Prusa USS Drybox_MK adapter+universal Puck remix + Spool holder with Biger Grip. CoreOne+/L compatible

26.4.2026 Update

• "I've added a new modified universal spool holder."

• "Reinforced grip for better control of the holder."

"This redesigned spool holder offers an improved, sturdier grip for easier operation."

"Optimized for compatibility with the USS drybox."

FOR USE WITH CORE ONE+/L PRINTER 

Print PETG 3 perimeters

19.4.2026  Update

• added remixed universal puck.

• more detailed assembly instructions.

To assemble the MK adapter with a remixed puck, you need these parts.

SCREWS

• M4×8     4 pcs

• M3 ×20

• M3 ×25

NUTS

• M3×10 (extended nut)

WASHERS

• M4(M3) (large area)

“I consider the use of a spacer nut to be a good idea, as it allows the parts to be firmly clamped together. It is possible to use heat‑set inserts, but in this solution I believe there is a long‑term risk of them being pulled out. A long nut appears to be the more reliable option.”

“This nut is not commonly available in hardware stores. Prusa uses it in their models, and it is available in their e‑shop.”

Set šestihranných distančních sloupků | 3D tiskárny Original Prusa přímo od Josefa Průši

Print remixed puck

• PETG

• 0,2mm structural

• 3 perimeters

• 8 top layers

• 25% infill

• Infill/perimeter overlap 20%

Changes to the remixed universal puck

• Increased clearance: Now accommodates a large M4 washer and socket head cap screw.

• Adjusted center hole: Diameter reduced from 4.4 mm to 3.3 mm.

• Reinforced base: Wall thickness under the screw increased from 3 mm to 4 mm for better durability.

• Compatibility: Universal spool holders can also be used – find the models on my profile (see link below).
  

“In the original model, the head of the M3 screw tended to push through the material, as shown in the photo.”

“On the remixed puck, it is possible to use cylinder‑head screws together with a large‑diameter M4 washer to provide a larger tightening surface.”

Assembling a remastered version of the puck

• “Screw in 4 pieces of M4×8 screws.”

“Assemble the MK adapter and the remixed universal puck.”

• “Use an M3×10 mm standoff nut, an M3×25 screw, and a large‑diameter M4 washer. The large‑diameter M4 washer was chosen intentionally to provide a larger tightening surface.”

• “Insert the holder arm into the assembly as shown in the photo.”

• “Use the second universal puck together with an M3×20 screw and a large‑diameter M4 washer. Assemble the parts as shown in the photo and tighten the screws firmly.”

“This is what the completed assembly looks like in cross‑section. Do not mix up the M3×25 and M3×20 screws. In the model, I used large‑diameter M4 washers with an outer diameter of 12 mm and a thickness of 1 mm.”

“I remixed the MK adapter to allow the use of cylinder‑head screws, and I also reinforced the wall and the central pin mounting.”

“This is how the original MK adapter model failed when pressure was applied to the central pin.

“Reinforced construction of the remixed MK adapter part.”

Print remixed MK adapter

• PETG

• 0,2mm structural

• 3 perimeters

• 20% infill gyroid

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  

“If you already have the original universal pucks printed and want to use them together with the remixed MK adapter, you must use a different screw length. I also recommend using a large‑diameter M3 washer.”

screws

• M3*25

• M3*16

• “I recommend using a large‑diameter M3 washer.”

• Compatibility: Universal spool holders can also be used – find the models on my profile (see link below).