Verifying good hex crump

[cinergi]

I wanted to ask if anyone has tips on verifying a good cold-weld hyrdaulic hex-crimp. I'm worried that the hacksaw method I used is making it look better than it was.
My first attempt at a 3/0 cable with a 3/0 lug and a 3/0 die:



OK, die is too small. So I went up 1/2 a size to 3/0+ which looked perfect and then I took a hacksaw to it:



So, it looks perfect and I couldn't scrape at it to get any free-floating wires, but that may have just been the hacksaw. How else could I get a cross-section that doesn't alter the original crimp?

 

[Luthj]

The best option is a pull test, but that typically takes hundreds-thousands of pounds for larger cables. Assuming your cable was a firm fit in the lug, the level of compression shown will result in a cold weld, and air tight crimp.

You can use some acid to etch the surface. That will make any voids obvious.

 

[Zil]

I test my crimps using a voltmeter. Put a load through the cable and measure the voltage drop across the connection. The government certifying test is "pull test" Chart here. https://marinehowto.com/wp-content/uploads/2016/01/04-Marine-Wire-Termination.jpg

 

[cinergi]

Cool .. the wires in question include 3/0 ... not sure how I'd do a 350 - 800 lb pull test on that without special equipment...
As far as testing voltage drop ... not sure what's acceptable for various lug sizes ... ?

 

[Deleted member 9967]

I wanted to ask if anyone has tips on verifying a good cold-weld hyrdaulic hex-crimp. I'm worried that the hacksaw method I used is making it look better than it was.
My first attempt at a 3/0 cable with a 3/0 lug and a 3/0 die:

View attachment 25814

OK, die is too small. So I went up 1/2 a size to 3/0+ which looked perfect and then I took a hacksaw to it:

View attachment 25813

So, it looks perfect and I couldn't scrape at it to get any free-floating wires, but that may have just been the hacksaw. How else could I get a cross-section that doesn't alter the original crimp?

May I ask what tool did you use to make the crimp?
Thank you

 

[Zil]

voltage drop is not dependent on lug size. I look for less than 0.001 volt on connections and 1.5 % on overall circuit.

 

[cinergi]

May I ask what tool did you use to make the crimp?
Thank you

TEMCo TH0005: https://temcoindustrial.com/temco-hydraulic-cable-lug-crimper-th0005-11-us-ton-6-awg-to-600-mcm.html

 

[Deleted member 9967]

TEMCo TH0005: https://temcoindustrial.com/temco-hydraulic-cable-lug-crimper-th0005-11-us-ton-6-awg-to-600-mcm.html

OOOOOH, heavy duty stuff eh? Nice tool.
How does it feel to use this tool? By that I mean, is it easy or cumbersome because of its size?
Can you easily put the wire and lug in the end and hold it there while using the crimper function? Or do you have to hold each end with one hand and "try" to crimp it?
Thanks for the link

 

[cinergi]

OOOOOH, heavy duty stuff eh? Nice tool.
How does it feel to use this tool? By that I mean, is it easy or cumbersome because of its size?
Can you easily put the wire and lug in the end and hold it there while using the crimper function? Or do you have to hold each end with one hand and "try" to crimp it?
Thanks for the link

Definitely awkward to use. I put it on the ground with the pump handle up in the air and pump with one hand while holding the wire & lug with the other hand. I wouldn't want to do a lot of crimps this way.

 

[Deleted member 9967]

Definitely awkward to use. I put it on the ground with the pump handle up in the air and pump with one hand while holding the wire & lug with the other hand. I wouldn't want to do a lot of crimps this way.

Ah ok then. I suspected that this would be the case.
Thanks for your help.