VZ61 Multipiece Lower, Release V1, Public Beta

 Yeah, I'm slow.  Truth be told, I have not edited this much since 2021, and have not tested it past 50 rounds.  In that time I had a lot of important stuff going on and kind of just forgot about it.  I am releasing this to the public as an open beta test.  I want to move on with other projects, but I will eventually finalize this.

Montage of old versions.

The only thing I did recently was make a PDF instruction manual and create a screw jig that has not been tested.  The VZ61 frame I tested in the video was a slightly older variant that actually stretched lengthwise (to the point where the upper would not close) and had noticeable egging of the screw holes, which I addressed by adding more material around the screw holes.

That being said, print at your own risk.  ONE DAY, I'll actually return to this project and finish it.

For more detailed build instructions, read the PDF included with the files.  Please feel free to post any questions, suggestions, or ideas in the comments section here.

THE LINK ON ODYSEE!!! CLICKY HERE!!!

More info from the included PDF:

Note: This package was made and released in August 2024. I am uploading a print file that I haven’t touched since 2021 and forgot about it because I had a bunch of stuff going on. Currently outside of the country until 2025. Trying to wrap everything up and release it now that I have a bunch of down time, and everything is based on notes and old pictures. Will update this documentation along with updates to the STLs in the next year.

INTRO: Yes, there's already a CZ61 / VZ61 Skorpion that takes an AR15 FCG (special thanks to FreeMenDon'tAsk's VZ61 which I used to compare/verify dimensions) but mine can be printed piece by piece at a time (for smaller printers) and replaced when worn out. Also I hate leaving my printer on for more than 12+ hours for large prints. You can inconspicuously print these pieces on school library or company printers and not arouse suspicion (tell them it’s Radio-Controlled Car parts). Additionally, my front pivot pin area is reinforced with metal so it doesn't need an ungainly thick pivot area. Some of individual printed pieces are simple enough that they can be replicated using metal bar stock and simple tools. The ultimate goal is to have a mostly metal (if not all) receiver.

Future Updates: There's still some minor fixes I need to do, like add more material around the screws so they don't crack. Maybe make the front and rear side plates one piece. I also want to make a semi-auto VZ61 FCG version since I now have several sets of these trigger groups that need a home. Also maybe Walther PPS Mag-well since I have a bunch of these magazines.

The final phase for this is to create a set of jigs so that you could re-create the 3d printed parts out of metal stock - at least for the side plates. The front, center and rear trunnion would always be 3d printed due to their complexity, but I want to try casting them from aluminum, brass or zinc some day. I haven't got that far yet because I got bored of this project so I'm trying to push the files to the public for testing.

Old footage:

Rhineland Arms FG-9 Review

Unboxing and video review.

Skip to 3:45 to watch it jam.

Basically it sucks and don't buy it.

VZ61 Proof of Concept, status update

Video of my own version of the VZ61 “SkARpion” receiver - so called because its a Skorpion with an AR fire control group.  Yeah, its been done before, but I like mine better because its metal reinforced, user-assembled, and will include modular magwells, grip assemblies, and FCG containers.  It isn’t dead and I havent forgotten about it.  It needs a few tweeks before I am ready to release it to the public, hopefully by Christmas.

Printer Maintenance log

 Went about a whole year without doing any serious PM and calibrating on my Ender 3, aside from minor bed level adjustments.  It finally started seeing problems after running 8 hours a day for a whole year, with a week of rest per month when I left town.  Fortunately these are fixable along with most parts of the Ender.

Space between lines - not good!

The first thing I noticed was spaces between lines on the top layer, then failure to extrude.  At first I suspected a clogged nozzle, then I thought the table had somehow shifted away from print head causing thin lines.  I guess it was a combination of both (and I suspect a weakened extruder feed might be the next problem area in a few months).  I attempted to disassemble the print head for cleaning but then the aluminum heat sink broke from the heating block!  There was burnt carbon crud in the nozzle and hotend.  Luckily I had a spare printhead with hot end assembly.  The old Bowden tube was trimmed to it's extreme shortest length from previous maintenance.  Everything had to go.  I also discovered that saving brass print nozzles and cleaning them is a waste of time since you can buy a whole bag of 10 for $15.

Bowden tube should touch the nozzle.

After installing the hot end assembly and leveling the bed, I was getting horrible stringing.  It was from where one layer ended and the printhead moved to the next layer, leaving a trail of residual filament behind.  Settings needed to be re-adjusted.  The first thing the experts say is to modify retraction settings.  I used this guide to help troubleshoot.

Stringing like dog fur.

Modifications made and results:

• Changed extrusion temp from 217c to 208c - no change.
• Reduced print speed from 40 to 35 - no change
• Increased retraction distance incrementally from 5 to 10 - success!
• Retraction speed from 50 to 55 - minor improvement.  It should be noted that this might be too fast and cause the extruder gear to rough it up and cause wear.
• Changed top layers to 2 from 0 (might have been accidently changed at some point?) - no change
• Infill gap overlay from 30% to 70% - very minor improvement.

Troubleshoot by incrementally changing settings.

Helpful troubleshooting links:

All3dP - Fix stringing guide
All3dP - Guide to gaps between lines and other layer problems

Scrapwood shelf, 3d printed legs

A low-poly shelf leg, roughly seven inches long, to be attached to a scrap piece of 3/4" thick board to be used as a shelf. Link here on Thingiverse. Use it to display your gun stuff! Actually it's to make room on my kitchen countertop for a coffee machine, but you can put some heavy stuff on it.

Mockup - Sig Nambu?

No, just kidding. This is actually a mockup of my p08 magwell shoved into a p320 testing jig I made. I actually was testing if this unholy union is feasable and it technically should be with modification of the slide holdopen device. I originally stated I wanted to keep the original mag catch but there's enough free grip space to go back to the drawing board and make something more modern. Modern proprietary magazines are the devil.

Bringing back the 9mm stripper clip (work in progress)

Started out building an MP34 9mm Steyr magazine well.  Ended up going all the way with a stripper clip loader just like on the German MP34.  Will eventually release a Colt/Uzi magazine version for public consumption, the MP34 version is my personal project.

It works but needs a few tweaks.  Used 40 S&W rounds for testing as that's what I had immediately available.