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Spool holder for Bear upgrade MK3/MK3S

by RH_Dreambox Mar 19, 2019
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I just wanted to thank you for the great design. Had to make a trip to the hardware store, but it was totally worth it. I've tried a few of these top mounted holders in the past and the weight of the spool always causes the holder to bend a little which inevitably ends up with the spool falling off after some time. The spools stay in place since the rollers are forced horizontal by the M5 screws and no sign of any movement of the spools which is awesome! My only nitpick would be to make a version that would clip around the aluminum extrusions instead of having to use T-nuts to mount :P. Thanks again!

Thank you for your positive response!
I started with a smaller design, but changed it to a stronger one as I felt it bend and the spool "hung down" after a while.
We'll see if in the future I can change it to a model without screws.

It is not immediately clear how the rollers attach to the mounting posts that screw to the 2040 extrusions. Could you clarify please?

Four M5 T-nuts and four M5x10 screws are used when mounting the spool holder.
Unfortunately, if you have already mounted your Bear upgrade, you will have to unload on the upper beam to mount the T-nuts.
Then you need to redo the Z-level calibration.
Hope you are satisfied with the spool holder:-)

Ahah, I would just use drop-in T Nuts for that task :). I was more asking about how the rollers attach to the arms, there doesn't look like a mounting point.

Sorry, but I misunderstood your question. This is how it looks.

I thought I had M5x40 screws on hand but it seems I only have M3x40 since these were the most commonly used in the building of the Prusa printers. Would it be a monumental task or bad design to make the rollers attach with M3 screws? I have plenty of M5s to attach the holder to the frame, just nothing in the 40mm range to make the rollers work.

Yes, M3 is OK. The filament spools are not that heavy.
But you may also need to use two washers if the mounting hole is too large.

Perfect, thank you

A side-mounting version of this for reverse bowden setups would be really awesome!