Thermister leads and heater core for the 3d printers...

Just wondering, if I wanted to make a swappable extruder for my Prusa i3, is it ok to cut the leads for the heating element, fan, and thermister and put regular molex or some other kind, of connector close to the extruder,
or do i have to worry about special types of connectors...I understand thermocouples are more finicky when it comes to non direct connections to the Ramps/printer board? I was thinking it might be kinda cool to be able to swap out the entire extruder, for one that does PLA instead... I know most can do both, but I also understand it might be better to do them in separate extruders all together ( In this post i refer to the extruder as the whole thing: Extruder, heater core, thermister, cold end, hot end etc...)

any comments?

I made my extruders swappable on my OrdBot. I did it by fitting an 8 pin DIN plug and socket. The DIN plug is clamped to the end of a spring containing the wires that run to the extruder. The socket bit on the x carriage is soldered to the heater, thermister and hotend fan. Nice and neat and works well with no problems. I have a regular Arduino mega 2560 and Ramps board.
I can now change out an extruder very quick. My plan is to make it easy to experiment. I am trying to get twin extruders to work. Unsuccessfully so far.

cool would it be possible to post a picture? That does make better sense... 1 connecter with the appropriate number of pins:

2 for extruder fan
2 for thermister
2 for hot core
4 for stepper motor
2 for print fan (for PLA)

not sure I would want to use a common ground in this case... or is that what you did to reduce the number of pins?

Sounds like you need a second printer........

Just use a 15 pin d-sub connector.

Ben

I was wondering about doing something like this.
But I thought it wasteful to swap out the whole extruder, motor and hot end.
So I'm going to try changing just the nozzle instead.
I've bought an all metal hot end and a couple of nozzles, one 0.3mm and one 0.5mm.
I realize I'll have to unscrew them while hot but I'm thinking I'll make a tool to unscrew it so I don't burn myself.

Gordon

I forgot to say that I have a Bowden tube setup, so that means 4 less wires. The motor (a Greggs Wade variant) is fixed to the top of the printer.




The extruder fan has been temporarily removed in the photo. I run it in parallel with the extruder heater.
I decided to keep the thermistor wired with its own two separate wires, making just 4 wires in all (2 thick ones and 2 thin ones).

The wires from the socket connector are soldered through to the j head, so I mounted it in a slot on the x carriage to allow easy removal.

I am open to suggestions as regards plugs but I wanted the plug to fit to the end of a wiring spring that can be seen in the photo. Running the wires inside a spring neatens up the printer and improves safety.

I have been experimenting with twin extruders and I have 2 sets of identical springs/ plugs and extruders made up. Also a different x carriage for twin extruders.

I might buy some wing nuts to make everything even more easy to swap out but without using tools.

Wow that looks sharp, very cool!...

My current extruded is more of a makerbot style,
The whole thing screws on with two screws to the prusa i3 x carriage.
Here is a picture:



Edited 1 time(s). Last edit at 10/09/2014 05:57PM by Waltermixx.

40-pin IDC ribbon cables, aka IDE cables, are really good for this sort of thing and they're commonly used in the DIY audio field. All the plugs/sockets are cheap, the cables are often free, they fit on 0.1" perf board and you get about 20 connections trivially, with the ability to gang a few conductors together for the high current loads.

With a bit of strain relief, the wires are as durable as most other moving-wire approaches and the ribbon nature means they're kind of self-supporting over short distances - see the ribbon in a Makerbot for example.