RE: [rp-ml] FW: Geometric Accuracy of RP parts

From: Marshall Burns <>
Date: Wed Dec 29 2004 - 18:07:46 EET

I agree that Bob has asked an interesting question. I wouldn't hold out
for answers from the vendors. Their R&D staffs are largely focused
"inside-the-box." (Isn't that amazing for technology of this ilk!)
Innovation of this sort is more likely to come from university research
or even a smart NASA intern. The problem isn't getting reflection of the
laser beam. If you can see it, it's scattering, and yes, that means
there's data available to be collected. The problem is interpretation of
the information and coordination with the build process. Nice, meaty
problem for a PhD thesis.

What I find interesting about Bob's question is the idea of letting the
laser in a laser-based process serve double duty as the inspection
laser. Cool!

By the way, Jim, I presume that when you talk about "lasers" in space,
what you really mean is focused sunlight. It's easier to transport and
maintain the equipment for that, right?


> -----Original Message-----
> From:
> [] On Behalf Of Good, Jim
> Sent: Wednesday, December 29, 2004 06:30
> To:; 'Anshuman Razdan'; 'Good, Jim';
> Cc: 'Marshall Burns';;
> Subject: RE: [rp-ml] FW: Geometric Accuracy of RP parts
> Those are questions I'll have to ask the vendors. It seems
> to me the hardware/software should be capable of doing this.
> Real-time adjustment would be beneficial and it may already
> be incorporated into the system. I'm not smart enough to
> know whether this is true or not. I'll discuss these topics
> with the vendors and I'll report anything of value to the List.
> Jim
> -----Original Message-----
> From: Rose & Crangle, Ltd. []
> Sent: Wednesday, December 29, 2004 8:15 AM
> To: 'Anshuman Razdan'; 'Good, Jim';
> Cc: 'Marshall Burns';;
> Subject: RE: [rp-ml] FW: Geometric Accuracy of RP parts
> Many rp methods use lasers to bond or cut. Is it correct
> that every laser beam has some reflectivity, however small?
> If so, is it possible to detect that bounce-back on a
> real-time basis? If so, can that be used as feedback to
> detect not only the bonding/cutting position of the beam in
> four dimensions, but also the heat at the target spot? If
> so, can software be programmed such that if variances from
> design exceed certain pre-set or dynamically reset values,
> the laser beam can be immediately fine-tuned in power as well
> as in x-y "aim" without halting the laser bonding or cutting?
> Bob Crangle
Received on Wed Dec 29 16:46:12 2004

This archive was generated by hypermail 2.1.8 : Tue Jan 12 2010 - 19:37:12 EET