Crimping electrical wire terminals?

[conks01]

Hi,

I've bought a typical crimping tool from Maplins but having had 20 practice runs I've only succeeded on 4 occasions.

The wire is 1.5mm but I'm not sure of the terminal size. They're red and the smallest type in the box.

Is there a rule thumb that you go one size down from the wire size and could this be the reason for my poor form?

Cheers.

 

[Momac]

I recently bought some of these - no crimping
http://cpc.farnell.com/wago/221-413/compact-lever-connector-3-way/dp/CN20136?MER=e-bb45-00001003
http://cpc.farnell.com/wago/221-412...ll+Categories&categoryNameResp=All+Categories

 

[PuffTheMagicDragon]

What is "typical"?

This type or better will give good results:

This type won't:

 

[sarabande]

so many different styles and standards of crimping to meet the wide variety of wire types and operational requirements.

Can you post a pic or link to the crimper pls ?

I've standardised on Klauke kit for agr use. The 507 has dies to meet all the cabling and terminals you meet in everyday use.

http://www.klauke.com/katalog/en/k-507-crimping-tool-with-interchangeable-dies/


IIRC recommended by our forum boat sparks.

 

[guyd]

im ex aerospace electrical contact design engineer.

use the big type posted above. not the prrssed steel rubbish. buy from elec wholesale eg http://www.neweyandeyre.co.uk/?branchId=MJC&source=gmaps

strip off just enough to poke in the crimp. surprisingly little, like 4mým. twist to keep together. shove in. crimp. ideally a squirt of grease to prevent corrosion but in theory not necessary as the crimp should be air tight.

if the wire is v small then strip off 10mm, fold in half, then twist. not ideal but does the job.

if you cant afford crimp tool as above then solder.

 

[William_H]

If you were concerned about quality control in industry you would have a system of regularly checking the crimp tool and process by fitting a lug to each end of a piece of wire then measuring the force required to tear the crimp off. Sorry no idea what force would be appropriate for different sized crimps and wire but you should be able to tug fairly well without the crimp letting go.
good luck olewill

 

[alahol2]

For the small amount of crimping I have needed to do I got one of these... http://www.amazon.co.uk/Draper-35574-Ratchet-Action-Terminal-Crimping/dp/B0001K9TGA
So far, all my crimps have survived the 'pull test' that I have administered. They seem to be decent quality and produce a consistent result. I try to buy decent crimp connectors from reputable sources, not just the cheapest I can find.

 

[skipmac]

What is "typical"?

This type or better will give good results:

This type won't:

Yes.

 

[grumpy_o_g]

im ex aerospace electrical contact design engineer.

use the big type posted above. not the prrssed steel rubbish. buy from elec wholesale eg http://www.neweyandeyre.co.uk/?branchId=MJC&source=gmaps

strip off just enough to poke in the crimp. surprisingly little, like 4mým. twist to keep together. shove in. crimp. ideally a squirt of grease to prevent corrosion but in theory not necessary as the crimp should be air tight.

if the wire is v small then strip off 10mm, fold in half, then twist. not ideal but does the job.

if you cant afford crimp tool as above then solder.

Could you clarify exactly what grease you use and when and where? Putting an insulating lubricant between the crimp and the cable does not seem logical...

 

[nigelmercier]

Could you clarify exactly what grease you use and when and where? Putting an insulating lubricant between the crimp and the cable does not seem logical...

I don't know about guyd, but I use Contralube, which unlike silicone is non-insulating.

 

[macd]

For the small amount of crimping I have needed to do I got one of these... http://www.amazon.co.uk/Draper-35574-Ratchet-Action-Terminal-Crimping/dp/B0001K9TGA
So far, all my crimps have survived the 'pull test' that I have administered. They seem to be decent quality and produce a consistent result. I try to buy decent crimp connectors from reputable sources, not just the cheapest I can find.

That looks like the sort of thing thing produced by the million in the Far East and re-badged by Draper. Probably not the finest tool for the job, but affordable, good enough and certainly far, far better than the "This type won't" meantioned by Puff in post #3.

In my experience any problem usually comes when crimping terminals of non-standard wall thicknesses when they can't bite down hard enough. The pull test usually reveals this, but it's a pain in the neck in you've just bought 50 duff terminals. (You're probably better placed than me for buying terminals with decent provenance.) To a degree the crimping depth can be adjusted by the camwheel. (If present, it's probably on the other side of the one pictured in Puff's link.)

 

[sarabande]

I suspect that "grease" is jargon for Contralube or similar.


And I am not too sure about the "airtight" bit. That would require specially selected crimp shapes and wire.

Klauke have very extensive technical support literature, and this one is well worth reading to know about wire types, die shapes and compliance testing.

http://www.klauke.com/en/electrical...ch-method-is-correct-crimp-types-at-a-glance/

 

[conks01]

so many different styles and standards of crimping to meet the wide variety of wire types and operational requirements.

Can you post a pic or link to the crimper pls ?

I've standardised on Klauke kit for agr use. The 507 has dies to meet all the cabling and terminals you meet in everyday use.

http://www.klauke.com/katalog/en/k-507-crimping-tool-with-interchangeable-dies/


IIRC recommended by our forum boat sparks.

Crimper is as per pic two above. Cheapie from Maplins.........

 

[sarabande]

then I think you have an opportunity for indicating that the responsibility for a low success rate is due to the tool, and not to the care you have taken with the work on your own electrical system.

I submit the risks of using a poor quality tool on a critical system are not acceptable. If you had an electricain in to do the work, you woudl not want a 1 in 5 chance of 'good' connections, would you ?


If you are in the South West, you can borrow my Klauke 507 crimper.

 

[SiteSurfer]

I recently switched to one of these from EBay after reading comments on here:

and also switched to these kind of crimp connectors:

and with the rewire I've done so far have been more than happy with the results, coupled with a bit of heat shrink where I felt it would help.

 

[conks01]

Thanks all. I've gone for the Amazon type and (hopefully) better terminals. Cheers.

 

[guyd]

sorry, should have been clearer. a grease or silicone to seal out water ingress into the crimp and wire AFTER its been done. the corrosion tracks up the wire under the insulation, making future repairs a pain.

'liquid insulating tape' is quite cool, but quite expensive (amazon or ebay, about a tenner a small pot)

the crimp should have squished all the wires into tiny tiny hexagons, only visible if you cut it in half and polished the end, and use a microscope. there should be no air whatsoever in that cross section or corrosion will quickly occour, boats or not.

 

[grumpy_o_g]

sorry, should have been clearer. a grease or silicone to seal out water ingress into the crimp and wire AFTER its been done. the corrosion tracks up the wire under the insulation, making future repairs a pain.

'liquid insulating tape' is quite cool, but quite expensive (amazon or ebay, about a tenner a small pot)

the crimp should have squished all the wires into tiny tiny hexagons, only visible if you cut it in half and polished the end, and use a microscope. there should be no air whatsoever in that cross section or corrosion will quickly occour, boats or not.

Ah, with you now. Yes, that makes sense though we (RAF in the 70's and 80's) usually used either adhesive heatshrink or a drying lubricant and a stretchy tube applied with three prong pliers type things - I never knew why one would be specified sometimes over the other. Also totally agree with your last sentence - a properly done crimp should effectively just one lump of metal with no air gaps at all. Decent crimping tools (including decent dies) are essential.

 

[alan_d]

I don't know about guyd, but I use Contralube, which unlike silicone is non-insulating.

Are you sure of that? The manufacturer's website claims:

Contralube can be termed ‘dielectric’ which translates to a material which has negligible electrical or thermal conductivity. Although contralube770 may be physically bridging a gap between two separate pins/circuits it will not allow the current to pass between the pins. Contralube has similar conductive properties to air, so if you do not experience arcing/shorting between pins in unlubricated connectors then the addition of contralube770 should not change the performance/characteristics of the component.

Could you clarify exactly what grease you use and when and where? Putting an insulating lubricant between the crimp and the cable does not seem logical...

According to the manufacturers of Contralube:

Myth 2 – Lubricants interfere with conductivity
Tests on lubricated and nonlubricated connectors show virtually no difference in contact surface resistance. A contact surface is a series of microscopic peaks and valleys – like a mountain
range. Current flows through the peaks – the mountain tops, known as asperities. A contact lubricant fills in the valleys, protecting the metal from oxidation and is squeezed out of the asperities, allowing the current to flow.

 

[Seven Spades]

What is "typical"?

This type or better will give good results:

This type won't:

Absolutely correct. I have the top pair on my boat and it is one of the most useful tools onboard.