3D Laser scanner Arm Project

[Ragnarok]

Hi, I want to build a 3D laser scanner Arm, I already have done some little concept testing about the arm, and the laser scanner, I will attach some pictures, both test have been successful enough.

For the arm I have used a pic microcontroller, its ADC module and serial communication with the pc, the program is made on java using jMe for the 3D arm, the arm was constructed using aluminum bars and common potentiometers, those potentiometers and the ADC module of the pic works flawless, I cant wait to see how the 16 bit adc, and the BI6187 potentiometers will work!.

I want the 3D scanner to be multi platform so, the software for the 3D laser scanner is made on java using JMF, JMF does not support Camera Exposure control so I think I will use DSJ for the real prototype (Although this will hit the portability I will see how to solve this later ).I'm using my Sherline rotary table as a turn table, a laser line from ebay and a web cam(320x240 sensor), the result is a kind of good point cloud( of a clon form SW).

Now that the mayor concepts are tested I want to make a more professional prototype,but... here is my first problem, as you can see on the photo the potentiometer on the base is broken, this is because the potentiometer was the base joint and the load was on the potentiometer joint.

I just know a little about mechanism, I want to put a ball bearing to get the load and the potentiometer inside it, here are some prototypes I been working on for the base joint an the hinge joint.

I want to know your comments and Ideas on how to put the bearing to get the load ( maybe another type of ball bearing), and at the same time have the potentiometer rotating in the middle of the joint, or any idea to about the project will be very appreciate, I will post frequently about the progress of the project.

PD: I will get a better camera to take pictures because the quality of the web cam is very pour... as you can see.

Daniel Jimenez

[wanispissd]

The point cloud looks good -- How did you do it ?

Right now I have been lucky enough to obtain an ancient, working FARO arm and I have been researching for a while about making a 3D laser line scanner probe for the end of it. Im fairly handy with the mechanical bits - but fall short on the software side of things.

Ive seen a ton of companies that seem to make their scan probe with a red line laser projecting perpindicular to a pair of cmos sensors (mounted at angle, but fixed relative to the line laser). Seems like this type of thing wouldnt be hard to build - but I have no idea where to start on the software side to get an array of points out of two web cams and a red line. do you have any ideas ?

hope you don't think im hijacking your thread .... seems like breaking up the project would be a good start - the arm part is relatively easy compared to the scan head (in my opinion)

[fergusda]

I was considering a similar project using a faulty/broken Faro arm as a base.

You may want to consider using thru-hole encoders in place of the potentiometers. You could collect digital signals rather than analog, which may be more accurate. High resolution (2000 steps/rotation) can be found cheap on ebay.

The encoders could be mounted outside of the joint, so you could put together a stronger bearing/joint assembly with a shaft that passes through and allows you to attach an encoder.

I believe Blender has a scripting language that could potentially allow you to capture 3D data in real time directly in Blender. A true open source Faro challenger!

-Dan

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