Derivative of the Rostock 3D delta printer -
[cc by sa 3.0]
7/31/2013
Cerberus Pup is an experimental 3D Delta Robot printer that uses spectra filament for the vertical carriage drive system instead of traditional toothed belts. Please be aware that there will probably (and most likely) be significant changes and improvements made to this design. - A photo gallery of the Ceberus prototype can be found in the G+ gallery here: http://tinyurl.com/CerberusPup
A BOM is available here - http://tinyurl.com/Pup-BOM-Google-Spreadsheet - there are still some issues with the BOM, please contact Steve Graber to help correct any issues you find.
Print Files:
Qty - Filename
3 - 1x.125 aluminum bar.pdf
3 - 2x.125 aluminum bar.pdf
1 - Extruder_Lever.stl
1 - Extruder_Mount.stl
1 - Jslot_insert.stl
1 - JSlot_plate.stl
1 - Platform_and_Shroud_Assem_Traxxas.stl
1 - Pup_Base_Template.PDF
3 - Pup_Bottom_Bracket.stl
3 - Pup_Upper_Bracket.stl
3 - Pup_Upper_Idler_Adjuster_Bearing_Carrier.stl
3 - Upper_Idler_Axle_airtripper.stl
3 - Pup_Vertical_Carriage.stl
2 - VIKI_LCD_Panel_Side_Mounting_Bracket.stl
1 - Viki_Panel_Surround.stl
2 - Viki_to_Pup_Hangar_Bracket.stl (mirror 2nd copy)
Experimental Files:
1 - Platform_Geomag_v2_with_shroud.stl
1 - Pup_vert_carriage_Geomag_v2.stl
You will need to print a set of Xnaron magnetic rods available here: http://www.thingiverse.com/thing:87839 - Your printer needs to be very accurate and you will have problems aligning the steel balls perfectly on the platform. This is why this feature is experimental as it was difficult to attach the balls to the ends of bolts with epoxy with any dimensional consistency.
Notes:
All machined parts required to build Cerberus Pup are now all available for purchase at http://3d.grabercars.com. They are manufactured on a CNC lathe to very tight tolerances.
SPECTRA FILAMENT VERTICAL CARRIAGE DRIVE SYSTEM: Cerberus does not use belts or leadscrews. It uses a very strong braided filament called spectra. This is commonly used as fishing line. Cerberus uses 65lb test line. The drive system requires a threaded 'spool' or 'drive reel' that grabs the spectra very securely. CNC machined delrin filament drive reels are now available for purchase at 3d.grabercars.com - It is not recommended to use 3D printed drive reels because the print accuracy of your printer will suffer.
VERTICAL CARRIAGES: The Cerberus vertical carriages move up and down the extrusion towers by rolling on 3 cnc machined delrin 'w' rollers per carriage. Each roller consists of a cnc machined delrin cover with two 623 bearing pressed in. The roller rides in the T-Slot of the OpenBeam or Misumi 1515 extrusion. This makes for a very smooth and accurate linear carriage system. Dual 623 V Rollers can be purchased from 3d.grabercars.com
FILAMENT TENSION SYSTEM: Due to the high tension required of the spectra filament drive, the upper idler adjuster bearing carrier requires one machined delrin V-Groove idler filament bearing per vertical tower, riding on an 8mm shaft. This upper idler bearing transfers the upward motion of the spectra filament at the top of the printer towers into downward motion. I used a printed 8mm idler bearing shaft borrowed from Airtrippers Bowden extruder (Search www.thingiverse.com) and manufactured the delrin V-Groove idlers with 8mm I.D. hole on a CNC lathe.