I don't think you have to laser your own paste stencil any more than your assembler would, there's a ready made industry out there. First hit on Google...

http://www.smtstencil.co.uk/?gclid=C...FU0A4wodF1p6rA

Don't think you need a worm for the rotation, a dinky stepper will easily microstep anywhere you want, with no load mirostepping really works!

Is an elbow arm really the best solution? As soon as you locate over a camera you can't "teach" the arm and you are back to positioning by co-ordinate :naughty: