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Offline BR549

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Re: Encoder Problem
« Reply #10 on: March 09, 2012, 08:59:30 PM »
THis could also be a lost steps senario IF the only thing you are looking at is the DROS.  Just because Mach3 puts out the pulses does not MEAN that the motor actually follow it perfectly all the time. In this case IF the motor lost steps the Axis Dro would say one thing BUT the encoder would say another.

Just a thought, (;-) TP
Re: Encoder Problem
« Reply #11 on: March 15, 2012, 10:40:39 PM »
Hi Rich,
I built a system that works great using Mach 3 and steppers.
I want to put encoders on this system and have no idea how to do this.
What can you tell me?

Please let me know,
Thanks,
Brian

Offline RICH

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Re: Encoder Problem
« Reply #12 on: March 16, 2012, 06:27:25 AM »
Brian,
What do you want to do accomplish by adding the encoders?
RICH
Re: Encoder Problem
« Reply #13 on: March 16, 2012, 08:41:09 AM »
Well, the machine is pretty darn accurate right now. Cutting circles though I think can be just a bit better, but
let's just say you crash and the drives go into a fault or protection shutdown. I'd like to be able to just ref zero and start up again.
It only happens once in a while but it does happen; or let's say I'm free machining a block and I keep resetting the 3 axis's; after I'm done I would like to just hit ref zero and then be able to punch in my left hand corner vise coordinates and just start machining instead of having more time wasted by edge finding the corner again.
Re: Encoder Problem
« Reply #14 on: March 16, 2012, 10:40:25 AM »
What you want is home switches, not encoders....
Regards,
Ray L.

Offline BR549

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Re: Encoder Problem
« Reply #15 on: March 16, 2012, 11:09:56 AM »
I take it you are trying to replicate the ABS encoders found on moderm machine tools on a MACH3 budget ??

Install encoders route them to Mach3 DROs,

Calibrate the encoder to machine travel

When you Refhome the machine to Machine 0,0 then zero the encoder DROs as well.

IF you munch the machine and want to get back to zero do a compare of where you are to the Encoder DROs then calculate how far to move to get back to encoder 0,0 then move and setmachine Zero to 0,0.

THat is the simple version,


Home switches would be simpler(;-)


Personelly I would study and practice more with Gcode and the CNC so you did NOT munch the machine as often.

(;-) TP


« Last Edit: March 16, 2012, 11:11:53 AM by BR549 »

Offline BR549

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Re: Encoder Problem
« Reply #16 on: March 16, 2012, 11:15:10 AM »
ALSO I believe the Rogers Machine encoder board WITH their plugin is what you are looking for. If my memory serves me their setup has a auto correction function built in.

http://romaxxcnc.com/encoderinterface.html

(;-) TP
« Last Edit: March 16, 2012, 11:19:53 AM by BR549 »
Re: Encoder Problem
« Reply #17 on: March 17, 2012, 12:37:45 AM »



Well as you put it "munching" the machine only happens once in a great while and frankly it's all been due to a bug in Mastercam 9 that we are trying to figure out.
As far as home switches are concerned, I have them and they work great, but what I want is something that will give feedback to the machine while it's cutting to make sure it's in the right place.
The machine I built out of a 1965 wells index is holding a tolerance of +/-.0001-2 with no problem. I just think it skips a beat once and a while.





I take it you are trying to replicate the ABS encoders found on moderm machine tools on a MACH3 budget ??

Install encoders route them to Mach3 DROs,

Calibrate the encoder to machine travel

When you Refhome the machine to Machine 0,0 then zero the encoder DROs as well.

IF you munch the machine and want to get back to zero do a compare of where you are to the Encoder DROs then calculate how far to move to get back to encoder 0,0 then move and setmachine Zero to 0,0.

THat is the simple version,


Home switches would be simpler(;-)


Personelly I would study and practice more with Gcode and the CNC so you did NOT munch the machine as often.

(;-) TP



Re: Encoder Problem
« Reply #18 on: March 17, 2012, 12:40:53 AM »
Interesting, thanks.

ALSO I believe the Rogers Machine encoder board WITH their plugin is what you are looking for. If my memory serves me their setup has a auto correction function built in.

http://romaxxcnc.com/encoderinterface.html

(;-) TP
Re: Encoder Problem
« Reply #19 on: March 17, 2012, 12:49:10 AM »
I have them - but, if you ref zero and then indicate the corner with an dial indicator - then ref zero and indicate it again over and over or after parts are cut it moves just a hair......0001-.0002'
I cut production parts all day long with this and it works great, I just want something that is 100% reliable, not 99.9% like I have now.
I cut parts that are .03 x .025 x .06 with tabs on them that are .008 x .015 x .015
If you're off by .001 you'll see it.

What you want is home switches, not encoders....