CAN cable for tool distribution board to tool board

dc42

I am about to make up these cables myself, for using a Tool Board on the E3D Tool Changer. I bought some of this https://www.ebay.co.uk/itm/Spectra-Strip-13-Twisted-Pairs-Ribbon-Cable-455-278-26-26x7-34-5-Metres-OMR4-02/251792806204. I plan to extract two of the pairs and use those.

Here are some other possibilities:

Take a High Speed ADSL cable and cut off the RJ11 connectors
Take an Ethernet patch cable, cut off the connectors, remove the sheath, and extract two of the twisted pairs
I have some flat Cat 6 Ethernet patch leads (see https://www.kenable.co.uk/en/search?controller=search&search_query=flat+network+cable) which are very flexible in the thin direction. So I could cut off the connectors and use two of the pairs in one of those.
This http://www.farnell.com/datasheets/1377874.pdf is available from some of the usual electronic component distributors

Whichever I use, I will solder the ends to the 4-pin JST connector tails provided in the connector packs, using heatshrink sleeving to insulate each connection and more heatshrink over each bundle to add mechanical strength.

Over short distances it may be possible to use just one pair between the distribution board and the tool board, in conjunction with two ferrite beads at the distribution board end; but I haven't done any measurements on this setup yet.

bot

In some regions, this is only an option for registered companies, but Misumi has a range of cables designed for movement, with a categorization scheme that tells you how good it is for shielding, flexibility, etc. All of their products (listed under the Misumi brand, but are actually other brands) have very good specifications listed.

Here is one example. On that page, they link to a customizable industrial network cable that could also help. They have tons of stuff.

Danal

You can also harvest from old USB or Mouse cables. Some very fine stranded wire is available that way. Fine in terms of both "small/thin" and "good quality".

deckingman

On the subject of making up cables, I bought a cheap kit off of eBay or Amazon (can't remember which). I was able to make some using single strand solid core cable, but I found that trying to get 4, multi strand wires into the 4 separate inputs of an RJ receptacle was simply impossible for me to do.

A Former User

Keep the part of the cable stripped of the sheath short, straighten and arrange the wires so they sort of keep their shape before sliding the plug on.

On the other hand you can get three piece plugs with a sort of a tray to line the wires in + strain relief that may make it easier. (Not sure if they make them for RJ11/RJ14 or just RJ45 though)

mundsen

Is something like this an alternative?

https://www.aliexpress.com/item/32819201617.html?spm=a2g0o.productlist.0.0.6c4e22d80MuYak&algo_pvid=ad45ae30-2fb9-4f57-950c-7ce82b598ece&algo_expid=ad45ae30-2fb9-4f57-950c-7ce82b598ece-0&btsid=0ab50f6115832276850845160e3dd3&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

deckingman

@bearer said in CAN cable for tool distribution board to tool board:

Keep the part of the cable stripped of the sheath short, straighten and arrange the wires so they sort of keep their shape before sliding the plug on.

On the other hand you can get three piece plugs with a sort of a tray to line the wires in + strain relief that may make it easier. (Not sure if they make them for RJ11/RJ14 or just RJ45 though)

That's what I tried to do and managed it with solid core conductors, but trying to arrange the multi-core flexible stuff to keep it's shape as I slid it into the plug, I found extremely difficult to do. Obviously it must be possible because I bought flexible leads which I cut one end off, but it's not something that I could master - younger eyes and hands might help.

oliof

After fighting through some confusion with straight-through twisted pair, I sacrificed a quite flexible Ethernet cable that came with my wifi access point, did a terrible solder job that's hidden by two to three layers of heatshrink tubing, and the magic smoke stayed in the boards (-:

Now that that's out of the way, I need to make new board mounts for the distribution board and the tool board. Luckily I have added some mount holes for additional things to my carriage, so I do not need to completely redesign it (-:

A Former User

@oliof said in CAN cable for tool distribution board to tool board:

did a terrible solder job that's hidden by two to three layers of heatshrink tubing, and the magic smoke stayed in the boards (-:

If you're unable to secure the heatshrinked part of the cable I'd try to get a hold of some JST ZH terminals and crimp to the twisted pairs instead of soldering; looks like you have a very narrow section for the cable to flex between the heat shrink and the connector?

gtj0

@deckingman said in CAN cable for tool distribution board to tool board:

@bearer said in CAN cable for tool distribution board to tool board:

Keep the part of the cable stripped of the sheath short, straighten and arrange the wires so they sort of keep their shape before sliding the plug on.

On the other hand you can get three piece plugs with a sort of a tray to line the wires in + strain relief that may make it easier. (Not sure if they make them for RJ11/RJ14 or just RJ45 though)

That's what I tried to do and managed it with solid core conductors, but trying to arrange the multi-core flexible stuff to keep it's shape as I slid it into the plug, I found extremely difficult to do. Obviously it must be possible because I bought flexible leads which I cut one end off, but it's not something that I could master - younger eyes and hands might help.

Yeah the stranded conductors have very little memory compared to solid ones. I've used several methods...

Arrange the conductors then use a dab of superglue to fix them to a small piece pf paper leaving a few millimeters at the conductor ends to slide into the pin slots.
Use a tiny bit of Kapton tape across the conductors, again leaving a few millimeters free to slide into the slots.
Heat the conductors with a heat gun, pull them through your fingers to straighten them, then let them cool and stiffen.

deckingman

@gtj0 Good tips - thanks.

dc42

@oliof, I recommend that you zip ties the cables to a secure point on your print head to provide strain relief, and leave the wire ends going into the JST ZH connector loose and flexible so as to avoid pulling on the crimp joints. Here https://miscsolutions.wordpress.com/2020/03/04/converting-the-e3d-tool-changer-to-duet-3-with-hemera-tools-part-2/ is how I did it.

dc42

@bearer said in CAN cable for tool distribution board to tool board:

@oliof said in CAN cable for tool distribution board to tool board:

did a terrible solder job that's hidden by two to three layers of heatshrink tubing, and the magic smoke stayed in the boards (-:

If you're unable to secure the heatshrinked part of the cable I'd try to get a hold of some JST ZH terminals and crimp to the twisted pairs instead of soldering; looks like you have a very narrow section for the cable to flex between the heat shrink and the connector?

The only time I tried to use JST ZH connectors without using pre-made tails, I gave up trying to crimp them, but soldering the wires to the crimp pins worked. But I have a smaller crimping tool now.

oliof

@dc42 cable strain relief will be part of the board mount, and I can remove the lower heatshrink tube freeing up the wire ends a bit. Thanks for the recommendation!

dc42

BTW while commissioning the Hemera tool in my tool changer I found a bug in the 3.01-RC3 tool board firmware. See https://forum.duet3d.com/post/136597 for how to get a fixed version.