Si's Super Selector

MMU2 selector with;

removable blade block

• Dual Blades
• Removable Blade Block for easy blade changes
• Magnet to improve FINDA (short magnet from the original IR sensor)
• Clip-on FINDA Shade/Reflector
• FINDA adjustment wheel
• FINDA cable strain relief (with addition of a bit of filament)
• Push-thru tubes & PTFE tube insert in the feed to the FINDA BB make it a lot more reliable printing TPU.  (2mm ID tube is best for TPU)
• Cutaway to see inside and allow for easy cleaning with vacuum cleaner.

3 x M3x8mm bolts with hex nuts needed for the Blade Block Cover.

1 x M3x16mm bolt with square nut needed to lock the blade block in place on the body. 

The blade block and cover have dovetails, that are purposely tight. and will need running up and down the dovetails a few times to bed them in.  DO THIS BEFORE PUTTING BLADES IN!

Putting the 3 hex nuts in the blade block is a bit tricky.  Easiest way is to slide them into the cut-outs so they sit over the hole, then screw a longer bolt from the other side and pull them to seat the nuts in place.  (standard Prusa method).  

It's important the bolts holding the cover aren't interfering with the dovetail.  Mine fitted perfectly (on this version ;)), but due to differing tolerances with prints and bolts, you could add washers to the bolts if they're a tad too long.

The Blade block is designed so that the cover holds the blades.  With the cover laid on the table, put the blades in place, in the cover, then press the blade block in place.  This will hold the blades in place while you pop the 3 bolts in and nip them up.

The block with blades and cover then slide in the body and get held in place with the M3x16 bolt

The length of the PTFE tube insert is important, because there's a locator tab on the Blade Body that holds the PTFE insert tube in place.  Easiest way to cut it, to correct length, is to push it into the body, without the blade block in place, so you can cut it off flush, then put an inside chamfer on the end.

I've added front plates for M6, M10 push-thru fittings and one for M6x6x8 Threaded insert

Also included;

• modded extruder Adapter and top plate for push-thru fittings.
• Tool and block for easier removal of the brass bush/bearings.
• Bracket/mount leg with holder for a 13x19 switch

UPDATE

This was working great on firmware 3.10.1 (1.0.6), however when I updated to 3.13.2 (3.0.1) it homed ok, but after a cut, it would become slightly miss-aligned. so I've edited to fix this and added a v2 model, which works with the mmu3 firmware and with the mmu3.  I haven't tried the V2 model with the old 1.0.6 firmware, so I've included the 2 models.

V1 works with mmu2 firmware 1.0.6

V2 works with mmu3 firmware 3.0.1

Occasionally,  the filament would try to come out of the side hole, or get stuck, after the finda bearing.  This happened when the filament was near the end of a roll, and extra curly, so I've adjusted the filament path slightly, under and after the bearing, to fix this.  It's been ok since.

Also added a cutting block/guide for cutting brass tube, for the brass Bushings/Bearings

edited - bearing path, filament path, cutouts,

added - Memovable blade block with dual blades, ptfe tubes to filament path, FINDA adjustment wheel, Finda led cover/reflector, finda cable, stress relief