3D Printed Pistol Grips

May 6, 2017 Jonahlyn Gilstrap

When I told my Dad I got a 3D printer for Christmas, he asked if I could recreate the grips from my Grandfather's Spanish Allies pistol. This was my first 3D printer so I had a lot to learn. This post documents my progress learning how to model and print the grips.

Picture of original pistol grips

Originals

In the beginning....

I started by taking a lot of pictures. I considered trying to figure out how to scan it, but since I didn't have a 3D scanner. I decided to try to model it instead.

I took a bunch of measurements, drew a lot of sketches, and took a bunch of notes. I'm not much of an artist, but it sure did come in handy as a reference while modeling. 

Sketch with measurements
To take the measurements, Dad gave me a pair of dial calipers. He wanted me to learn how to use analog calipers rather than relying on a digital reading. Dial calipers are easy to read once you get the hang of it (Thanks Dad!). My calipers measure in inches, but its easy to convert Inches to MM: X inches x 25.4 mm = X mm

 
I attempted to model the grips using Wings3d and Blender, but I ended up making the most progress using OpenSCAD. The most challenging feature of the model for me was the knurled surface that gives the grip its bumpy texture. While I did make progress with creating knurls in Blender, I couldn't quite figure out how to get the exact shape I needed. I couldn't get my head around boolean modeling in blender, but I was amazed at how much I could do with it in OpenSCAD. Luckily, I found the Knurled Surface Library v2 by aubenc on Thingiverse that made this a lot easier. Given the right parameters this library will render a cylinder with a knurled surface. It generates a lot of geometry that will slow down preview and rendering quite a bit. I found it more tolerable to create a stand-in cylinder with no knurls and work with the stand-in until I was ready to render.
 

The printing process

I printed the grips in PLA plastic on an Einstart-S 3D printer. It had to be printed vertically in order for the knurls to print correctly.

The grips are mirror images of each other, printed vertically and back-to-back. The extra material underneath the grips is called a "raft" and helps keep everything upright. The build plate itself is wrapped in blue painters tape and a thin layer of crafting glue is applied to the tape before starting the printing process to help keep everything attached to the build plate.

As you can see I went through many iterations and failed prints in the process. I've printed these things more times than I can count. This has been a great learning experience so far and I'm not even finished yet.