Welcome to the SeeMeCNC Community

Hey,

So I'd say I'm about 85% through my H1-1 build and have hit a snag with the PCB heatbed. I have the thermistor working correctly but the board will not heat. I am using RAMBo with the 12v output (Labeled heat-bed) connected in parallel to both 12v inputs on the Phebe. This does not work, however. I have also tried hooking up only one set of 12v leads which doesn't work either.

Sorry to ask but after hours of googling I could find nothing for a RAMBo setup in terms of wiring plans.

Thanks,

Splooshy

Splooshy when you turn on the bed heat does the red LeD above the black bed connector light up?

There is a red LED that turns on but it is not the one directly in front of the black bed connector, I don't know if this matters. The light that is on is directly in front of is labelled Heat 1 (I dont have hotend wired yet).

Thanks for the reply.

Just an update on my situation here: I believe it must be a software problem that the power is going to the wrong RAMBo output considering it does turn on a red LED, just not the correct one. When I get home I think I'll try sticking the black connector adjacent to where the light is, assuming this is the plug that power is being sent to when I turn on the heat bed.

I'm mostly posting this as a reminder for myself for when I get home but any help would be appreciated.

Splooshy,

Have you found the solution? I am running into the exact same issue. The output and temp sensor connections that Repetier host turns on is for the 2nd extruder instead of the heated bed connections.

Thanks,
Craig

Splooshy wrote:Just an update on my situation here: I believe it must be a software problem that the power is going to the wrong RAMBo output considering it does turn on a red LED, just not the correct one. When I get home I think I'll try sticking the black connector adjacent to where the light is, assuming this is the plug that power is being sent to when I turn on the heat bed.

I'm mostly posting this as a reminder for myself for when I get home but any help would be appreciated.

Don't do that, the heated bed draws almost 10A, it'll blow the fuse on the 12 V line.
RAMBO has 3 independently fused 12 V lines, the black connector for the heated bed runs though the 20A thermal fuse, the red Hotend connectors run through a ceramic 5A fuse and the motor connectors through a 2nd 5A fuse.
They aren't fuses you can source locally, I know this because I blew one.

Are you sure you are using Johns firmware, is the MOTHERBOARD set to 301 at the top of configuration .h? If the firmware was configured for a RAMPs board it would do exactly what you are seeing.

I agree the probability of a blown fuse is high if using the 2nd extruder output.

I was using the firmware from https://github.com/johnoly99/Repetier-for-rambo. I ended up making some modifications so that it turned on the heated bed output and would read the temperature at the 3rd port instead of the 2nd port leaving it open for a 2nd extruder.

I'm not sure if this was the best firmware to start with or not. If there is a link to better, please post away. Once I sort out my end-stops I will submit a pull request with the required changes.

With regard to those annoyingly tiny fuses - I blew the one right under the 20A resettable and ended up soldering 24ga wires to the "top" so I could use it to attach a tiny automotive fuse of the same rating. Looks like hell but it works very well.

g.

ccavanaugh wrote:I agree the probability of a blown fuse is high if using the 2nd extruder output.

I was using the firmware from https://github.com/johnoly99/Repetier-for-rambo. I ended up making some modifications so that it turned on the heated bed output and would read the temperature at the 3rd port instead of the 2nd port leaving it open for a 2nd extruder.

I'm not sure if this was the best firmware to start with or not. If there is a link to better, please post away. Once I sort out my end-stops I will submit a pull request with the required changes.

That's the one I was using until I blew the 5A fuse, and it was turning on the right pin for the heated bed.
I had to make some changes for the digipot values and motor directions, but otherwise it seemed correct.
Mines currently temporarily wired up through a RAMPs board I had lying around, while I wait on Digikey to ship me a fuse or 10.
The SeeMeCNC hotend pulls a lot of current about 2x more than most conventional RepRap hotends, my math says that 5A should be sufficient for a hotend and a fan, but mine blew, AFAICS without a short.

geneb wrote:With regard to those annoyingly tiny fuses - I blew the one right under the 20A resettable and ended up soldering 24ga wires to the "top" so I could use it to attach a tiny automotive fuse of the same rating. Looks like hell but it works very well.

g.

Yeah I seriously considered this, not the best choice by Ultimachine, I think the hotend fuse is underspecified given the number of outputs the board supports, but the bigger mistake is they should have at least picked something that could be sourced easily.

I strongly suspect their choice of fuse was more due to real estate savings than worrying about the optimal part choice.

They could have deleted the fuses entirely and made it a very visible requirement that the end-user fuse all the power output lines.

g.

I switch to stock Marlin firmware this morning and everything works out of the box with Rambo.

It polls the heated bed temperature from the correct input and turns on the correct heated bed output.

Splooshy wrote:Hey,

So I'd say I'm about 85% through my H1-1 build and have hit a snag with the PCB heatbed. I have the thermistor working correctly but the board will not heat. I am using RAMBo with the 12v output (Labeled heat-bed) connected in parallel to both 12v inputs on the Phebe. This does not work, however. I have also tried hooking up only one set of 12v leads which doesn't work either.

Sorry to ask but after hours of googling I could find nothing for a RAMBo setup in terms of wiring plans.

Thanks,

Splooshy

Had the same problem here, after a couple of weeks I found the solution, so I'm sharing it with You.
It's an issue caused by the combination of the Repetier-for-Rambo firmware ( https://github.com/johnoly99/Repetier-for-rambo ) and a Rambo Board. From my understanding and with reference to the "heated bed configuration" part of the Configuration.h file, the firmware uses to direct the power output of the heated bed to an "HEATER_1_PIN", see line 378. Now, as Rambo has actually got 2 heater lines for extruders and one dedicated to the heated bed, the HEATER_1_PIN happens to be the one used for the possible second extruder, that drains power from the "MOSFET" input line and not from the "HEATED BED" input, which isn't good, as heating the first extruder and the heated bed with the same power line will drain too much current.

Searching the pins.h file, You can find listed the pin dedicated to the bed heating, which is named HEATER_BED_PIN and numbered 3. See line 891 of the pins.h file.
So, what You have to do here is:

substitute line #378 of Configuration.h (reading "#define HEATED_BED_HEATER_PIN HEATER_1_PIN") with:
#define HEATED_BED_HEATER_PIN HEATER_BED_PIN

Then recompile and reload the firmware.

That worked for me, hope will help You too.

@demiurgo

Thanks a lot for the instructions, and thanks to everyone who posted. Having this kind of community is amazing at my skill level. Thankfully I figured it out on my own by modifying (i believe) the pins.h file to re-configure where which port it was outputted to. I popped two of the three little fuses I bought and have had no trouble since.

My entire project is now computer controllable (all heaters working well [hot as fuck though]!) but not yet automated by the GCode. This is the final step.

Wish me luck and thanks again for all the assistance. I'm not kidding, I really appreciate it.

Thanks,

Splooshy