Author Topic: calibration  (Read 739 times)

suwaiket

  • Newbie
  • *
  • Posts: 4
    • View Profile
calibration
« on: September 03, 2019, 08:31:37 AM »
Hi
My cutting is about 0.2 % off what is in DXF file. Does the Bencutlaser has a motor steps length/distance calibration ability ?

Suwaiket

Zax

  • T2Laser
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6816
    • View Profile
    • T2Laser
Re: calibration
« Reply #1 on: September 03, 2019, 09:51:04 AM »
0.2%  ???

So on a 100mm shape it's 100.2, that's probably just the width of the laser beam.

suwaiket

  • Newbie
  • *
  • Posts: 4
    • View Profile
Re: calibration
« Reply #2 on: September 03, 2019, 11:26:39 AM »
Probably, thanks, however, the error is noticeable in cuts around one meter.

ThothLoki

  • Hero Member
  • *****
  • Posts: 2161
  • Tinkerer
    • View Profile
Re: calibration
« Reply #3 on: September 03, 2019, 05:00:04 PM »
What are you motor steps? Is it the same error % on both axis?
Laser: A5 2000mw with L7 Board / A3 2500mw PWM with Mana SE -- All using T2Laser
3D Printer: Monoprice Maker Select v2.1
Image Resizer Applications (All OS): http://benboxlaser.us/index.php/topic,1434.msg17297.html#msg17297

Administrator

  • Administrator
  • Hero Member
  • *****
  • Posts: 2833
  • Administrator
    • View Profile
Re: calibration
« Reply #4 on: September 03, 2019, 05:54:51 PM »
Hi
My cutting is about 0.2 % off what is in DXF file. Does the Bencutlaser has a motor steps length/distance calibration ability ?

Suwaiket

BCL does not have that capability. Make absolutely sure your laser system is rigged correctly. Belt tension, all nuts tight on the wheels and elsewhere, etc. If you machine is rigged correct, you should be able to burn pretty accurately. 0.2%I would say so, so check your machine carefully.

This post should have been in the BCL Software section else I won't see it. I just happened to spot it but I don't read every post around here outside of BCL Software. Unless you meant the Benbox software which is vastly different from my BenCutLaser (BCL) software.


« Last Edit: September 03, 2019, 05:55:51 PM by Administrator »
Admin -- Ralph -- support @ BenCutLaser dot us
https://www.dropbox.com/s/qv1qee2vb65785t/SetupBenCutLaser3.2a.zip?dl=0
BCL Paid license: $49.95
via Paypal to bclpp@primemail.com

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2915
    • View Profile
Re: calibration
« Reply #5 on: September 03, 2019, 06:11:03 PM »
I have been seeing a similar problem with a 3D printer. The X/Y steps /per mm is set at 80. 80 is too little and 81 is too much. Currently looking at getting stepper driver that do 128 or 256 micro stepping or switching the motors to those that do 400 steps per revolution. The ideal (simple) solution might be to change the firmware to change the steps/mm to a float.
SARCASM - Just one more service we offer here.

Administrator

  • Administrator
  • Hero Member
  • *****
  • Posts: 2833
  • Administrator
    • View Profile
Re: calibration
« Reply #6 on: September 03, 2019, 06:14:32 PM »
These little lasers are not capable of tolerances better than 0.2%. Even if you can get that, it won't stay. As you use the machine, parts get lose or come lose. Your firmware idea is a good one. But it's not a mod that everyone can do. You have to know what you're doing.
Admin -- Ralph -- support @ BenCutLaser dot us
https://www.dropbox.com/s/qv1qee2vb65785t/SetupBenCutLaser3.2a.zip?dl=0
BCL Paid license: $49.95
via Paypal to bclpp@primemail.com

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2915
    • View Profile
Re: calibration
« Reply #7 on: September 03, 2019, 06:21:09 PM »
99% of my laser burns are under 200mm in slate or wood. Doubt I could measure the result to any degree of accuracy.
SARCASM - Just one more service we offer here.

suwaiket

  • Newbie
  • *
  • Posts: 4
    • View Profile
Re: calibration
« Reply #8 on: September 03, 2019, 07:30:10 PM »
Although BCL missing calibration capability it might be something to conceder as a future updates, in general it is awesome software for the price. I guess mean while gut some rigging to do.
 Thanks all

Administrator

  • Administrator
  • Hero Member
  • *****
  • Posts: 2833
  • Administrator
    • View Profile
Re: calibration
« Reply #9 on: September 03, 2019, 08:00:28 PM »
George (@ggallant571) hit the nail on the head. This type of calibration is best handled in the firmware, not in CAD/CAM Software. BCL software (as well as T2) can send the g-code configuration settings to the laser machine, but, as George pointed out, if you need Double data type precision vs Integer precision, that has to be handled in the firmware. BCL and T2 cannot force Double data type precision on the firmware if it wasn't designed for it.
Admin -- Ralph -- support @ BenCutLaser dot us
https://www.dropbox.com/s/qv1qee2vb65785t/SetupBenCutLaser3.2a.zip?dl=0
BCL Paid license: $49.95
via Paypal to bclpp@primemail.com

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2915
    • View Profile
Re: calibration
« Reply #10 on: September 03, 2019, 08:26:29 PM »
I am going to try and cheat using my homebrew cut/burn Linux application. Plan is to set the steps/mm to 4X (320) in firmware and scale by 0.25 in software. The  X/Y/Z are all transmitted in floating point notation. Probably will need to fudge the acceleration and limits and adjust the phase of the moon. Might do it first on 3D printer as printing a 20x20x20 test cube is easy to measure

BTW - what machine do you have that spans a meter???
SARCASM - Just one more service we offer here.


Zax

  • T2Laser
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6816
    • View Profile
    • T2Laser
Re: calibration
« Reply #12 on: September 04, 2019, 05:28:22 AM »
T2Laser does have a calibration feature which updates the firmware automatically. You can also calculate the steps yourself and enter them using the $ commands, but in this case I don't think 0.2% is an error due to the motors but as Ralph said it's probably mechanical.


ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2915
    • View Profile
Re: calibration
« Reply #13 on: September 04, 2019, 06:52:11 AM »
If you primary concern is cutting accuracy I would suggest converting to linear bearings and leadscrews.
SARCASM - Just one more service we offer here.

Zax

  • T2Laser
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6816
    • View Profile
    • T2Laser
Re: calibration
« Reply #14 on: September 04, 2019, 07:39:04 AM »
Use ballscrews for a laser, you need the speed rather than the torque.