1 Topic by WWC

  • WWC
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  • Registered: 2013-06-30
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Topic: ATX Power Supply

Hi
I am looking at buying a SD2. What i would like to know is, what is the power supply output voltage. I suspect 12Vdc but i do not know that as fact.
The reason i am interested in this information is:
I had the idea to buy a base mdl then buy a heated bed and replace the non heated bed with it.
The main difference i can see in the base mdl and the PRO mdl is the use of a 120W power supply instead of the 70W for the base mdl.
So to accommodate for the higher wattage i though i would use an ATX power supply that i already have.
Why would i do this instead of just purchasing the PRO mdl?
It would save approx $50. With the shipping and VAT / DUTY i will also need to pay every bit helps as i am currently living in south Asia.

Can anybody see a major problem with my plan?   

Thanks for any reply's.

2 Reply by Necromant

  • Necromant
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  • From: Moscow, Russia
  • Registered: 2012-12-17
  • Posts: 43

Re: ATX Power Supply

WWC wrote:

Hi
I am looking at buying a SD2. What i would like to know is, what is the power supply output voltage. I suspect 12Vdc but i do not know that as fact.
The reason i am interested in this information is:
I had the idea to buy a base mdl then buy a heated bed and replace the non heated bed with it.
The main difference i can see in the base mdl and the PRO mdl is the use of a 120W power supply instead of the 70W for the base mdl.
So to accommodate for the higher wattage i though i would use an ATX power supply that i already have.
Why would i do this instead of just purchasing the PRO mdl?
It would save approx $50. With the shipping and VAT / DUTY i will also need to pay every bit helps as i am currently living in south Asia.

Can anybody see a major problem with my plan?   

Thanks for any reply's.

The stock for pro model delivers up to 10 amps at 12v. The only problem I see with ATX - thin wires. It can deliver a lot of current (I'd count to 15Amps to be safe) , but the 12V rail is split in a dozen of wires. To be safe, I suggest cracking ATX open, detaching all the thin wire stiff and soldering some nice 18AWG wires. But don't do it, unless you have the skill.
Also, keep an eye on this thread, I will be doing this hack to an ATX PSU this weekend: http://www.soliforum.com/topic/3260/wip … -overhaul/ and post the results.

Necromant's Website

3 Reply by WWC

  • WWC
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Re: ATX Power Supply

Necromant

Thanks for the input. Because i am new here i will give a little background on me I have used the ATX supply on many projects including a have made and using a 24V by combining 2 supplies. 2 outputs, a -12v to +12v variable and a +24V variable.

When i questioned Solidoodle about this they said i had to use there supply. That is there sales and disclaimer for using a non factory supply i am sure.

I have also seen others using an ATX on line as well, so from that and from your input i am confident to purchase the SD2 how i have planed. 

Thanks so much

4 Reply by Necromant

  • Necromant
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  • Registered: 2012-12-17
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Re: ATX Power Supply

WWC wrote:

Necromant

Thanks for the input. Because i am new here i will give a little background on me I have used the ATX supply on many projects including a have made and using a 24V by combining 2 supplies. 2 outputs, a -12v to +12v variable and a +24V variable.

Not  a very good approach, since "-12v" is a very weak supply, compared to +12v. If you crack it open, there are a bunch of resistors, that set the voltage. Usually the circuit is pretty simple, and datasheets are easily googled. So a little resistor replacement and you can get a pretty wide voltage range.

WWC wrote:

When i questioned Solidoodle about this they said i had to use there supply. That is there sales and disclaimer for using a non factory supply i am sure.

Well, looking at my bunch of hacks... If there was any warranty for that, it should be void long ago. Since I live half way across the globe from Solidoodle LLC, and russian postal service are a bunch of slowpokes - it's far easier to make repairs myself, than wait for a two months for replacement part, even if it's free. In your case this may be different.
A tip - make sure you print all the replacement stuff that can possibly break the very first evening you get acceptable print quality. And the very first - jigsaw puzzle replacement, fan duct. And get some nice M5, or even M3 threaded rod with a high 12mm lead nut. Stock 5/16 rod gives unacceptable wobble.

Necromant's Website

5 Reply by WWC

  • WWC
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Re: ATX Power Supply

[ Not  a very good approach, since "-12v" is a very weak supply, compared to +12v. If you crack it open, there are a bunch of resistors, that set the voltage. Usually the circuit is pretty simple, and datasheets are easily googled. So a little resistor replacement and you can get a pretty wide voltage range.]

I should of discribed my power supply better.  You are correct in the -12V single wire  is only 300 mili ampa ( guess ) .

What i did was i took the 12V output from one supply and connected it  directly to the ground of the second supply. So if you measures from ground of first supply to output of second supply you get 24V, with some loose of course. Next  if you now change your " ground " point to the connection between the first supply and the second supply then measure the voltages at either output you now get a -12v and a +12v, with loose of course. This way you can get the amperage out of the supplies that is stated on the data sheet.

Special Note:

These things MUST be taken into consideration if attempting this hack.

1) The first supply must be an isolated ground
2) The dual supply side must have its own ground
3) The single supply side must have its own ground
4) DO NOT EVER connect the ground from the dual side to the single supply side

I have an Eagle schematic that i have made that i will share if interested in this hack.

I actually removed both supplies from there metal housings and made a wooden box with an appropriate face plate so i have no stray grounding issues.   


Thanks for the tip on printing anything that can break first.
The M5 threaded rod would before the Z Axis?
jigsaw puzzle replacement?