Hi
I have a kossel delta type from Biqu, the motherboard is one of these, [reprap.org] I would like to fit a 24v power supply to it, if possible. The board checks out as being able to take 24v, but I was wondering what else I would have to change to make it run 24v, successfully?

I know things like the fan, would either have to be changed, or move it to the 12v output, but I was wondering if the thermister and hot end needed to be changed as well.

Thanks for your help

Dr Bob

The hotend heater needs to be specced for 24v, the thermistor is nothing to worry about. You already got the fans in view, that should be it.
Some boards need to be configured differently for 24v (jumpers etc.), make sure you know what to do.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Srek,
Thanks for the quick reply, does seem simple to be fair. I'll get the bits I need in, and start the upgrade this weekend.

Again thanks for the info

Dr Bob

Don't forget the heated bed!

think if i was going 24V I use mks mosfet to control the bed, inpart to keep the heat off the main board.

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jinx
think if i was going 24V I use mks mosfet to control the bed, inpart to keep the heat off the main board.

False logic; for a given power the current is lower at 24v so the heating in the MOSFET is lower.

That's true but I use one for my bed on one machine as it enables me to have a second psu for the bed only, at 24v and I don't want another 12 amps going through my controller if I can help it let alone 15-18 amps.

Edited 1 time(s). Last edit at 07/19/2017 05:34PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

am curious just how much current would a Mk3 aluminum bed draw at 24V

Short answer, half of the current at 12v.
Long answer, they're meant to have resistance of 5.2ohms so 4.6amps at 24v.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

thanks DJ

Actually, that was a question I had, but I guess you're right, it not going to matter so much with a 24V supply. I have a MOSFET attached to the old set up. I'll leave it there for now and see how it goes. I wonder if the MOSFET is playing up because sometimes the light comes on like it heating up but does nothing.

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Bob
I wonder if the MOSFET is playing up because sometimes the light comes on like it heating up but does nothing.

got a multimeter? take a voltage reading at the terminals

I took a different approach. I got tired of waiting on my bed to heat up. So I bought 120 -240 Volt PCB heater for my 200 x 200 mm bed. It uses the board to control a 120 volt SSR. It heats up about as fast as my hot end now and all I have on 12 volts are the motors and fans. Not a heavy load. Why try to heat something with low voltage, you need larger wiring to get the same KWH, and I know you have 120 volts to the 12 volt power supply. An SSR is about 5 dollars.

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jinx

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Bob
I wonder if the MOSFET is playing up because sometimes the light comes on like it heating up but does nothing.

got a multimeter? take a voltage reading at the terminals

I got it checked out by a helpful electrician who was at work, he said at best, it's inconsistent. So it's now working hard in the builders skip outside

Thanks for the help everyone. Great advice and help. I thank you

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I got it checked out by a helpful electrician who was at work, he said at best, it's inconsistent.

It's never a bad idea to check electronics visually for cold solder joints, shortcuts or cracked tracks.
Prefereably, before one switches them on the first time.