Tokyo Marui 5.1 HiCapa 3D-Printed Carbine Kit Build (Part 4 - FINAL, POST-MORTEM)

At long last, this project is at a close. You can download it here: https://www.thingiverse.com/thing:3712294


I originally started the design July 1st, 2017. The first iteration of the files was completed January of 2018. The project was then shelved for quite a while until I picked it back up in November of 2018, and worked endlessly until June 25th of 2019 - today! - to get this final product.

My first impression of the kit is that it is shockingly robust for a completely PLA FDM-printed kit. The one weakness the kit has is the stock tang, and that isn't likely to break unless you put your full weight on it (which you shouldn't do with an airsoft gun in any case).

I ended up threading the muzzle for future accessories (barrel extension, receiver extension). The Action Cam mount on this iteration is also the pre-final - the final version is easier to mount an action camera to.

Old vs. New designs.

Now, for the dead horse segment: the POST-MORTEM.

Successes:
-Aesthetic design is lovely.
-Control group is very easy to access.
-Installation and removal of the airsoft toy is a breeze.
-Feel when using it is awesome.
-AR stock was a good idea.
-Charging handle worked out great after a last-second tweak.

Failures:
-Some dimensions are still too tight and require sanding.
-Full-length optic rail would have been good.
-Longer grip rail would have been good.
-Uses too much hardware (nuts and screws).
-Should have used an original stock design.

In the future, I may come back and address these failures. But for now, the kit is in a form I'm comfortable with releasing publically, and I can't wait to use it at a game.

For those of you who followed along, thanks for checking out my posts here, on Twitter, and of course downloading and trying out the kits on Thingiverse. Thank you to those who held regular correspondence with me about possible ideas for the kit and motivation to continue onward.

For now, I'm off to different projects. After two years off-and-on of developing this kit, I think it's time to handle easier-to-swallow projects for a while.

-Craig

Tokyo Marui 5.1 HiCapa 3D-Printed Carbine Kit Build (Part 3)

The sun is on the horizon for the Hi-CAPA Carbine Project.

After a last few sessions of tweaking, I've now completed the VERY FIRST functional prototype of the V2 kit.

The parts aren't fully hand-finished because this was just a fitment and function prototype.

A few areas need some change. Namely, the slot in the receiver for the accessory rail is slightly too tight, the charging handle binds up slightly toward the rear of the stroke, the reliefs for the manual safeties aren't big enough to let your thumb through, I need to inset a hexagonal slot for the M5 nut the AEG buffer tube screws into, and the grip magazine holder also doesn't quite hang on to magazines.

Otherwise... this was a monumental moment for this project. The airsoft pistol is fully capable of cycling in the kit, and despite the charging handle hanging up sometimes, it's still completely functional - it just needs to be guided forward sometimes. The stock mounting option works great, and I'm now very glad that I went with four M4 screws instead of two, as they're keeping the entire assembly rock solid.

At the suggestion of a Thingiverse user, I've decided I'm going to skip the receiver grip extension for "production" models - most people wouldn't use it anyway, it's not incredibly ergonomic, it complicates printing, and its design still needs to be fleshed out further. The model with this extension is referred to as the "HCC-2B", and the model without is referred to as the "HCC-2A".

After some brief adjustments before the final model, the file will be available for public download on Thingiverse on July 1st, 2019.

See you then.

-Craig