New PSU
Posted by dmould
I've just replaced the PSU with the 30amp unit discussed in another thread. It has a voltage adjustment preset which I've set to give 14 volts on its output. The voltage across the bed heater is now 13 volts. I'll see whether the fan survives, but so far so good. The bed gets to 110 degrees in 6 minutes - which is a huge improvement on the 30 minute plus time I had been experiencing. The PSU is also more compact and quieter.
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Re: New PSU April 01, 2014 10:48AM |
Registered: 10 years ago Posts: 5 |
Do you power the RAMPS from the same 30amp PSU? I just purchased my first 3d printer kit and am trying to decide on a PSU. I'd like to power the RAMPS and heat bed from the same PSU but don't want to fry anything in the process. Did you have to take any special precautions with your setup?
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Re: New PSU April 02, 2014 09:00AM |
Registered: 10 years ago Posts: 2,472 |
Quote
The_Ross_
Do you power the RAMPS from the same 30amp PSU? I just purchased my first 3d printer kit and am trying to decide on a PSU. I'd like to power the RAMPS and heat bed from the same PSU but don't want to fry anything in the process. Did you have to take any special precautions with your setup?
The Duet has everything on one board and has one 12V input that powers everything. If you are using different electronics, check that everything you connect to the PSU can take the increased voltage (I doubt it will be a problem). On the Ormerod, the only component that is not rated to take more than 12V is the fan - which if necessary could be supplied via a simple inline analogue regulator - but it appears to survive on 14V so I have not done so.
Dave
(#106)
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Re: New PSU April 02, 2014 09:44AM |
Registered: 10 years ago Posts: 5 |
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Re: New PSU April 10, 2014 11:44AM |
Registered: 10 years ago Posts: 327 |
Hi guys,
Any idea what the total 12v draw is?
I got the 30amp supply from Ebay (it was only a quid dearer than the 25amp one) and I am trying to decide the best fittings/cable to use. I guessed from DC's github page that he was using one of these. They are 20amp, which suggests the total draw is less than that.
Regards,
Les
Any idea what the total 12v draw is?
I got the 30amp supply from Ebay (it was only a quid dearer than the 25amp one) and I am trying to decide the best fittings/cable to use. I guessed from DC's github page that he was using one of these. They are 20amp, which suggests the total draw is less than that.
Regards,
Les
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Re: New PSU April 10, 2014 12:01PM |
Registered: 10 years ago Posts: 145 |
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Re: New PSU April 10, 2014 01:32PM |
Registered: 10 years ago Posts: 76 |
As you are using the new power supply for a month now. How is the fan doing, is it still handle the 14V without problem.Quote
dmould
I've just replaced the PSU with the 30amp unit discussed in another thread. It has a voltage adjustment preset which I've set to give 14 volts on its output. The voltage across the bed heater is now 13 volts. I'll see whether the fan survives, but so far so good. The bed gets to 110 degrees in 6 minutes - which is a huge improvement on the 30 minute plus time I had been experiencing. The PSU is also more compact and quieter.
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Re: New PSU April 10, 2014 03:07PM |
Registered: 10 years ago Posts: 14,672 |
I calculated the maximum power draw to be less than 20A at 12V. I am using the 25A supply. If you turn up the voltage to make printing ABS easier and also increase the stepper motor currents, then I think the draw might exceed 20A but should still be below 25A unless you add extra extruders.
You can reduce the fan voltage back to 12V by putting a few silicon diodes in series with it.
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 can reduce the fan voltage back to 12V by putting a few silicon diodes in series with it.
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].
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Re: New PSU April 11, 2014 02:05PM |
Registered: 10 years ago Posts: 2,472 |
Quote
Chaisaeng
As you are using the new power supply for a month now. How is the fan doing, is it still handle the 14V without problem.Quote
dmould
I've just replaced the PSU with the 30amp unit discussed in another thread. It has a voltage adjustment preset which I've set to give 14 volts on its output. The voltage across the bed heater is now 13 volts. I'll see whether the fan survives, but so far so good. The bed gets to 110 degrees in 6 minutes - which is a huge improvement on the 30 minute plus time I had been experiencing. The PSU is also more compact and quieter.
No problems whatsoever (touch wood).
In case it is any help, I've attached the SCAD and STL files for the PSU cover I made. It has openings for a mains inlet and a 20 amp connector. The 20 amp connector I used has 4 pins, so I have used 2 pins for each side (+ & -), meaning that it should be able to handle 40 amps.
The parts I used are from Farnell (http://uk.farnell.com/) - part numbers 1856749, 1856747 and 1430808
Dave
(#106)
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Re: New PSU April 12, 2014 03:17AM |
Registered: 10 years ago Posts: 327 |
Nice work Dave,
Nice thinking about the 4 pole connector, I wish I had thought of that, although the dimensions and fixings look very close to the Neutrik one, so maybe I could swap if needed.
I have just starting printing my cover for the second time, I had to make a few changes. (I forgot to allow the thickness for the holes, so they are 2mm out and I have shaped it more to stop blocking some of the vents).
I'll post mine here too in case anyone is interested, once I have verified it.
Couple of questions?
Regards,
Les
Nice thinking about the 4 pole connector, I wish I had thought of that, although the dimensions and fixings look very close to the Neutrik one, so maybe I could swap if needed.
I have just starting printing my cover for the second time, I had to make a few changes. (I forgot to allow the thickness for the holes, so they are 2mm out and I have shaped it more to stop blocking some of the vents).
I'll post mine here too in case anyone is interested, once I have verified it.
Couple of questions?
- Why 3mm thick? I find 2mm is pretty rigid.
- How long did yours take to print?
Regards,
Les
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Re: New PSU April 14, 2014 03:12PM |
Registered: 10 years ago Posts: 2,472 |
Quote
Pointy
Nice work Dave,
Nice thinking about the 4 pole connector, I wish I had thought of that, although the dimensions and fixings look very close to the Neutrik one, so maybe I could swap if needed.
I have just starting printing my cover for the second time, I had to make a few changes. (I forgot to allow the thickness for the holes, so they are 2mm out and I have shaped it more to stop blocking some of the vents).
I'll post mine here too in case anyone is interested, once I have verified it.
Couple of questions?
- Why 3mm thick? I find 2mm is pretty rigid.
- How long did yours take to print?
Regards,
Les
I find that 2mm can flex, whilst 3mm feels a lot more solid for items where weight is not an issue. There can be a fair bit of twisting force applied when you're not too careful pulling the plugs out. I don't recall exactly how long it took to print - probably in the region of 4 hours or so at a guess.
Dave
(#106)
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Re: New PSU April 15, 2014 04:20AM |
Registered: 10 years ago Posts: 76 |
I brought a LED power supply intended to use for powering my ormerod.
Some how the one i got after dial up the pot i got max 12.7 V which is a lot less than yours.
(See the attach picture). Any way it was rated at 12v 350w. Is it having issue if i use it for ormerod.
Can it perform better than the supplied ATX power supply?
Some how the one i got after dial up the pot i got max 12.7 V which is a lot less than yours.
(See the attach picture). Any way it was rated at 12v 350w. Is it having issue if i use it for ormerod.
Can it perform better than the supplied ATX power supply?
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Re: New PSU April 15, 2014 07:51AM |
Registered: 10 years ago Posts: 14,672 |
Quote
Chaisaeng
I brought a LED power supply intended to use for powering my ormerod.
Some how the one i got after dial up the pot i got max 12.7 V which is a lot less than yours.
(See the attach picture). Any way it was rated at 12v 350w. Is it having issue if i use it for ormerod.
Can it perform better than the supplied ATX power supply?
Yes. The ATX PSUs supplied with the Ormerod have poor regulation on the 12V output (so do all ATX PSUs to some extent) and there is a significant drop in the output wires and in the wires between the ATX distribution board and the Duet. See [forums.reprap.org]. By using a supply with a single 12V regulated output and thicker wires between it and the Duet, you will increase the available voltage at the Duet and the bed heater significantly, even if you set the PSU to 12V.
Edited 1 time(s). Last edit at 04/15/2014 12:55PM 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].
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Re: New PSU April 15, 2014 08:14AM |
Registered: 10 years ago Posts: 2,472 |
My LED 12V supply cranked up to 14V no problem (and can go higher). Perhaps check yours to see if it has a fixed resistor at one end and/or the other of the adjustment pot., and if so change it to a slightly different value (lower if at the high voltage end of the pot, higher if at the low voltage end). My biggest issue with the ATX PSU was the time it was taking to heat the bed to 100deg for ABS - more than 30 minutes. It now gets there in better than half the time. Plus I take the Ormerod back and forth between office and home a fair bit, and the LED PSU is easier to move around.
Dave
(#106)
Dave
(#106)
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Re: New PSU April 15, 2014 11:06AM |
Registered: 10 years ago Posts: 76 |
Thanks all,
I did change to the new PSU and try a small print. The heatbed and hotend temperature go up much quickly than the supplied ATX power supply.
I thought I going to use it at 12.7V (still not brave enough to make any modification to the high voltage electronics
)
The voltage shown on the display I installed on the psu never drop below 12.7 from start to finish the print.
Edited 1 time(s). Last edit at 04/15/2014 11:06AM by Chaisaeng.
I did change to the new PSU and try a small print. The heatbed and hotend temperature go up much quickly than the supplied ATX power supply.
I thought I going to use it at 12.7V (still not brave enough to make any modification to the high voltage electronics
)The voltage shown on the display I installed on the psu never drop below 12.7 from start to finish the print.
Edited 1 time(s). Last edit at 04/15/2014 11:06AM by Chaisaeng.
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