connecting the heated bed

[barnett]

Hi,

Wiring on my Rostock Max wood kit is basically done, but I'm not seeing any info on just how to connect thermistors and power to the heated bed. I see on the Reprap wiki where wires go to the Rambo, but can someone tell me what to do with the other end of those wires?

My confusion is that
- I'll have two wires from the board for heat, but there are 4 terminals on the bed
- solder these wires or glue them with the silicone?
- thermistor wires to bed will go to the thermistor? Where does that connect to the bed? Does that use the silicone?

I suppose I'll have similar wiring questions about the hot end.

Thanks!
Barnett

[kometen]

Hi,
I have done my wiring this way:

Instead of running 2 wires, I run 4.
2 goes from terminal Heat 2 minus and then connected to each of the minus 12V terminals on the heated bed. And 2 wires from Heat2 plus connected to each plus 12V terminal.
I have soldered them.

I mounted the NTC in the socket for the sensor in the 2 outer holes. I have bend the wires so the NTC resistor head is laying close to the mark on the pcb. And then the NTC wires from the controller to the V- and V+ terminal on the heater bed.
As the temperature is low I have also soldered these.

When you get to the hot end - be carefull to have the NTC solid mounted with the heater head. Otherwise the plastic tubing inside the hotend will melt!


Good luck
Best regards
Poul

[JakeCShake]

Barnett and I (his brother in law) have a functioning machine. Yeah..!!!!!!! Everything works now, we calibrated all axis's and are ready to mold.. The heated therimstor on heatbed is curing tonight. The heatend works great.....now we need to start molding.......any advice as to the the software???? Pictures to follow.......right barnett?? It all looks ready to do all......great project....very excited

[JakeCShake]

We used sillicone to cover thermistor on heatbed....and resistors on heatend. We also used silicone to set the thermidor on the hot end. Look great but let us know.....Bar, can you send close ups..???

[JakeCShake]

FYI.....I don't think you need four contacts......we have stable temp with two...this comes from prototype 6.......we look great after two weekends...?!??!?!?...FYI.....

[fredini]

Hi,
Can someone explain something about step 20.2 in the manual- attaching the thermistor to the heated bed? Why is the tape needed on the leads where they go through the holes in the bed? If I'm soldering where they attach to the board on the backside, this can't be to insulate them from making contact. WHat is the purpose of this?

20.2 – Mount the thermistor to the heated bed. Thread the thermistor leads through the holes
shown below and place a small amount of tape over the leads where they enter the Heated Bed. Apply
a small amount of RTV over the thermistor. This will affix it to the board and protect it. Flip the board
over and solder the leads in.

[geneb]

fredini, you're soldering the thermistor wires to the back of the board after you pass them through from the top side. The RTV (or Kapton if you have some) does two things - it affixes the thermistor tip to the board and it prevents the thermistor leads from shorting together from being bumped into, etc.

Does this answer your question?
tnx.

g.

[fredini]

Thanks, Got it.
I was confused by this wording as it seems to be asking you to avoid lettinng the thermister leads touch the sides of the holes you are putting it through:

place a small amount of tape over the leads where they enter the Heated Bed.

[geneb]

Ok, now I understand the confusion.

I've added this sentence after the snippet you posted:

"This will help pin the leads in place so they can’t be bumped by something and short together."

g.