Heat Bed Issue

[RamJam]

Hello all,

New here so hope ive posted this is the correct place.

Bit of a backstory (Sorry). I've obtained a 3D printer from a friend, however it wasn't working, so ive needed to repair it. Everything is now working correctly apart from a Max temp error i get for the heat bed. After fault finding and swapping the thermistors over i have identified the heat bed thermistor is the issue. Because of this i removed the heat bed and saw that the pad for soldering one end of the thermistor cable to was missing. Because of this they have soldered the cable end to edge of the surface mount thermistor. (Being a Helicopter and aircraft electrician this made me cringe) The thermistor is also becoming unmounted from its pads too.

So thats the story,

My question is, instead of purchasing a new heat bed with intact solder pads and thermistor, could i just purchase a "through hole thermistor" and using heat resistant silicon from work fix it to the bottom of the heat bed? Would this work in the same way?

P.S my current heat bed is the "ALU MK3 by REPRAP.


Many Thanks in advance

RamJam

[Roxy]

First, all of these parts are easily available on eBay. If you look at the Configuration.h file you will see the thermistor types for the different parts of the printer defined. You should be able to order one very easily on eBay. And for that matter the heated beds should be available at reasonable costs too.

But to your question: Yes, you can do that. Preferably, you want the thermistor touching and in contact with the heater PCB board. A lot of people tape the thermistor to the bottom of the heat bed with klapton tape. I do that, but I typically put a small piece of spongy foam under it to keep a slight amount of upward pressure on it in the hopes that it will keep in better physical contact with the heater plate.

[LuckyImperial]

Ram,

Yeah, it's totally normal to do a through hole thermistor for the heat bed. But like Roxy says, they're usually attached via Kapton tape, which is probably a little easier to deal with than Silcone. I like the sponge idea too.

http://roaddoglabs.com/wiki/images/t...assembly_2.jpg
http://www.ultibots.com/epcos-100k-thermistor-1-pack/

[RamJam]

Cheers for the replies, been a massive help!