Controlling a Cetus3D with Duet3D 0.8.5

fotomas

dsmudger

I would say these are major steps

Homing switches (I use a microswitch for X and an old dc42 IR sensor for Z and Y)
Make adapters or get new cables to stepper motors
Make adapter or new cable for hot end
Power supply (I am using the original Cetus power supply)
Configure the Duet3d (steps/mm and heater values you can see above, the rest I think may vary in your case)

Original connectors can be forced into the Duet board, but I ended up making adapters both for the steppers and the hot end. Pictures below show before the adapters during "proof of concept phase". On the hotend it self I made a new board using experimental circuit board and matching connectors. There was too much interference in the ribbon cable for the signal from the IR board so I added an ethernet (twisted pair) cable for that.

If there are any questions I would be happy to help.

dsmudger

Thanks a lot, that's beyond useful.

Cetus MK3 already has 3x homing switches, so sounds like I might even already have all I need.
Adapters seems the right way to go so it's easily reversible, but eh, 'ain't gonna need it '.
Duet 2 Wifi came with a little bag of JST connectors; if I'm lucky, the metal crimp terminals might be the same. If so I'll just need to change the plastic shells over (while carefully counting on my fingers which colour goes to which pin). If I'm extra lucky and Cetus doesn't change their wiring too often, maybe it'll even match your photos and help confirm I'm on the right track

Big thanks again for that, I'll try to post something once I get things going

cookie

@dsmudger I just got my MK3 running and the Duet Wifi is laying around. Seem like I’ve to figure out the right crimping tools or learn how to crimp without them. I’m so novice when come to wiring works. Will keep you update when there is progress.

Thanks

A Former User

@dsmudger

re adapter: https://www.thingiverse.com/thing:3465278 is what i did for what may be the same "problem"

And JST XH terminals which Tiertime use aren't compatible with the molex picoblade, you will need to replace terminals, or as I did, buy male JST XH and make adapters just to make it reversible.

cookie

@fotomas said in Controlling a Cetus3D with Duet3D 0.8.5:

On the hotend it self I made a new board using experimental circuit board and matching connectors.

Hello, @fotomas

I'm working on MK3. The X,Y,Z motors and endstops are working as it should now. But when come to 16 pin connector wiring to hotend's motor, heater, thermistor and fan .. how you figured out which is which?

Thanks,
Cookie

fotomas

Dear @cookie

That is quite easy.

Just measure the connections between the Control board end and the daughter board that has separate connections for each "thing". Thermistor, stepper motor, fan, heater. If I remember correctly the hearer uses double wires for both + and -, most likely to increase the cable area.

A Former User

They used the same layout on my Up Mini 2. Doubling the heater wires to increase current carrying capability of both wires and connectors. From your picture they use the same pinout as well.

cookie

@fotomas thanks!

I spend a few hours figured out, I’m a novice when come to electronic. I tried mapping out the circuit board and use thermistor to check each pair connectivity, then could identified them all

Then, Cetus use PT100 as thermistor. Did you swap out to something else or buy PT100 daugther board?

Also, you get new heater or not? And did you splice the wire for double heating pin, right? Still not sure how to do it right ..

fotomas

@cookie

I'm using the original cetus thermistor. It works well after finding the correct values for it.

I do not think a negative B value is common.
M305 P1 R4700 T112 B-425 C7.060000e-8

dc42

@fotomas said in Controlling a Cetus3D with Duet3D 0.8.5:

@cookie

I'm using the original cetus thermistor. It works well after finding the correct values for it.

I do not think a negative B value is common.
M305 P1 R4700 T112 B-425 C7.060000e-8

Looks like you are using a PT100 but you have connected it directly to the thermistor input. This will give you a very poor resolution and you should use the PT100 daughter board instead. However, if you want to use a direct connection then I suggest this:

M305 P1 X501 R47000

This says you are using a PT1000 sensor, but inflates the series resistor value by a factor of 10 to compensate for the fact that you are actually using a PT100.

arcadeperfect

Hi guys great thread!

I have a couple of questions -

Why do you think they shipped the cetus with 38 ohm steppers? Is there some reason to use high resistance motors?

Is there any advantage to the mark 3 if you're just going to rip out the electronics?

Thanks

Ted

Hello
I'm also replacing the main board of my Cetus MK1 with a Duet Maestro.

I'd like to run both the mainboard and the original heatbed with the original 19V PSU that came with the Cetus. The original main board did limit the current or voltage of the heatbed somehow to not overburden the small PSU. It is that way limited to around 60 °C. For 100 °C it has a connector for an external PSU with more power. As I'm fine with that temperature I want to ask you if it is possible with the Maestro to limit the current or voltage for the heatbed as well? I don't want to destroy my PSU or risk the print to fail due to an underpowered Maestro where the current is sucked away by the heated bed.

If it is not possible, what PSU dimension do you recommend for the Cetus? I wonder if the MeanWell HLG-320H-24A is big enough, even for 100°C later on?

A Former User

@ted said in Controlling a Cetus3D with Duet3D 0.8.5:

As I'm fine with that temperature I want to ask you if it is possible with the Maestro to limit the current or voltage for the heatbed as well?

It is only possible to limit the average power, by means of controlling the maximum duty cycle of the PWM signal for the bed.

https://duet3d.dozuki.com/Wiki/Gcode#Section_M303_Run_heater_tuning
https://duet3d.dozuki.com/Wiki/Gcode#Section_M307_Set_or_report_heating_process_parameters

P parameter in M303 and S paramterer in M307

Veti

if you get an external mosfet for the hotbed its easy to use 2 power supplies. You can even use different voltages that way.

Ted

Thanks for the fast answers! I then will buy a new PSU. I go for a one PSU for everything solution.

Are 320 Watts of the HLG-H320-24A enough for that small heatbed and then 100°C? Next would be 480 Watts and much more expensive. I prefer the HLG series as it works with passive cooling.

Veti

there is the Meanwell UHP-350-24 in between.

Ted

I now migrated to an Duet Maestro to using a absolute silent and not even warm HLG-H320-24A PSU.

While I'm very happy with the basic setup I have problems with those original high impedance motors. The problem is the same as mentioned before: The motors are getting very loud when moving. For me that happens only for fast travels starting with > F270 movements (G1 Z50 F270 S1 at 256-microsteps and 1359,68 step/mm). Altering the relevant depending values this is regardless of microstepping mode (1-256) and current (200-1400 mA) chosen.

With command G1 Z50 F270 S1 the movent can't be heared at all.
With command G1 Z50 F273 S1 it is a random mix of loud and absolute silent movements intervals.
With command G1 Z50 F275 S1 it is a loud all the time.

I've attached my config.g to this post: 0_1556283965533_config.g

My motors have something about 30-31 Ohm per phase.

Do you have any idea?

Veti

M350 X256 Y256 Z256 E16 I1 do you really need this? this might put quite a high strain on the cpu. 16 with interpolation should be fine in most cases

M203 X1000 Y1000 Z1000 E1000 Thats a very high z speed.

You Probably want to adjust the Hybrid Threshold V for the motors to not go into spreadcycle at higher speeds
see https://duet3d.dozuki.com/Wiki/Gcode#Section_M569_Set_motor_driver_direction_enable_polarity_and_step_pulse_timing

Ted

@veti said in Controlling a Cetus3D with Duet3D 0.8.5:

Hybrid Threshold V

Was hard to find out what you meant what you meant with Hybrid Threshold V but found the relevant parameter. It is working now – In absolute silence! Thanks a lot for the hints!

I set the threshold to 100 (whatever unit this is) by extending the already in my config existing command M569 P0 S0 to M569 P0 S0 V100 for all my axes (P0 up to P4).

I not completely understood how this threshold works. Especially I'd like to know why someone would want to switch to Spread Cycle for higher speeds? Higher torque?

Veti

@ted said in Controlling a Cetus3D with Duet3D 0.8.5:

I not completely understood how this threshold works. Especially I'd like to know why someone would want to switch to Spread Cycle for higher speeds? Higher torque?

if you enter M569 P0 you will see the speed at which the driver switches from stealthchop to spreadcycle.
however at high speed (i think above 60mm/s) the switch can cause layer shifts.

to enable spreadcycle all the time use the D2 option