It took me a while to find much information on this, so I’m paying it forward to hopefully make it more likely that the information finds its way to someone who needs it! If you’re fairly new to machining, I’m going to discuss toolposts in general a little bit. If you just want to see the 9×20 process, feel free to skip below!
What is a QCTP?
A QCTP, or Quick Change Tool Post, is a type of toolpost for a machine lathe which, as the name implies, allows for much faster tool changes than traditional lantern or turret type toolposts.
It’s a pretty standard upgrade for most lathes which are used in any kind of production capacity, since the ability to move through a rapid sequence of tooling allows for efficient machining of multiple identical parts.
There are two main types of QCTP that tend to be used: two position “Aloris”, and 40 position “Swiss-type” or “Multifix” styles. The US tends to use the two position, and Europe the 40-position, though that’s not an absolute. They all use a lever that cam-locks a variety of toolholders in position against a post which dictates the angle they’re at.
Because, apparently, I’m incapable of being reasonable, I decided for my second trick I’d do the LPA NN-14 that Han gives Rey on Takodana in The Force Awakens. Not in foam or resin, but in metal.
It caught my eye, because despite being objectively fairly unbalanced, lumpy and ugly, it has some individually beautiful design elements, as well generally appearing to be an homage to Original Trilogy lightsabers. It looks to be the only blaster we’ve seen so far manufactured by LPA, which makes sense because it’s heavily divergent from the general design lines common to most of the blasters we see in either Old Republic/Pre-Empire or Empire/First Order settings.
On top of this, it’s relatively simple to machine manually due to its mostly 30’s machine-age aesthetic. This is very appealing to a guy who hasn’t yet built any CNC technology! Similarly important for me right now is that every part of it fits into a 4″ square, which is all the space that my lathe milling attachment gives me- and even then, the extremes are iffy because the dovetail ways and gib on the thing don’t have a lot of grip on each other and can rack under pressure from the cutter. Sometimes it’s better to flip parts around near the end of its travel.
This isn’t going to be a completely exhaustive build log by any means; that’ll come if I can find the time when I build version 2, hopefully later this year. But I will touch on the highlights, with plenty of pics to break it up. Don’t be fooled, this is still a seriously substantial write-up, should probably grab a beverage of some sort… But there’s a lot more to it than this. Ok, let’s get started.
The idea of this series is to focus on a handful of specific, fairly self-contained parts of the build that can easily transfer to other prop builds, kit assemblies, whatever. To look at some of the more “functional” aspects of a prop build that can be used to improve a project beyond good assembly and paint. Check it out:
This one even manages to be about 35% shorter than my usual running time! 😀
One idea I also had was to make an L-shaped slot so that the handle has a point to catch for an empty/missing magazine, and then could be flipped forward after “reloading”. Since the BR85 seems to have a closed-bolt firing position or a floating bolt assembly- it gets fully racked back-and-forth after replacing the mag in the game- this wasn’t really relevant to this build, but there may be some other weapons (particularly pistol slides) that operate that way in-universe.
For a pistol, you’d need a separate lever that could flip the lever (connected to the slide) back up into the main guideway. Alternatively, a spring-loaded crossbow-style wedge, that allows you to rack the slide back, and then pops up into the main cylinder in front of the returning piston head. The wedge itself would be directly connected to the release lever that would allow you to depress it back out of the cylinder. May be easier that way, since you wouldn’t need to allow a floating, rotating bolt to connect to a linear slide. Anyway, random ideas aside…