Fueled by a print I did of someone else's Baofeng battery compartment, I set out in Tinkercad to create my own 18650*** battery compartment for a Yaesu FT-60. This was my first radio, and I can't see spending $20-$40 for replacement batteries for it. Now I can use the common 18650 batteries and get almost twice the power for a few dollars less than even knockoff batteries made for the radio.
It takes a little more work than just slapping an SD card with the Gcode into the printer, but it is still fairly easy. The print works without supports, too. It's 10% fill which is pretty economical on plastic used and weight.
I use Altoids tins for contacts. I've found that the steel used in the tins is easy to cut, bend, and solder. I've used a rotary tool and kitchen shears to cut the metal into the shapes needed. Either way works, but the rotary tool with a cutoff wheel does provide cleaner edges. Be sure to tin the steel so it is less prone to rusting and corrosion.
The springs used came from a cheap ink pen. I had to search a couple of pens before I found a spring that was capable of being soldered. Using reclaimed springs from an old battery box might work better for you because those springs easily collapse into a smaller footprint. (Look at the Yaesu AA battery box...those are nice springs.)
***This box is designed for FLAT TOP batteries!!!
Surely any brand of plastic will work. I use Hatchbox and Amazon Basics regularly.
I used rectilinear fill and 2 perimeters. PLA was extruded at 195 degrees C on a heated plate at 60 degrees C. Later in the print it drops to 50 degrees C. The extruder is a 0.4mm. I wish I had a 0.3mm...Wishes, Wishes.
Rafts and supports aren't necessary. I sometimes use a glue stick to make sure the first layer adheres really good. This does make the finished part nearly impossible to remove.
Altoids tins make great contacts!
The only post printing thing you need to do is create the contacts. I cut some Altoid tin to the size of the holes then measured each one. The radio contacts are folded to give them some bulk. You can see in the pictures the contacts that I made.
The springs are from a run-of-the-mill inkpen stolen from an auto repair place. I take one spring and cut them to size and solder them to the plate of steel from the Altoids tin.
Once the contacts are in place, I made two grooves for wires to be soldered. I soldered the wires with the contacts while they were already installed in the box. This is risky because the PLA will also melt, so be very careful. Might want to solder the internal battery contacts outside of the box then install them, and then solder the wire to the back of the radio's contacts. The radio's contact slots are more robust than the internal ones.
Finally, the spring plate was JB Weld-ed into place. I later decided to JB Weld the wires at the top of the battery box, too.
The four contacts! The top two are not recommended. I changed them to a button style by punching them with a square drill bit (a makeshift center punch). It is less prone to tearing the cover of the 18650 batteries this way.
Take note of the wires connecting the battery contacts with the radio contacts. This was my first try at battery contacts. Do not do them like this unless you want trouble. Look below for a better idea.
The revised contacts are better. I cut the tin to size then use a punch and hammer to knock a "Button" from the backside. This works so much better than my original plan. I still solder the tin, or "tin" it, so that it won't rust.
I'm not much of a 3D designer in CAD, but I can maneuver through Tinkercad pretty well. I know it sucks when it comes to easily rounding edges and contouring, but it makes up for it in the ease of getting a rough shape down. I had to work through 3 revisions to get everything like it is. I started out with an extremely FAT design because I didn't take into account the cavity of the FT-60 radio. I was able to knock off 0.180" because of that.
I used Slic3r to slice it. The green one that I printed was printed on an XYZ printer using their slicer, and it didn't do very well. I also printed that one with supports, but the XYZ supplied slicer isn't the best. The tabs fell right off, and the resolution stinks! It was a good starting point, though.
Someone may be able to alter this file in another CAD program to make it more contoured, but as it is it works perfectly.
These are the three revisions. The green one was way too big. The left black one was okay, but had a few mistakes. The right one had the addition of the battery snap and shaved some plastic off to allow it to slide under the belt clip.
These were the second and third runs of the last revision. The process is repeatable and results in great battery boxes. These two are for a friend. Notice that I used some JB Weld to secure the wires at the top.