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Revision as of 07:16, 8 February 2014 by Cdaringe (talk | contribs) (BOM: Flat BOM)
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Crystal Clear action run.png

Release status: working

Cossel dev2.png
Delta robot 3D printer with extrusion frame
CAD Models
External Link


cOssel is an iteration of Johann's Kossel. Design intents are equip a dual head end effector and to move the linear rails to an open design. It also uses 20x20 instead of 15x15. All other tweaks are minor. This design otherwise entirely copies Johann's delta-bot intent. Default configuration is setup for Dual Extruders, heated bed, and EE fan.

Non-contact Autoleveling

cOssel attempts to enable a low-power, non-contact autoleveling sensor as an alternative to using a retractable mechanical switch as used in other Rostock/Kossel deltas. This feature is still experimental as most IR sensors have not been proven repeatable, thus is still unfit for use. Video: Infrared Leveling


Pre-install nuts for easier extrusion install

The assembly process should take a short weekend to complete. Make sure that you have a standard tool set, including ball-end metric allen keys.

Main Vertical Assembly

Base Connections

Upper Assembly


End Effector

End Stops

The following images show the terminal block on the board. I ended up removing the terminal blocks from the boards to reduce interference from the carriage assembly as it approached the Z_MAX home position.

Rod Ends

It is assumed that your push rods have already been cut to size by yourself or a vendor. If not, cut your rods to length.

  1. Place the rod end ball standing vertically on a stable surface.
  2. Place the rod end socket loosely over the ball end ball.
  3. Space a pair of needle nose pliers around the perimeter of the socket.
  4. Press firmly down and click the socket over the ball.
  5. Prepare the epoxy solution.
  6. Apply dab of mixed epoxy onto threaded 4mm dia, 20mm long set screw
  7. Thread set screw into rod end as deep as it will go
  8. Apply another dab of epoxy onto the set screws, this time, more generous
  9. Gently place the set screws into the carbon fiber tube.
  10. Firmly press both opposing rod ends together along the tube axis.
  11. Set rod to try. Ensure that rod ends are parallel with each other.

Filament Delivery

Spool Assy


Frame - External



Fan I/O

The RAMPS_1.4 board does not by default have sufficient IO to power three heaters and additional fans for the extruder heaters. Products exist already to serve this need, but I decided to build my own. I added a constant 12V drop for a always-on stepper driver cooling fan (so long as PS-ON is on), and a PWM circuit for a single extruder cooling fan. I shall use only one fan for both extruders.


The BOM for COssel is large, thus has been collapsed to not overflow the page. Expand the table below for a flat Bill of Material for procurement!

Item Qty
2020-134mm 1
2020-200mm 3
2020-300mm 3
2020-371mm 2
2020-50mm 2
2020-800mm 1
bearing_608z 2
bearing_624z 2
bed_glass 1
belt_gt2 1
bracket_extruder_mount_groovemount 1
bracket_heater_sppt_wood 1
bracket_power_supply 1
bracket_tee_2020 9
drive_filament_dia 1
extruder_maker_gear 2
fan_40mm_12VDC 2
fitting_one_touch_4mm 3
gear_drive_belt_gt2 1
motor_nema 1
motor_nema_geared_5.18_1 2
nut_extr_m4 26
nut_extr_m5 (open_rail_kit_excess) 22
nut_m3 19
nut_m3_jam 5
nut_m4 6
open_rail_bearing 8
open_rail_nut_m5 5
open_rail_scrw_m5_std 4
open_rail_shim 3
open_rail_shim_eccentric 2
open_rail_spacer_bearing 4
open_rail_wheel_delrin 2
open_rail_wheel_sst 2
open_rail-700mm 1
pcb_arduino_mega 1
pcb_heater 1
pcb_opto 1
pcb_RAMPS_stack 1
power_supply 1
pulley_belt 1
rod_carbon_330mm 1
rod_ends 2
rod_threaded_8mm-271mm 1
rp_base_vertex 1
rp_block_bed 1
rp_bracket_axle_spool 3
rp_bracket_lateral_sppt 1
rp_bracket_lateral_sppt_mirrored 1
rp_bracket_RAMPS 1
rp_extruder_join_lower 1
rp_extruder_join_upper 1
rp_fan_mount_motor_drivers 1
rp_flag_carriage 1
rp_idler 1
rp_idler_boss_bearing_8mm 2
rp_idler_mirrored 1
rp_idler_strut 2
rp_mount_fan_ee 1
rp_opto_mount 1
rp_plate_slider 1
rp_ram 1
rp_upper_vertex 1
screw_m3_12 4
screw_m4_10mm 8
screw_m4_12mm 2
screw_m4_set_FLEX_20 2
scrw_4mm_10 2
scrw_4mm_8 2
scrw_finish_#6 1
scrw_m3_10 4
scrw_m3_12 2
scrw_m3_15 2
scrw_m3_20 9
scrw_m3_25 1
scrw_m3_35 1
scrw_m3_50 2
scrw_m3_FLEX_15 2
scrw_m4_10 13
scrw_m4_15 9
scrw_m4_25 2
scrw_m4_FLEX_10-12 2
scrw_m4_FLEX_14-16 1
scrw_m5_9 (open_rail_kit_excess) 20
scrw_set_m3 2
spring_m3_extruder 2
spring_m4 2
switch_thermal 1
tab_felt 1
wire_raceway_10in 1
wire_raceway_25in 1
wire_raceway_5in 2
wire_raceway_8in 1
wire_wrap_10ft 1
wshr_4mm 2
wshr_m3 23
wshr_m4 42
wshr_m4_fender 2
tubing_4mm_bowden_1000mm 2