Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: ShoeSam on May 06, 2011, 06:20:47 PM

Title: It's SLOW Going!!!!---can someone explain???
Post by: ShoeSam on May 06, 2011, 06:20:47 PM
OK...I am new here......and usually work with Big Machines......but my question is related to the Hobby Machine I am playing with.....( TownLabs TL518)

I have a great CAD program for doing complex Surfaces....( Rhino )
I have a great CAM system for doing toolpath generation...( Madcam plugin for RHINO)
Simulation in MADCAM tells me I have a 50 min cycle time for Z level roughing.....( GREAT!)

Code output from Post processor is ok ( lots of X movements {with no other AXIS changes} written as a bunch of small steps....uuugh)

ACTUAL RUN TIME ( even using G00 command lines)........over 8 hrs.......

BOTTOM LINE.....THE THING IS JUST BARELY MOVING!!!!

What is creating this problem???

My Guess.....

the small steps do not allow the ACCEL/DECEL curve of the drives to be over written in the smoothing algorithm....hence even though my feedrate is set to 2000mm/min, actual traverse is more like 100mm/min...

How do I overcome this??

Play with motor tuning?

Any help appreciated!

Sam
Title: Re: It's SLOW Going!!!!---can someone explain???
Post by: ger21 on May 06, 2011, 06:32:03 PM
Make sure you're in CV mode (G64).
Title: Re: It's SLOW Going!!!!---can someone explain???
Post by: ShoeSam on May 09, 2011, 09:09:23 AM
G64 has no effect.

Does anyone have some ideas on how to make this thing hum?......

Please Help!

ShoeSam
Title: Re: It's SLOW Going!!!!---can someone explain???
Post by: Hood on May 09, 2011, 02:02:26 PM
Quote
Code output from Post processor is ok ( lots of X movements {with no other AXIS changes} written as a bunch of small steps....uuugh)

If your CAM is doing that then I would complain to the CAM vendor, no point in having lots of small X only moves when a single line would do.

Setting a larger lookahead may help but if the code is crap the results will be likewise.
Hood
Title: Re: It's SLOW Going!!!!---can someone explain???
Post by: ger21 on May 09, 2011, 04:02:33 PM
What are your accel and velocity settings in motor tuning?

Any chance the FRO is set very low?
Title: Re: It's SLOW Going!!!!---can someone explain???
Post by: ostie01 on May 09, 2011, 04:06:34 PM
I think it will also depend on how vectors are draw.

In Vcarve, if I do not join vector, gcode output is also made of a series of small line of code with a z move between each each.

This is something you could look at too.


Jeff