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Author Topic: Help controlling a stepper motor as a lowRPM spindle  (Read 17809 times)

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #70 on: September 12, 2012, 03:29:39 PM »
And in respect to a certain tennis player:

M215 (Hood)
M216 (Terry)
M215 (Hood)
M216 (Terry)
M215 (Hood)
M47 (Andy Murray return and keep on going)

 :D

Offline Hood

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #71 on: September 13, 2012, 03:08:08 AM »
Ha ha, he seems to be on top form at the moment for sure, Olympic Gold and now the US Open wonder if he can do Wimbledon next year.
Hood
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #72 on: September 24, 2012, 03:48:02 PM »
Hood,
I have been reading some comments on the forum about Constant Speed of a Spindle RPM and the feed rate of of an axis. One of the Administrators put up some code that I tried but do not see a difference in the spindle RPM when I run it. The code is basically

G96S20M3
G95
G01X10Z0.5F0.03 (feed 10" @ 0.03"/min)
G97S10M3
G01X0Z0F10
M5
M30

Is there anything you can see that I am doing wrong? I have not touched any settings in my Configuration, is there something I need to set?

Barry.

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #73 on: September 24, 2012, 04:15:36 PM »
CSS doesnt work correctly and never will iun Mach3, Mach4 I am assured will.
Having said that the spindle should increase/decrease with the dia, it is the feedrate of the axis which is not correct as Mach basically keeps a constant feedrate with respect to time rather than with respect to rpm (When in G95)
Where is your axis starting from when you are in CSS?
Could it be you are at max revs when yu are calling the G96?
Hood
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #74 on: September 25, 2012, 08:34:39 AM »
Hi Hood,
Here is what I am trying to do.
I have a round bar that I need to put on a bead of weld along the length. The bar can vary in diameter and length (between 0.5" - 1.5" diameter and 3" - 24" in length). Up to now we have never had an issue, as the calculation is based on a surface speed length of 59 ipm. The calculations for the different diameters is relatively easy, and I have created an Excel form that spits out the RPM for the spindle. I now have a part that is tapered, and is 0.5" at  the small end, getting to 1.25" at the large end over a length of 8". I wrote a program that started at 0 at the small end of the part, and made the appropriate moves in the -X and +Z direction to get me to the large diameter end of the part. I then had to split up my G01 moves, and insert a new spindle speed based on the diameter at that point. As I split it up 5 times, there is a noticeable thickness change in the part at each point I changed speed, and I know the more I split it up, the smoother the part.
As my boss wants a completely (or smoother) finish, I looked into the CSS function and have tried a sample I read on the forum. The one I sent you runs at the X-10" at F0.03 without changing the spindle speed. I have deliberately left out the Z moves to avoid confusion, and I did set my G48 max speed to S100 ( I never should have to get to that speed, 30 RPM is usually the fastest). Is there something I'm not doing right?

Thanks, Barry.