Anyway to get the heatbed heat faster?

Anyway to get the heatbed heat faster? I took few minutes to ten minutes.

Easiest way I think is to increase the power supply voltage a bit. It won't make it that much faster, but at least a little bit. Either by hacking the Alpine PSU, or replacing it. I think just applying a few amps of "dummy load" to the +5V rail of the stock PSU would increase +12V stability under load, but I haven't tried it out.

Heating power goes as the square of the supply voltage. Increasing the voltage by 10% (from 12V to 13.2V) will decrease the time taken to reach PLA bed temperatures by around 20%. When heating the bed to higher temperatures that are close the the maximum achievable by the bed heater, increasing the voltage will speed up the process even more.

If you are comfortable doing mains wiring, you can use a 12V 300W PSU of the sort readily available on eBay, and print a cover to guard access to the terminals like this one that I made. These power supplied are voltage-adjustable over a small range.



Edited 1 time(s). Last edit at 07/28/2014 05:28AM by dc42.

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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].

Upgrading to this power supply is it directly power to the Duet?

I just run with a modded Alpine PSU which connects in the same way (via that power adapter board). I guess dc42 just runs the power straight into his Duet without that.

Quote
antlvk
Upgrading to this power supply is it directly power to the Duet?

Yes, I feed the 12V output straight into the Duet (and also the DueX4 because I have one of those too).



The terminal block I am using is on the large side, but at the time it was a choice of 5A or 30A.

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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].

300w are same as 20a 12v powr supply?

300W is 25A @ 12V. A 20A supply would probably be sufficient, but the 25A supply costs hardly any more. I now have a second nozzle, heater and stepper motor on my Ormerod, so I am glad I went for the 25A one.

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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].

I bought a 30A 12V LED PSU (looks the same as DC42's photo) but mine has a small pre-set that allowed me to adjust its output voltage, and I am running my Ormerod from 14V. The fan is about the only thing that might be damaged by over-voltage, but (touch wood), it seems to cope OK with 14V. I print ABS so need a hot bed, and the original PSU struggled, so I printed with the bed at 100 deg, which took well over 30 minutes to reach. I now use 110 deg, which it reaches in under 15 minutes.

Dave
(#106)

means everything that connected to the due board also have more voltage.... ok.... next project.

Quote
antlvk
means everything that connected to the due board also have more voltage.... ok.... next project.

The Duet is rated to run at up to 35V so not a problem. The hot end heater will put out more power on 14V so its PID parameters may need adjusting, but my 0.78e and later firmware supports a new S parameter in the M305 command to make this easy. So as Dave says, only the fan is potentially a problem. Putting a couple of 1N4001 diodes in series with it would bring the voltage from 14V back down to about 12V.

The 12V 25A PSU that I bought has a preset to adjust the output voltage too, but currently I don't print ABS so I still have it set to 12V.

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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].

I'm not sure if this works on the default MK2a heatbed but I upgraded to a MK3 Alu heated bed which I hooked up 24v to the 12v connections on the heated bed, and currently I have an SSR controlled by the heatbed output powering a secondary 24v power supply(didn't go full 24v yet as I am not certain if all my components can handle it). It heats to 120c in about 2 mins tops. Another plus from running a secondary PSU is that I no longer get the voltage variance spike when the heated bed cycles on and off. I'll try 24v on the spare MK2a I have and I'll update on the results.

Prefinity, any photos of your mk3 connection, sounds interesting

and i've ordered an 12v 360w 30a psu

Edited 1 time(s). Last edit at 07/30/2014 01:05AM by antlvk.

Prefinity, be careful! I wouldn't put 24V through the Mk2a heated bed. It has a resistance of around 1.3 ohms, so at 24V will draw 18 Amps and 443 Watts! I have no idea what will happen to the PCB, and you'll definitely need to make sure the wiring can cope; I'm not sure the ribbon cable will, and may heat up quite significantly.

Ian
RepRapPro tech support

You can also better insulate the underside of the heat bed so less heat is wasted. I taped the carbourd to the heatbed and that seemed to help. Iv also replaced the wieres from the Duet to the bed with to try to reduce the resistanc but im not shore if its made a much diffrence.

Heat Gun?

regards
Andy

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Ormerod #318
www.zoomworks.org - Free and Open Source Stuff

Quote
kwikius
Heat Gun?

regards
Andy

It would certainly improve the heating time - but I think a significant risk of inadvertently melting some of the printed parts. It would also be easy to crack the glass and/or end up with cold spots on the bed.

Dave
(#106)

Some folks on this forum who print ABS have said that they put a heat-insulating mat on top of the heated bed while it heats up.

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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
dc42
Some folks on this forum who print ABS have said that they put a heat-insulating mat on top of the heated bed while it heats up.

That's so routine for me now that I had completely forgotten to mention it! I'm still using the white foam that the original Ormerod ATX power supply was packed in. I just plonk it over the bed while it is heating, and remove it just before homing.

Dave
(#106)

HI Dc42,
do you have a name for those connectors/plug?

If you mean the large round connector on the PSU enclosure, it's a 20A Neutrik connector.

Edited 1 time(s). Last edit at 03/17/2015 05:45AM by dc42.

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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].

I have just modified my Ormerod 2 to allow for faster heating. I have removed the MDF/wood rectangle that makes-up the bed support as well as the aluminium heat spreader. Doing this makes the bed a lot lighter and it reduces the thermal mass considerably. I have then used an aluminium foil blanket (just a folded rectangle) to cover the bed during heating. The result is that the glass bed (with the standard power supply) heats up to 115 degrees in 10 mins. The picture frame clips only just grip the glass onto the bed heater, but everything seems stable enough at the speeds I am printing at (I am using a 0.3mm nozzle since I need high resolutions). I am struggling to see the need for the MDF bed support or the aluminium heat spreader - my son's Ormerod 1 has been running in a very similar configuration for sometime (i.e. without the heat spreader) without any problems. I have just ordered a 30W silicone heating mat from RS (300oC limit) to incorporate into the aluminium blanket to increase the heating rate. I will report back with the results when it arrives.....

Quote
ChristofSchwiening
I have just modified my Ormerod 2 to allow for faster heating. I have removed the MDF/wood rectangle that makes-up the bed support as well as the aluminium heat spreader. Doing this makes the bed a lot lighter and it reduces the thermal mass considerably. I have then used an aluminium foil blanket (just a folded rectangle) to cover the bed during heating. The result is that the glass bed (with the standard power supply) heats up to 115 degrees in 10 mins....

You could also try some reflective material as isolator under the bed, I changed the standard cardboard to radiator foil and sealed it with kapton tape around the corners, heat up time from 15 to 110C is 10 minutes with 11,2V measured on the Duet in (Alpine PSU)




..and no I don't see the aluminium heat spreader do any good either, lost that many moons ago

Erik

So, the 30W (RS 731-366) 150x200mm blanket placed on top of the heated bed (with tin foil above) has decreased the warm-up time. It now takes 7 mins to go from room temperature to 110oC. I have measured the voltage going to the heated bed and it is 11.37V. So, there is scope for a bit more power there....I guess I need to break open the power supply and see if there is a pot to tweak!

Quote
ChristofSchwiening
I guess I need to break open the power supply and see if there is a pot to tweak!

If it's an ATX supply supplied with Ormerod 1, no - although there us a thread on this forum dating from some time last year describing how to modify an ATX PSU to increase the voltage and improve the regulation on the 12V rail. If it's an Ormerod 2 with the Chinese LED-type PSU, I would expect there to be be a pot, accessible through a hole close to one end of the terminal block, and RepRapPro should be able to tell you more.

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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].

Yep, just tweaked the pot on my Ormerod 2 up to 13V (when the bed is hot). It does make a difference to the clamping of the bed temperature during the print. It nows holds solid at 130 degrees C during the print. The adhesion with ABS is now excellent even without any acetone treatment - in fact it may be too good!