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I want to build a FreeLSS-based scanner

Posted by av8r1 
I want to build a FreeLSS-based scanner
December 21, 2016 01:57AM
So I started building the Atlas scanner (Thingiverse number 1280901) And, well...I hate it. Too many printed parts, too many vitamins, nut traps that are too big because no one can draw a hexagon 5.5mm across flats...I think I can do better.

Need one piece of information though: Distance from the motor shaft to the camera lens?
Re: I want to build a FreeLSS-based scanner
December 21, 2016 09:03AM
making an educated guess, I'm going to start with 250mm.
Re: I want to build a FreeLSS-based scanner
December 22, 2016 06:54AM
Okay, never mind. The people maintaining FreeLSS don't know what the hell they're doing. The install instructions on their github page produce errors, not all libraries and packages are out there...so I'm back to the familiar conclusion that if I'm going to get somewhere, I'm going to have to go outside, dig a hole, mine some germanium, make my own transistors, re-invent digital computing from scratch, and write my own software just to make sure the failure of humanity doesn't creep in.

I mean seriously folks, has anyone gotten one of these damn things to work?
Re: I want to build a FreeLSS-based scanner
December 23, 2016 03:42PM
This one seems to work;-

[hci.rwth-aachen.de]

[mariolukas.github.io]

[www.watterott.com]

Here's something I wrote about the subject in 1991, but the copyright remains with the publisher;-

Quote


QAs a video professional. I have yet to find a
ray-tracer program that's fast enough to he
usable in my business (I produce video logos and
graphics for television advertising). Could you tell
me whether there is a way to scan in objects in 3D
to the machine without drawing it all by hand? I
would he grateful for any help.

A There is no commercially available package to
do this, but after some thought it's theoretically
possible. |i does however involve quite a bit of extra
hardware and specialist 3D programming (it's a bit like
ray-tracing but in reverse). For those who fancy a chal-
lenge, here goes:

You have a robotic arm linked to your Amiga
through the serial port and controlled by the computer
- nothing outrageously special about this really. In the
arm's hand you mount a black and white video camera,
linked to the Amiga via a digitizer. You need a fairly
flexible arm. because the camera might have to look
around odd corners or see under overhangs.

Program the robot arm to move the camera around
the object, and take a series of black and white images,
Supposing that the object is illuminated well and is sit-
ting on a black background, the computer could workout
what the object looks like in 3D from the shades of light
and dark, if it knows the position and angle of the light
source. Then it would write that information into a file
suitable for a ray-tracer.

Although this approach would be quite cheap, it
would be slow and inaccurate. You would probably
need to tidy up the 3D object in the computer after-
wards with ray-tracing software. However, it would
certainly remove a lot of the leg work involved with
ray-tracers, as standard digitizers and flatbed scanners
are useless for 3D work.

A slightly different approach currently being used
in Virtual Reality research is to put the object on a
turntable and spin it slowly. A laser beam bounces off
the object, and by measuring the return time the depth of
all surfaces can be worked out and the overall shape
calculated. Despite being more expensive, it's very
accurate and takes less computer power, because the
mathematics are less complicated.

Looks like my musings have been answered. smiling smiley
Re: I want to build a FreeLSS-based scanner
January 05, 2017 03:02PM
Quote
av8r1
I'm back to the familiar conclusion that if I'm going to get somewhere, I'm going to have to go outside, dig a hole, mine some germanium, make my own transistors, re-invent digital computing from scratch, and write my own software just to make sure the failure of humanity doesn't creep in.
Arrogance is such a terribly heavy burden. smileys with beer

Quote
av8r1
I mean seriously folks, has anyone gotten one of these damn things to work?
I got mine put together and running in one weekend. It took about a week of printing, but the assembly wasn't that terrible. (I used a little bit of tape to hold the nuts in the nut traps and it was a breeze) The software wasn't too tough to figure out either, though it was half a year ago, so I don't know what state the installer is in now.

Good luck.
Re: I want to build a FreeLSS-based scanner
January 16, 2017 10:50PM
I must admit, LSS kit looks easier to assemble (no soldering required). The Hat for the Fabscan Pi has to have the through hole components soldered, and not all of the wires are pre-tinned. That's with the Watterott kits.

The Fabscan Pi is more complex to build, but in theory, being enclosed and better camera, I should get better accuracy. It is also maybe easier to modify the design if you want a bigger scanning volume. I like it a lot, and am trying to contribute to it. But it is an ongoing release.

Whether you need the extra possible accuracy that for the job you are attempting is a different story. "Good enough for the job" is a consideration. You only get one red line laser with the basic Fabscan Pi. And one servo to move it with. Another green line laser and servo help improve accuracy, in theory.

What I've found really annoying about this sort of project is sourcing suitable line lasers. They're kind of treated as an "adult" item in the UK, disclaimers everywhere about unsafe usage, danger, etc etc. "Would sir like to collect that in a plain brown bag, or anonymously posted to be signed for? No, we can't use regular mail, sorry." Bah. Makes me sick.

Anyway, still trying to calibrate and measure accuracy. I think I'll try doing a known object (scalpel handle with metric measurements on it) to check that.
Re: I want to build a FreeLSS-based scanner
January 30, 2017 10:06PM
Quote
DragonFire
I must admit, LSS kit looks easier to assemble (no soldering required). The Hat for the Fabscan Pi has to have the through hole components soldered, and not all of the wires are pre-tinned. That's with the Watterott kits.

The Fabscan Pi is more complex to build, but in theory, being enclosed and better camera, I should get better accuracy. It is also maybe easier to modify the design if you want a bigger scanning volume. I like it a lot, and am trying to contribute to it. But it is an ongoing release.

Whether you need the extra possible accuracy that for the job you are attempting is a different story. "Good enough for the job" is a consideration. You only get one red line laser with the basic Fabscan Pi. And one servo to move it with. Another green line laser and servo help improve accuracy, in theory.

What I've found really annoying about this sort of project is sourcing suitable line lasers. They're kind of treated as an "adult" item in the UK, disclaimers everywhere about unsafe usage, danger, etc etc. "Would sir like to collect that in a plain brown bag, or anonymously posted to be signed for? No, we can't use regular mail, sorry." Bah. Makes me sick.

Anyway, still trying to calibrate and measure accuracy. I think I'll try doing a known object (scalpel handle with metric measurements on it) to check that.

I ordered 2 off ebay with no problem. They are 5V but still work a treat.
Re: I want to build a FreeLSS-based scanner
April 26, 2017 01:02PM
With any of the DIY 3D scanners, calibration is critical otherwise it will not work well at all. I built a hybrid of the Atlas and Ciclop from what I found in forums and on Thingiverse ((PiClop) but had to make my own board for it. I liked some of the features of the Ciclop but did not want to have to run it from a PC. The Pi camera has the unfortunate problem that it is fixed-focus so you have to remove all the glue from the lens and manually refocus it. Otherwise you can add a lens mount and varifocus lens. How is the Hat for the Fabscan Pi ?
Re: I want to build a FreeLSS-based scanner
June 14, 2017 06:54AM
3D Scanner interface electronics are currently available for the Raspberry Pi in a HAT format, for use with the FreeLSS software - if anyone is interested. eBay item #: 172729121100
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