This is an experemental Belted Flexible Filliment extruder which uses the mechanicals from a Bondtech extruder, coupled with a zero backlash belt design and a wade-ish style motor mount, coupled with the feed tube of a lulzbot flexystruder. It should extrude flexible filliment faster, with greater retraction accuracy and less weight than alternatives.

LulzBot

TAZ 5

No

Yes

0.5mm

80% or better

You will only need support for the fan duct return, Everything else will print without it.

Hardware required:
1 65T plastic (carbide) GT2 pulley w/8mm bore, flanges, set-screw
1 36T aluminum GT2 pulley w/5mm bore, flanges, set-screw
1 GT2 belt, 2mm pitch, 200T, 400mm length, 6mm-with, fiberglass-reinforced, closed-loop (Gates GT2 2mr-88-5 or 2mr-88-3 or equivelent)

1 68mm long M8 bolt
2 M8 washers
2 608 bearings
2x M4 x 55 cap screws
2x M4 nuts for extruder mount
2x M4 Washer
4x M3 10mm SHCS for stepper mount
2x M3 10mm SHCS for Side pod mount
1x M3 14mm SHCS for Side pod
1x M3 8mm for tensioner

1x Bondtech 3.0mm Extruder mechanical kit (http://shop.bondtech.se/ec/kits/bondtech-extruder-v2-30-mechanical-kit.html)

2 M3 x 12mm cap screw for side pod
8 M3 heat set plastic insert for tensioner, and extruder body and side pod
1 M3 thumb screw cap for M3 cap screw
75mm - .25”ODx.125”ID PTFE tube (~2.5”)

3.5mm drillbit (Mcmaster Carr)
6.5mm drillbit (Mcmaster Carr)
13mm drillbit (Mcmaster Carr)
1 hexagon nozzle with a 0.6mm end
2 40mm fans
the stock Lulzbot filliment cooling fan nozzle
12 M3 bolts and washers for the various fan mounts.

Assembly: Print the main body and all sub pieces. Insert all the heat set inserts (2x in the main body, 2x in the side pod pieces, 1x in the tensioner)
Press fit the secondary extruder hobbed wheel shaft ontp the side pod pieces, and install the secondaey wheel. Then Take the main body and use the 6.5mm drill to enlarge the filliment tube. Insert the PTFE tube and then use the smaller 3.2mm drill to widen it out. Findally use the 13mm drill to carve away the PTFE tube in the areas inside the filliment chamber, as seen in the pictures.

THen fit the hobbed wheel to the 8mm bolt along with the bearings and a washer on each side. The pulley acts as the bolt retainer. Install the large pulley on the end of the bolt assembly after it is in the housing. Loosely fit the NEMA 17 motor to the extruder body and with no tension on the tensioner, fit the smaller pulley and the belt to the motor. Next tighten the tensioner and motor mount screws when the belt appears taut.

The hexagon hotend installs as normal. Install the heat set inserts into the extruder fan mount locations, bolt and wire everything up accordingly. This extruder carriage will fit a standard TAZ V notch mount.