12 Inch - Power Supply Wiring Question

[Schnupp]

Im about to finish my 12 inch Markerfarm build and have a question about the power supply wiring.

It appear that the polarities are wrong in the makerfarm build guide for wiring the power supply.
IMG_3206.jpg
Am I just seeing this wrong or is the wiring diagram on the right correct? Thanks!

[sniffle]

Not exactly you have to look really closely at your pwoer supply. All 3 of my positive and all 3 off my negatives were grouped together. So there are wires that looked crossed that arent... Took me a few to get straight as well on my 12"

[Schnupp]

Thanks for the comment sniffle I looked in the 10in build guide and the pictures for how to wire a rambo made more sense.

Now im having a different problem though. When I plug in my power supply cord the rambo board led does not turn on and the lcd screen is black. Then I connected my printer to my computer via the port on the rambo board and everything turned on as it should.
Is something shorted or do I have a poor connection supplying power to my rambo from my power supply?

[sniffle]

Google "reprapelectro rambo 1.1b manual"


There is a jumper that needs to be swapped so that it uses the 12v input instead of the 5v from the usb.

When you start looking remeber that the board is mounted upside down and it is over next to the usb port

[Schnupp]

haha yeah that was the problem. Now im all ready to print but my LCD wont notice my SD card when its inserted. Does the SD card need to be formatted a certain way?

[sniffle]

Have you flashed firmware to the board and made sure that #define sdsupport has been uncommented.

Umm outside of that... I have no clue i had no issues with mine. Also dont forget that the cables are upside down as well.

[Schnupp]

It was the SD card that I was using. It was a cheap one. Replaced it with a better one and the card was read fine.
Thanks again sniffle

[sniffle]

No problem :-)

[TechMasterJoe]

Tip run Pos from PSU direct to hotbed only run GND to the in and out on the Relay board it will save you some cable and help the hotbed heat up a bit faster.
I'm using a good 30AMP psu and it has a hard time with the hot bed my amp meter says full load printing with hexagon hotbed and all axis on draws 29.4amps

i replaced the hotbed cables with 12awg silicone ultra flex cable used in R/C cars it's like a wet noodle compared to the junk on the bed.
you will need a good 60w with a 5mm tip or a 120w gun type to solder to the bed as it acts like a heatsink and suck the heat away
(i used my 60w hakko and a 4.2mm 30deg CH tip it did fine 3 or 4 sec per wire at 460c)

[clough42]

Tip run Pos from PSU direct to hotbed only run GND to the in and out on the Relay board it will save you some cable and help the hotbed heat up a bit faster.
I'm using a good 30AMP psu and it has a hard time with the hot bed my amp meter says full load printing with hexagon hotbed and all axis on draws 29.4amps

i replaced the hotbed cables with 12awg silicone ultra flex cable used in R/C cars it's like a wet noodle compared to the junk on the bed.
you will need a good 60w with a 5mm tip or a 120w gun type to solder to the bed as it acts like a heatsink and suck the heat away
(i used my 60w hakko and a 4.2mm 30deg CH tip it did fine 3 or 4 sec per wire at 460c)

460C? Wow. You've got that thing cranked. You using lead-free solder?

I'm using a Hakko FX-888, and I don't think I've ever had to go about about 375C. I solder most things at 350C (Kester SN63PB3v #50/245) and only go to 375C to rework lead-free stuff.