I’m going to order a new lens from Just Add Sharks, which will need fitting in one of our lens holders. So the timetable is delivery plus an evening to remove the old lens and fit the new one.
Laser Cutter NOW BACK IN SERVICE
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Can we not just put.lens no2 back in it’s holder in an orientation that avoids the spot?
It’s not possible. The blob is too near the center.
Would it be a good idea to order more than one lens as a backup if it happens again?
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Just to confirm - is the laser cutter still out of order? If so do we know how long it’s likely to be for?
Yes it is still out of order. It will be back in service as soon as we receive the new lens (I have ordered two, so if this happens again the downtime will be much shorter). They’re being supplied from the UK so delivery should be quick. As soon as I have a delivery date, I’ll update this thread.
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Great thinking on ordering two, thanks for working on all of this Tom.
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Lens is going to be delivered to my house on Monday. If for some reason it’s too big to go through my letter box, I’ll get it from the sorting office Tuesday morning. Laser cutter should be back in service Wednesday at the latest.
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The lenses arrived TODAY!
If any other @lasertechs or other qualified persons fancy fitting one today or tomorrow, please let me know! (I don’t have time myself)
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I’m about today!
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It turns out that these lenses are fractionally too large for the holders 
19.5 vs 20mm
Can anyone think of a clever way to enlarge the hole? A20mm end mill? Hand file and patience?
I’ve been thinking about it on the train home.
Turn down 20mm aluminium rod so that it just fits inside the 19.8mm of the holder.
Part off and centre drill 3mm. Make a thin 20mm washer and mount 19.8 thick washer in lens mount, secure with thin washer and 3mm nut and bolt.
Can now use the thick washer to centre lens holder in four jaw chuck.
Undo nut and bolt to remoce thick and thin washer.
Bore out lens holoder to required diameter.
ps How does one set up discourse to understand english rather than american?
Dont know if I’ve understood what we are talking about but:
Do we really want to alter the housing?
Can’t we make something new for the new lens and keep the old housing for future lenses that are the right size?
Not talking from any experience or expertise on the matter. Just out of fear of buggering things up more.
I kind of agree, but At a guess, as with all other parts of this machine, I assume that the the lens and holder possess ‘security by obscurity’ and thus being a non standard size lens is not an accident.
We do have two or so mountings for for lenses past though, so given the potential difficulty we might have fabricating a replacement, some minor mods to one of those doesn’t seem too silly 
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Seems ok if we have two housings
The lens should be fine to be a bit higher from the bed, if we adjust the focus stick accordingly.
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We should be able to CAD a lens holder and get it 3d printed – @andrew_d’s brother made a model before.
In the meantime why not just use the damaged lens? It still works and the risk from the lens material seems to have been a misunderstanding.
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@lasertechs what’s the policy on using the laser with the damaged lens? I have a quick router template i’d really need to cut today
They’ve previously said no in the past few days when people suggested this.
Alright. Any suggestions on places I could outsource to that are good?