Machsupport Forum

Mach Discussion => Mach Screens => CVI MachStdMill (MSM) => Topic started by: Calum on August 26, 2010, 03:42:10 AM

Title: Wrong feed rate
Post by: Calum 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 ???
Title: Re: Wrong feed rate
Post by: Brian Barker 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
Title: Re: Wrong feed rate
Post by: DaveCVI 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

Title: Re: Wrong feed rate
Post by: Brian Barker 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
Title: Re: Wrong feed rate
Post by: Calum 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
Title: Re: Wrong feed rate
Post by: Calum 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
Title: Re: Wrong feed rate
Post by: Brian Barker on August 27, 2010, 04:42:57 PM
When you are setting a tool length offsets are you using a touch off plate?
Title: Re: Wrong feed rate
Post by: Calum 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
Title: Re: Wrong feed rate
Post by: DaveCVI 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
Title: Re: Wrong feed rate
Post by: Calum 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
Title: Re: Wrong feed rate
Post by: DaveCVI on September 12, 2010, 02:04:30 PM
Calum -
My SS test set up is currently unavailable so I can't see 1st hand what happens with a SS right now.

However, on a PP, the actual feed rate DRO = F word * FRO % to within +- 1 of the least significant digit.
Also the FRO does change the FR as the FRO is changed.

So, if there is a bug, it would appear to be SS/Mach related.

Dave
Title: Re: Wrong feed rate
Post by: Calum on September 13, 2010, 04:29:21 AM
Hi Dave,

I fixed the feed rate override, it was the No FRO on Queue setting on the Mach general config.

If just installed beta 10 but still have the low feed rate guess its something to do with Mach and/or SS but I can put up with this.  Everything works fine and is usable, thanks for all of your dedication and hard work, I love the new screen and wont go back to the old one now.

Calum :D
Title: Re: Wrong feed rate
Post by: Simon0362 on September 13, 2010, 09:07:20 AM
Hi All,
I was using my mill at the weekend and suddenly realised that the actual feedrates did not seem to be the same as the feedrates in the Gcode - on several occasions I saw a F100 followed by G0 commands but could hear and see on the feed rate display something significantly faster - at least twice as fast. Most of the cuts were short so the machine did not have the chance to ramp up fully but I had the impression that I was seeing G0 speeds rather than G1.

I am running beta 9 and 043. 019.

If this problem has also been seen by others and dealt with in this new release I will update. However if not, I will attempt to gather more information if required (what though...?)

Regards to all,
Simon

PS Extremely impressed with MSM despite tyhe beta level problems.
Title: Re: Wrong feed rate
Post by: DaveCVI on September 13, 2010, 09:43:22 AM
There were feedrate issues in mach 3.43.19 - recommend that you update to 3.43.22 - is has solved the feed rate issue for others.
Also best to update MSM to Beta 10 (0.3.14). The MSM level (beta 9 vs beta 10) won't matter with respect to the feed rate issue, but you might as well have the other minor fixes that come with Beta 10.
Dave
Title: Re: Wrong feed rate
Post by: Simon0362 on September 13, 2010, 05:14:20 PM
Dave,
Thanks for the information, I have just downloaded (but not run) the updates. Sorry I didn't read the previous feed rate thread first either... :-[
Simon