Laser lens

(Esther Gladstone) #1

I found the laser lens a bit worse for wear this morning, some of the plastic holder has melted and stained a bit of the lens. I’ve tried cleaning up as best as I could and the centre of the lens is pretty unblemished, but the lens can quite easily fall out of holder when cleaning.
Any thoughts?

(Dermot Jones) #2

@Jonathan @petra

(Louis) #3

This was reported, @petra and I were going to assess the damage when we look at the machine tonorrow night…
Will put a plan into action for a replacement.

(unknowndomain) #4

Why is the lens holder still plastic, isn’t it worth throwing some money at having a metal one sintered ? How many lenses have to break because someone forgot to tighten it up and the plastic melted before this is addressed?

(Louis) #5

If you recall, our original trotec lens in its metal holder got destroyed the same way… the only difference is that the metal holder would probably survive the error. I have got a quote for getting a one off metal holder made and If the consensus is a metal holder so be it?

(unknowndomain) #6

Maybe I am confused/wrong but I recall the laser cutter surviving the lens falling out with the metal holder because my understanding was that the plastic lens holder melts when the laser beam hits it and then causes the lens to crack due to heat, where the metal holder is not able to melt?

(Louis) #7

The metal holder we had originally had the lens glued in place, when someone forgot to tighten the locking ring, the lens shited and the laser beam destroyed the lens. We tried to place a replacement lens in the holder but the aperture was the wrong size for the lens. We then replace the holder with plastic ones. Lately the lenses have been destroyed in the same way, people forgetting to tighten the locking ring. A metal holder will mean the survival of the holder when such an error occurs but may not save the lens within it…

(Calum Nicoll) #8

What about some kind of catch to ensure it can’t slide out if left unscrewed. Will still need to be screwed in to keep it focused but would eliminate the sliding out issue. @Will and I chatted about this issue a while back and it shouldn’t be too hard to make.

(unknowndomain) #9

A small magnet drilled into the back of the lens holder would attract to the metal bracket that holds the lens holder.

(Calum Nicoll) #10

I like that idea, really elegant - is the metal bracket not aluminium though? (though we could add a second magnet)

(unknowndomain) #11

Theres a galvanised steel bracket at the back of that as I recall which is what the timing belt attaches to.

(Calum Nicoll) #12

Ah yeah I think you’re right, good shout.

(david) #13

I have some small cylindrical magnets - 3mm diameter - that may be what you need. If you think they will be useful let me know and I’ll drop a few off.

(Louis) #14

how about people just take care when they use the machine. I am really against drilling and fixing magnets into the laser head.

(Dermot Jones) #15

Interesting ideas here…

But as @Jonathan said: let’s just take care of it from now on

Also it was good to hear that the member who had the mishap owned up immediately – we all make mistakes!