Small cable connecting

I am upgrading an old CNC router and have lots of small stepper cables to join up new to old. Could use small "chocolate blocks" but would prefer something smaller, like a little crimp or solder ferrule. Then I can group them together tidily with some heat shrink.

Any suggestions gratefully received.

Hi, how about soldering them and heat shrink tubing, or the automotive red butt connectors.

Hi Rod , MAPLIN shops have a large selection of all sizes of connectors of all shapes. They are on the internet.

"MAPLIN electronics " hope there is one near you . good luck Maurice.

There are butt connectors that are pre insulated. I have removed the plastic from them, soldered wires then heatshrink sleeve covered them...

If the cable is braided and the joint subject to vibration then crimping is preferred because solder joints lack flexibility and can crack through fatigue.

If you can position the joints away from vibration and strain though, solder joints will be fine and much more compact.

Jon

Chris - yes thanks I have considered both options but I have 10 wires in each bunch x3 off steppers. This gets a bit bulky even with spacing out. Probably not a more suitable solution, but thought I would inquire!

Think telephone cables when they jointed 100 pair cables, in a tent no the side of the road !!

If they are small cables then I would recommend press fit connectors, these are self sealing. I have used them when at work on machinery.

http://www.maplin.co.uk/p/2-way-jelly-crimp-connectors-100-pack-n72dv

Brian - Thanks. Ordered a pack of those. Never seen them before. - I had best buy a tent too, in case things get out of hand.

Based on Scotchlock, ideal for telecoms.

You can purchase uninsulated crimp ferrules that are intended to be used on the ends of multi strand wires going into contactors etc. They are available in a multitude of diameters. I have used them (along with heat shrink tubing) to make very effective joints in cables.

Rod, just a little caution - I believe those Telecom type connectors are intended for use with solid single-core copper wire, rather than the stranded one would normally find on motors and machine wiring.

Dave

Crimping is the way to go. Use a bootlace ferrule and cover the join with heat-shrink sleeving, not the quickest method but reliable:

Used this to extend cables for the 3D printer.

John

Computers have managed with multi cable connectors. Must be something that will fit, somewhere -even an ECU on a scrap car?

Have a look at *Rapid Electronics* web site, they have a very large selection of multi pole crimp connectors. I have usually found what I am after there. Otherwise I go to RS. They are not always the cheapest, but you only want to do these connections once.

Neil

One issue with the telecoms style gel crimp connectors is the low current rating, in round numbers they are typically 50 mA at 50 V.

Being an old fashioned sort I prefer the twist together, older, sleeve and heat shrink route. Staggering the joints makes for a less bulky, but rather longer, junction. If you re worried about vibration then binding in a stiffener should sort the issue. A single conductor out of a three core mains cable should be ample. Leave the insulation on. Vibration can be areal issue but probably not a home shop worry.

Clive

I call this a Post Office Splice and I think it may be what Clive calls a Staggered Joint in his post.

First strip and lay the two wires crossed end to end.

Then twist the two wires together, ideally finishing with a couple of tight turns at each end. (My example isn't the best!)

Finish by soldering and insulating with heat shrink tube or tape. As you see in the photo I made the classic 'Electricians Mistake'. This is forgetting to fit a tube, grommet or shroud on the wire before making the connection such that you have to take it all apart again.

Dave

Edited By SillyOldDuffer on 03/12/2017 13:54:10

Dave (S.O.D.)

I'm pretty sure when Clive mentioned staggering the joints, what he was referring to is if there are multiple distinct cables, and hence multiple joints, staggering them so the final 'bundle' isn't as fat:

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Dave (IOM)

Thanks Dave - that makes sense, I'm sure you're right. Staggering would also reduce the risk of an insulation failure as well: I never quite trust tape.

In the last place I worked they bought a CNC spark erode with 4 axis control in an auction and some nice person had disconnected it with a hacksaw instead of unplugging and unscrewing the cables between the control cabinet and the machine body. I was given the job to re-connect all the wiring and after a few days got it working. After a few trials I found that using bootlace ferules that had the plastic end removed by holding it on to a grinding wheel on the end for a few seconds you can slide the remainder off and just crimp the cables not forgetting to have a piece of shrink tube over first. I used various sizes as the cables were not all the same and some were control and some were power for the drives etc. I then wrapped the joint cables in each bundle with spiral wrap and a tape to join the original mesh cover.

David

Edited By David George 1 on 04/12/2017 22:17:56