6DOF Micron-resolution adjuster design
6DOF Micron-resolution adjuster design
(OP)
I am starting to design a sensitive alignment device to carry an optical part and position it with 6 degrees of freedom relative to an optical system. It must stay with the product as periodic realignment will be required. The spec details are:
Optical part dims: 25mm x 20mm x 5mm
Range: 2mm all axes
Resolution: 1 micron
Environment: controlled atmos but 1g motion up to 20Hz
Qtys: 200 off in batches of 20
So it is a lovely design problem really. I am after advice on successful design practice. I am keen to control all backlash, maintain alignment over two years, allow adjustment with simple tools and to provide a neat locking solution.
I may well use a differential screw adjuster as found on micrometers (any design references anyone?). I am also keen to employ flexures as these seem prudent in this case.
I hope this makes sense, thanks in advance for any help.
Matt
Optical part dims: 25mm x 20mm x 5mm
Range: 2mm all axes
Resolution: 1 micron
Environment: controlled atmos but 1g motion up to 20Hz
Qtys: 200 off in batches of 20
So it is a lovely design problem really. I am after advice on successful design practice. I am keen to control all backlash, maintain alignment over two years, allow adjustment with simple tools and to provide a neat locking solution.
I may well use a differential screw adjuster as found on micrometers (any design references anyone?). I am also keen to employ flexures as these seem prudent in this case.
I hope this makes sense, thanks in advance for any help.
Matt





RE: 6DOF Micron-resolution adjuster design
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There is also an excellent book on flexure-"Flexures."
http://www
RE: 6DOF Micron-resolution adjuster design
If this is new territory to you, look into "Exact Constraint" by Blanding. ISBN: 0791800857. $70. It's really good.
Back to the problem. Do you really need adjustment in all 6 DOF?
If you do, look into Stewart Platforms (also known as hexapods). 6 legs meet at 3 feet. Maybe you could use a preloaded turnbuckle for the adjustment on each leg giving you 6 DOF. With the right preload and low mass, you may be able to eliminate the need for a troublesome lock. A problem with the Stewart Platform is that there is no pure adjustment in Cartesian coordinates (x,y,z,theta-x,etc.)
Good luck.
Tom
RE: 6DOF Micron-resolution adjuster design
I'd already checked out the hexapods, thanks, but it is likely the lack of cartesian adjustment will be a problem as you suggest.
Our alignment process is very likely to require a settting of the rotational DOFs and then the translation (and possibly fine iteration thereafter).
Matt