Re:Backlash Compensation

Hi, I'm new to EMC2 and I'm impressed with what I see so far. Just joined the forum.

A first question about backlash compensation. Unfortunately my mill has some backlash and I'd like to configure EMC2 to compensate for it. From what I've read you do it in the HAL via the config files. I'm wondering if anyone can share same examples with me and piont me to the precise place to make the configuration settings. I'm not sure how to proceed and what are the HAL commands to set the backlash compensation? Would be nice if backlash compensation and related settings could be done through stepcon.

Do I do this in custom.hal? or somewhere else?

Anyway this is a very professional engineering excercise (EMC2 that is)

Cheers,
Peter.

Alex, Thanks I see it now. Do I understand correctly that the compensation file is used to specify backlash at various points on the leadscrews?

Cheers,
Peter.

Peter,

Look in the Integrator Manual for "BACKLASH" it is applied to the entire axis. Also look at "COMP_FILE" for a compensation structure.

Rick

Thanks Rick,
I've been studying the manual, the compensation file looks quite sophisticated, I've configured simple backlash and will do some analysis on the screws to create a compensation file.

Thanks for all thehelp.

Peter.

I have been using EMC2for a few months, and find it to be abig improvement over my previous CNC program. However, I need to add 'backlash' to get the accuracy I desire for cutting wooden gears. I have searched the site and all the manuals and have found references to backlash but not how to enter it. MY ".ini' FILE DOES NOT SHOW IT, AND IT IS NOT AN OPTION IN STEPCON.

YOUR RESPONSE TO THE ORIGINAL E-MAIL AND THE REPLY SEEM TO INDICATE THAT BACKLASH SHOULD BE IN MY ".INI" FILE. IS THIS THE CASE AND, IF SO, HOW DO I ADD BACKLASH TO THIS FILE?

I greatly appreciate any guidance you can provide.

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Hello,

Just edit your .ini file.

If they are not there already add
BACKLASH = x.xxx
(where .xxx ist the amount of BACKLASH) in the .ini files under each axis that you want to add backlash to.

From the manual...

BACKLASH = 0.000
Backlash in machine units. Backlash compensation value can be used to make up for small deficiencies in the hardware used to drive an axis. If backlash is added to an axis and you are using steppers the STEPGEN_MAXACCEL must be increased to 1.5 to 2 times the MAX_ACCELERATION for the axis.

Rick G

There are two ways to do compensation.
simple backlash compensation as Rick just described.

Or sophisticated screw compensation. Unfortunately not described in the manual very well.
look here:
wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Screw_Compensation
Chris M

i think you just edit it with a text editor

enrique hello, I'm from Argentina, someone can answer in Spanish?, my English is very bad, I fix the backslash and not as editing the file, I am translating with google translator, but his translation is not clear, Please anyone who can help me thank him,

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hola soy enrique, soy de argentina, alguien puede contestarme en espanol?, mi ingles es muy malo, quiero corregir el backslash y no se como editar el archivo, estoy traduciendo , con los traductores de google, pero su traduccion no es clara, por favor cualquiera que pueda ayudarme se lo agradecere,

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gracias