Replacement Blue Thing (Lens Removal Tool)

Oh no, you dropped the blue thing! That ring magnet is so easy to break. Or maybe blue things just don’t bring you joy, so you discarded it. Whatever, who am I to judge? But now, my friend, your cuts are getting weaker and your lens probably needs cleaning. What to do? Is your beautiful machine naught but a paperweight for lack of a blue thing?

Well, let’s fix the problem…

  • Order a new blue thing. Oh wait, that’s a bit expensive and slow.
  • Source a replacement ring magnet. Talk about expensive! And in terms of fragility, back to square one.
  • Take the cover off your print head, remove the mirror, and push the lens out from above with a q-tip. Effective, but boring, and be careful with the exit drop and the fiddly re-insertion!
  • Use your laser to make a replacement! Now we’re talking. And while we’re at it, let’s make it better than the original.

Not only will this replacement not-blue thing effectively remove the lens just like the original, it also uses magnets to hold the lens in place during re-insertion. No more awkward balancing acts! Feast your eyes on this casual horizontal approach:

There’s a small catch. (Isn’t there always?) You’ll need some little neodymium magnets. This design is for 4.75mm (3/16in) cubes. Fortunately they are easy to source online (like here, or at another magnet source you find attractive), often quite cheap in “toy” form, which is how I got mine. For far less than the price of an actual replacement tool, you can purchase gobs of these little magnets for use in this and future projects.

Here’s the (1/8" or medium thickness) design, with a .006" kerf, suitable for medium draftboard. Included on a hidden layer is the un-kerfed original so you can adjust kerfing and magnet holes to your liking.


Assembly Instructions (click to expand)
  1. Press two magnets into two opposite holes of part B, both in the same (north or south) orientation. The magnets should be flush on one face and proud on the other.
  2. Press four magnets into the holes of part D in a radial orientation (either north or south, facing away from the center). The magnets should be flush on one face and proud on the other. Pay attention, the radial arrangement is important! Otherwise the lens will snap to one side or the other and won’t want to come out of the head.

  1. Press parts C (no magnets) and part D together so that the magnets protruding from part D hold them together (friction fit).
  2. Insert the long end of each part A “leg” into part B so that the notches face outward. The thinner tips will pass completely through part B, forming a “ring” of the proper size to hold the lens centered in “cup is up” position.
  3. Press the C/D assembly onto the other end of the part A support legs, flush magnets facing outward.

And drop away, this little not-blue thing won’t break. Enjoy!


Nice! But medium draftboard is 1/8" thick.


Freakin’ awesome, thank you!


Indeed it is, good catch! Fixed.


I´ve never dropped mine, yet the ring magnet is broken.
Thanks for the share @timjedwards


In light of your design, I now refer to the ‘blue thing’ as the blue meanie.


Very helpful! Thank you :slight_smile:


I’ve been doing the Q-tip thing ever since we moved, because my blue thing somehow didn’t end up getting packed with my Glowforge stuff. I can’t believe it never occurred to me to make one. I guess I’m just not as brilliant as you are! :smiling_face_with_three_hearts:


Silly question, but if you have magnets in the insertion side, doesn’t the lens just pull right back out when you remove the tool? Other than that, looks great! Very useful.


Good question! There are only two magnets on the reinsertion side, and the protruding support tips ensure a gap between those and the lens. That keeps the magnetic field strong enough to hold the lens in any orientation, but weak enough that it easily releases once the head’s magnets have grabbed hold.


Perhaps these ring magnets ?

Hmm, those are a difficult size and form to imagine in this particular design.

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I would have to use my 1/8x 1/16 round magnets as I have no square ones. Also, a stack of circles would have been my go-to on this or even one of the dowels I have about. There are several approaches. so you might want to link the ones you are using :slightly_smiling_face:

This is just fabulous!! Thanks for the share!!!


I still have my blue one, and it’s not broken, but I’ve bookmarked this for future use. Thanks for sharing!!


Wow! Thanks @timjedwards ! Not only is this useful, but a very entertaining write-up!




Awesome! I just happen to have a bunch of those little magnets and I will definitely make one of these. But, shouldn’t it be painted blue?


Be a rebel! Paint it yellow!


Excellent design Tim! Eliminating the reinsertion balancing act is a stroke the original design should have incorporated considering the fragility and expense of the lens.
Well Done!