Onyx Limited

[e_hutch]

My heated bed stops at 69 degrees and will not continue to heat regardless of what I command, is there a limit in the software? I checked the max temp in the configuration.h and it says 120 degrees. What am I missing? I upgraded the wiring in the initial build to 10 gauge.

Autotune timed out after reaching 69 degrees also.

[IMBoring25]

Paging Gene to the white courtesy phone...

Upgrading the wire gauge is considered to be frowned upon because the screw terminals on the board are not designed for heavier-gauge wire and there is the potential for a poor connection there, with any number of possible consequences.

Do you have the ATX power supply or the 29A LED PSU? The former was barely adequate in the best of cases and there were bad ones, but check the resistance of your wiring first.

[e_hutch]

I have the new power supply, I trimmed the wires at the Rambo terminal, they fit quite nicely. It heats great until 69 degrees then seems to limit itself.

[e_hutch]

I may autotune it at 65 then try again, maybe it is a problem with the defaults, gotta wait for the current print to finish. Is it better to autotune from room temp, or does that matter?

[e_hutch]

Autotuned from 50 degrees with pillow case over the bed, the first timed out, results were:

PID---1------------2------------3
Kp----589.01-----164.92-----100.97
Ki-----259.42-----3.88--------3.98
Kd----334.34-----1753.78----640.73

Ran again from already heated:
PID---1-----------2------------3
Kp----520.29----173.13-----78.53
Ki----231.14-----3.66--------4.27
Kd----292.79-----2048.84----361.06

afraid to use these values because of the huge differences.

[Jrjones]

Try using dead time instead of PID for the bed, I found that the bed is able to keep a steady temperature better with dead time than PID. http://www.repetier.com/dead-time-control/

Sounds like maybe your HEATED_BED_PID_MAX is not set to 255 ?
What is the value of your PID_MAX?

[e_hutch]

Just set the Bed PID drive max and Bed PID max value to 255, it was set at 200. temp is passing through 73 now! I will try the dead time control next. thanks!

[e_hutch]

still takes upwards of 30 minutes and has a hard time maintaining temp once the towel is removed, but it at least gets there.

[Jrjones]

What voltage do you measure at the output of the Rambo terminals?
I just recently replaced my ATX power supply with a 30A one similar to the one SeeMeCNC now supplies, and it takes about 20 minutes to get to 110° with a towel on top. I can maintain 110° without the towel on the bed.

I've adjusted my voltage to 12.6V at the input terminals on the Rambo, and on the heated bed terminals I get 12.2V when the heater is 100% on.

I do have extra insulation underneath my bed which I found helped the warmup times and to hold the temperature. http://forum.seemecnc.com/viewtopic.php?f=36&t=8986

[e_hutch]

I only get 9.38V directly off the terminals

[Jrjones]

What do you measure on the output terminals of the power supply?

[e_hutch]

yeah, I was just looking at that, 9.69. that would explain it.

[Jrjones]

Adjust the little potentiometer on the power supply, should be beside the power on LED

[geneb]

The compression terminals are designed for no more than 14ga wire. Shoving 10ga in there is ill-advised.

And NO, don't screw around with the output voltage of the power supply.

g.

[e_hutch]

I trimmed the 10ga to size for 14ga connectors, several of the forums recommended this, regardless I would prefer not to rewire. I adjusted the potentiometer before I read either of these posts, the most I was able to get was 11.14V, but still better than 9.69. I am running it up now to see how it does.

[Jrjones]

If his power supply is only outputting ~9.7V, that means it should be adjusted.
It could also mean the 110/220V switch is on 220, but that is bolded in the manual to double check the correct setting.

Regardless of the cause, I would make any adjustment to the power supply without the rambo connected and verify the proper voltages/polarities.

[e_hutch]

I have a nearly identical power supply in another printer, and I usually get about 12.3 out of it too.

[e_hutch]

If his power supply is only outputting ~9.7V, that means it should be adjusted.
It could also mean the 110/220V switch is on 220, but that is bolded in the manual to double check the correct setting.

Regardless of the cause, I would make any adjustment to the power supply without the rambo connected and verify the proper voltages/polarities.

YGTBSM! I usually only get to work on this late at night after my six kids (two of which are newborns) go to bed! 2nd stupid mistake, three strikes and I'm out. thanks for even pointing out the obvious.

[teoman]

10 AWG is not exactly what is recommended (if you are referring to my post). It was designed for 14 AWG and that would be the best choice. Using 18AWG wire as described in the kit is not a good idea in my very humble opinion. 10 AWG can be used if you have nothing else.

[Jrjones]

YGTBSM! I usually only get to work on this late at night after my six kids (two of which are newborns) go to bed! 2nd stupid mistake, three strikes and I'm out. thanks for even pointing out the obvious.

Glad I could help. I thought I would point it out just in case, haha.

[e_hutch]

10 AWG is not exactly what is recommended (if you are referring to my post). It was designed for 14 AWG and that would be the best choice. Using 18AWG wire as described in the kit is not a good idea in my very humble opinion. 10 AWG can be used if you have nothing else.

I cannibalized another printer with larger wiring, it is much beefier for sure, I did not have any 14 AWG handy.

To all of you, thanks for the help/advice! currently holding temperature well while printing a lock pinning tray for my brother in law. I'm just happy that my boneheadedness didn't burn up my Rambo or anything.