As a very pleased owner of the Think3dPrint3d Kossel Mini kit (Duet 0.85) I see more reasons why people are buying such clones beside the lower prices. An average maker like me, will have major problems building his own printer just from a BOM and some drawingings. Maybe not only for skill but also for time reasons.

Before I decided to build my own printer, I did a lot of research what is available on the market and where to buy. Happily I found the kit from T3DP3D. When looking around nowadays , there are not many well documented and advanced kits that don’t come from China sources, may be the original Prusa i3 and a few others. Even fewer are featuring the Duet Wifi. I don’t know why T3DP3D has discontinued the kit, but there where good reasons I assume.

In summery most BOM are based 90% on Aliexpress and the remaining parts are often from USA, where ordering directly mostly ends up with unpleasant hours in the local tax office (at least in my German city). I think most people feel ordering a few more parts from Aliexpress is just comfortable, so why looking for the original designs.

I can’t judge the current 3D printer market, but the success of the original Prusa i3 seems to prove that there is a demand for good maker kits, even when not in the lowest prince range.

Personally I would like to see a good kit, with all the recent developments that are available or discussed on different threads of this forum.

Layer shifting has been resolved with this version!

I have a Duet 0.85! can you please also submit 1.20beta10+2 for this model?

config.g below

[c]
; Configuration file for Mini Kossel Release 3 kit from Think3DPrint3D
; For additional help see http://reprap.org/wiki/Configuring_RepRapFirmware_for_a_Cartesian_printer and
; http://reprap.org/wiki/Configuring_and_calibrating_a_delta_printer_using_the_dc42_fork_of_RepRapFirmware

; Prologue and communications section

M111 S0 ; Debug off
M550 PMiniKossel ; Machine name and Netbios name (can be anything you like)
M551 Preprap ; Machine password (currently not used)
M540 P0xBE:0xEF:0xDE:0xAD:0xFE:0xED ; MAC Address
;*** Adjust the IP address and gateway in the following 2 lines to suit your network
M552 P0.0.0.0 ; Un-comment for DHCP
M555 P2 ; Set output to look like Marlin
M575 P1 B57600 S1 ; Set auxiliary serial port baud rate and require checksum (for PanelDue)

G21 ; Work in millimetres
G90 ; Send absolute coordinates…
M83 ; ...but relative extruder moves

; The following section is not required for Firmware V1.09r and above
; Turn off fans: by default PWM fans on Duet V0.8.5 are inverted
; M106 I1 ; fans are inverting
; M106 S0 ; Turn off Fan 0

; Movement section

M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M574 X2 Y2 Z2 S1 ; set endstop configuration (all endstops at high end, active high)
;*** The homed height is deliberately set too high in the following - you will adjust it during calibration
M665 R106.156 L215 B85 H246.073, X-0.501 Y1.067; set delta radius, diagonal rod length, printable radius and homed height
X2.53 Y0.90 Z-3.43 ; put your endstop adjustments here, or let auto calibration find them
M92 X80 Y80 Z80 ; Set axis steps/mm
M906 X1000 Y1000 Z1000 E800 I60 ; Set motor currents (mA) and increase idle current to 60%
M201 X1000 Y1000 Z1000 E1000 ; Accelerations (mm/s^2)
M203 X20000 Y20000 Z20000 E3600 ; Maximum speeds (mm/min)
M566 X1200 Y1200 Z1200 E600 ; Maximum instant speed changes mm/minute

; Heater and thermistor section

;*** If you have a Duet V0.6 board NOT stickered "4.7K" change R4700 to R1000 to the following M305 commands. Leave at R4700 for all Duet V0.8.5 boards
M305 P0 T100000 B3950 R4700 H0 L0 ; Put your own H and/or L values here to set the bed thermistor ADC correction
M305 P1 T100000 B4388 R4700 H0 L0 ; Put your own H and/or L values here to set the first nozzle thermistor ADC correction. DC42 recommends 4388 for E3D V6 with Semitec 104-GT2 thermistor
M305 P2 T100000 B4388 R4700 H0 L0 ; Put your own H and/or L values here to set the second nozzle thermistor ADC correction.
M570 S180 ; Hot end may be a little slow to heat up so allow it 180 seconds
M143 S285 ; Allow up to 285°

; Tool definition section

M563 P0 D0 H1 ; Define tool 0
G10 P0 S0 R0 ; Set tool 0 operating and standby temperatures
;*** If you have a dual-nozzle build, un-comment the next 2 lines
;M563 P1 D1 H2 ; Define tool 1
;G10 P1 S0 R0 ; Set tool 1 operating and standby temperatures
M92 E402 ; Set extruder steps per mm

; Z probe section

;*** If you have a a switch as a zprobe instead of an IR probe, change P1 to P4 in the following M558 command
M558 P1 X0 Y0 Z0 ; Z probe is an IR probe and is not used for homing any axes
G31 X0 Y0 Z1.47 P500 ; Put your own value of Z-probe height here during calibration. Z1.55

; Epilogue

;*** If you are using axis compensation, put the figures in the following command
M556 S78 X0 Y0 Z0 ; Axis compensation here

M208 S1 Z0.0 ; set minimum Z - can be negative but not recommended. Use G92 instead.
;
M501
T0 ; select first hot end
[/c]

1. Delta (Kossel Mini T3DP3D)
2. https://www.thingiverse.com/thing:2323213/#files -> Apple-Watch-Phone-Stand_V7.0.stl
3. there are no lost steps. No debugging output from USB logging and M122 didn't show any problems

It seems that after finishing the two solid layers every new layer gets skewed. With 1.20beta8 I could finish the print without any problems.

Something is definitely odd with this firmware release.
First image 1.20beta10, totally messed up. Second one 1.20beta8, all going well until now!

@dc42:

It appears that the dead time found by auto tuning was 2.1 seconds, which is suspiciously low. What type of hot end is it?

Genuine E3D V6 with supplied standard thermistor.

I have a strange issue with heater auto tuning and current stable firmware 1.19 (2017-08-14).

Performing auto tuning for my heater with M303 H1 tunes to 200° C what is pretty similar to my default printing temperature (195°).
The values written to config-override.g are: M307 H1 A397.5 C173.2 D2.1 S1.00 B0
When printing with those values after some time the temperature starts fluctuating and ends with a heater fault.

After removing the model from config-override.g and rebooting the duet the output from M307 H1 is totally different:
M307 H1
Heater 1 model: gain 340.0, time constant 140.0, dead time 5.5, max PWM 1.00, mode: PID
Computed PID parameters for setpoint change: P13.4, I0.095, D51.4
Computed PID parameters for load change: P13.4, I0.949, D51.4

Neither in config.g nor in config-override.g any other M301/M307 entries can be found.

What can be the cause for the temperature fluctuations with the values obtained from PID auto tuning?

I ordered an assembled kit (screwmount version) and I‘m very curious how it will perform compared to the IR sensor (tilt problems etc.)

I didn’t find a dedicated effector design for my Kossel Mini (Think3DPrint3D). What will be the best way to mount the piezo20, just screw underneath the original effector?

I made a lot of more tests and for me the problem seems to be related to the speed difference between infill and walls or between inner outer wall(s).
When printing the object with constant speed, even high one (e.g. 80 mm/s), for all features the quality is better than with different infill/wall speed.

Also printing more walls is not helpful but identical speed for all walls will improve the quality as well.
In summary my printer, hotend (E3D V6) or settings can not handle speed changes well with respect of constant extrusion.

As far I understand pressure advance should be a solution for such issues however not for me (tried various settings).

My solution for now: infill at 80 mm/s, three walls at 40 mm/s.