This one has been a challenge. Many moons ago, I used my 3D printer to make a replacement for the threaded mirror retaining rings on my red/black CO2 laser. They are approximately 20 mm diameter with a thread pitch of 1.0. The 3D printed versions no longer secure the mirrors properly. The threads have worn away or vibrated and abraded, but they just don’t hold.
Unfortunately, I can’t find the rings I’ve removed, although I’m certain I did not dispose of them.
I’ve also discovered that I’m unable to find replacements online. Reddit has provided suggestions for search terms but all those returned nothing useful.
It’s possible that a K40 uses the same threaded ring, but searches with that focus are also lost.
Would someone know of a source to purchase a few of these retaining/locking rings. There’s plenty of links for the removal tool, but zero for the rings.
Look around on the cloudraylaser.com site. They have a ot of accessories for reasonable prices. You might have to buy a mirror set to get what you need, but still reasonable.
Yes, that was one of the “close calls,” but nothing there will do the job. I’d rather not purchase an entire assembly times three just to get a few washer-like locking rings, albeit with threads.
Someone else asked about these. I’ve been active with lasers for about 5 years and have never seen a ring that holds a mirror or a ring that holds a lens in that I can remember.
I think you’ll have to break out the 3d printer for another set or find the ones you removed…
Just out of curiosity, why did you go through the trouble to remove and create new rings for a 3d printer?
They look like a straightforward project, but I’d really want the mirror mount in hand before I spun up the lathe. The mirrors in my laser are 25 mm, so the rings are definitely not the right size for yours.
Other than the size difference and the material being raw aluminum, my lost retaining rings are the same as shown in the photos. I’ve been able to find M20-1.5 pitch bolts but I also don’t think it’s exactly 20 mm diameter. That’s more the diameter of the cavity between the threads, making it a more experimental project than ever.
I’ve been hoping to find at least one of the rings, allowing me to use it as a template for lathe work. No luck yet, as our house and hobby room is barely walking room and all the expected locations have been excluded by inspection.
The lens in the nozzle is also retained by a threaded ring with divots for a spanner. Too many different models out there to make general assumptions on any specific model.
I’ve printed many parts for my laser but I’m not sure how hot the back of the mirror gets. So printing it would be easy as 1.5mm pitch is possible. Just don’t know if it would hold up. I use a silicone o-ring, which would help.
Finding someone who sells a custom ring would be difficult, because how many would they sell?
No printer? You can order custom printed parts in many materials but you would need to provide the design.
There are tolerances involved in metric thread systems, but the M designation tells the nominal outside diameter of the outside thread.
As a rule of thumb, the finer the thread, the closer the designation is to the actual diameter.
And the inside diameter of the inside thread tells roughly the core diameter of the outside thread.
In any case, if the M20x1 is the correct thread size, M20x1.5 won’t help You one bit.
Way too coarse.
If You’re absolutely sure that the thread is M20x1, for the thread You can use:
or eqvivalent data.
Most metric threads have their close diameter x pitch imperial “match” and vice versa, so a bit of care has to be taken to identify which one is the correct one.
There are some subtle -often difficult to measure with basic hand tools- differences even though the threads may mate satisfactorily, and depending on the application, those differences may matter or they may not.
In the case of M20x1, the imperial eqvivalent is 13/16 - 28 28-UN as can be seen on the linked spec sheet.
Because from the past experience I do know well enough that any thread in optical devices can be anything at all, even though they might be close enough to some standard threads to fool a casual measurer.
Like M5×0.8 vs.10-32: close enough to get a turn or two into the nut, yet wrong enough to strip the threads right off when you’re insufficiently awake.
If you wanted to make this part in plastic using a FDM printer the only limitation is how fine is the thread. Everything else you can tweak in until it fits. Based on an 0.4 mm nozzle I wouldn’t go under 1mm pitch. They do make 0.2 mm nozzles which I don’t have.
So I would design, print, try and redesign until it works. A ring like that would take under 15 minutes to print so it’s pretty easy to do.
I have three on my machine and honestly could not think of a reason that they would get lost in the first place.
I have a friend with a resin printer who is probably willing to assist me by making these parts. I have located the OpenSCAD file with which I created the originals as well as the STL. I had printed them with an FFF printer (FDM is ) at 0.10 layer height but I think resin is going to be stronger.
The reason they are lost is that the original rings were replaced with a trio of 3D printed versions that did not require a spanner. The originals are “somewhere” in our borderline-hoarders house, an affliction that will follow me to my death, I suspect.
@ednisley, the tolerances aren’t too critical I suspect, as the replacements merely have to thread in and not strip out. They aren’t experiencing much force, other than the gantry movement and the occasional removal and replacement for cleaning.
I looked at the OpenSCAD file and that’s the library I used, providing for the diameter and pitch. The brain cells are failing almost as fast as the collection of various hobby devices, so it was forgotten up to this point.
) at 0.10 layer height but I think resin is going to be stronger.