ATX supply board

Somehow my duet stopped receiving power from the supply. So I took the supply off, turned it on, measured the output, zero volts.
I pick the supply to turn it off and ... Zzzaaaappp. Electricity off at home and a good shock for me. And some smoke.
So, I am really done with these led supply also for the ormerod, I already had two roasted with the mendel due to whatever defect.

I would like to use an atx/six however I have no idea where to get the old ormerod boards? I dropped an email to reprap, but if anybody has ideas let me know.

Thanks,
.

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I'm sorry to say that all the "bargain" power supplies appear to be a big risk as you've found out. Most budget ATX supplies are just as problematical because the 12V is not welll regulated. Have you considered buying a lab. bench supply like this one for example?

[static.rapidonline.com]
I'm using one of these after getting fed up with 11V not heating the bed and hot-end decently. It goes up to 15V which may be a bit much for the 12V fan, but 14V is OK. Having a readout for current is also very useful when experimenting with the electronics.

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RS Components Reprap Ormerod No. 481

Hi Fpex

Is this the LED power supplies that we supply? We now supply a much better quality 12V PSU (see the two different PSUs we have supplied with Ormerod 2 here [reprappro.com] ). The older one was usually okay (though it didn't like input voltage spikes much), but if the case got bent, the contacts on the back of the board could potentially short out. The new PSU is much more robust.

The problem with using an ATX PSU is that it isn't really designed to supply 12V at high current, so when it is put under load, the voltage on the 12V rail drops. I think I read some comments from dc42, who said that there are some types of ATX PSU that will give good 12V supply, but can't remember where I saw that! dc42, can you remember?

We do still have plenty of the old ATX power PCBs, as used on the Ormerod 1: [reprappro.com]
If you want to order one, contact Sally on info@reprappro.com and she can send you a quote; we don't list them on our webshop.

If it is one of our PSUs, we'll happily consider replacing it under warranty.

Ian
RepRapPro tech support

Quote
droftarts
The problem with using an ATX PSU is that it isn't really designed to supply 12V at high current, so when it is put under load, the voltage on the 12V rail drops. I think I read some comments from dc42, who said that there are some types of ATX PSU that will give good 12V supply, but can't remember where I saw that! dc42, can you remember?

I had good results with the Corsair CX430M. The 12v rail held up better under load than the Alpine PSU I received in the kit. My measurements are at [forums.reprap.org]. But I switched to a cheap Chinese 12V 300W LED power supply shortly after that, and a year on, it is still working.

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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].

Hi Ian

I got your email and message here. Thanks!
It was the original psu from the ormerod2 kit and it see that now the psu is different and even the mounting has changed,

A LED psu is cheap and better than an cheap atx. However, I seem to attract bad psu. The original and replacement psu of my mendel tricolour took fire and I moved there to an atx be quite 430mx that works without a problem. I just had to figure out how to solder all wires.
And now the psu of the ormerod gave me a huge shock and even forced the house protection off ... So I am inclined to use an atx, mostly for safety reasons,

Dc42 I guess the issues with atx is related to cheap ones. More expensive ones with high vantage and efficiency should be ok. Sure the atx ends up costing a lot when compared to the kit itself. My only issue is that if I go atx I need to drive four hot ends (assuming I ever find the time to find finish it), so an atx might not be a good choice there.

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

The other advantage of the LED power supplies is that if you need more heated bed power, you can turn the voltage up. If you do this, make sure you stay within the total power rating of the PSU.

My rules for using a cheap Chinese LED PSU:

1. Check that there is good continuity (very low resistance) between the chassis and the mains ground connection.

2. Don't run the PSU near its maximum power rating, get one with extra power capacity. I use a 25A PSU rather than the 20A one supplied with the Ormerod 2, it only cost about £1 more.

3. Get it from a UK supplier that has been selling them for a long time.

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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].

after burning three from reprap, the question is from where.
I guess the idea if to have oen that can be cracked up to 14v for the bed without affecting the rest too much, right?

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

Quote
Fpex
after burning three from reprap, the question is from where.

Three - really? It sounds that the one RRP used to supply with the kit wasn't up to the job. Of course, I don't know that the one I use is any better, other than having an extra 5A of capacity - but it has survived over a year of use. I use the 12V 100W version of the same supply to power my Delta printer, and that has been OK too, although it has only been running for a couple of months.

Quote
Fpex
I guess the idea if to have oen that can be cracked up to 14v for the bed without affecting the rest too much, right?

The only item you need to worry about is the hot end fan, which may be rated at 13.2V. It will probably be OK on 14V, however you can put a couple of silicon diodes in series with it to drop the voltage back to about 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].

Three bad PSUs is either very bad luck or may indicate that your mains supply has spikes or surges. Were there any electrical storms in the area when the PSU went faulty? Additionally, if you received an electric shock and tripped the house RCB when you picked up the PSU, it tells me with 100% certainty that your PSU was not adequately earthed. Perhaps you had substituted a 2-wire mains cord? If there is continuity between the PSU chassis and the earth pin of the mains plug, it's time to call an electrician to check your house wiring urgently - bad house wiring could also be the cause of all the failures plus presenting a significant risk of both electrocution and fire. If the PSU does not have the earth pin of its inlet connected to its chassis then it is either double-insulated or it is illegal in the EU unless sold only for mounting inside another enclosure. If it is double insulated it is extremely unlikely that you would have received a shock from touching its case.

One possible solution if your mains supply is a bit iffy is to use a car battery to supply the Ormerod, and keep the battery permanently connected to a battery charger that is designed to provide a "float" charge as well as a normal charge. A charged car battery should have enough power to allow you to print for at least 4 hours even if the mains fails, and if connected to a suitable charger will provide around 13.8 volts. Battery chargers are usually more robust than regulated PSUs.

Dave

The house is not the issue, it is really bad luck,
The first had something in it that took fire as soon as I let the printer work a bit longer than few minutes are commissioning (it was long ago). I only noticed it afterwars.
The second one was at the office. So no idea if the issue is in the electrical system if the place. But I doubt it. However, keep in mind that the mendel design is a bit tricky with supply connections while the ormerod are much better, so for that psu I expect the problem was the printer itself.
This one, looks somehow banged up. I would suspect poor shipping. I though nothing if it ... Till Ian mentioned that it might create a problem In the older psu sent out.

I just had a friend over and he convinced me to stick to led psu since t, as we Italian say, the third failure is the last. :-)

But hey, I am know here to suffer from bugs and issues normally rare in tech (if Famous German car maker makes a recall for a bug at the automatic transmission, I was patient zero!!)

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

If you are having to buy your own LED PSU, I suggest you go for the 300W (25A) one (although you will probably need to print a new enclosure for it) - and check with a multimeter that there is continuity between the input earth terminal and the chassis when it arrives.

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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].

Thanks!

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

Search Amazon for '12V 30A LED power supply'; I generally prefer the PSUs like this: [www.amazon.co.uk]
They are made from much thicker metal, and are much more robust, have a fan, as well as being 30A. It's what I use at home. The old Mendel 12V PSUs were cheap. I've constantly asked for a better PSU, but it was RS Component's compliance department that finally caused the change - our old PSU used leaded solder, which they didn't like! So we changed to the new one, but it's still really only rated for 20A. But does have a fan, and a much stronger metal case. We even source them from a UK supplier!

Ian
RepRapPro tech support

that one lookd much more solid!

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com