Ord Bot: Heating Bed unable to reach 110C. Please Help !

Having and issue with the Bed taking forever to heat up, and only reaching 67C. Should place a towel over it as I have seen it being recommended?


Also, if my extruder is having issues staying at the 230 abs temp, should i change the fan speed in Slic3r so that it does not spin as fast and cool the hotend?


Sincerely,

Janski

What voltage are you getting at the bed when it is heating up? What's the resistance of your heated bed?

Have you run PID auto tune? Are the nozzle and heater block insulated somehow?

I have not long built an OrdBot Hadron. The bed that came with my kit needs +12v on terminal 1 and terminals 2 and 3 need bridging together and connected to -ve. If you don't bridge the connections, it acts as a 24v bed.

Mine is still slow. I put some loft insulation under the bed and use a piece of thick cardboard on the top during heat up.

I also used to have cycling with my hotend until I did a PID autotune. I have got a jhead and use a 40mm fan which is on full all the time. It is very stable now.

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NewPerfection


Have you run PID auto tune? Are the nozzle and heater block insulated somehow?

I have ran auto tune for the Heater but not for the bed. What would be the command for auto tune heater bed that is connected to ramps 1.4 "D10" port?

I am also insulating the block.

Please advise

Janski

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Janski

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NewPerfection


Have you run PID auto tune? Are the nozzle and heater block insulated somehow?

I have ran auto tune for the Heater but not for the bed. What would be the command for auto tune heater bed that is connected to ramps 1.4 "D10" port?

I am also insulating the block.

Please advise

Janski

I don't know about ramps, but the Marlin autotune bed command is M303 E-1

If you do a M105 while trying to heat up, does the response for the bed give you an B:67 /110 @127 or so on it? The @127 means the board is trying to give you full power. If so, it isn't the PID/autotune settings. And the PID wouldn't kick in until 10C below the setpoint anyway. If your board is putting out full power, it could be a thermistor reading low problem (measure the actual temperature) or an insufficient power to the heatbed.

If M105 gives you a lower number than 127, the controller is trying to give you the N/127 fraction of full power and could be a problem with the PID/autotune config. You should be able to figure out what the full power going into your bed is by P_bed=V*V/R. Many people have success with 120W [reprap.org] heaters, which measure about 1.1-1.2 ohms and use about 10A at 12V. If you are actually putting 120W in and only getting to 67C, the energy has to be going somewhere.

Dear DaveX,

As per your comment I ran the PID autotune for the 120W reaprap.org heater bed that I am using.

ok B:69.09 @:128
ok B:69.17 @:128
ok B:69.23 @:128
ok B:69.33 @:128
ok B:69.47 @:128
ok B:69.61 @:128
PID Autotune failed! timeout

It looks as though it reaches 69.61 but then fails.

As I have previously noticed a lot of my issues are due to improper soldering job. Currently I am using a 16gauge wire. Attached is the snapshot of what it looks like.


Please advise.

PS: i have ordered a 40w 5mm cartridge heater for the hotend, hoping this will help in maintaining constant temp. But am still puzzled by the heater bed

Sincerely,

Janski

The picture makes your problem clear. Pads 2 and 3 need to be soldered together along with the black wire, assuming you are using a 12V power supply. If you are only soldering to one of those pads, the heated bed will draw much less current, and fail to heat properly. The reason there are two pads there is to allow for 24V operation, where you would only connect to one of them.

It also looks like you need a higher power soldering iron and more solder. The heated bed wires should run up through the holes, and then be soldered with a generous amount of solder. It takes a fair bit of heat to do this as the copper pads on the heated bed are fairly large.

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NewPerfection
The picture makes your problem clear. Pads 2 and 3 need to be soldered together along with the black wire, assuming you are using a 12V power supply. If you are only soldering to one of those pads, the heated bed will draw much less current, and fail to heat properly.

So what you are saying is that I should solder Red wire to #2 and Black wire to # 3? Instead the pictured 1 and 2?

Please explain what you mean by "Sadler together". Not sure if I am understanding that part and yes I am using a 12V power supply

Sorry for newbie questions but appreciate your input

Janski

Did you not read my post? That is what I said.

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Janski
So what you are saying is that I should solder Red wire to #2 and Black wire to # 3? Instead the pictured 1 and 2?

Please explain what you mean by "Sadler together". Not sure if I am understanding that part and yes I am using a 12V power supply

Sorry for newbie questions but appreciate your input

Janski

The red wire should be soldered to #1. The black wire should be soldered to both #2 and #3. There's even a diagram on the heated bed its self that shows this.



Edited 1 time(s). Last edit at 02/27/2014 04:34PM by NewPerfection.

Thank you both Dave and Cameron .

I believe I understand what you both mean now.

Excuse my lack of understanding as I am very new at electrical terminology and practice.

Can I simply push the black wire (stripped ) through #2 into #3 and Sadler generously? Or would I have to cut and strip a wire to create a bridge between #2 and #3 and then connect the black wire to the bridge ? Or it does not matter as long we have electrical current passing through both pads?

Janski

It doesn't matter as long as you have good electrical contact between the pads. Easiest way would be to push the wire through #2 and into #3 as you suggested. Then solder generously.

Edited 1 time(s). Last edit at 02/27/2014 05:23PM by NewPerfection.

You guys are awesome. I appreciate your time with these newbie questions I will be saldering it up and will post results.

Loving the open-source community.

-Janski

oops "solder"