Has it really been that long since I’ve worked on this project? Yes… yes it has. It’s been far too long, so long in fact that Trigun got a re-boot in the form a new anime, Trigun Stampede! Well, really, it’s only been a little over two and half years at this point, so maybe not that long? For some reason in my mind, I thought it was longer. I’d thought I’d started this before the pandemic, but I guess it was probably due to my time getting to telework during the pandemic that I really was able to have the ability to make the most progress on this project. And so much has happened since then. Unfortunately, not all that much has happened with this project.
After the last post, I set the replica aside to ponder on some design changes I wanted to make with it. I did some more tweaking, tried to come up with a good idea for how to reliably make it auto-ejecting like in the manga. I played around with it, having far too much fun with my new replica. So much so that I broke it, and then just didn’t feel like fixing it despite having some ideas. And so it remained a display piece on my shelf while I worked on other projects.
Recently though, I was spurred into opening up the project files again and attempting to make some headway on the issues I needed to fix.
I think I sat and stared at the 3D model for this project for far too long, scratching my head and trying to figure out better ways to design some of the features I’d settled upon. I’d made it as ‘functional’ as I could, and I was happy that I’d gotten the double-action feature of the revolver working. However, the timing of the motion was ‘okay’ at best. The hammer would strike just as the cylinder moved into it’s final position. Since this is a non-firing replica, that doesn’t really matter all that much since the movement is just for show. But it would be nice to get the timing more accurate and get the assembly to move more consistently (more than occasionally it wouldn’t catch the cylinder, or it wouldn’t rotate fully, so it would end up out of alignment).
I initially designed this project prior to getting my Prusa printer, so I was used to needing larger tolerances due to under or over extrusion and other odd issues (I probably didn’t have my first printer tuned all that properly). Now that I had the Prusa and had some experience with it, I was able to tighten up some of the tolerances. And after breaking the revolver playing with it too much, I knew what parts needed to be beefed up to make it slightly more robust and so it would have less slop in how the cylinder sat on its shaft.
Since I had a number of design changes in mind for how to tweak things with the revolver, I figured I might as well re-print everything on my Prusa, that way I could have both the old design and the new side-by-side for comparison. Off to the printer! I started with the rear frame and trigger mechanism since those were the major portions of the model that I was going to be tweaking, and I knew I was going to have to re-print them multiple times if I was going to test things out.
Several of the things I ended up changing from the original design were the hammer spring rod, making it print as one single piece and adjusting the geometry of the hammer where it attached to it. Most of the adjustments I knew I was going to make were really centered around the transfer arm. And finally, I changed how the magnets were inset into the frame. Where I’d previously been planning to glue them in, I decided since I was going to be printing so many test iterations of the design, I didn’t want to glue magnets into each one, so I added some internal pockets for the magnets to slide into snugly while still allowing them to be pushed out from the opposite side (I was hesitant to do this since I wasn’t sure how it would affect the magnet’s holding force).
With the cylinder’s movement consistent with very little wiggle, I was able to tighten up the design on the cylinder catch. Cool, it was spinning and catching correctly. Now, I just need to get the timing correct. After staring at it more and playing around, trying to see how everything interacted, I realized that the transfer arm didn’t have enough extension; it wasn’t moving as far as I wanted it to with a pull of the trigger. It also didn’t fully engage with the cylinder ratchet all the way through its motion. It imparted enough momentum to cylinder to finish its spin, but giving that the extra distance would help both the timing of the cylinder movement and the timing of when the hammer struck.
There were a couple things limiting the distance the transfer arm could travel. One, was the trigger geometry. I noticed that if I tweaked the shape, I could get a little bit more pull motion. This in turn would translate to more travel distance for the transfer arm. Second, was the spring compression. I thought I’d given it consideration before, but I really hadn’t fully taken into consideration the measurement of the spring when compressed. Springs don’t just compress down to nothing, no… no, they have a compressed length and a free length. And while I did want some pre-load on the spring, I had a bit too much, so it was thicker than it needed to be when compressed. This was where I realized I could shorten the transfer arm to give more room to accommodate the spring’s compressed length.
Now that I had more travel distance for the transfer arm, that not only helped the timing issue, but gave the hammer a larger motion on a trigger pull too. It made it feel more correct, whereas it had felt like too short of a motion before. I still had an issue with the transfer arm not engaging the cylinder ratchet through the complete motion, but a change in the geometry in how the arm engaged with the ratchet may help with that. I thickened it slightly so it would hit more of the surface area of the ratchet and would stay in contact with it longer. That had the unfortunate side-effect of reducing the springiness of that part of the arm. Which, since I was designing this to print as a single piece and not two pieces with a spring between them, like the hammer and pawl, was not ideal. I needed that part of the arm to flex fairly easily. Thankfully I was able to gain back some of the springiness of it by adjusting the length of that part of the arm.
Now that I was happy enough with the tweaks I’d made, before finishing printing the rest of the model, I decided I would dive into the some variants of parts that I’d wanted to model up for some time. If you refer back to my first post with all the reference material I gathered for this project, I noted that the design of certain parts of Vash’s revolver changed throughout the manga. The main three things that changed were the grip, the sight, and the hammer thumb-cap. And these were legit design changes, from the revolver getting repaired or remade and were consistent for most of the references they appeared in.
In the first few volumes of Trigun and Trigun Maximum, the revolver’s grip appears to be made of wood or some other molded material and looks as if its split into two halves with mounting screws on either side. Later on in the manga, the grip changes to a single molded piece, at least, I assume because of a cap on the bottom. Now, there are several images of the cap on the bottom of this grip, and there are no mounting screws anywhere on it. Unfortunately I couldn’t think of a good way to have it mount securely without at least one screw.
After the grip, I wanted to have a couple variations of the sight on the rear of the revolver too. For most of the first part of the story, and into the middle, the rear sight is depicted as it would be for a normal gun sight, a block with a gap in the center to aim down and align with the front sight. Which, the front site is more or less just a block on the end of the barrel and is not really practical for aiming at all, but this gun wasn’t really drawn for perfect realism. Towards the end of the story, after Marlon remakes Vash’s revolver, the rear sight officially just becomes an angled block at the back.
Finally, the hammer thumb-cap. In the beginning of the story, it has a much more stylistic, integrated design with the hammer, and was rather inconsistent in shape. It was only toward the middle of Maximum that we see it clearly depicted as a curved block with rounded edges and a cross-hatch knurling. That was the design I personally liked the best, but I also wanted to do the variation of the cap that we see at the end of Maximum where it has changed to be similarly a curved block, but longer and with a partial straight knurl.
With the new variations on the grip, sight, and thumb cap, I felt like it was time to finish printing off the rest of the parts for this iteration of the replica.
I ran out of the original Hatchbox Silver filament I’d printed the previous iteration in, so I was using a different brand that was supposed to be “silver”, but I feel like its a much more dark grey than silver in my opinion. But hey, this latest iteration printed on the Prusa was looking really good despite the color difference. And if functions much nicer too after all the tweaking. It feels more correct with the tighter tolerances on the cylinder.
I also committed to purchasing properly sized magnets with appropriate strength when I’d decided to add in the magnet pockets. The pockets separated the magnets I was using from each other just enough for them to start losing holding strength for the forces I was subjecting them to; that, and coupled with the fact that I was using salvaged magnets to glue into the frame cause I hadn’t wanted to spend money just to throw the magnets away after gluing into the test pieces. For the new magnets, I found some 10x5x3mm N52 strength magnets that worked as well as, if not better than I was expecting. If you do try to fire the revolver too fast at an odd angle, it will still try to pop open, but hey, that was about the best I could do with the space constraints I had for the magnets, I’d love to have added larger ones, or at more points on the frame, but the space just isn’t there.
Despite the tweaks and advancement to the part design that I’d made on this new iteration of the revolver, I still wasn’t able to figure out a good way to make it auto-eject. I’d toyed with a number of ideas on the previous iteration, modifying the cylinder in an attempt to have the ejector be spring loaded to pop out of the cylinder, and be held back by a catch inside the front frame; but I’d had no good way to actuate that catch properly to release the ejector when the revolver was opened. I tried having it be balanced against another spring with a large ball bearing, thinking that the impact of swinging the front of the revolver open would jar the balanced springs enough to pop the ejector… which kind of worked… but not well, especially as it would try to pop up the ejector when closed. I tried having a connecting rod that slotted down into the hinge and was hit by the block I have inside the hinge, shoving the rod up into the catch to spring it open… which also kind of worked… but there was no way to reset the catch without rotating the front of the revolver back into place, and so I couldn’t reset the ejector to be able to reload the revolver or close it.
The most recent idea that I’d been keeping in the back of my head, was to use a “V” style lever arm to act as an actuator for a catch, that similarly to the connector rod idea would interface with the block in the hinge and would, I think, work better for a catch release, and I could add a spring to it so it would properly stay in place. It’s hard to describe in words, I did make an honest attempt to model it out, however as I was modeling it, the further I got in tweaking position and operation, I realized I did not have a good way to properly insert it into the front frame of the revolver. It just turned out too large to slip in a slot that would be hidden behind the barrel. So, ultimately that idea hit a rather robust roadblock as well despite, getting a fair ways in modeling it.
I’ve also looked at using the spring-loaded plunger latches, similar to how a click-pen works, but I have no idea if I could get that to work properly either. I think this is just really beyond me at this point. I’ve more or less just about given up on trying to make the auto-eject work how I want it to. And that’s probably a lie. I may have given up again for now, but I’m sure I’ll revisit it again.
If nothing else, I am happier with this new design iteration and that much closer to calling the project complete.
In the mean time, if I take any longer to write and edit this post, Season 2 of Trigun Stampede will have released, and as much as I want that to happen, I’d rather get this post posted and be happy with the progress I’ve made on this project. Hopefully I’ll get around to a Part 4 post where I’m actually doing finishing work and not just more design iterations. Fingers crossed.
Jumping Ship 