Bed temperature

1) The bed temperature of my Mendel Max with the MK2a Heatbed has been 20 degrees Celsius low from the 110 desired from the start. The MOTHERBOARD is 33. I have tried all of the TEMP_SENSOR_BED settings. Number 1 gets the closest. I raised the bed temperature to 130 degrees to finally get a print. All was fine until I upgraded Pronterface. Now, It can take 45 minutes to reach any set temperature between 100 to 130 degrees. Can someone provide a link that explains the CONFIGURATION_H settings and what the settings mean? Is there a correction factor for the temperature difference? Why does the new Pronterface take such a long time to reach temperature? What am I missing?

Sounds like my Prusa i1 at the beginning.

Do you see an LED showing when the bed is being heated, and is it on continously for the 45 min.?

Do you have any insulation under the heated bed? I used folded aluminium foil, others use wool felt for example.

Also, check the tightness of all related electrical contacts.

---

Yvan

Singularity Machine

Pronterface only tells your Mendel max a temperature.
Your printerface upgrade has nothing todo with it.

Check what Yvan says.

Yes the LED is on solid for the 45 minutes. The bed is insulated.

To test my bed configuration I hooked up the bed heater directly to the power supply. The desired temperature (130 degrees C) was obtained in 18 minutes from 22 degrees C, 135 degrees C was reached 12 minutes later. I'll say it again, I did not have a problem with the bed reaching temp until I upgraded Pronterface. Since the upgrade I am having to start all over again with calibration. The Z axis lifts 1/2 of what it used to and crashes into the print after the first layer. I have tried to go back to the original Pronterface without success.It exits immediately. The log is full of line errors. Any other suggestions?

Someone with more expertise than me will have to step in, but I find it odd that the LED is on solid, yet temp rise is very slow. From what I know, if the LED is on, the bed electronics are fully ON. So what is the voltage output at the leads to the bed when the LED is on? Could it be low? When you connected the bed directly to you power source, there is almost no voltage drop in that configuration so that would heat up the bed faster than through the electronics.

Maybe it is time to look into the firmware? Odd that you have to do caliberation all over again...?

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Yvan

Singularity Machine

It sounds like there isnt enough current getting to you bed. Enough to power our LED but not enough to raise temp.
Can you post Multimeter readings for Resistance when bed is off and voltage at connector then at bed (when power is on?)

If your also having z axis problems as well I would say you have loaded incorrect firmware.
Pronterface has no effect on z axis lift either.

If the light is on your bed is heating unless there is some hardware fault. Check connections,measure voltage at heatbed.
Someone else may be able to help with configuration file if you post what firmware you are using.

The power supply is at 12.27 volts until the bed heater is switched on. The power supply drops to 10.7 volts. I have installed a separate heat controller and 30 amp power supply for the bed. I am now monitoring the temp of the glass not the heater. This seems to work well. The bed heater response is much improved.

I looks like the Pronterface issue is directory related. I don't understand which files slice3r and Pronterface are using and where they are at and where they are supposed to be and which configuration I should use for my setting.

What is the firmware? How do I tell what firmware I am using?
I am a intermediate C++ programmer and am trying to understand what the ramps board is running to control the axis, etc. I am really interested in controlling more than 3 separate extruders. I found a Marlin 2011-May Reprap firmware C++ listing, but I see references to Java for the ramps board on the Net. What is the Arduino and it's software doing in all of this? Can you point me in the right direction?

So your saying you have fixed the 2.2v drop at your power supply with a bigger supply yes?
I believe you will see firmware info when you connect to your printer in pronterface.

Load a job up ready to print. Find an edit button, I think file>edit and you will see a text box full of text.
This is the Gcode that was produced by slic3r that pronterface is going to send over your USB>serial connection to your printers firmware. Up the top in the header you get some info on things like bed temp and layer height etc. Check that this is all correct.

But confirm you have fixed your power supply issue first.

Although this won't solve your immediate problem, once you have got that sorted out you can dramatically reduce the time that the bed takes to get up to temperature by putting a "blanket" on the top of the bed. I use a 200mm square of MDF with two layers of metalised bubble film on it. Time to 110 degrees is shortended from 20 minutes to 8 minutes.

******* Please remember to take the blanket off before starting to print ********

Firmware is Marlin 1.0.0

Below is copy and paste from the pronterface window.


;----------------------------------
start
Printer is now online.
echo: External Reset
Marlin 1.0.0
echo: Last Updated: Jul 16 2013 13:04:34 | Author: (none, default config)
Compiled: Jul 16 2013
echo: Free Memory: 5311 PlannerBufferBytes: 1232
echo:Hardcoded Default Settings Loaded
Setting bed temperature to 145.000000 degrees Celsius.
Setting hotend temperature to 235.000000 degrees Celsius.
SENDING:M105
ok T:84.2 /235.0 B:103.0 /145.0 @:127 B@:127
Reset.
Setting hotend temperature to 235.000000 degrees Celsius.
Setting bed temperature to 145.000000 degrees Celsius.
SENDING:M105
SENDING:M105
SENDING:M105
Reset.
start
echo: External Reset
Marlin 1.0.0
echo: Last Updated: Jul 16 2013 13:04:34 | Author: (none, default config)
Compiled: Jul 16 2013
echo: Free Memory: 5311 PlannerBufferBytes: 1232
echo:Hardcoded Default Settings Loaded
ok T:25.1 /0.0 B:33.9 /0.0 @:0 B@:0
Setting hotend temperature to 235.000000 degrees Celsius.
Setting bed temperature to 145.000000 degrees Celsius.
SENDING:M105
ok T:37.4 /235.0 B:33.9 /145.0 @:127 B@:0
ok T:36.2 /235.0 B:33.9 /145.0 @:127 B@:0
ok T:35.1 /235.0 B:34.2 /145.0 @:127 B@:127
;------------------------------------------------------

I don't understand what the upgrade has to do with the ability to print, but I was printing until the upgrade.
That issue is closed.
I still have a temperature problem with the bed. With the separate power supply the so called desired temperature is reached rather quickly, 15 minutes. Not the 45 minutes I was experiencing

As an experiment I made a small container just big enough for the hot-end to be immersed in water. I set the hot-end to 235. Theory is the hot end cannot exceed 100 degrees Celsius. The container of water showed sines of boiling when the temp of the hot-end in pronterface reached 97.8 degrees The infrared thermometer showed 96.5. The hot-end never exceeded the 97.8 degrees. I feel confident that the hot-end configuration to be accurate.

The hot-end and the bed have 22 degrees when at room temp.

Pronterface shows the bed to be 145 degrees but the painters tape on the glass shows 95 degrees with the infrared thermometer. Without the glass there is a 15 degree difference. I am thinking there is a thermistor issue that came with the kit. I have ordered thermistors from china to try. Can someone recommended thermistor and supplier?

Is the following correct for configuration.h?

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
// bed is within 3
#define TEMP_SENSOR_BED 1

Never mind all of the above. The problem is the heatbed. The temperature is as desired at the back where the thermistor is at. The temperature in the middle and the opposite end is 20 degrees lower.

have you put a multimeter to the terminals on your bed to see what volts its getting, ive heard people go on about pid settings but i aint got that far myself

---

Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]

gwbcomm Wrote:
.......

> I don't understand what the upgrade has to do with
> the ability to print, but I was printing until the
> upgrade.
> That issue is closed.

You upgraded pronterface and you started have this issue.
I believe it is a coincidence.
Get a multimeter and see what the voltage is at your bed.

Someone correct me if this is incorrect but pronterface sends a gcode command to heat your bed to a temperature.
Your firmware takes over from there to operate your hardware. If you haven't changed your firmware and your bed is still heating at all then the problem is with your hardware.

Maybe you bumped a wire and have a poor connection somewhere.
In any case it is easy to rule this out. Check the voltage at your bed when it is heating. Idealy you want 12VDC

If anybody is interested>
The power supply and bed heater were replaced with no improvement. I am embarrassed to say that replacing the wires to the heatbed fixed the problem. They was no indication of a problem using a volt/ohm meter in test wiring, voltage, etc.

Crazy! Well good to keep in mind then. Were the previous wires brand new and of a sufficient guage? Hard to imagine they were not, they would have overheated...

---

Yvan

Singularity Machine

I'm starting to wonder if my wires are causing the same issue... My power supply is low to start with... 11.21 volts with nothing but the Extruder fan running.
When the bed heater is on, hothead off, the supply is outputing just over 9 volts. This is a brand new kit.
I'm going to do some digging on this power supply and see if I can find any info on it, but I'm a wee bit upset at the moment...

R

Hey all... At least now I know... I'm having a very similar issue and trying to determine if it's the Power supply, or something going on with the RAMPS or Heater...
The PS is only outputting 11.2V @ idle... only the Hothead fan is on.... When the bed heater kicks on, the PS drops to 9.04V at the supply,
Same where the power goes into the RAMPS, and 8.94V coming out of the RAMPS at the heater terminals...8.89v at the heater itself. The pot to adjust the voltage does nothing at all...

I'm guessing I've got a bad supply, maybe a weak cap or something. It's a brand new printer kit, but with one of the cheap 12V/35A Chinese supplies.

I'm going to contact the kit seller and hopefully he'll replace it. I'm also going to go down the an electronics reclamation place and see if I can score a surplus
medical or industrial supply... the output from those things is crazy smooth and solid. If I can, I'll keep the replacement as a backup.

This thing drove me nuts for hours last night, not being able to figure out why the table and head wouldn't get hot enough. I thought it
was a firmware or software setting, but had those covered. At least now I know!

Ron

If you drop to 9.04 at the supply, the supply is either FUBAR, or is not large enough for the job. In either case, it needs to be replaced . . .
If you are only dropping .1v from the supply to the RAMPS heater terminals, that is doing pretty well, as is only losing another .05v between the RAMPS and the bed heater itself.

I think a good power supply will make you a happy camper . . .

- Tim

I agree with you Tim... from quite a bit of browsing around, it looks like the same generic 12V/35A just about all of the under $500 kits come with. I just happened to get a bad one. No worries. At least I know I'm not crazy or blind!

Ron

I continued having problems until I took some extreme measures. I purchased another supply just for the bed heater. A 12 vdc relay across the ramps heater output switches the heater current from the separate supply. 10ga wire handles the juice.

hhhmmmm....

You mention that the temperature has been 20 degrees too low from the beginning....

Is the thermistor insulated? I use a dab of clear silicone caulk to attach my thermistor to my heated bed. Silicone is stable up to 250 degrees after it cures, so it's well suited for use with a heated bed. Silicone caulk is easy to get a hold of, but they also make weird silicone tape.

I think if you have a unit that's working well, except for a single component, the best solution is to focus on the component.

The bed heats up, although it's under-temp, but that's not a complete failure.

Some other things that might indicate different types of faults:
Since your using pronterface, Does the heating element cycle on and off?
Does the chronically low issue persist over a range of temperatures, or is it just at 110?
if you set it to 60 degrees c, would it only heat up to 40?
If you set it to 130, would it heat up to 110?

Have you tried other printing hosts?
Did the issue occur with them?

Well folks, turns out I'm just a dumba$$...
neglected to check to see what voltage the power supply
was set for.... it was set for 220V... 110V in the US. As embarrassed as I am to admit something so stupid, maybe it will prevent someone else from the self induced frustration I had!!

Just did my first test... a small link for a web cam mount... It worked, on the second attempt... about 5 layers into the first attempt, the GFI it was plugged into popped. Swapped outlets, started over... It completed it, but I have some tuning to do... it looks... blurry... I think temps are too high. I'll play around with it over the next few days as time allows, definitely would like to get it running pretty decent over the weekend!

R