Messages

1011

General Mach Discussion / Re: CNC router shudder and jerky / jitter doing 3D toolpaths

« on: February 06, 2016, 03:21:14 PM »

Maybe we should put the G8 command on the "Did You Know This" thread.......

RICH

1012

General Mach Discussion / Re: CNC router shudder and jerky / jitter doing 3D toolpaths

« on: February 06, 2016, 03:20:08 PM »

So need to pencil in another G code on to the cheat sheet! 

RICH

1013

General Mach Discussion / Re: CNC router shudder and jerky / jitter doing 3D toolpaths

« on: February 06, 2016, 07:36:06 AM »

Something to try, would be to use exact stop for the posted code.
Air run the code.

Reduce velocity values for each axis in steps of 20% each time you run it and see if the problem stops.
If not, then start reducing the accel values by 20% at the lower velocity setting. See if the problem stops.
If not, then your motors ( actualy it could be a combination drive / motor / settings ) may be the problem and it has to do with acceleration. To make small combination moves you need almost instantaneous accel ...decell.  
Fortunately if your problem is repeatable you can play around and try to find what is causing it.

FWIW:
I had problems with my mill and it drove me bonkers. Wasn't skipping in the traditional sense, ( couldn't hear a skip at those silly 0.0001" moves), could not tell exactly when,  it was random in the 1000's of lines of code and never had a problem with 2D machining.  Put dwell in the code and could never duplicate it at different locations and like you the code was for very small moves ( had external DRO's to compare Mach to actual location).

Adjusted the machine to reduce / MINIMIZE the torque required to move all axes and still MINIMIZE the backlash.Adjustment done such that I could measure the required torque to just move the axes and also see what the backlash was. In the end the required torque to just move the axis was reduced from around
80 / 90 in oz to about 15 in oz and for 350 in oz motors that's a great improvement.
Things improved.....so i changed the steppers to 500 in oz and have not had a problem since.

In general a lot more torque was available which provides for improved acceleration ( you higher up on the curve for given motor rpm.....actual in or closer to max power on the curve.

Just some thoughts and have fun playing around,

BTW.....One can do all the advanced calculations etc. they want using computer programs but
when the day ends good old fashion test, measure, try is sometimes required.

RICH

1014

General Mach Discussion / Re: CNC router shudder and jerky / jitter doing 3D toolpaths

« on: February 04, 2016, 07:56:49 PM »

Are you using steppers or servos?

RICH

1015

General Mach Discussion / Re: New to CNC and need some assistance please

« on: February 01, 2016, 08:44:40 PM »

" Soft Limits" are actually virtual limits set in the software? I don't have actual limit switches installed on my machine.

Yes, if you don't have actual switches you are depending the software to not allow movement of the axis ( tool is a better word ) beyond the limits.
 

RICH
  

 
  
 

1016

General Mach Discussion / Re: Stepper Motors Heating Up

« on: February 01, 2016, 08:37:17 PM »

Motor Heating:
I have left  mine on  for a day and they didn't get  hot. Hot ( human reference ) starts at =140deg F such that you can't hold your hand on the motor. You can get burnt. I can run them for hours and they only get warm.
All depends on the motor, how it's wired, and of course the drive ( amps & current reduction if used).

WORK OFFSETS

G54 is the default Work Offset when Mach starts.  
Forget all the other stuff and keep it simple for now.
Define actual Machine Coordinate 0,0,0 to Mach ( it's now referenced / homed...whatever jargon you want to accept).
So the controller knows where your Home is, now the controller  needs to know where the work / part/ stock is.
If not at MC=0,0,0 then it is away home and you need to define that to Mach.
You move to some point / datum / location on the work /part stock from Home and that distance from
home to the work is called a Work Offset which is from Home to work and can be G54, ETC.
G92 is a legacy command and is the reverse of G54, and G54 replaced it. Never use the two together.
A G52 is a datum /  offset from the Work Offset Datum.
SEE ATTACHED PIC

How does it all make sense...... well it depends on how you work and the machines configuration I guess.
BTW, the lathe is different in that you can Zero out the MC to 0,0 at anytime and it does save the G54 is so desired.

In general hopefully correct,
RICH

MODIFIED: Added pic

1017

General Mach Discussion / Re: Hit hard with the turret on the spindle... Damn!

« on: February 01, 2016, 07:55:30 PM »

MC,

Let not you heart be saddened for the force will be with you no matter what you use.

RICH

1018

LazyTurn / Re: Problems starting up with lazyturn

« on: February 01, 2016, 07:53:01 PM »

Finally it works the only thing Im yet facing is that in the rel world the settings doesnot correspond.
1mm equls in mach3 now 0,05 mm so that the machine blocks t the end.

Happy you got it working.

Not sure what you saying in your reply.
For LT, if in metric, draw in mm, use LT in mm, Mach should be configured for mm.

RICH

1019

LazyTurn / Re: Problems starting up with lazyturn

« on: January 31, 2016, 06:56:21 AM »

Better yet,

Install on a thumb drive, and run it in XP.

I will do exactly what is in the manual putting it on a thumb drive and run from XP, but probably won't be today.
Got to go,

RICH

1020

LazyTurn / Re: Problems starting up with lazyturn

« on: January 31, 2016, 06:49:59 AM »

Here is what I would suggest:
You can run LT outside of MACH / independently:

So create a directory / folder, say call it, Lazyturn.
Now install LC, the update to LC, and the LT version in that folder.
This should be done per what is written in the manual.
Run LT from that folder.

I don't know what else to say,

RICH