Interested in duet, some info needed

Hello
I'm revisioning my corexy printer
The one I'm using is my first I built ever and I'm not a guru in 3d printing.
Now my electronic is Ramps/arduino mega 2560, nema17 on each axis and extruder, inductive proximity sensor for z probe, 2 PSU - ATX 12V 12A for electronics and 24V 15A for heated bed, with a power expander module (ssr) to control heated bed.
Marlin Kimbra as firmware.

My z probe is not reliable so I ordered a BLTouch to use for z probing/homing.
Then I wanted to have a little more juice on XY and I ordered 2 nema17 59Ncm
Then...
Then I was looking for some board that could work at 24V so I can use only one PSU (24V 720W) for electronics and HB and by the way I was looking for 32 bit.
One improvement I was thinking to do in next future was octoprint and I discovered Duet, that has almost all I was looking for..

I think It's a really interesting board and I really like the way it's controlled.

Some questions before I click on trigger..

I saw two version 0,6 and 0.8.5 (and I read at the end of this year a newer version will be available..)

0.6 should be enough for my corexy, but will it be supported in the next future or not?
what are the advantages of 0.8.5 over 0.6 except of course one driver more..? I saw 0.8.5 has voltage regulators on bord..
Will bltouch work with these boards?
Are both 0.6 and 0.8.5 controllable by gcode for current/microsteps?

And, at last, do you think printing quality could be increased by using these 32bit boards?

Thanks
Pietro

Edited 1 time(s). Last edit at 05/30/2016 05:13PM by pieri70.

In brief:

- For the improvements in the 0.8.5 board over the 0.6 board, see section "New Features in Duet 0.85" at [www.think3dprint3d.com]

- I know that people are using IR, FSR, microswitch and inductive Z probes with the Duet, but I haven't heard of anyone using bltouch with it. I see that bltouch needs 5V power, which the Duet can provide; but does it also need a 5V control signal? The control signals on the Duet are 3.3V (as on most 32-bit boards). I suspect that bltouch may need additional firmware support.

- Motor current is controlled by the firmware, configured in the config.g file on the SD card. Microstepping on the Duet 0.6 and 0.8.5 boards is set to x16. It can be reduced by cutting traces on the PCB, but it is very rare to need less then 16x microstepping when using a 32-bit controller board.

- There are lots of Duet 0.6 boards in the field, and we will continue to support them in firmware.

- Whether print quality would be improved will depend on whether your existing controller board and firmware is able to keep up with the printer, and whether your printer would benefit from additional firmware features supported by the Duet, such as extruder pressure advance.

You might like to ask about experience with the Duet in CoreXY printers on the CoreXY forum.

HTH David

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

The BLtouch is an interesting idea, notably because it will be quite insensitive to temperature.
There is a demo with Smoothie, so I suppose it does accept 3.3V signal.

It is told that it uses the same signal as an RC servo, then it qualifies this signal as PWM, while servo signal are not PWM, but specific signals. The time diagram is not clear, so I think some questions shall be asked to the designers. And it most probably needs additional firmware.

Just a note about Duet 0.6. From user viewpoint, it works like the Duet 0.8.5 (I have both) but you have more possibilities of extensions on the 0.8.5. Even if you don't want a second extruder, its associated hardware could be used for a chamber heater, or another temperature control on the hotend, or an ambient temperature control.
You can use the second controlled fan to cool the hotend instead of having a fixed fan (while some prefer to have fixed voltage fan for the hotend for safety reasons - thats include me).
In that hobby, you always do unplanned things.
And there may be not many genuine 0.6 still on sale (the remaining stock of RepRapPro).

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

Quote
dc42
I see that bltouch needs 5V power, which the Duet can provide; but does it also need a 5V control signal? The control signals on the Duet are 3.3V (as on most 32-bit boards). I suspect that bltouch may need additional firmware support.
.....
HTH David

Quote
PRZ
The BLtouch is an interesting idea, notably because it will be quite insensitive to temperature.
There is a demo with Smoothie, so I suppose it does accept 3.3V signal.
It is told that it uses the same signal as an RC servo, then it qualifies this signal as PWM, while servo signal are not PWM, but specific signals. The time diagram is not clear, so I think some questions shall be asked to the designers. And it most probably needs additional firmware.

Thanks David and Pierre
BLTouch has a line that must be connected to endstop pins (black and white in picture) and a servo wire that has negative, +5V and servo signal.


I think the BW one is a simple circuit open/close (switch) so any voltage is good because it takes the signal coming from the endstop pins and takes it to GND.
The +5V must be provided because it powers the solenoid that moves the pin
Then a servo signal must be provided

Here is the description

Quote

BLTouch uses the same servo signal which used in previous servo line.

■ Solenoid Push-pin Up ➡ servo signal 90Degree(ex : M280 P0 S90 ) ← PWM
■ Solenoid Push-pin Down ➡ servo signal 10Degree(ex : M280 P0 S10 )
■ Manual Self-test ➡ servo signal 120Degree(ex : M280 P0 S120)
■ Alarm Release ➡ servo signal 160Degree(ex : M280 P0 S160)

※ BLTouch can be operated in the following condition.

- One PWM (or Software PWM) for control
- One I/O for Zmin
- GND and +5V power

However, Firmware updating might be needed on a case.

Quote
PRZ
Just a note about Duet 0.6. From user viewpoint, it works like the Duet 0.8.5 (I have both) but you have more possibilities of extensions on the 0.8.5. Even if you don't want a second extruder, its associated hardware could be used for a chamber heater, or another temperature control on the hotend, or an ambient temperature control.
You can use the second controlled fan to cool the hotend instead of having a fixed fan (while some prefer to have fixed voltage fan for the hotend for safety reasons - thats include me).
In that hobby, you always do unplanned things.
And there may be not many genuine 0.6 still on sale (the remaining stock of RepRapPro).

Ok, but in case I want to extend functionalities on duet 0.6 I can buy a Duex4, right?

I use Hotend fan always at 100% so a 12V source or 24V fans should be used...


And what do you think about powering the whole system by a single 24V 30A PSU?
Will the stepper torque increase at high speed or do I risk to get interference between Heated Bed power consumption and stepper?
I mean, when HB turns on at 100% less current is available to stepper motors..

My HB is rated at 210W, let's say 24V 10A, may be 20A-25A PSU could be enough...

And of course I should change Hotend heater and Fans...

Thanks again!

Ah, with this info, it is more clear.
The M280 code (RC servo command) does not exist in RepRap Firmware, but it may be a nice addition as RC servo are a low cost manner to motorise some stuff.

The command signal of a servo is a repeated signal of length 1000 microseconds (servo at -90°) to 2000 microseconds (servo at +90°), every 20 ms. from 500 microsecond to 2500 microsecond, angle goes from -135 to +135°.
That is a frequency of 500 Hz. 1000 microsecond will be a percentage of 5% and 2000 microsecond is 10%.
So, in fact, it is indeed a PWM signal of 500Hz, varying from 5% to 10% for 180° travel.
5% corresponding to the -90° left position 7.5% the center position and 10% the+90° right position.

The Marlin version of command M280 don't use negative angle, but I did not found the offset they define (not documented on the RepRap wiki...) and so, what does correspond to center and given angles?

The Smoothieware version of M280 just use percentage, so M280 S5 is 90° left and M280 S10 is 90 right.

What you can try with existing firmware/hardware is to use the 2nd fan output, supplied in 5V on a resistor (see schematic for 5V fan) and try to control it with the M106 command (fan control). I don't know if it is sufficiently precise, but I assume the BLTouch is somewhat tolerant to poor signals as it work in on/off mode.

With this setup M280 S5 on smoothie will be M106 P1 S0.05, so look the Smoothie variant, as the given example of code is for Marlin.

A firmware mod might be better, I think one of the connector probe pin can be used for PWM.
That is a point for the Duet 0.8.5, which have a dedicated probe connector, while for Duet 0.6, you have to install 'flying wires' for an IR probe.

Edited 3 time(s). Last edit at 05/31/2016 06:56AM by PRZ.

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

Mhhh
for sure duet 0.8.5 is a really nice and powerful board..
I made a simulation on Think3DPrint3D website and it will cost around 150 euros delivered to me.. And it's a little out of budget for my homemade printer (it will be 250E complete with actual setup..)
I thought to buy 0.6 from replikeo, but then I discovered it is a chinese clone and often there were problems with their boards..

So I'm still looking around.
Today I discovered also Alligator board has RRF ported to work on it.

I think I need more study..

Thanks!

Note than on the Duet 0.8.5 expansion connector (not on the Duet 0.6) the Fan1 signal is available on pin 18, so you may wire directly this pin to the servo signal. However, it is probably inverted, so you may use 'M106 P1 I1' to invert signal

Edited 2 time(s). Last edit at 05/31/2016 07:35AM by PRZ.

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

Duet 0.8.5 is also sold by builda3dprinter.eu [builda3dprinter.eu] in the Nederlands, so you may save a few euros on shipping, however, they seems to be always out of stock. You may ask them.

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

We are there..
110E ex vat + shipping..

Thanks anyway!

@pieri70
So, did you buy the Duet 0.8.5 and wired it up with BLTouch?
I am very interested in your progress since I am building an CoreXY and dont know what board to use and I really like the idea of the BLTouch.
Regards
Per

Hi per
no I went for a radds 1.5 with arduino 2 and marlin kimbra firmware.
that fw allready had all needed to control servos
I use octoprint to remotely control my printer
I connected successfully bltouch and it moves correctly its pin.

I'm making test on the bench, nothing set to work with radds and bltouch