Geeetech

My situation is a little different.
This is because my printer already has two external extruders.
I also have a different version of the printhead:
https://www.geeetech.com/assembled-jiet ... p-749.html

If you like Marlin, you can try it out from a double-headed printer.

I made this upgrade but seems the input for the second thermistor is broken on the board, I even changed the pullup resistor with no luck. Are there any other unused pin on the GT2560 A+ I can use to plug the thermistor of the second extruder?

Hi, you can refer to this :http://www.geeetech.com/forum/viewtopic ... 20&t=18020

Hi, just wondering if anyone has done this upgrade to their I3 Pro B?

I have ordered all the parts and I have tried fitting them, but I am struggling with the dual print head assembly.

The two print heads are connected by an aluminium bar which both the threaded extruder tubes pass through and which has a 'foot' on either end which is about 5 or 6mm thick. By comparison the single extruder which this assembly is replacing has a flat plate which the extruder tube passes through but it doesn't have 'feet'.

The extra thickness of the feet means that the extruder nozzles sit 5-6mm higher on the double extruder than on the single extruder. The vertical movement on the printer can't bring the head any further down, so the only way I can see to make up this difference is to move the heated bed up by 5-6mm, but this is more than the screws and springs holding the bed in place can reach.

So, either I am doing something wrong with the assembly of these parts, or I need to replace the hot bed adjusting screws with longer ones and with longer springs.

If anyone has actually upgraded their I3 Pro B, can you tell me if you hit this problem and if so, what you did to fix it?