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easy bed temp control mod that will not void warranty
#1
Ok so I was thinking at work today about my printers bed temp limit of 90. I came up with an easy solution that works rather well. you will need the following.

Stereo volume control 100k dual-ganged with audio taper
a male and female two pin connector (like the connectors on the thermistors, sorry I don't know what they're called.
22 gauge solid wire.
a way to measure the resistance
a way to measure the bed temp

First wire the two gangs on the volume control together in parallel.
Test to see if you are getting about zero to 50k ohms. (two 100k resistors in parallel halves the resistance) 
Then wire the control in series with the thermistor.
basically you build a jumper with the connectors, cut one of the wires and attach each to one leg of the volume control. The control set at about 23k ohms got the bed temp to about 110 for me.

What's happening?
If everything is right, when you turn the knob to increase resistance, you will notice the temp on your machine dropping. Since it thinks it is cooler than it actually is, it keeps heating the bed.

You shouldn't do this if you have no way of testing the bed temp, as it has the potential to keep heating well past factory settings.

One of the benefits to doing this is after the print sticks you can gradually turn the temp back down. turning the knob all the way down allows the machine to act as stock.

Things to do:
Build a box for the control, and a knob, with a stop on the bottom, for keeping me from turning the heat up way to far.
Other thoughts were I could just use a marker and make marks at the setting that worked.

If someone knows how I could program an arduino to read the resistance and display the real temp, I would be greatly appreciative.

If anyone can post the wiring diagram, that would be neat too.
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