Back-Mounted Top Spool Holder Adapter Base (Qidi Q2)

It serves as an alternative base for my top-side spool holder system. I designed it for users who prefer not to use either the original side spool holder extension or my Spool Holder Support Leg.

It is fully compatible with all Top_Holder Extender variants (from here), so you can simply choose the extender that matches your riser height.

The center is intentionally offset so the load is transferred toward the corner of the printer, which is the stiffest and most rigid part of the frame

Printing
Print the part on its side (recommended) or flat.  with supports enabled from the bed plate. If printed flat - internal supports may needed, so i recommend to print it on the side.

4 perimeters, 4 top/bottom layers, 0.6 mm inner wall width, PETG, ABS, or ASA recommended (PLA should also work)

Assembly
Print this base together with the appropriate Top_Holder Extender part for your riser height, remove supports, then assemble the two parts.

Note

The rear-mounted version has a couple of drawbacks:
it prevents the top glass panel from sliding backward;
it occupies the rear spool holder mount.

For these reasons, I generally recommend using my Side Top Holder setup instead. However, if you prefer mounting the spool at the rear, this version is available as an alternative.

Enjoy)