This STL is a precision‑designed 28oz tube adapter built specifically for the Kobalt 24V cordless caulking gun. The adapter features top‑mounted external threads that match the Kobalt collar, dual elongated side cutouts for weight reduction, and internal angled bracing to handle the high plunger forces of a full 28oz cartridge. The open semicircular base includes an alignment notch for smooth tube insertion.

Because 28oz tubes are 4 inches longer than standard 10–12oz tubes, this adapter repositions the cartridge so the Kobalt plunger can fully dispense the material without bottoming out.

Optional Helper Cylinder (Not Included in Project Yet)

Users may also print a lightweight helper cylinder to assist with the second half of dispensing once the plunger reaches the end of its normal stroke.

Recommended helper cylinder dimensions:

- Diameter: 51 mm (~2 in)

- Length: 89 mm (~3.5 in)

This helper piece simply sits behind the tube to extend the plunger’s reach. The locking‑tooth interface for the Kobalt pusher is still under development, so this part is not included in the current STL.

Print Requirements

Due to its overall length, this adapter is best printed on a large‑format printer such as the Creality K2 Plus. Smaller printers will not have the required build volume for a single‑piece print.

Recommended Settings

- Material: PETG or ABS

- 0.4 mm nozzle

- 3–4 walls

- 20–30% infill

- Supports required for internal ribs and thread overhangs

This design is ideal for contractors, makers, and DIY users who want to run full‑size 28oz tubes on their Kobalt cordless caulking gun with a strong, reliable, custom‑printed adapter.

28oz Caulk Tube Adapter for Kobalt 24V Cordless Caulking Gun

0.2mm layer, 4 walls, 15% infill