SILVIUS extruder: Belted 1:5 BMG dual gear by Baltojikale

Last crawled date: 3 years ago

SILVIUS extruder: Belted with 1:5 reduction and BMG dual gear.
https://discord.gg/nKkq2rkG for discussion and suggestion on upgrades.
I was inspired by direct drive extruders like Orbiter, fliexishaft remote extruders and Voron M4. Though had personal view on all listed extruders:
Orbiter: Small gears not printable with standard 0.4mm nozzles, even though I have resin printer did not wanted to print as resin is somehow brittle.
Flexshaft remote direct drive extruder (thing:4009262): Have printed and used (1:10 ratio) gearbox until worm gear worn out. Too high reduction (1:10 or 1:30) as worm gears works with high friction. Prolonged printing times as extruder retraction speed, acceleration speed and max speed has to be much slower. Also did not like sound of flex shaft during retractions.
Voron M4: Design on paper looks quite heavy. Very nice design but look over engineered. Odd belt size.
What inspired in those named extruder:
Orbiter – lightweight extruder without motor ~60g. Moderate reduction 1:7 (
Remote direct drive flex shaft – simple lock mechanism, and small footprint.
Voron M4 – 3 plate design (back plate, midsection and face plate), as it easy to print.
Requirements: Direct drive, Light weight, easy to print, moderate reduction, pancake motors (nema 14/ nema 17), BMG dual gears, micro bearing, mounting holes for horizontal or vertical attachment, simple and light lock mechanism, E3D V6 heat break mounting hole.
Few requirements ware dictated by the parts I had at the moment (namely Triangle labs volcano clone). So came up with this design after third iteration:
Features:
-1:5 reduction. 16t vs 80t pulley system wired with 200mm gt2 belt
-BMG dual gear filament griping system
-Light weigh: extruder with nema17 pancake stepper weights 196 g (while stepper with wires weights 129.5g). So using nema 14 extruder weight should be like Orbiters (140g).
GT2 80t gear is easily printable. whole design easily printable.
Satisfying filament locking system
Easily adaptable for mounting to various printers as only one part should be edited (back plate)
Easily adaptable to nema 14 or 17 motors as only face plate should be chosen
-Can be made into vertical or horizontal motor mounting position.
Disadvantages: Design could use more refinement: filament guide to hot end from BMG gears, 80t pulley fixing to shaft works well but don’t like looks of wood screw, quite large footprint of pulley system.
Hardware:
1x set of BMG style filament dual gears (8mm)
1x set of E3D style hot end
1x gt2 200x6 mm belt
1x 16t gt2 pulley
1x nema14 or 17
1x 4x2 PTFE tube ~50mm
2x MR95zz bearings (5x9x3)
1x 50x 5 mm round aluminum tube for shaft
3x round headed M3 x 30 mm screws (Philips)
3x round headed M3 x 6 mm screws (Philips)
1x round headed M3 x 40 mm screw (Philips)
7x M3 x 4mm heat set inserts
1x 20x5 or 20x6 mm spring
1x M3 nut
2x M3 washers
1x wood screw (12-16 mm length, 2.5 mm OD (threads included))
1x 22x3 mm rod/ pin or M3 screw
Tools:
2 and 3 mm drill bits and Cordless drill;
Solder iron with tip for a heat set inserts;
Files and sand paper (optional to clean up prints).
Assembly:
Most of the assembly is straight forward. Only heat set inserts and extruder shaft require additional attention. Shaft requires one small hole/ indentation for BMG set screw and one pass through hole which is needed for key of 80T gt2 pulley. Spacing between holes approx. 28 mm. Spacers go on shaft. Other than that may some cleanup of 3d printed parts require as sanding or hole cleanup with 3 mm drill bit.
Printing:
Some parts require small supports (mid plate, fan ducts). Other than that 0.2 - 0.3 resolution is enough.
Print quality using Silvius extruder:
first print layer consistency. 60mm/s, 0.2 mm layer height. no additional calibration. Due to 1:5 reduction extruder is capable of high extrusion rates (only simple extrusion test was performed)

Heat dissipation systems:
As this post is about extruder not about fan system I chose to go with simple 40x40x20 24v fans. Locally Sunon brand fans are quite available thus fan duct system was adapted for them. Suggestion to uses whatever you like or you have. I went with those as they were available and runs quite at 21 dBa. Current extruder design involves 4 mounting holes for fan systems also back plate or front plate can be expanded to accommodate any fan duct systems. E3D style fan which was included in triangle labs volcano hot end clone kit was not used as it was louder. Thus designed that “monstrosity” which is present in photos.