Wednesday, November 18, 2015

PM522 Washbear 2.0 Files Are Here!

Part 1 - Part 2 - Part 3 - Part 4 - Part 5

Here's a breakdown of how the revolver cycles plus a live fire test using all eight chambers!

Since we have a safe working prototype, I decided to release the files. Click here to go to the download page.

Thursday, October 1, 2015

PM522 Washbear 2.0 3D Printed Revolver Updates

Part 1 - Part 2 - Part 3 - Part 4 - Part 5

I've done some small modifications to improve on the old Washbear. The main change is that I moved the firing pin so that it hits on the right edge (3 o'clock) instead of the top edge (12 o'clock) of the rim.

Tuesday, September 29, 2015

PM422 Songbird 2.1 Files Are Here!

Part 1 - Part 2 - Part 3 - Part 4 - Part 5 - Part 6

I finally got around to putting the .zip file together. FP tested 2.0 and made a couple of suggestions which are reflected here. In this version, I got rid of the slots in the side of the frame and moved the branding. I also made some minor dimension changes.

The file contains three barrel types. Only the one named PM422FRICTIONBarrel2.stp has been tested. The other two are experimental. Click here to go to the download page.

Monday, September 28, 2015

PM522 Washbear 1.1 3D Printed Revolver Test Fire

Part 1 - Part 2 - Part 3 - Part 4 - Part 5
Awesome news here! Development of my PM522 Washbear 3D-printed revolver is coming along great and we've achieved a world first!

Gunnit Rust: PM522 Washbear

Here's a summary of the different cylinders we've tried:

-The original multi-part cylinder with tension rods didn't hold up. It fired two shots and cracked on the third, which deformed the cylinder enough to jam the action. The tension rods actually sheared cleanly at the point where the bullet exits the casing.

-So we tried making the tension rods thicker. On that version, the tension rods survived firing but the cylinder still cracked.

-So then we tried my resin-filled ABS idea. That one fired six shots, but was too damaged to reuse.

-So I made a version with no tension rods and I tightened up the headspace, hoping that the front and rear of the cylinder would contact the frame when fired and the frame would take the pressure. FP has printed this version in Taulman Bridge (a nylon filament) and it awaits testing. He also modified that design to accept steel chamber liners. Here's a video of the test fire with an ABS cylinder with steel liners:

It works!!! This is the first repeating firearm ever made with a consumer-grade 3D printer! (Not counting the Shuty because it uses a Glock barrel).

Now, it is kind of cheating to use the chamber liners, so hopefully the nylon cylinder will work and we'll have a true polymer pistol. Also you'll notice in the video that he had some trouble moving the trigger forward. This is because after a round is fired, the firing pin is still under tension from the striker bands while it rests in the dent it created in the primer. For the cylinder to rotate, the firing pin has to cam out of the dent, causing unwanted resistance. I've fixed this issue in the next version, coming soon.

What else...Oh, PM422 Songbird 2.0 has been successfully tested with internal bands! I'll be getting rid of the slots in the side and I might relocate the branding. I just have to export some files and get the .zip folder together. It should be out within a week.

Questions? Suggestions? Let me know in the comments.

Part 4

Monday, September 14, 2015

A Quicker, Cheaper, Stronger, and More Efficient Way to Make 3D Printed Barrels

Part 1 - Part 2 - Part 3 - Part 4 - Part 5

Be sure to read Part 1 for some background on my PM522 Washbear revolver.

In its current state, the cylinder of my revolver design takes over 20 hours to print and eats up a good deal of filament. It's a lot of resources for a consumable part. So I came up with an solution to improve the production of these types of parts. It's essentially my take on the method used by this group from Yale, wherein a hollow shell of the part is printed and then filled with a two-part resin. I modified my cylinder model to be two pieces of the shell, seen here:

Saturday, September 5, 2015

PM522 Washbear 3D Printed .22 Revolver Concept

Part 1 - Part 2 - Part 3 - Part 4 - Part 5

The guys over at FOSSCAD have challenged me to design a 3D printable revolver. Here are the goals that I set:
- Safe (failures will not harm the operator)
- Printable on a Rostock Max or smaller printer
- Minimum of type and number of non-printed components
- Double-action or double-action-only
- .22LR or larger caliber
- Ergonomic
- Simple operation
- Easy replacement of consumable parts
- Minimize resources required for consumable parts
- Durable frame
- 4+ shot capacity
- Easy acquisition of non-printed parts

That's a pretty long shopping list. I spent a lot of nights sketching on paper and modeling in Autodesk Inventor and came up with this, the PM522 Washbear revolver:
Hit the jump for a full breakdown.

Saturday, August 22, 2015

PM422 Songbird 2.0 3D Printed .22 Design Updates

Part 1 - Part 2 - Part 3 - Part 4 - Part 5 - Part 6

Version 2.0 is ready to print! For the uninitiated, the PM422 Songbird is a single-shot .22 LR pistol that is 100% 3D printed with the exception of rubber bands (in place of springs) and a roofing nail to serve as the firing pin. Obligatory glamour shot:
Looks a lot like the first version, right? Let's break down the changes and improvements (photo heavy):