making J bass covers

[Gnobuddy]

Thinking back, I think they're called 'plectra' for the quill part.

Interestingly, in British English, a "plectrum" is the thing that we call a "guitar pick" in North America. "Plectra" (or "plectrums") is just the plural of plectrum. A little Googling says the word originates in ancient Greek ("plektron"), which apparently means "thing to strike with".

I was curious about the durability of 3D printed items, and a little research turned up the fact that the stuff that's used in most affordable 3D printers is called PLA filament. Wikipedia says PLA is "Poly or polylactic acid or polylactide is a biodegradable and bioactive thermoplastic aliphatic polyester derived from renewable resources, such as corn starch, cassava roots, chips or starch, or sugarcane."

In other words, this stuff (PLA) is actually designed to break down over time - not at all what you want for durable, long-lasting items (like pickup covers or plectra for a musical instrument). PLA is used for exactly the opposite reason, because you want your 3D printed doodads to break down fairly quickly, and not survive for a hundred years in a landfill.

However, PLA is not the only material widely used for 3D printing. ABS (plastic) is also used, and it is a much more durable material. Finally, it's also possible to 3D print with Nylon, though it requires an all-metal "hot end" for the 3D printer. Nylon is a very durable material.

I would assume the fumes from ABS and Nylon are toxic, and appropriate precautions should be taken.

More here: https://www.matterhackers.com/articl...ing-with-nylon

-Gnobuddy

[Mick Bailey]

I've had some 3D printed ABS off different machines and it had shear lines - almost like wood grain. Maybe down to how the layers fuse to each other. Larger parts are OK by way of the increased cross-section, but thinner components still don't compare to an injection-moulded product. It has to come down to the process and quality of the machine. In fairness to the 3D process itself, there has to be a difference between a component made on a $1000 machine compared to one costing 10x or 100x the price.

[Gnobuddy]

(Ed: 3D printed) components still don't compare to an injection-moulded product.

Oh, I agree completely. As I wrote earlier in this thread, the 3D printed finish doesn't even match up to the quality of cheap plastic toys at the dollar store.

That said, personally, I wouldn't care if my pickup covers had fine grain on them, or were slick-smooth. But everyone might not feel the same way.

-Gnobuddy

[David Schwab]

Somewhere on here is a description of Kent Armstrong's process for resin casting potted pickups that was written up by jonson. It may have been in the middle of a different thread but should be findable. I looked for it but no luck yet. From what I remember it was reasonably now tech.

I have a few of Kent's rubber molds that he used with Pete Skjold.

It's not at all a hard thing to do. I make rubber molds when I need to make a pickup in a "non standard" shape.

Just get a small plastic box, or even a food container. Put your slug (pickup cover) in with the top facing up, and then mix the rubber and pour it in. I use the rubber from Micro-Mark.

You have to figure out how to suspend the pickup without it touching the bottom of the mold. I use some heavier magnet wire to suspend the pickup. I got that idea by looking at an old Alembic pickup. Then I use MG Chemicals back potting epoxy.

Here's a mini humbucker and a Yamaha bass pickup both molded and cast in black epoxy. The molds take on the details so well that the mini bucker is as shiny as the metal cover was that I used for the slug!

[StarryNight]

wow, those look really good! Great info. Thanks David!

[markbush]

Awesome those looks so great. Thanks, David.

[markbush]

I have started my 3D printing journey and have learned so many things about them from printer deets. I am trying to sell miniature figures on eBay or ETSY. Do you have any recommendations for me?

[RedHouse]

I've been doing some custom covers out of wood using a CNC router machine setup:



Top picture shows the router setup, the part has to be machined from the top and bottom sides so it needs to be able be flipped and maintain registration. The piece in my hand is a test-run to get the parameters down but I held it in the picture next to the jig so you can see the process. The "jig" holds the material (in this case it was some scrap rosewood) with 4 corner registration pin/screws which screw into the waste-board which has had threaded inserts embeded in it. Then next to it is the part flipped over and placed into another part of the "jig" and the back/rear of the cover is machined.

The second picture is of the actual custom set I made for an Italian luthier, these custom Classic Rick pickups were done in Gaboon Ebony, he wanted Rickenbacker style pickups in a T-bird sized/shaped cover and wanted them to look "more organic" than a chrome t-bird cover so I made these in ebony.

The third picture is for another customer who wanted wood covers but in a medium tone/shade, so these were done in a light walnut and one has a thin coat of tru-oil on it to show him what it will look like as a finished part.
(BTW, the ebony ones in the 2nd pic have no finish per customer's spec)

Wood is very do'able and you can choose from many species.

Doing these isn't for the "everyday" build, it's a lot of work from start to finish, several programming steps, the machine files. and running the programs in the end.

[RedHouse]

The next picture is a test-run on some covers for a personal build of my own...
(when I get some time, LOL!)

[Leo_Gnardo]

The next picture is a test-run on some covers for a personal build of my own...
(when I get some time, LOL!)

Impressive!