Bolt testers wanted

[kingmt]

I was playing around with some ideas and I ended up creating a bunch of different bolts. I would like to get some independent feedback on these designs.

The first 2 designs are venturi style. The difference being 6 or 8 hole.

The second 4 designs are variants similar to a ANS pre-2k venturi bolt and Techt's Hush bolt.

[kingmt]

So here is the deal. I will print and send you the 7 bolts to test. All I would ask for is postage.

Information I would like to see: what psi is needed to fire at 280fps for each bolt and impressions on the sound signature

I have measurements for the following guns
Autococker 2K
Ego
Impulse
Intimidator
3 different length Spyders


If you have something else I will need measurements from you.

[Sheepdog]

Love the ambition, knowledge and proficiency utilizing equipment on this one! I would absolutely like to know more about your aim. As far as autococker, regarding psi, there are a lot of factors that come into play. I'm sure you are aware. As long as the control marker stays the same, the data should be useful. The aspect I am curious about is sound control. Longevity and bolt stability are also at play.

Sheepdog

[Snowpuff]

What material are you printing it our of?

[kingmt]

I forgot so many things in my first posts.

The inspiration for the expanding twisted bolts came from shooter311 in this post https://www.mcarterbrown.com/forum/c...ac-bolt-design

My goals for the bolt are to be as efficient as possible with a significantly reduced sound signature. Something along the lines of if I am more than 40 feet away you won't know I am shooting until you hear the paintball whizzing past your head or it hits you in the face. I was playing when the original Shockers came out and there was a guy that I played with several times. He was really good at being stealthy and sneaking arourd the side. Then he would open up and by the time you figured out where he was it was too late because you were lit up.

For the psi comparisons I am going to send an open face bolt to use as a baseline. So same gun, multiple bolts to get a basic idea. But at the same time I want as much data as possible. If I really wanted to go nuts I would run a fluid analysis on the design. I still might.

As for the material, the first batch I printed is in Anycubic ABS-like 2 Pro. I seemed like a decent starting point and it is reasonably cheap. If the bolts start wearing to much I can switch to a more expensive engineering resin. Phozen makes an extremely strong engineering resin, but its $80 per liter vs $26 for the Anycubic. So also one of the data points I would like to get from people is how the bolts wear under heavy use. I would love to see someone run 3-4 cases with the bolt to get an idea of the wear. My other current project is a bullpup marker and once I get it assembled I am going to put it on full auto and shoot a tank dry.

The first batch of autococker 2K bolts finished overnight. In the other thread Jonnydread expressed an interest so I started with the 2K bolts. For not dialing in the resin and guessing at the timings the results are decent. Out of 14 bolts I had 3 absolute failures and 1 partial failure. I also learned that orienting them face down was a bad idea. Pictures coming soon

[SignOfZeta]

“Printing”? Surely you mean it’s made from PEEK in a Nexa 400 or whatever, right? That bolt is pointlessly crazily thin in the middle for FDM. Is that even 1/8”? Even for aluminum that’s pushing it and for no reason I can contrive on my own. It’s just…intentionality fragile.

As long as I’m pooping on parties…didn’t we figure out ages ago than all this bolt sculpting was totally pointless or has there recently been some new discoveries?

[kingmt]

It is printed on a resin printer. Specifically a Phrozen Mighty 4k. I am printing at a resolution of 52 micron by 52 micron by 50 micron. Or 0.052 mm by 0.052 mm by 0,05 mm. So I can reliably print walls that are 0.1 mm thick. I will see if I can dig up some pictures of the detail I can print. I once printed some things where my signature on the side was 0.5 mm tall, and it was readable. The thinnest part of the bolt is 5 mm. The resin I am printing with is mostly rigid, it will bend under pressure, but if the bolt is being bent there is something seriously wrong with your gun.

As far as the sculpting goes, that's part of what I want to find out. Does it work or is it worthless? One of my goals is to reduce the sound signature as much as possible without being horribly inefficient.

[kingmt]

First batch of bolts has been printed. White is boring so I added some CMYK dye to the resin. I was hoping to get a nice rich purple... As expected I found a couple issues here and there.


Turns out Fusion 360 changed their thread builder since the last time I created and printed a design with threads. From what I gather the new builder is correct and the old one flawed. It just happened that the flaw make 3d printed threads work and the new ones are too tight. I adjusted the treads and I am printing up some test bolts and nuts to see if I need to go with variant A or B


Orienting the bolts face down on the build plate turned out to be a bad idea. Removing the supports chewed up the walls on the face of the bolt.


This is what I love about resin printing. Fine detail