2024 ECCF Mini 2nd Place

What This Is

This is the Sep 2023 version of the RC-TNT HT Feather, a performance-focused competition chassis for the Axial Capra UTB18 – now with side and roof panels from your UTB18!

It’s designed to optimize the rig for comp crawling, with a focus on clearing obstacles and lowering your center of gravity.

Crucially, it is a bolt-on upgrade. You only need to supply your own slightly longer screws. I’ve even got instructions for you!


What’s It Cost?

Nothing! Unless you get ShapeWays to print it for you, but in any case, I’m giving this away. Print it yourself, build it, enjoy it.

All I ask in return is that you consider signing up to my email list (bottom of page). I won’t spam you. It’s basically a way for me to let you know when I release something cool that you’ll probably be interested in. If you like my YT channel and/or the files on these pages, it’ll probably be right up your alley.

Don’t worry, it’ll only be sporadic and I’ll safeguard your email address. I’m very pro privacy and will not abuse your trust. Thank you!

RC-TNT HT Feather V2.36 Front-RHS

What You Get

You get four files in this download:

  1. LHS chassis piece;
  2. RHS chassis piece;
  3. spacers; and,
  4. PDF assembly manual.

Current version: 2.36 (updated version with side panels)

IMPORTANT UPDATE APRIL 2024: the chassis is not WRCCA-compliant as it’s a little too short!! I’ll design a new Mini chassis to address this, but in the meantime, I have an 11.4g fix, plus 4x 8mm flat screws. Download this and affix with two screws on each side on the rear of the chassis, inside the shocks. It’ll give you the extra 34.5mm needed to get this thing into spec! My sincere thanks to Youtube commenter rcarty419 for catching this and my humble apologies to all affected by this careless oversight. I hope you continue to find this model useful, despite this little setback. THANK YOU!


No 3D Printer? No Problem!

See our ShapeWays shop: https://www.shapeways.com/shops/rc-tnt

(I’ve kept my mark-up under $10 total for a full chassis kit purchase, if you’re wondering! It’s still not cheap. Got a 3D printer at your local library, maker space, men’s shed, high school or technical college? Take the STL files with you and get to it!)

RC-TNT HT Feather V2.36 Sliced

Pictured above: RC-TNT HT Feather V2.36, sliced on Bambu Studio in 0.2 res with 6 walls and 20% infill. This is stronger at higher detail. As above, 0.24 res/line width, 4 walls and 15% infill is also fine. I’m also using Tree support at 5 degrees, in order to help print that rear window arch cleanly in the Silk PLA+ filament I’m testing (Silk can be difficult to work with, so I’m experimenting).

How To Use

Here’s how to print them:

Quantity: 1 of each piece. The spacers are required for installation and the correct number and sizes are supplied in the single STL file.

Material: PETG or PLA+ (any brand) – we’ve had success with eSUN and SUNLU. There’s no standard for PLA+, but it gives strength and flexibility to PLA and has been good.

Resolution: I’ve been using 0.24, but any of 0.2, 0.24 or even 0.28 will work. Lower res is stronger, higher res is smoother. 0.24 is a good mid-point.

Infill: doesn’t really matter, but 15% should be fine.

Walls: 4 or 6, gives a little extra strength on those thinner parts.

Supports: none should be fine, but you could use Tree(Auto) or Default(Auto) and 5 degrees as the angle. That will support the middle of the rear-window arch, should your printer require the help. You don’t need to support anything else, and even this is optional on modern printers. Your mileage may vary.

Rafts: none

Orientation: on the flat side of both chassis parts. They’re designed to just work.


See the included Build Guide for assembly instructions. You’ll need 8x M3 8mm and 8x M3 18mm low-profile head screws – flat or button will work. Screws available here.


RC-TNT HT Feather V2.36 Rear-LHS

Terms of Use

These files are provided for your personal use and enjoyment only. Please don’t print and sell them, nor the stl files (if you see them for sale in the wild, do me a solid and let me know!)

Please also don’t upload these to any of the online 3D printable sites. I’ve chosen not to do that and would appreciate you respecting that choice, as I’ve freely shared the files with you to print here on RC-TNT.com.

Thank you and please enjoy!