Ontos by Impulse Ungineering

(35cm OD plunger tube coming soon in end september 2025!)

https://www.printables.com/model/1313153-nerf-ontos-tryhard-primary-for-filthy-casuals
Ontos is a tryhard primary for the filthy casual, easily hitting 170-250fps. It's low-hardware, low-budget, low-effort, and low-weight - tailor made for, and by, the lazy and the poor. Designed around only one screw size and 9 hardware items total, the BOM is a third the length of comparable springers such as the SBL and the Alchemist. For this, you get the following: 

Track-based bearing prime - instead of plastic bearings on a metal barrel, Ontos has metal bearings on a plastic track. These metal bearings are smoother, more robust, and cheaper than plastic contemporaries. A flat track also has more contact area than a round barrel, resulting in a smoother ride. On prototypes, you can't even feel the bearings rolling. This is effectively "linear rail at home" for a fraction the cost.

Quick spring swap - Turn the spring rest a quarter turn and it unlocks for easy spring swapping and spacer tuning.

Lightweight, Self-tensioning frame - With a combination of canted screw bores, unconventional joinery techniques, and a healthy dose of keying features, the frame panels are preloaded against each other without the need for a bar tensioner. The blaster is remarkably rigid despite not using flat bar, and much lighter than designs that do.

Baller Customization - The whole shell prints flat for optimal strength. This also means you can easily AMS skins onto the first layer with almost no purge filament.

Integrated barrel collet - Quickly swap between barrels with no tools. 

4-point adjustable stock - Designed with velociraptors and gibbons in mind. 

Hardware kit comes with
- Worker 1.6-250 spring (fits worker springs)
- Anodised grey 40cm barrel
- Anodised grey 38cm OD plunger tube, will require this variant of print 
https://www.printables.com/model/1372944-ontos-remix-for-35-38mm-plunger-tube
- trigger and catch spring
- ball detent