I mentioned yesterday that I planned to post this, and here we are! I don't know whether this will become a regular series. I don't even know how much longer I will be a librarian. I am growing frustrated beyond belief with the administrative level of library life, but I do like my immediate co-workers, the constant variety of work, and the majority of my patrons. This is the story of how everything went awry, and yet turned out OK in the end for one such patron.
@generikat's husband T. coaches a horde of youth in marksmanship. One of them is in need of a custom left-handed firearm, but a proper grip sculpted for a southpaw is not a cheap accessory to buy. Fortunately, the shooter's family found a 3D model for sale, and the library 3D printer was able to make it into reality. But it wasn't quite that simple.
The file was huge, nearly 2 GB. There was no way I could slice that. And when I loaded it into another modeling program (slowly...) to see if I could simplify it, there was a mesh error. I had it repair the mesh (very slowly...) and then drastically reduce the polygon count on the model through a few steps (even more slowly still...) to ensure I didn't change anything vital. But after all that was done, I had a model I could slice and send to print.
The model had a lot of overhangs, so I needed to make sure there was plenty of support. It also needed a little more structure than most, so I added an extra perimeter pass on each layer. Estimated print time was well over 10 hours, but I didn't want to skimp. Unfortunately, not only did this print time add more possibility of failure, but the cost in plastic also exceeded our informal policy on how much to risk on failed prints or a no-show for pickup. I wasn't worried about the latter, but my library's printer was already down for the count due to some repairs, so I had to ask another library in the district to pick up the job.
I queued up the print remotely at the end of the day and fired off an e-mail to the person in charge of printing at the other library, letting them know it was a bit outside our parameters and asked whether they could make an exception in this case. The next day, I got a reply saying while the answer would have been "no," another staff member had already showed up first and bumped my file ahead in the queue because everything else was from library staff, and patrons have priority. All's well that ends well, though, and the print finished without any catastrophic failures! I fired off a quick text to the Kat, and she replied that T. had even smiled when the news was relayed to him.
That's an upside-down pistol grip for a lefty. It's a bit small for my hand, but perfect for a youthful shooter or just someone with a slighter build. Instead of gripping it like I might on a normal pistol or pistol-grip rifle, it is cradled in my hand as more of an ergonomic extension of my arm. I wouldn't want to use it on an everyday carry gun (where does the magazine go?) but I bet it will really help with Olympic-style competition marksmanship. The extended palm swell lines up the whole grip quite effectively, and should keep alignment more consistent for the shooter.
You can see the two support material sections on either side of the grip. They came off easily. If you're unfamiliar with how these printers work, imagine a very precise robotic hot glue gun squirting out a 3D model one layer at a time from bottom to top. Each part of the model needs some degree of support or it sags. Support material is a thin scaffold automatically generated by slicer software to hold up areas that would otherwise not print properly. I also had to make sure the support didn't try to fill in the entire pattern of voids, because the default option tries to do way more than necessary, and would have filled in the entire model.
I'm not too worried about the material being harmed by recoil. Pistol or rifle, air or .22LR, this is robust enough for the job. It's a grip, not a pressure-bearing component in the action itself. I couldn't legally print a receiver for a patron's firearm anyway, even if some mad lads have pushed the envelope in that respect technologically.
Have you had a situation where everything went wrong, but in a way that still worked out in the end? What adventures have you had in the world of 3D printing or firearm/airgun accessories?
