How to use a ratchet crimp tool

[Dr Mike Oxgreen]

For years I've always used a non-ratchet crimp tool - you know, the type everyone says you shouldn't use - and I simply squeeze as hard as I can. Never yet had a crimp fail to grip the wire properly.

Last week I finally succumbed to peer pressure and bought a proper ratchet crimp tool ( this one, to be precise), and yesterday I tried using it for the first time.

I must have tried 7 or 8 times, and every time it failed to grip the wire properly. I nearly ran out of the correct size of butt crimp connectors. To my mind, it just didn't seem to be squeezing hard enough before the ratchet releases the pressure. Eventually I gave up and went back to my trusty non-ratchet crimp tool, and that worked first time.

So what was I doing wrong?

The tool I've bought crimps in two places, whereas my old tool only crimps in one spot. What's the purpose of that? I normally crimp the wires into a butt connector one end at a time; is the new tool meant to crimp both ends simultaneously, or is it somehow meant to crimp onto both the wire strands and the insulation? If the latter, then my butt connectors don't have enough length of metal to allow you to crimp onto the insulation as well, and in any case the insulation won't fit into the little metal cylinder. And surely if you crimp onto the insulation, that'll reduce the pressure on the copper strands and give a poorer crimp? Am I using the wrong type of connector?

[pherlopolus]

Are you putting the connector in the right way round? The only failures I get are using the wrong size connector for the wire.

I have been known to recrimp on the next size hole down occasionally, but prob not needed.

I always made sure the crimp is horizontal, with any join facing down too.

[Smiler.]

If you're using the insulated crimp terminals I think you are (the sort I use), I think that's the wrong tool.


This is what you want:



The ridge on the tool corresponds with the part on the crimp opposite to the cable entry (or is it the other way around)


And no, butt crimps need each end crimped separately.

[Dr Mike Oxgreen]

Not sure I understand. Do you mean was I putting the connector into the tool the right way round? If that's what you mean, then I'm not sure - but now I come to think of it, the first end did seem to work correctly and it was only when I tried to crimp the other end of the butt that it failed every time.

I wasn't aware that it matters which way the crimp connector goes into the tool. Do the two crimping 'jaws' apply different pressure (perhaps because one of them is indeed meant to be crimping onto the insulation)? Otherwise I can't see why it would matter.

Yesterday I was using red crimp connectors (actually more a pinky colour) with heat shrink insulation. These would only just allow all the copper strands into the crimp, so should have resulted in a nice tight crimp. Should I have been using a blue one instead? But surely a larger crimp connector would have given an even slacker crimp?

[Dr Mike Oxgreen]

Thanks Smiler, maybe that's the problem. I'm using butt connectors with heat shrink insulation.

(Must get myself a proper heat gun, which would work better than shrinking it with a match!!)

Edited to add: The one you've illustrated only seems to crimp in one point, although it looks like it creates a 'longer' crimp, which to my mine seems better.

Edited again: With the one Smiler has illustrated, it clearly does matter which way round you use it. But my new tool seems completely symmetrical when viewed from the end of the jaws.

Edited by Dr Mike Oxgreen on Sunday 15th February 08:08

[Smiler.]

Dr Mike Oxgreen said:

Thanks Smiler, maybe that's the problem. I'm using butt connectors with heat shrink insulation.

With the one Smiler has illustrated, it clearly does matter which way round you use it. But my new tool seems completely symmetrical when viewed from the end of the jaws.

That's why I think it's the wrong tool for the type of crimp you are using.

[jjones]

I suspect you are putting the connectors in from the wrong side.

For the ones you have..

Insert the connector into the crimps, with the side with the wire on the same side as the coloured dot. On the other side of the crimpers check that the connector (this doesn't work for butt connectors you sort of have to guess a bit where with these) bit that gets squished is flush with the side of the crimpers. Poke the wire in and you should see it appear on the opposite side of the cimpers, get it flush with the edge of the connector then squeeze. Perfect everytime.

p.s I have the exact same crimpers as you and have no issues.

[Dr Mike Oxgreen]

Here's an end-on view.

It is entirely possible that I was crimping the second end of the butt with the 'open' end going the other way.

Edited by Dr Mike Oxgreen on Sunday 15th February 08:25

[Salesy]

Only crimp one end at a time.

Place first cable in then crimp try to line the edge of crimper about 1-2mm in from end of butt splice.

Then turn round and do other end.

As a previous poster said you can sometimes get away with going a size smaller

[Getragdogleg]

You can turn the tension up on the little toothed dial. that can make the grip harder.

[Dr Mike Oxgreen]

Salesy said:

Then turn round

I'm increasingly suspecting that this is the step I was missing out, and this is why my second crimp always failed.

And now I've looked more closely at the tool, I can see that it's not symmetrical. One of the jaws has an indentation that will give a gentler crimp - I suspect this is indeed intended to crimp onto the insulation:

[ch427]

Some cheap tools can be a waste of money as they do not put the correct pressure on the crimp.

[Dr Mike Oxgreen]

Getragdogleg said:

You can turn the tension up on the little toothed dial. that can make the grip harder.

Oh, that's what it's for! Thanks.

ch427 said:

Some cheap tools can be a waste of money as they do not put the correct pressure on the crimp.

Indeed so, but I think on this occasion it was the fault of the idiot holding the tool!

I think Smiler may be right, in that this tool isn't really intended for this type of connector - but now I understand that it DOES matter which way round you crimp I think it will do the job.

Thanks everyone - looks like I won't be chucking this tool in the bin!

Edited by Dr Mike Oxgreen on Sunday 15th February 08:48

[jjones]

Right now get a set of wire strippers!

http://www.screwfix.com/p/c-k-automatic-wire-strip...

If you don't have something similar you do not know what you are missing!

[McWigglebum4th]

Can anyone point me towards a decent ratchet crimp tool for use with insulated crimps

As the one i currently have may have to be beaten to death with a big hammer

[ch427]

The best one ive used and now own is made by ck tools. Not cheap but when you use it on important jobs you need to be sure of quality joints.