QIDI Q2 Manual Belt Tensioner

10-13-25: V1.1 and Step Files added. Slight height adjustment of 1.5 mm due to center adjustment bolt hole being off by that amount. Also should give a little more gap between assembly and belt.

10-13-25: V1 out for testing. Two Versions. Recommend trying “Short” version (3mm shorter), but my printer had to use the “Long” version. I have not printed the short version, so let me know if the model is good, but this model should be easier to install, and give a bit more flexibility to people with newer tighter belts. 

Recommend you print this in some temp tolerant and probably CF/GF infused material. These sit awfully close to the motors in a very tight space, butted up against the back wall of the chamber.

I used ISANGU PC-CF (which is more like an ABS dominant blend at best). Further testing needed on how hot it gets in that particular area, and what filament is best.

I cannot comment about any long term, degradation, and wear at this point. I simply installed them, and somewhat tuned belts.

Parts Required

4x M3 Heat Set Inserts. ~3mm Length

2x M3x30mm Socket Head Cap Screw (The ones that came with your printer for securing down the bed during shipping)

Printing:

Recommend 4+ Walls, and 25% Honey Comb infill

Tensioner Ends should be set to 100% infill, or its possible the screw punctures the middle when tightening, as its barely 2mm between both holes.

Installation Steps:

-Insert 4x M3 Heat Set Inserts, one for each part. For the Belt Tensioner End, it's the smaller of the two holes

-Run ALL screws through all holes, to ensure good fitment, and clearance.

-Turn OFF printer and Remove Back Panel. Recommend removing the PTFE tube from the print head and de-routing it out of the cable chain, and disconnecting the Fan and Board connections that go to the back panel itself. While you don't have to fully remove the back panel, installation will be much easier.

-LOOSEN (Try not to remove) All 8 bolts from both printer belt tensioners.

-Remove BOTH Auto-tensioners (Crucial, or you will be fighting a tensioned belt)

-Fit Check just the Manual Tension block you printed. Test run through the 2x self-tapping screws, and ensure your holes are aligned with the printers housing, and tighten. This allows you to gauge what depth the screws go during full installation.

-Fit Check the adjustment screw, and run it through the Manual Tensioner body with it installed. The screw should perfectly align with the printer's Belt Tensioners “Spring Alignment” nub. This is the end where the Manual Tensioners End goes, but this fit check is checking the alignment of the screw and the block, to ensure you are squared up, and that again the housing is capable of fully seating


Install each Manual Tensioner as follows:

(This part may be easier with the “Short” version. Instructions are based on the “long” version which is a tighter fit and what I used)

-Assemble the Manual Tensioner and End together, but keep the end flush up against the body

-Insert a tool or use your hand to pull the tensioner backwards (e.g ADD Tension) to fit in the entire assembly. The hard part is clearing the “Spring Alignment” nub on the printer's belt tensioner housing, with the “hole” on the Manual Tensioner End. You will have to man/woman-handle the belt.

-Fully Tighten down the Manual Tensioner in its housing. If you fit checked like I said earlier, then you should know how tight is actually tight, and square to the housing. If this isn't fully seated, you will not get alignment with the adjustment screw and nub, and your belt will likely rub against the housing. This step is crucial.

-DO NOT start adjusting the tensioners until both are in, and leave the printers tensioners loose. You need slack in the belt for the second install. Repeat steps above.