Author Topic: Wrong feed rate  (Read 12652 times)

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Offline Calum

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Wrong feed rate
« on: August 26, 2010, 03:42:10 AM »
I have noticed that the feed rate when running a job is around 10% of what the gcode set so I had a look into the CV setting which took a while and a bit of reading of old posts in the forum but I think I have now got it switching between CV and ES mode the way it should.  But the feed rate is not showing what was requested, for example when I enter a simple move in MDI, G1 X300 F1000 the FRO shows 973.  When I run the following gcode

G1 X0 Y0 F1000
G1 X100
G1 Y100
G1 X0 Y0
M30

The FRO shows a feed rate of 937 for lines 1 -3 and 2930 for the return to X0 Y0.  It seems to do this in both CV and ES mode.

I have tried this in Mack3.42.40 and it all goes as it should.  I then tried it with the the 1024 screen on Mach3.43.19 and observed the same error I had with MSM beta 5 and Mach3.43.19.  Looks like a bug in this version of Mach or something corrupt in my XML, can anyone confirm this one way or another please?

Calum ???

Offline Brian Barker

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Re: Wrong feed rate
« Reply #1 on: August 26, 2010, 01:26:38 PM »
I have tested here and I am getting good speeds.. If you could please post your XML and I will test it here.
Also if you could please tell me what your systems pules frequency is on the diagnostics page.

Thanks
Brian
Fixing problems one post at a time ;)

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Offline DaveCVI

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Re: Wrong feed rate
« Reply #2 on: August 26, 2010, 08:10:41 PM »
Calum
he, he, old habits die hard  ;) - when Brian says "diagnostics page" (1024 speak) he means (in MSM speak) Hardware  page, PP driver tab, "pulse Freq"" near the bottom of the "Mach Driver Metrics" panel.

Dave

I have tested here and I am getting good speeds.. If you could please post your XML and I will test it here.
Also if you could please tell me what your systems pules frequency is on the diagnostics page.

Thanks
Brian

Author of the MachStdMill Extensions for Mach3
www.CalypsoVentures.com

Offline Brian Barker

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Re: Wrong feed rate
« Reply #3 on: August 27, 2010, 09:22:24 AM »
I have tested this (he is running a SS) and I can see that the problem is in the data that I am getting back from the SS.. I think I need to talk to Greg to see if there is a better way to get this working. I don't like how I am getting the rate for each axis back..

The good news is that the axis are at the right speed! The readout is the problem... If you would like to test this you can do a move of 2 units and command 1 unit per min. The move should take 2 min (this is how I made sure your feedrates where correct)

Thanks
Brian
Fixing problems one post at a time ;)

www.newfangledsolutions.com
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Offline Calum

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Re: Wrong feed rate
« Reply #4 on: August 27, 2010, 03:52:12 PM »
Thanks Brian, I was wondering is my issues were because of the SS, I'll give it a test.

Could this be the reason I sometimes get a multi axis move when I'm setting TLO etc?

Calum

Offline Calum

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Re: Wrong feed rate
« Reply #5 on: August 27, 2010, 04:27:39 PM »
Yes that's fine, I'll ignore the read out for now and just get on with it.

Thanks Brian ;D

Offline Brian Barker

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Re: Wrong feed rate
« Reply #6 on: August 27, 2010, 04:42:57 PM »
When you are setting a tool length offsets are you using a touch off plate?
Fixing problems one post at a time ;)

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Offline Calum

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Re: Wrong feed rate
« Reply #7 on: August 27, 2010, 06:04:38 PM »
Yes.  I did report this multi-axis move in this forum and Dave got me to send him the probe log file and XML which he forwarded to you at the time.  Just wondering if this could be an SS issue too.

Calum

Offline DaveCVI

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Re: Wrong feed rate
« Reply #8 on: September 10, 2010, 11:01:18 PM »
I am told that the feed rate issues are repaired in mach 3.43.22
see http://www.machsupport.com/forum/index.php/topic,15471.msg107016.html#msg107016

Dave
Author of the MachStdMill Extensions for Mach3
www.CalypsoVentures.com

Offline Calum

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Re: Wrong feed rate
« Reply #9 on: September 11, 2010, 08:01:27 PM »
Great thanks Brian and Dave I now have the TP, MT and probing all working with my SS, the feed rate is much better than it was but the FRO is now always a bit on the low side, 100 mm/m reads 89-95, 1000 reads 925 and 3000 reads 2920, is this some calculation overhead in Mach or SS?  Or is there a setting I've missed.  I get the same resoults in CV or ES mode.

I note that the feed rate override don't change the feed rate while the machine is running but will work if it is set before I run the code, is this an intentional change?

Calum