Controlling a bed with secondary supply
January 28, 2016 02:09PM
I am considering using one of these

[www.ebay.com]

one the 12v terminal of the duel (new version) to control a 300x300 bed with secondary 24v supply (assuming i manage to find a 24v kapton or pcbs heater). Would it work? How do i change the firmware to use bangbang instead of ppm?

Thanks.


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Re: Controlling a bed with secondary supply
January 28, 2016 02:15PM
The bed uses bang bang control

Dave.
Re: Controlling a bed with secondary supply
January 28, 2016 02:18PM
I though it was pwl, ouch. All these years of having the wrong assumption.


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Re: Controlling a bed with secondary supply
January 28, 2016 05:53PM
Quote
Fpex
I am considering using one of these

[www.ebay.com]

one the 12v terminal of the duel (new version) to control a 300x300 bed with secondary 24v supply (assuming i manage to find a 24v kapton or pcbs heater). Would it work? How do i change the firmware to use bangbang instead of ppm?

Thanks.

The clicking sound will drive you mad. I suggest this instead [reprap.me], or this [www.auberins.com]. Both should be good, although I haven't used either, I use an AC mains voltage bed heater and a DC-AC SSR. Avoid the cheap DC-DC SSRs you get on ebay.

If your 24V bed takes no more than about 14A, your alternative is to run the whole machine from 24V and drive the bed heater from the Duet. You will need to change your hot end heater cartridges to 24V (which will be tricky if you have RepRapPro hot ends with 5mm cartridges, but easy if you have standard 6mm cartridges), and your fans to 24V.



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].
Re: Controlling a bed with secondary supply
January 29, 2016 01:44AM
Thanks dc. I am going to drive the bed with a. Led supply tuned up to 14v to a 12v kapton heater. last night I run into issues of realising 30x30 24v heater are not easily availabke in Europe.
I did not think of the noise actually ... Something to consider! Thanks.

Edited 3 time(s). Last edit at 01/29/2016 02:38AM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 29, 2016 09:50AM
Quote
Fpex
Thanks dc. I am going to drive the bed with a. Led supply tuned up to 14v to a 12v kapton heater. last night I run into issues of realising 30x30 24v heater are not easily availabke in Europe.
I did not think of the noise actually ... Something to consider! Thanks.

Using 12V to heat a bed of that size is a seriously bad idea IMO. These people [www.aliexpress.com] will make a silicone bed heater to your own size, voltage and power specifications, at a good price. They made me a 300mm diameter 240V 350W one for my delta.



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].
Re: Controlling a bed with secondary supply
January 29, 2016 09:56AM
I know ... 12v means waiting forever.
Somebody from another group was suggesting today to use a Keenovo silicon heated from 220v with external PID. Sounds like a good idea, even if it will be annoying to remember to turn on and off the bed, but for that size it maybe be best.

BTW this is for a duet 0.8.4 OB printer I am building. Not for an ormerod, i hope it is ok to discuss it here still.

Edited 1 time(s). Last edit at 01/29/2016 09:57AM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 29, 2016 10:48AM
Quote
Fpex
I know ... 12v means waiting forever.
Somebody from another group was suggesting today to use a Keenovo silicon heated from 220v with external PID. Sounds like a good idea, even if it will be annoying to remember to turn on and off the bed, but for that size it maybe be best.

No need for external PID, use a zero-crossing DC-AC SSR to control the 220V heater from the Duet. This is what I do on my delta printer. See the link in my signature for more. But be careful: it's easy to make the mains connections safe on a delta where the bed is fixed and the wiring can be hidden under it, but not so easy on a printer with a moving bed.

Edited 1 time(s). Last edit at 01/29/2016 03:36PM by dc42.



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].
Re: Controlling a bed with secondary supply
January 29, 2016 02:10PM
That's why I ordered a 24V DC bed for my new printer


Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.
Re: Controlling a bed with secondary supply
January 29, 2016 03:37PM
Good point. Having 220 moving around is not a good idea. Where did you get the 24v bed?

Edited 1 time(s). Last edit at 01/29/2016 03:38PM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 30, 2016 02:46AM
From the same guys dc42 linked above.

You only have to ask them and they will give you a special offer. Mine is based on the offer here: [aliexpress.com]

You have to tell them the size, voltage, wattage, if you want adhesive (thermal tape for connection) and a thermistor. I was an idiot not to choose a thermistor. I hope that will not be a problem later.


Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.
Re: Controlling a bed with secondary supply
January 30, 2016 02:53AM
Thanks,
I will ask them for a 300w version with a ntc 100k. Thanks. With adhesive is best.

You better ask them what they put as thermistor or I cannot see how to set up the firmware for it.

Edited 1 time(s). Last edit at 01/30/2016 02:59AM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 30, 2016 03:20AM
Normally you will get the standard Chinese thermistor:

M305 P0 R4700 H0 L0	B3950 T100000.0	; Put your own H and/or L values here to set the bed thermistor ADC correction

or for the older boards:

M305 P0 R1000 H0 L0	B3950 T100000.0	; Put your own H and/or L values here to set the bed thermistor ADC correction


Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.
Re: Controlling a bed with secondary supply
January 30, 2016 03:42AM
I prefer to know what i get ;-)
I just ordered a 300x300 24v 400W bed and a good SSR that can receive directly the 12v from the duet. I now need to find a proper supply.
Then I can put this printer aside ands try to fix my ormerod2

Thanks guys.

Edited 1 time(s). Last edit at 01/30/2016 08:11AM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 30, 2016 09:48AM
what about connecting nozzle to same power supply as heatbed, or would that just create more issues and chance of frying things. I dont know why I would like the hot stuff on one capable safe supply, and the other for just ramps
Re: Controlling a bed with secondary supply
January 30, 2016 09:53AM
Well, my (ordered) 30x30 plate is 400w, and later i might even upgrade to a 30x40 that will be even higher.
In these circumstances (and even not considering this printer mounts a kraken) i prefer to split supplies to avoid load issues.

Edited 1 time(s). Last edit at 01/30/2016 09:58AM by Fpex.


----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com
Re: Controlling a bed with secondary supply
January 31, 2016 01:53PM
Can anyone recommend a quick disconnect power connector that I can connect near the bed, so I can split when needed.
I need a few suggestions so I can find one that fits with the design.
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