Heated Bed Temperature Issue (MakerGeek Heat Plate)

I am trying to get my MakerGeek Heated bed setup and am having an issue getting it up to temp (sort of).

If I set the temp to 70 in Slicer it will get to 66-67 relatively quickly and then take forever to get to 70. I suspected the plate was struggling to simply get to 70.

Due to this I set the temp to 63, since it got there quickly. When I do that, the same type thing happens such that it gets to 59-60 and takes forever to get to 63 (15-20min). My measured temp is about the same btw as showing on the terminator btw.

Additionally it never starts printing (I suspect because it tried to get a degree or 2 above before it launches). Also for some reason it does not home first which I would expect.

Questions:
1. Any thoughts on why my print run is struggling to get the bed to the right temp, a) quickly b) at all.
2. Is it odd that it does not home in first? Seems odd to me but I suspect it does the heat bed before the home but am not sure. I know the hot end heats up post home.

Any help would be appreciated. Thanks!

(I moved this hear since I started this discussion on a previous thread)

bigfilsing [ PM ]
Re: Kossel Extruder Motor: I presume it's blown? Best Alternative? new
March 28, 2015 08:23AM Registered: 2 years ago
Posts: 316
For the heated bed you may want to try PID auto tune

With the machine cold ( at room temp)
Power on
In pronterface console issue the command
M303 E-1 C3 S70

This will heat the bed to 70 deg and let it cool off 3 times ( might take a while ) when done it will give you some optimised PID values that you then put in you config.h file

You can also do the auto calibrate for the hot end ( but not at the same time)
M303 E0 S200 C3
The number after the letter C denotes the number of times it cycles the test (the S number being the temp). More is better but i've found that 3 gives reasonable results in a reasonable amount of time

I have little experience with ABL so i cant really help there

Good luck

PS As a by note now you have just connected the 11amp power !! Its all over the wiki page ...surely youve read that !!! If you havent ...you should [reprap.org]

Anyway just be sure your power supply can handle the load now the bed is connected. If its on the limits of its rating you may get voltage dips which can lead to all manner of issues while printing.

I don't use Marlin, but this sounds from an old configuration.h file I have laying around that you may be running the heated bed in bang-bang mode with BED_LIMIT_SWITCHING defined to enable hysteresis.....

I'm going to run the M303 E-1 C3 S70. Are the results provided at the end of this process? I presume so. I will launch after this post.

On the BED_LIMIT_SWITCHING defined to enable hysteresis. I see this in config.h but am not following what it is using. Both PID and BANG have max values of 225.

In relation to an old config. I'm using Marlin/Arduino 1.0.6. I don't see specific values listed the Marlin.ino file which state specifically what version the config is. Maybe the 1.0.6 defines that.

I'll go run the M303 deal now. Thanks for the help.

The auto PID worked perfectly. Thank you.

Note: I didn't realize at first that it needed to be redone if your targeted to a different temp. Once I realized that (since I changed from 70 to 60 on my heat bed), all is perfect.

I'm on to more exciting prints now. I just did the 45 degree overhang. That worked well. I tried a car with only the wheels holding the car up, that didn't go so well...