RJ45 ethernet connector for hotdend

[ramai]

I do networking for my job, so I have a lot of ethernet tools. I am in the middle of rewiring my hot end, and it dawned on me that it would be awesome if I could use the 4 twisted/shielded pairs in an ethernet cable to run my hot end with the fans etc. I would have a simple RJ45 connector clip into it, making it super easy to disconnect. Has anyone done this? Are the wires up to the task?

[Xenocrates]

For the fans/thermistor, possibly. for the hotend power, almost certainly not. It has a rather low ampacity of approximately one, and so would have serious issues with anything above a 12W load (per pair), meaning a hotend would need to have, for the cartridge heaters, essentially an entire connector dedicated to it. I would recommend actual power connectors instead, such as MOLEX's.

For example, these:
http://www.mouser.com/Search/ProductDet ... u7TA%3d%3d
http://www.mouser.com/ProductDetail/TE- ... aRnkGcY%3d
which take pins like these:
http://www.mouser.com/Search/ProductDet ... puCQ%3d%3d
http://www.mouser.com/Search/ProductDet ... Vwxg%3d%3d

Fans, depending on which ones, may actually be too high a load for RJ45 and standard ethernet cables.

Good luck, and don't let the smoke out
if you do though, I know where to get Genuine Lucas electrical smoke

[maralb]

wasp Delta italy use hot end connect RJ45
[img]http://www.personalfab.it/wp-content/up ... G_9901.jpg[/img]
maybe use this system ???
[img]http://i.ebayimg.com/00/s/OTA1WDkzOA==/ ... J/$_57.JPG[/img]

down hotend Wasp old

[Eric]

Cat 5 spec is 24awg wire. Cat 6 is 23 awg. Current ratings are easy to find for wire sizes. But remember you have to significantly derate wire that's bundled in a cable, for heat dissapation reasons. In this application, use stranded patch cable wire, not the solid stuff.
Typical RJ45 contacts have a 1.3-1.5A rating, depending on manufacturer. You might get away with more, especially if you religiously avoid hot-plugging it.
If you have a 40W hot-end at 12V, that's going to draw about 3.33A. Clearly too much for one pair...but you might get away with three pairs.

What you can actually get away with on personal projects and what the specs are likely two different things.
So possible, probably. Advisable, maybe not.

[626Pilot]

Don't do it.

Ethernet cable is made with solid wire, which is not suited to constant flexing and vibration. It will get work-hardened, and sooner or later it will fail. I used Cat-5 for my hot end wiring for awhile, but eventually one wire got flaky, and then another. There's enough stuff to go wrong with a 3D printer already before you choose what kind of wire to use.

It's better to use stranded wire. I use this shielded, 12-conductor robotics cable: http://www.mcmaster.com/#8082k43/=108uypq" onclick="window.open(this.href);return false; - That is adequate for running current to a hot end, and it's designed specifically for constant motion and vibration. The remaining conductors are for fans, LED rings, and a Z probe.

If you want to do it cheaper, you can get stranded 8-conductor wire here: http://tricklaser.com/Wire-8-conductor- ... 8CON22.htm" onclick="window.open(this.href);return false;

If all you want to do is run wire to a single hot end or extruder motor, any old 4-conductor speaker wire will do, although shielded wire is less electrically noisy. I ran 2-conductor speaker wire to power the hot end when I was still using Cat-5. The ampacity charts don't lie. Even if it wasn't prone to failure under the punishment of being used in robotics, it would still be inadequate to transmit power.

[ramai]

Thanks everyone for weighing in. It looks like the consensus is a big fat NO. Thank you pilot for bringing your real world experience on the matter. If you used it, and it failed, thats good enough for me to drop it all together. I guess I'll stick with my MOLEX's but crimping those tiny wires is a pain.
That wasp thing looks pretty cool though!

[geneb]

Grab the v1 manual and look how I did the optional quick disconnect for the hot end. It uses a male & female four pin latching connector to do the job. Hansen Hobbies sells the pins, the shells, and even the right crimper.

g.