haven’t seen anybody use a connector for easy removal of the hotend. my printer has a dual head layout and i’ve thought about using a molex plug (like this one - http://www.aliexpress.com/item/10-pairs-6-Pin-Tamiya-Kyosho-Molex-Plugs-ESC-Battery-Connectors/1128874658.html ) so each hotend has 2 wires for the heater cartridge, 2 wires for the thermistor, and 2 wires for the layer fan) this way i can easily swap hotends and remove for calibrating/replacing stuff.
i’ve came up with almost nothing except a vague warning about not soldering the heater cartridge wires to the connectors…
I suggest you bump it to 12. Thats what I did for my hotend. With two heaters, two thermistors, 6 pin only leaves you with 2 pins for a fan, unless you’re using a common ground between all the above. I wanted a fan for the heat break and one to direct at the print so that would be at least 8. 12 was the next size up at mcmaster. 4 left, maybe for a z probe in the future. Also my original design included a peltier cooler on the heat break, so that was 10 pins used at first. I’ve since pulled the peltier and replaced it with a second heat sink on the other side of the cold end.
I tried a molex connector and kept having shorts or a loose connection. It may be that my luck totally sucks though. My next attempt may involve a small piece of pcb and some angle pins and connectors. I hate crimping for connectors.
Very important to use the proper crimping tool to clamp the pins to the wires. If you arent going to crimp the pins with the proper tool then don’t bother. A bad connection on a heater wire can catch fire when the last strand of a stranded wire carries the full current of the heater. Much current in too small of a wire gets hot. Hot wire has more resistance. More resistance means more heat until it all goes on fire.
My hot end fan and thermistor are on connectors already so all I had to was find a good connector for the hot end. I went with pololu T connectors item #925. They are small 2 wire connectors rated for 50 amps (too much is just enough) I have been switching between 3 hot ends for well over a year and never had a problem. If you drill a small hole on the terminals and feed the wire thru the hole then wrap it around the tab and solder it you get a much better looking and straighter connection. Don’t forget to put heat shrink tubing on before you solder the wires for the professional look.
in europe, we use MPX connectors for this. 8 pins, 3A each, smallest footprint and soldered connections. 6 pins leave you 2 pins short in a standard setup, like @Chapman_Baetzel already mentioned.
I use a 14 pin connector for the complete hotend, including motor, heater, thermistor, material fan, Cooling Fan and light. Since i use 24 V i get a way with a bit smaller connectors http://www.te.com/usa-en/product-1-794617-4.html
I’m looking at this connector: GX16-10-pins-16mm-aviation-connector. (AliExpress)
I want to be able to change my hotend for printing with different materials. So I can use my Diamond hotend for multicolor PLA and a single hotend for other filaments. As it is a bowden setup I can get 2 fans, PTC and the heater (2 sets of contact) connected this way.
@Chapman_Baetzel i think i will go with an 8 pin connector, 12 is just too much and i don’t see myself using 10 - so i think 8 gives me the “future proof” i need
@NathanielStenzel & @Chapman_Baetzel - i’m still a little nervous about the molex option, exactly becuase of these types of warnings, if i were to crimp and solder would that improve/solve the problem?
@david_merten thanks, it seems like a pretty decent connector - i might consider a 6 pin molex for thermistor/fans/z probe and a t connector for the hotend, might be a way to bypass the problematic molex…
@Rene_Jurack i could not find any 8 pin mpx connectors only 6 and isn’t 3A a little low? i think the heater cartridge is 40W and on 12V that means 3.3A (so at least 4.5-5A for safety is required), or am i wrong?
@Neil_Darlow i understand the specifications and reasoning behind your comment - it’s why i was asking this to begin with. but, is there a specific 6-8 pin connector that lives up to those specs that you can recommend (and does not cost more than the hotend itself)?
@Menno_Lauwerens that was a type of connector i was looking at, but i could not find how it handles high wattage, and the only thing i could find was a total rating of 5A for 2-6pins and 4A for 8 and more. don’t know if that’s a per-pin rating or total for pins. it was borderline anyway (molex was supposedly good for 10-12A per pin), so i crossed it off my list, do you have some more info on it? it definitely has the “looks” factor
@Mark_Rehorst Ribbon connectors are not a bad choice.
They are available with gas-tight connections and if you are using PCBs you can use the transition variants that solder to the PCB where removal isn’t a requirement.
The only downsides to using ribbon cable are: 1) Ensuring that sufficient cores are used for power distribution and 2) Provision of some form of support for the cable at the connector exit to prevent fracturing of the cores due to movement. In fact, it is a good idea to support the ribbon cable along its entire length.
@Mark_Rehorst that’s actually a very interesting idea, i could definitely go for that.
could you provide more details about:
which flex cables are you referring to - the kind used (e.g) internally in printers and cdroms or the kind used in (e.g) pata cables and gpio extenders?
which connector did you use to connect it to the board? does it have a locking mechanism?
how do you then distribute connection to the heater/motor/thermistor/probe/etc? do you have screw terminals? or molex/other type connectors?
aren’t those types of wires usually rated for low amperage?
and isn’t 3A a little low? i think the heater cartridge is 40W and on 12V that means 3.3A (so at least 4.5-5A for safety is required), or am i wrong?