shame what he does to his optics with the smoke. The lens surfaces may be cleanable, but first surface mirrors as the octagon beam scan mirror may be harmed by the residue or cleaning attempt.
It is funny you mention that, because in my other thread pertaining to PCBs, my last post in their pertained to thoroughly cleaning my LaserJet 6L and this included the laser and optics. All kinds of nicotine residue were on the main components Seemed to turn out okay, because it now prints crystal clear pages once again.
But you are right, I was very leary about the attempt to clean them.
Yea, I have seen that one also. In fact, that is the same spare laser controller that I have. It is out of a LaserJet 6L. I think his problem is that he is attempting to expose in one pass, whereas the other guy makes several passes,
Or you could just reduce the speed of the pass. The second guy also keeps the lens in place, this might be an advantage but might also absorb UV. It's very cool and could be built really small and neat, I think I would use a moving platen or even a little conveyor, a wide timing belt would be good enough for my small PCBs.
No doubt about it, it could be made a lot smaller and neater. I would imagine that reasonably priced old laser printers are being snatched up left and right for the optics to create one of these.
It would be much nicer if there was an accurate automated board flipper for exposing double sided boards, or two lasers operating in unison to expose both sides.
That's a good point,auto flipping might be a bit complex for the time you save but at the very least an indexable board carrier could work well. Two lasers would be very cool but I think I might avoid the hassle personally unless I was just moving the lasers physically otherwise one would probably need identical scanning units etc and alignment might be tricky.
One advantage of just flipping the board is that depending on how you mount it you can potentially use any board thickness without adjustment. An easy way would be to have the laser pointing upwards and the board indexed by two pins, gravity keeps the surface to be exposed at the correct plane.
Or you could just reduce the speed of the pass. The second guy also keeps the lens in place, this might be an advantage but might also absorb UV. It's very cool and could be built really small and neat, I think I would use a moving platen or even a little conveyor, a wide timing belt would be good enough for my small PCBs.
Graham
You can't get away from the lens unless you have some other way to correct for the changing focal distance as the beam scans. Also the lens corrects for the beam geometry at the surface which will range from circular at center to eliptical at the edges due to the changing angle of the beam relative to the copper surface.
He states on his website that he is not using the lens and that makes things worse but still good enough for him. Simply a case of a large depth of field on his lens and a small field of view for his small PCBs.
As the beam is focussed any ellipticity will make little or no difference and the surface. I think these are 1D F(theta) lenses which are designed to convert angle to position linearly and for larger areas I think that will be the real killer.
Comments
It is funny you mention that, because in my other thread pertaining to PCBs, my last post in their pertained to thoroughly cleaning my LaserJet 6L and this included the laser and optics. All kinds of nicotine residue were on the main components
But you are right, I was very leary about the attempt to clean them.
Bruce
Here is another guy trying the same thing but so far he has not had complete success: http://www.youtube.com/watch?v=G9h9tzfpaY8
Graham
Yea, I have seen that one also. In fact, that is the same spare laser controller that I have. It is out of a LaserJet 6L. I think his problem is that he is attempting to expose in one pass, whereas the other guy makes several passes,
Bruce
Graham
It would be much nicer if there was an accurate automated board flipper for exposing double sided boards, or two lasers operating in unison to expose both sides.
One advantage of just flipping the board is that depending on how you mount it you can potentially use any board thickness without adjustment. An easy way would be to have the laser pointing upwards and the board indexed by two pins, gravity keeps the surface to be exposed at the correct plane.
Graham
Frank
As the beam is focussed any ellipticity will make little or no difference and the surface. I think these are 1D F(theta) lenses which are designed to convert angle to position linearly and for larger areas I think that will be the real killer.
Graham
http://www.diyouware.com/
regards
Lachlan
Thanks for the link. Now that's what I was talking about in the other thread. Forget resistive inks and sharpies