Setting scale to a permanent setting

[LarryL]

Hi all,

Is it possible to set the scale in Mach3 to a permanent setting?  I have found that my CNC quilter using Mach3 is calibrated to 1inch=0.0478 on the DROs.  By manually setting the scale to 0.0478, my files reproduce to exactly 1 inch scale.  Can I make this permanent?

Regards,

Larry

[Overloaded]

Hi Larry,
 You can put this little script in a macro, then put the macro in the initialization string to run on a reset.
The dro will then be set everytime you start up.
Hope this is what you want. Other axis's can be done the same way.
Russ

[ger21]

Can't you just change the steps/unit?

[Overloaded]

......my initial thought as well Gerry, just figured I'd try to answer the puzzling question.
Perhaps the machine is set up correctly and the files are scaled. Might want to leave the machine true for other 1:1 projects.
Hope Larry comes back with more info.

[Overloaded]

then again, he did say PERMANENT......didn't he.

[LarryL]

Can't you just change the steps/unit?

Gerry,

While it is possible to set the steps/unit for the quilter, this doesn't take into account the size of the pulley on the motor.  Basically, what I am trying to do is compensate for that issue.  By setting the scale to 0.0478, it calibrates the system so that the output movement is exactly one inch.  My problem is that I am in Germany, and I have difficulty procuring the parts necessary to do the job correctly.  I am forced to use a work around by re-calibrating the system mathmatically.

Like Overloaded said, it is to be permanent.

Regards,

Larry

[Overloaded]

Larry,
  The steps/unit is setable for the purpose of compensating for pulleys and other drive line components/configurations, you should not have to change any hardware.
  I'm confused......would you describe you axis drive in detail ?
Pulleys, # of teeth, screws, linear belts, rack/pinion, ratios, etc   ... ? ? ? ? ?
I might be missing the obvious but this looks too easy to fix by simply adjusting the steps per as Gerry mentioned.

[LarryL]

Russ,

I'll have to get back to you later this evening.  I am at work right now and don't have my notebook in front of me.

[ger21]

All your doing by changing the scale, is adjusting the steps per unit.

For example, if your steps per unit is 100, changing it to 50 is the same as setting the scale to .5.

[LarryL]

Russ, Ger,

Russ, in answer to your inquiry about the type of axis drives that I am using.  This is a very straight forward belt drive that has two motors.  The x-axis is approximately 12 feet long and is a 1/4 inch open ended timing belt with 22 teeth per inch the pully is 9 mm in diameter with a 14mm shoulder and an external locking hub.  The y-axis is the same except for length.  It is 24 inches in length. The axis pulls the carriage for the sewing machine in accordance with the instructions in the gcode file.  The problem that I was having with the scale was very simple, every time I tried to run the system on a file of a given length, i.e. 1 inch, the pattern would sew 13 inches, so basically a 13:1 increase.  The cure was simple, scale it to a setting that would equal 1:1.  The quilter uses basically the same technology as a milling machine, except it doesn't cut a billit or block of wood, it simply pulls the carriage with the sewing machine on it.  The sewing machine is the real work horse.  It has a stitch length control attached at the pedal port which keeps the length of the stitch constant no matter what the speed is.  Now, here is where the problems start.  Most of the patterns that I have were downloaded from a commercial site, they are made, for the most part, for long arm quilting machines, these machines have a working area of anywhere from 8 inches high and 16 inches long to over 24 inches long.  My machine has a working area of approximately 6 x 9 inches, hence, pattern adjustment is necessary to keep the machine from trying to go outside the working area.  Take a look at the photos that I uploaded, and you can see what I mean.  There are no compound pulley systems on the machine.  Each pulley does one thing, it pulls along it's own axis, kind of like a cog-wheel train on a gear track.

Ger,

You mention that all I am doing is adjusting the steps per unit.  Well, I only needed to do just that, but on a permanent basis.  I wanted mach3 to present me with the proper scale that would give me one inch of travel when I told it to.  The macro that Russ gave me works perfectly, the settings are now present when I turn on the system and it works great.