In need of a new PSU...

[dcfc_sandy]

So I've built a Rostock Max v2, turned it on... and it didn't set fire to the house!

Printed some stuff in PLA that's come out nice and I'm finding ABS tricky... I get pretty good adhesion at 90C but can't hold the temp during a print, an enclosure isn't an option currently. So I reckon for PSU's I have three options

A) Take the TX750M (Semi-Modular) out of my desktop and put it in Rusty (the printer!)
B) Buy a new ATX PSU for Rusty, if so what is a good choice...?
C) Get a 24V PSU

What are your guys thoughts and whats the key benefit of 24V over higher wattage 12V?

Thanks!

[Earthbound]

No need to go 24v. A healthy 12v supply will do the job just fine. The problem with the stock power supplies is an inability to decently regulate 12v under PWM load and when it drops to 10-11v, the heater doesn't perform well. A cheap, 300W 12v supply is adequate. Higher wattage is even better - not because it needs more, but it means the power supply doesn't have to work close to its limit. Many are adjustable over a small range (maybe 10.5-13.5v) and dialing it up a little over 12v will increase heater performance.

[forrie]

My vote is for the Antec HCG 520w bronze.

Best proven bang for buck PSU money can buy (About $85 US). Should do the job easy...

[dcfc_sandy]

Wicked! Thanks both, time to blow the student finance on upgrades!

[stonewater]

if you don't mind waiting 30 minutes for your bed to heat up printing ABS then stick with 12 volt. a 24 volt supply cuts it to less than 10 minutes easy. other wise this thread:

http://forum.seemecnc.com/viewtopic.php?f=43&t=7766

this power supply

http://www.jameco.com/webapp/wcs/stores ... _295902_-1

add a DC to DC converter about 30 bucks off of amazon

Tom C

[dcfc_sandy]

With the 24V is it usually exclusively used to power the Onyx, or can I use it to power the whole machine as well... as ideally I only want one PSU

I've had a read through this http://forum.seemecnc.com/viewtopic.php ... end#p59750 and similar threads, still a bit unsure...

So if I had a 24V I would either need 24V fans, hot end etc... or use a buck converter to drop down to 12V. As well as obviously work out power consumption.

Thinking an new ATX is the way currently!

[Earthbound]

Stock Viotek (?) ATX power supply on my Max V2 gets the bed from cool ambient of basement to 100C in under 11 minutes.

[dcfc_sandy]

Its a DiabloTek, takes roughly 35 mins to get to 90C with a towel, whereas 60C in 10 mins no towel. Big issue is that its not able to sustain the bed temp. Had a fluctuation between 78.9C and 85.2C after the print had started

[stonewater]

its is not a problem, U use a 24 volt power supply a 24 to 12 converter for the Rambo and drive a solid state relay with the heated bed circuit for the low side of the relay. the Rambo the hotend and the fans all stay at 12 volt. the only thing that sees 24 is the bed and the hi side of the relay. the bed will heat wicked fast.

Tom C

[dcfc_sandy]

Wicked fast is exactly the speed I'm looking for!

Apologies for the naivety of this question, but I'm assuming if using the SSR to power the bed from the RAMBo, the 4 lines in on the RAMBo will no longer be required...?

[Shizuma]

if you don't mind waiting 30 minutes for your bed to heat up printing ABS then stick with 12 volt. a 24 volt supply cuts it to less than 10 minutes easy. other wise this thread:

You can get pretty fast heat up times even with 12V, just the PSU the printer comes with is complete garbage and really is only useful as a door stop or maybe a book end, with that one it would take a good 30 mins with a towel to get up to 85C (it couldn't even make it to 90C) and it couldn't hold that temp when printing, however I swapped it out for a Thermaltake SMART Series SP-550PCBUS 550W ATX and ran some larger gauge wire to the bed and now it takes 10ish mins to get up to 90C and can hold the temp just fine, and that's with no towel, though my build chamber is enclosed which probably helps a tiny bit on heat up times.

[DerStig]

I just installed a Cosair 850Watt PSU and it's WELL WORTH the $100 I spent on it. 110c bed temp in 11 mins. 275C print head temp, Trick Laser LED ring doesn't flicker. The printer is just much happier.

The PSU that ships with the kit is a joke get rid of it and be able to actually print ABS beautifully