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Author Topic: DRO's dont match movement?  (Read 2483 times)

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Offline Fastest1

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DRO's dont match movement?
« on: October 08, 2010, 02:48:21 AM »
Installed my G540 on my Dyna today. I was setting the steps per unit. I had everything in native units set to inch. After testing the X, Y & Z multiple times and getting 10094.7876 for X, 10161.0161 for Y and 10110.4477 for Z. In MDI  it will move the amount commanded (exactly) but shows something totally different in the DRO's. Looked all over at any and all of the settings. cant find anything out of the ordinary. I am running version R3.043.022. Anybody got any ideas as to why? I need to measure the distance it moves when I am jogging because my mill doesnt have 37" of Z! LOL It almost seems like it might be showing 10x what the actual movement is, but that is just a guess. I will measure it later or tomorrow, as 2 am is late. I am running at 75hz if that makes any difference.
« Last Edit: October 08, 2010, 02:53:15 AM by Fastest1 »
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Offline Hood

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Re: DRO's dont match movement?
« Reply #1 on: October 08, 2010, 02:59:33 AM »
Are you possibly looking at the machine coordinates?
If you press Zero for X, Y and Z do the DROs zero? If they do then you command a G0X10Y10Z-10 do the axis move correct distance and do the DROs show the correct distance?
Hood

Offline Hood

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Re: DRO's dont match movement?
« Reply #2 on: October 08, 2010, 03:03:11 AM »
Oh and with regards the 75KHz kernel, if you dont require that high a frequency then it would be best to lower it to the max your steps per unit/Velocity actually need.
Hood

Offline Fastest1

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Re: DRO's dont match movement?
« Reply #3 on: October 08, 2010, 03:18:23 AM »
I was under the impression kernel speed would allow more steps vs time? I am running around 10000 steps per unit so I thought that might help with the speed. The DRO's are wrong when jogging, seem to be fine by MDI. I will look into it more tomorrow but always Hood, Thanks!
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: DRO's dont match movement?
« Reply #4 on: October 08, 2010, 03:24:57 AM »
10,000 steps per inch will allow 150 IPM at 25KHz kernel, at 75KHz it would be 450IPM.
Of course its your motors that will determine what speed you can actually get and likely 25KHz or possibly 35KHz would be enough.
Hood

Offline Fastest1

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Re: DRO's dont match movement?
« Reply #5 on: October 08, 2010, 12:11:11 PM »
Hood, I reset the kernel speed to 35hz this morning with no difference that I can tell in operational speed. I did confirm that my machs native units were in inch and did a compplete restart of the system (mach and computer). I did a little test with jogging and for every 1" of movement in X of the table shows 9" in the DRO's ? MDI of G0 or G1 makes no difference if asking for Z-2", I get about .1535"?Ok I was testing while I was typing. I am an idiot apparently. I was off by the difference my paycheck should be. I needed 101552-101660 step per unit not 10161! Anyway all is working fine I think. I did uncheck CV and checked ES (exact stop). I am not sure which way this setting should be? Tips? Anyway I do have the steps working out alright at the moment.
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline Hood

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Re: DRO's dont match movement?
« Reply #6 on: October 08, 2010, 01:51:26 PM »
CV means Mach will move from line to line of code without stopping where ES Mach will decelerate at the end of a line of code then accelerate and run the next line. The majority of the time CV is preferred but on some machines, especially with slow acceleration, you may experience corner rounding on sharp corners. There are settings on General Config page to use if this happens but afraid I have never used them so cant advise.
Hood