Rostock Max V2 Shutting Down on Heatup UPDATE

[cplbob]

Complete noob here. I got my V2 kit a couple of days ago, and finally began the calibration process today. I made it to the setting the Z-height, but have run into a roadblock. I was able to PID autotune both my hot end and bed successfully, but when I turn them both on to start the process of setting the Z-height the printer shuts down as the bed gets within a couple of degrees of target. Any suggestions of where to start?

UPDATE 11/19
I got the new power supply, and installed it. However, now the problem is different. I can't turn on the bed at all without losing power just as I did before. With the old power supply I was able to get it to heat up almost to target. Now, just activating the bed shuts down the printer. I've unrouted the bed's wires, and inspected the wiring/soldering underneath. I can't see any places where it could be shorted. If I start the machine without the bed's power plugged into the RAMBO I can "activate" the bed in Repetier Host, and it thinks it's doing it. No temp rise, obviously, but no catastrophic failure, either. I'm really banging my head against a wall right now. Does anyone have any suggestions on what else I could check? Thanks.

[cplbob]

It's as if I can power and heat them independently, but when I try to do both I run into this problem. I just let my bed heat all the way up and stay there for awhile. When I turned on my hot end, I lost power when it got close to target.

I reduced my hotend temp to 190, and my bed temp to 40. I let it sit for a while and didn't have any issues, but I lost power when I upped the bed temp to 45.

[bot]

Are you running the external power cord to a power strip? I had a similar but different issue once. I have my Rostock plugged into a power strip and had a medium-large desk fan attached to the same power strip. Whenever I would shut OFF the desk fan, it would cause the Rostock to power down. Not when I turned it on, or had it running, only if I turned it off. Might have been a function of the rostock power supply or the power strip, not sure, but make sure you aren't tripping a limit on a power strip or something.

[redoverred]

Are there error messages? You can check them in the terminal of whatever software you're using, like MatterControl or Repetier-Host. I had a problem where the max hotend temp was set wrong and the software turned off the heat once it reached around 210 or something at first, but once I fixed that it worked better. Also, if you didn't PID tune (or dead-time tune) your hotend or bed it may overshoot your set temp by enough to have the software shut everything down.

[Earthbound]

The OP describes it as "shuts down" and "lost power". If the LCD backlight is off, the machine's power supply has shut down. There is no software/firmware control that does that in stock Repetier/RAMBo setup.

If it happens when both heaters are running for a period of time, then it's the power supply cutting out. Could be the p/s overheating. Mine did something similar although it was 45min into an ABS print at 230C/110C. I tried the same print with the rear plexi cover and one side panel removed to allow airflow. Ended up replacing both with vented pieces drawn up by redoverred. Try it without the covers. If it still happens, then you've got a bad p/s. If it doesn't, then just improve the airflow.

[cplbob]

@bot Yes, I had been running it through a power strip, and your message made me do a serious facepalm because I hadn't thought of it first. I had, by this point, removed all lower acrylic and the two rear melanine covers to increase airflow. With all of those panels off, and running directly out of an outlet, I was able to stay at target temp just long enough to set the z-height and get my hopes up.

Then it died again.

@redoverred I've been able to successfully autotune both the hotend and the bed without error. When I turn them on independently they have that initial curve that exceeds the target temp before the controller brings it back down, but that's normal, right? When it dies I get no error messages in my log.

@Earthbound Yes, it's a complete loss of power. Even at the power supply. I was laying in bed last night, and I came to the same conclusion about the Rambo not having "software" control of the PSU. If the failure was at the Rambo, or on the "other side" of the Rambo away from the power supply, then the power supply should still be running as long as the HW power switch stays in the "ON" position, right? This happens even with acrylic and other airway obstructions removed, but I do get more time this way. Like five minutes.

I've got a ticket in to SeeMeCNC, and I'm waiting to hear back. I was just hoping I had made an obvious newbie mistake, or that there were additional steps I could take to troubleshoot or rule out PSU failure.

Thanks, everyone.

[guanu]

this may sound strange, but try something for me... put your ear up next to the machine by the power supply.... turn on your bed heat... do you hear the power supply make a small scream sound? recently I had the same thing happen on a machine I built and found a defective power supply that made a buzz sound when I turned on the bed, and would die soon after like you describe. We will replace a defective psu no problem, so dont worry we will get you straight.

Guanu

[BenTheRighteous]

this may sound strange, but try something for me... put your ear up next to the machine by the power supply.... turn on your bed heat... do you hear the power supply make a small scream sound? recently I had the same thing happen on a machine I built and found a defective power supply that made a buzz sound when I turned on the bed, and would die soon after like you describe. We will replace a defective psu no problem, so dont worry we will get you straight.

Guanu

The whine is not normal?! Mine does that! Mine doesn't shut down though, but still, I thought the whine was normal... doh!

[cplbob]

@Guanu I listened for the "scream" just now. I didn't notice anything different with just the bed engaged. The PSU fans seemed to "lower" a bit, but I assume that's normal. With both the hotend and bed engaged I heard a mid-pitched noise. I wouldn't necessarily describe it as a scream, but my hearing isn't the best either. This noise persisted until, inevitably, it shut itself down.

[cplbob]

Okay, so I decided to try something a little different. I thought maybe I had chosen poorly on my black and yellow wires for my hot bed power pins on the rostock, so I went back and chose four new pins each from a different connector. I have a very vague understanding of how the inside of the PSU operates, and I thought maybe if I had too many wires on the same rail then the hot bed was pulling more than the PSU could handle. In the end it didn't matter. I still get immediate power loss when switching on the hot bed. Back to the drawing board.

[bot]

Damn, I thought you figured it out. What a let down. Thanks for the update, though. That kind of information is good to document.

[cplbob]

Additional update!
After having issue with my second power supply I decided to try running a secondary power source for the heated bed. I wired up the first PSU (that failed when the heated bed reached its target temp) to the connectors for the bed's power supply on the rambo, and let the new PSU (that fails when the bed is activated at all) power the rest of the printer. By their powers combined I was able to keep the printer running with the bed on. More tests are needed before I will call this a success (like actually being able to complete the calibration process), but I have to start putting her back together before I can do any of that. Also, I'm not too keen on keeping the "dual psu" solution long term as it's a little messy. Would upgrading to a higher quality/wattage PSU be advisable?

Thanks for all of your guys' help.

[cplbob]

So I'm up, calibrated and printing. I've got the two power supplies working in tandem to keep the printer powered, and I've got a Corsair 600w ordered so I can be down to using just one. I guess I just have phenomenally bad luck with power supplies.
Thanks again for all the tips!

[redoverred]

So I'm up, calibrated and printing. I've got the two power supplies working in tandem to keep the printer powered, and I've got a Corsair 600w ordered so I can be down to using just one. I guess I just have phenomenally bad luck with power supplies.
Thanks again for all the tips!

You also want to make sure that you're drawing power from more than one 12v rail inside the power supply. If you are drawing from only one rail, you could be tripping something with high current. I chose the 7 yellow+black wire combinations from several different connectors when I hooked up my PSU.

[Earthbound]

When I built my RMv2, I open up the power supply and cut out all of the unneeded wires. The downside to doing this is a complete trashing of any warranty, but I felt it was worth doing. The upsides are a much cleaner installation since there is no bulky leftover cable bundle that blocks air circulation, and I used some of the scrapped wire to add extra parallel feeders to the hot bed. Another bonus is you get to clearly see where the yellow power supply wires are coming from inside the P/S case. Most have multiple 12v outputs that are separate from each other. Not all outputs have the same capacity. The hot bed power input on RAMBo got fed from the sectoin that originally had the most yellow wires and the two smaller inputs were fed from the small 12v section.

[cplbob]

Granted, I didn't open either of the PSUs to run any traces, but I did try several combinations of black/yellow wires. All produced the same results. Admittedly, I am a little confused on one point. Both PSUs that were provided are marked as "Single Rail" design. Does that mean that there is only one rail for me to draw current from to begin with? If that's the case, then would wire selection make a difference?

[Eaglezsoar]

Granted, I didn't open either of the PSUs to run any traces, but I did try several combinations of black/yellow wires. All produced the same results. Admittedly, I am a little confused on one point. Both PSUs that were provided are marked as "Single Rail" design. Does that mean that there is only one rail for me to draw current from to begin with? If that's the case, then would wire selection make a difference?

PSU.jpg

If you have a single 12V rail then all 12V wires connect to the same point within the power supply and wire selection would not matter.
The only time wire selection would make a difference would be if your power supply has more than one 12V rail which is not what you have.

[cplbob]

That's what I thought, but I wasn't 100%. Before I got it up and running I was torn between some kind of short/defect in the heated bed or insufficient power supply being the cause of the malfunction. Based on what I've seen, the PSU that came in my kit just wasn't enough to power the whole printer on its own.

[lightninjay]

Do note though, that not all power supplies marketed as a single-rail supply are in fact single-rail.

I went through one such case when my printer was suffering a similar issue. Finding out that one of the rails was dead and buying a larger modular power supply, I hacked one of the modular cords and now if my supply dies, it's under warranty still

[Eaglezsoar]

That's what I thought, but I wasn't 100%. Before I got it up and running I was torn between some kind of short/defect in the heated bed or insufficient power supply being the cause of the malfunction. Based on what I've seen, the PSU that came in my kit just wasn't enough to power the whole printer on its own.

I agree 100%

[shentheory]

That's what I thought, but I wasn't 100%. Before I got it up and running I was torn between some kind of short/defect in the heated bed or insufficient power supply being the cause of the malfunction. Based on what I've seen, the PSU that came in my kit just wasn't enough to power the whole printer on its own.

Hey! I wanted to see if you had an update to this, as I'm having the same issue. I successfully completed the PID autotune for the hotend and the bed separately, and either one will heat up fine on it's own, but as soon as I heat them both up together for calibration, the whole thing shuts off in under a minute. This is the power supply that came with my kit. I would love to know what PSU you ended up trying and if you managed to get it stable. Thanks!!

[jckrieger]

That's what I thought, but I wasn't 100%. Before I got it up and running I was torn between some kind of short/defect in the heated bed or insufficient power supply being the cause of the malfunction. Based on what I've seen, the PSU that came in my kit just wasn't enough to power the whole printer on its own.

Hey! I wanted to see if you had an update to this, as I'm having the same issue. I successfully completed the PID autotune for the hotend and the bed separately, and either one will heat up fine on it's own, but as soon as I heat them both up together for calibration, the whole thing shuts off in under a minute. This is the power supply that came with my kit. I would love to know what PSU you ended up trying and if you managed to get it stable. Thanks!!

I'm also curious if you had an update. My Newly assembled V2 with the 600w Diablo power supply was shutting off during the heated bed auto-tune. I removed the plastic lower covers and was able to heat the bed and nozzle without any issue. I'm guessing there's not enough airflow to keep the power supply happy. The only thing I did with my build is I used 2 18ga wires in parallel for the heated bed instead of the single 18 ga wire as in the directions. Maybe I'm pulling too much current and See Me CNC used very small wire in the directions on purpose?

I also noticed the power supply doesn't make much noise when heating the hot end, but when heating the bed it emits a very high frequency, almost inaudible screeching sound. I also noticed the stepper motor is blocking the exhaust of the power supply. All my motors seem to be turning in the right direction, so maybe this airflow obstruction is causing problems as well.

[Eaglezsoar]

See this link for printing some panels for the Max V2 bottom that has holes for the fan.
This really increases the bottom cooling..
http://forum.seemecnc.com/viewtopic.php ... 3&start=10

[jckrieger]

After removing the plastic covers I was able to calibrate the heated bed and calibrate the towers. Shortly afterwards, the unit shut down. I'm thinking I also have a power supply issue.

I've read on this forum that the power supply is more likely to work correctly if the 5V rail has some load on it. Has anyone tried to load the 5V rail to resolve this power supply "instability" issue?

[jckrieger]

It looks like the problem isn't bottom end cooling. Even with the panels removed and only a single 18 ga wire going to the bed, the unit still shuts down randomly after a few minutes. After looking at the Amazon reviews for this power supply I'm not too surprised. There is a 1 star review with multiple failures for each good review!

Hopefully See Me CNC will be able to get me back up and running. I'm cringing thinking about trying to replace the power supply now that the unit is fully assembled and calibrated!