Questions on DUET board usage

Hi,

I have some questions related to the DUET and DWC.

1. Whenever I am printing any gcode file, in DWC, the total layer is always showing as '20'. I am using slic3r. Even for big files, having more than 200 layers it is showings as printing 'Layer :114 of 20'. Please check the attached file.
2. What is the maximum time printed with a DUET board? Means how many hours of print you can go with a DUET without any issues, with and without heat bed?
3. I am using a 12V, 40mm cooling fan on the top of the DUET board. Is it enough to cool the board when using Heatbed over a long print time. Ex. more than 24 hours of print? (Just I was reading another Topic, in which DC42 has stated that use the fan on the underside of the board to cool it properly.) My design is like that, the board is supported by a Acrylic at the bottom. How can I overcome this problem.
4. I am planning for a Auto nozzle cleaning in my printer. Currently using Nylon brush for cleaning the nozzles. This nozzle cleaning will be used whenever there is a pause / resume function. What will be the best material to clean the nozzle without damaging the nozzle.
5. If I use a 13.5V power supply to power my DUET, and the fans and heater cartridge are 12V, then will it affect these components in a long run?



Thanks

Edited 2 time(s). Last edit at 08/08/2016 06:43AM by selva_tvi.

1. This happened because the firmware thinks the object height is 5mm. My guess is that you have G91 followed by G1 Z5 in your end gcode, and this is confusing the firmware when it tries to work out the object height. A workaround is to add a comment starting with ";E" or "; E" to that G1 line.

2. I have done a 10 hour print and I expect others have done longer.

3. The bed heater mosfet runs cool on the Duet, so cooling it isn't necessary. If your heat bed takes much more than 10A then there is a PCB trace that can get quite warm, especially on the Duet 0.6. See [duet3d.com] for more. The best way to use a fan is to have it blow air along the underside of the board. See [duet3d.com].

4. This isn't Duet-specific, so you may get a better response if you re-post this on the General forum.

5. Heater - should not matter. Fans - ideally if you go above 13.2V then you should connect a silicon diode (e.g. 1N4001) in series with each fan to reduce the voltage a little. In practice, some people run 12V fans at 14V with no apparent issues.

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].

You haven't specified which board you have, so I'll give you my experience with the 0.6. I'm running it on 24V with the e3d Varipower heated bed (the bed from the BigBox) and the e3d V6. My board is suspended on an open-bottom mount (clicky!) with no active cooling and stays quite cool. As a precautionary measure to prevent the trace from burning out, like dc42 said, I soldered an extra wire between the positive bed terminal and positive power in. See most of the way down this thread (clicky!). Of course, this mod is only for the Duet 0.6, I am quite confident in my abilities to modify a board, and was most likely unnecessary. I did it only because it took me less than five minutes and couldn't hurt.

The longest print I've run was 43 hours straight without issue. Yes, that's what that whole lead up was for, haha. You don't have to worry about long prints. The Duet boards handle them just fine.

I semi-regularly do prints that are longer than 100 hours with a duet 0.8.5 using a heated bed. I've never had the board cause a print failure that wasn't due to a wiring fault of my own. (intermittent external 5v connection).

Thanks for the suggestions.

@Dc42 :

1. For the layer height, I tried the following, but didnt work. Please correct me.

End G-code:
M104 S0 ; turn off temperature
M140 S0; turn off heat bed
G1 X25 Y150 ; Move axis
G91 ;
; E
G1 Z5
M84 ; disable motors


@Masterjuggler : I am using DUET 0.6 board from Replikeo. I checked the photos. I will modify accordingly. Thanks

@n8bot : Thats great. Any photos of such a lengthy print.

Just to be clear, the only reason I did modify the board was because I trusted myself to do it correctly, and I'm running a 200x300mm bed at ABS temps. If you don't have a high power requirement (over 10A), you really don't need to do this.

Quote
selva_tvi
Thanks for the suggestions.

@Dc42 :

1. For the layer height, I tried the following, but didnt work. Please correct me.

End G-code:
M104 S0 ; turn off temperature
M140 S0; turn off heat bed
G1 X25 Y150 ; Move axis
G91 ;
; E
G1 Z5
M84 ; disable motors


@Masterjuggler : I am using DUET 0.6 board from Replikeo. I checked the photos. I will modify accordingly. Thanks

@n8bot : Thats great. Any photos of such a lengthy print.

You need:

G91
G1 Z5 ; E

---

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].

Quote
selva_tvi
...

@n8bot : Thats great. Any photos of such a lengthy print.

I think this one was just around 100 hours, but it was under-sized so picture this but a bit bigger (and higher mesh resolution):



more: [imgur.com]

@ Dc42 - Thanks a lot.. That worked easily.


@n8bot - Wonderful. I hope post processing has been done. What is the material? And speed?