workshop, workshop, workshop, workshop, workshop, workshop…
there are quite a few nit-picky details i have left out, and some people who helped a great deal, who i haven’t identified, in the attempt to make this less overwhelmingly verbose. sorry.
a few weeks ago, moe asked me if i could do some improvised repair work on a magnifying loupe belonging to her clinic.
what she brought me was a perioptix loupe, which was originally mounted on a pair of safety glasses, the frames of which had broken… and then been not quite repaired (a number of times, apparently) with the surgical equivalent of duct tape.
seriously… why smart people with degrees, DOCTORS, think sticky cloth tape is an appropriate medium to affect the permanent repair of a broken surgical instrument, is WAY above my pay grade… 😕
she also brought me a set of oakley “safety” glasses (i’m not sure if they are actually SAFETY glasses, because you can remove the lenses, and replace them with shaded lenses, which were included), the frames for which would be an almost perfect replacement for the broken perioptix frames… except that the frames are a “skosh” thicker, and thus, the screws that hold the loupe on to the original frames are not quite long enough to fit through the test hole that i drilled in the oakley frames, when i accepted the project.
thus commenced the arduous and frustrating task of finding screws that would fit.
first thing i did was measure the screws. what i came up with is that the screws are NOMINALLY 2-64 threads — i say “NOMINALLY” because they’re REALLY small (although not as small as most pivot screws for most musical instruments), and when threads are that small, unless the manufacturing is INCREDIBLY precise, there are going to be not-quite significant, but noticible differences between what the “standard” is, and what appears “in practice”.
then, i started casting around for somebody who had the correct size screws, reasoning that i’ve already got washers and nuts for the screws, so, if i can find someone who has 2-64 thread screws that are A LITTLE longer, i can save having to buy nuts for them. i figured that places that sell optical equipment would be a good place to start, but they all said that 2-64 is “a lot bigger” than they use currently, and, also, if it’s optical, they measure things using metric, rather than imperial measurements.
after checking with a few optical places, i confirmed that the screws were 1) probably metric, and 2) WAY bigger than the screws that are used in MODERN optical devices…
the magnifying loupe is around 7 years old, and they have already stopped making replacement parts for it. 😒
so, i figured that it would probably just be easier to make the screws myself… because that’s a skill that i have…
however, musical instruments usually do things with imperial measurements (at least, here in the land of imperial meaurements), and i trained as a musical instrument repair technician: i don’t even HAVE a metric thread-pitch guage…
so i contacted a friend (the guy who rebuilt my trombone slide a couple of years ago), and asked him if he had a metric thread-pitch guage, which he did. i brought one of the screws to him, and he told me, with confidence, that it was a 2.4-52 metric thread.
as i said previously, unless the manufacturing is REALLY precise, there can be enough “slop” in the threads that it may actually fit in more than one die, so i went out to find a 2.4-52 metric die, so that i could make my own screws.
home depot and lowe’s, as expected, didn’t have it, and i drew blank expressions from the employees who i asked if they knew where i might get something that small. 🤷
mcclendon’s was a little better: they, too, didn’t have anything that smalll, but they suggested that i go to swift tools, in auburn, which “caters to machinists”. i went down there… and their showroom is closed, due to COVID. 😒 so i CALLED them (from the parking lot in front of their location), and said that i was looking for a 2.4-52 metric die…
and they didn’t know what i was talking about. 😒
they said that there AREN’T ANY standard metric dies that are 2.4-anything. if i wanted a 2.0 die, they had them, and if i wanted a 2.5 die, they had them, but they had never heard of a 2.4 die, and, while they could have one specially made, it would be expensive, and i would have to be sure that it was what i wanted before they could even start on that project, because it would be expensive, and if it wasn’t what i wanted, i would have to pay for it anyway…
reaching the end of my rope, i contacted another friend who has the ability to get just about anything, and, with A LOT of back-and-forth, arm waving, and measuring things with my micrometer-caliper (which measures down to .00001 inch), we determined that it’s NOT a metric screw, that the screw’s outside diameter is EXACTLY the standard for an IMPERIAL 2-64 screw (down to five decimal places) and that all of these people who had been telling me that it was metric were, probably, wrong.
he, then, directed me to the McMaster-Carr web site, where he gets a lot his weird shit, and, sure enough, they actually have exactly the screw i needed… so i ordered a package of five, and mcmaster said that it would be delivered on monday.
by the end of tuesday, i was wondering where my screws were. the UPS web site, apparently, doesn’t know where it is… according to the UPS site, the package left pacific (which is just down the road from us) last wednesday morning, and then the package vanished… the web site now says that it’s scheduled to arrive on friday 4/23, but it still has the package leaving pacific, on a UPS delivery truck, LAST wednesday 4/14, and it hasn’t been seen since, so i don’t hold out much hope. calling UPS is a lost cause: their automated “customer service” robot assured me that a real person can’t help me, if the package didn’t arrive, to contact the sender, and unceremoniously hung up on me without even giving me a chance to speak to a real person.
so, i contacted the sender, who, graciously, sent out another package of five miniature screws, this time by fedex, which arrived this morning. 👍
except…
these screws are, guaranteed, 2-64 screws. the nuts that i have, which are the original, perioptix nuts, SHOULD fit…
but they don’t. 🤬🤬🤬🤬🤬🤬🤬🤬🤬
perioptix, apparently, had PROPRIETARY screws and nuts made to mount their magnifying loupe, just to make things EXTRA DIFFICULT for anyone (like me) who has the audacity to repair one of their products, rather than just buying a new one. 🤬
fortunately, McMaster-Carr doesn’t JUST have screws… and, for some unknown reason, the screws were 5 for $10, but nuts that will fit the screws are 100 for $2.
they’ll deliver them (by fedex) on wednesday. 😒
One thought on “the irritating story of the non-standard screw sizes… 😒”
Comments are closed.