This is approximately 1/6 scale. I say approximately because I cannot find any actual dimensions anywhere and used references from photos to approximate sizing to compliment the RocHobby 1/6 MB Scaler Willys Jeep. The cradle is sized to accept 1/6 scale 1000-pound bombs at ~78mm diameter. Assembly is pretty easy and straightforward but I would recommend that you review the assembly video from my YouTube channel for additional tips.

https://youtu.be/okbfhNJKq3w

There are a few additional pieces of hardware required for assembly:

• M4 x .7 x 16 Screws
• M4 x .7 x 20 Screws
• M4 threaded rod: https://www.mcmaster.com/93000A513/
• M4 x .7 hex nuts: https://www.mcmaster.com/90592A090/
• number 4 x 1/4" pan head screws: https://www.mcmaster.com/90935A131/
• 4 x 8 x 3 mm bearings: https://tinyurl.com/2y8rryty

Additionally, I used these other printables:

Wheels (be sure to re-size to 40mm overall diameter)
https://www.thingiverse.com/thing:3448541

Hitch (pintle) loop printed at current size
Now included with this download but used to be found here:
https://www.thingiverse.com/thing:2875478

Creality

Ender 3 Pro

No

Yes

0.2

20

I highly recommend that TPU be used for the tires since there is no suspension at all for these trailers. Infill was 20% across the board for everything but the use of gyroid infill pattern (Cura) for the tires. Review the YouTube video for other thoughts on print settings.

Fusion 360 used to design entire selection of parts.