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Author Topic: 3d scanning with mach3  (Read 2220 times)

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Offline comet

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3d scanning with mach3
« on: January 17, 2018, 04:47:11 AM »
Hi what is the latest state of play with scanning/probing/digitizing With Mach3?
I have done Probably 10 retrofits with mach 3 now so im fairly au-fait with the system, but have never previously needed a scanner.
  I would need to have at least a 200mm z depth of scan, and at least a 0.5 mm all round accuracy.
Basically its for scanning and reproducing worn out or damaged vacuum and composite tooling .
Any links to the latest discussions , tutorials and ideas would be greatly  appreciated.
Regards
   Tony

Offline Tweakie.CNC

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Re: 3d scanning with mach3
« Reply #1 on: January 17, 2018, 05:09:50 AM »
Laser scanners were discussed some years back but the early prototypes never really worked that well and were, I think, just discontinued.
Mechanical probing, especially with 200mm travel and to a 0.5mm tolerance, using the Mach3 Digitize Wizard will work OK but it is such a slow process (typically an overnight job).

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline comet

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Re: 3d scanning with mach3
« Reply #2 on: January 17, 2018, 06:56:34 AM »
Thanks for the rapid reply
Yes, from what I can see it is a lengthy process.
Can a measuring laser be used?
Im thinking it might be worth making a high speed z axis that I can bolt onto the side of the head and disconnect the z axis servo and connect it to the high speed head.
what is the maximum linear speed a probe can be launched into the surface?
Regards
 Tony

Offline Tweakie.CNC

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Re: 3d scanning with mach3
« Reply #3 on: January 17, 2018, 07:33:05 AM »
Hi Tony,

I think they are both valid ideas.

You would have to try it and see but the cheap measuring lasers may not have the accuracy you require. The high-end types (that measure the phase shift in the reflected wavelength) would certainly be good but may be way too expensive.

A high speed Z axis would be my preference but speed will surely be limited by the onset of surface contact bounce. I can’t easily see a way of detecting only the first surface contact on non-electrically conducting materials. This will give me something to think about.  :)

Tweakie.
« Last Edit: January 17, 2018, 07:35:08 AM by Tweakie.CNC »
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline RICH

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Re: 3d scanning with mach3
« Reply #4 on: January 17, 2018, 08:03:14 AM »
Quote
what is the maximum linear speed a probe can be launched into the surface?

It depends on how much travel into the material you can tolerate. The axis  must decelerate to a stop
after contact is made. For repeatable accuracy I approach  at max velocity and then  probe at slow feed rate and do not "double probe". Most of my probing is done manually for selected points or tool touch off. You can calculate it all.

RICH

Offline comet

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Re: 3d scanning with mach3
« Reply #5 on: January 17, 2018, 08:25:25 AM »
Yes, It would have to be a proper industrial measurement laser , or even ultrasonic?
The issue I have with that type of system is the laser being diverted off angled shiny faces might be a problem.
Using a mechanical system however I think it will boil down to how quick the z axis can go. although I suppose its the overrun past the trigger point that would be a limiting factor, but using a laser proxy sensor would alleviate any potential over run and crash potential.

Regards
Tony
Re: 3d scanning with mach3
« Reply #6 on: January 17, 2018, 05:59:45 PM »
Tony,
Take a look at the lasers offered by Automation Direct now. I think they have one that would meet your accuracy requirements, at a price that is worth the effort you won’t need to make. Reflection is not a real problem, pro photograhers have tons of tricks to deal with that which would work here.

Offline comet

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Re: 3d scanning with mach3
« Reply #7 on: January 18, 2018, 07:50:26 AM »
OK all I have "acquired" a keyance laser sensor which will do the job.
Is there a tutorial or video that shows you how to operate either the included digitizing software or the probit software?
I cant seem to find anything that takes you through the process?

Regards
Tony
Re: 3d scanning with mach3
« Reply #8 on: January 18, 2018, 06:03:42 PM »
Tony,
Good stuff, probably cost more than your machine if purchased new!

Offline comet

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Re: 3d scanning with mach3
« Reply #9 on: January 19, 2018, 06:00:59 AM »
Gary,
  Any Info of software set up etc? im OK setting the port/pins.
A probing for dummies would be a good start as I don't want to spend hours fiddling to find out there's a box I should have ticked, we've all been there!

  For instance:
Z axis travel height-- what does that mean?
Z axis probe depth--what does that mean?
Feedrate is that a global federate? or does it retract in rapid?
does the software "double trigger" ie trigger then re trigger for accuracy?
do you set the Z zero at the highest part of the object to be scanned?
is the x0-y0 set at the bottom left hand corner as per convention ?
where is the resultant point cloud saved?

These will seem like silly questions, but an answer can save me potentially making an expensive mistake!

Regards
  Tony Horton