared 1/3 Lower so with 2000 pulses per revolution it still comes out to the same pulses per mm. Is that normal?
Re: Problem with index homing
« Reply #11 on: September 03, 2015, 03:03:26 PM »

Set the encoder setting in the plugin to whatever pulses per rev it is.
For example if your encoder is 2500 line encoder then the pulses per rev will be 10,000, if it is a 1024 line encoder then it will be 4096  i.e. line count of encoder x 4.

Hood
Did you try 8000 ?
If you've entered 2000, it might quit looking after only searching 1/4 of a turn.

Maybe ?
Russ
Re: Problem with index homing
« Reply #12 on: September 03, 2015, 03:04:33 PM »
The gearing is 24 teeth on yhe x and y servos which mesh with a 60 teeth gear on the ball screws.
On the z axis the gear on the servos is 24 teth as well, but it meshes with a 24 tooh gear which in turn drIves the 60 tooth gear on the ball screws. I think my math is correct.
Re: Problem with index homing
« Reply #13 on: September 03, 2015, 03:06:00 PM »
I did try 8000. I even tried 10000 and it still would give the same error. 'Index distance not within allowed limit' 

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Re: Problem with index homing
« Reply #14 on: September 03, 2015, 04:17:21 PM »
What pitch are the ballscrews?

According to your info above all axes are 2.5:1.

Hood

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Re: Problem with index homing
« Reply #15 on: September 03, 2015, 04:30:52 PM »
Assuming the ballscrews are 5mm that would mean encoders are 250 line and thus you need to enter 1000 into the plugin.

Hood
Re: Problem with index homing
« Reply #16 on: September 03, 2015, 07:10:39 PM »
Oh lord, I'm so sorry hood. I wrote off that last reply about the gearing in a hurry on my phone and I didn't proofread. What I meant to write is as follows:
The gearing is 24 teeth on the x and y servos which mesh with  40 teeth gear on the ball screws.
On the z axis the gear on the servos is 24 teeth as well, but it meshes with a 40 tooh gear which in turn drives the 60 tooth gear on the ball screws. I think my math is correct.



Also, should I even pay attention to the encoder pulse count in the CSMIO plugin window? Will that tell me how many pulses per revolution the encoders have?

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Re: Problem with index homing
« Reply #17 on: September 03, 2015, 07:49:12 PM »
Ok it is late here so maybe my calcs are wrong but I make that 1.6666666667 :1 ratio for X and Y and 2.5:1 for Z.

Assuming 5mm pitch ballscrews then it would be 1500 for X and Y and 1000 for Z.

Not sure about the CSMIO, is it in the tuning window you are seeing the encoder counts?

Hood
Re: Problem with index homing
« Reply #18 on: September 03, 2015, 08:08:44 PM »
Those were my numbers as well. The window to which I am referring can be found by going to the top right of the menu bar in mach3 and clicking plugin control. There select CSMIO I think and the widow appears. Its the plugin window where you can see how much voltage is going to each drive and which inputs and outputs are active. I'm not at the shop currently, so I don't have it in front of me, otherwise I would take a picture.

jonathon

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Re: Problem with index homing
« Reply #19 on: September 08, 2015, 01:48:04 PM »
Did you get it working?
Hood