Hello all.
I have an object with a flat bottom and the top part that I am engraving has a contour. So this is not a cylinder object like a mug or
Tumbler.
The part in question is a 1911 hand grip.
I am running into a problem of the sides not engraving and the laser focal goes weak as the ends radius down.
What’s the trick? I have seen these hand grips engraved so I know if can be done
It is approximately a cylinder, but with a much larger radius than the usual mug.
You can try a lens with a much larger focal length than usual to get a longer “in focus” zone around the nominal focal point. If you set the nominal focus about halfway down the grip, the additional depth of field may keep everything in focus.
Alternatively, you could gimmick up a chuck rotary with a block to hold the grip as far as possible from the rotation axis, thus simulating a very large radius cylinder. You probably can’t get the grip far enough away from the axis to match its actual radius, but perhaps you can get it “close enough” to work.
You can guesstimate the grip radius by measuring the width and depth of the curved section, then doing math:
For sure, you’ll never heard “sagitta” in ordinary conversation!
Thanks for the input. What lense would you suggest?
Thank you. What lense would you suggest
I must defer to folks with a similar laser, who may refute everything I think I know [*]; one careful observation outweighs a thousand opinions.
There’s a relation between the focal length and the size of the work area, so you may find a longer lens can’t cover the entire engraving on the grip. If so, a rotary fixture will be the only way forward.
[*] F-theta lenses are optimized differently than “normal” thin lenses:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10766
