Crackers Makes a Terminal Crimper

I've been putting off replacing the battery terminals on my truck for, well a very long time. 

I bought a set of mil-spec terminals forever ago.

To install them I have to put ring lugs on both ends of the battery cables. This requires soldering or a crimper. 

Having failed traditional soldering on cables before, and really not liking the odds of getting a cold solder joint with the typical method using the solder pellets I'm not exactly eager to try again. (I'm usually a fan of soldering automotive wiring, just not battery cables.)

The hammer style crimpers work great, but I hate the look of the crimps. That leaves the compound/hydraulic type, but damn they are not cheap, and they're quite cumbersome making them fairly inconvenient for on-car repairs. 

I suppose I could make something easy enough. I'm thinking two opposing dies with a hinge on one side and a bolt to draw the two dies together on the other. 

I'm not big on making templates, or drawing plans so I figured I'd wing it. I cut two pieces of steel at a random length that felt like it would be comfortable to work with in tight places and awkward positions.

Turns out it was just over 9 inches. 

Then I had to swell the business end of my new tool.

In blacksmithing, this is called "upsetting". This gives me enough girth to start piercing the end. 

Here you can see the punch I'm using to pierce the eye. I started with 1/2" x 1" flat bar because I had it handy. It's a royal pain trying to pierce through the stock while you have the skinny side up. You really have to hammer on it just so, or it falls over or worse, your hole gets crooked. 

Good hand eye coordination is key, and fortunately having upset this first makes it a little more stable seeing as you have a "bell" on the end. 

You pound on the tool a few times then pull out and quench it in some kind of lube so your tool doesn't mushroom in the hole after losing it's temper and going soft.

Of course all this pulling out and lube does lose some of "the fire" so to speak so the steel has to get heated frequently as well. 

It's always easier to poke holes in something when it's super hot. I think in all I used 3 heats per hole. 

Overall, even with a rusty old tool like I'm working with, so long as you use lube, keep it cool, and don't try to pound your way home all in one go you should keep your tool hard enough to poke a lot of holes before it goes soft. 

I'm doing both dies at the same time, or rather alternating between them. When one goes from red hot to grey you can hammer on the other one while it goes back in the fire. "Lots of irons in the fire" and all. 

Next post we'll flip these things over and work on the other end for a while. 

Next step was to start working on the hinge end. The plan was to bend the end to about 45° then joggle the ends so they could overlap and still have the ends of the dies line up correctly. 

This usually takes 1 to 1.5 times the width of the stock to make the proportions aesthetically pleasing. I split the difference and marked the steel 1.25" from the end with a center punch. 

This mark also helps me recognize which end I want up when I make the bend. 

The whole idea behind forging this by hand was so that I could make a tapered hole for the tension bolt. Otherwise the bolt would bind before the dies could open up far enough to accept the terminals, rendering the tool useless. So making sure I had the holes facing the same direction was important. 

Shortly after bending it over the corner of the anvil I completely lost my ability to multitask and forgot to take a lot of pictures. By the time I realized I wasn't taking pictures I'd practically finished the forging work. 

Somewhere in this confusion I made the awkward decision to finish these two off without the aid of power tools. 

Not being able to use my toys meant a lot more work, but would ultimately be more satisfying for me knowing I was able to accomplish this the old fashioned way. I just had to put my head down, put my weight into it and get the job done. 

Also, something about the irony of a 100% hand made tool being used to make electrical parts really makes me giggle. 

After the ends were bent I spent some time making small adjustments, putting the two on top of each other and staring, more tweaks, etc. After a while I realized I had to poke a couple more holes before I could make any more progress. Then I was finally able to do a proper mock-up, with a 7/16-20 bolt scavenged from a bucket of AMC parts. 

 Fit is pretty spot on! 

Hammer forging and hot punching creates "fish mouthing" or lips on the ends that were most heavily hammered. A little time with a rasp smoothes all of that out pretty quickly. 

Fairly smooth, but there's a bit of misalignment, also a bit of a gap at the hinge that needs to be closed up. 

A few smacks with a 3# hammer takes care of that pretty easily. 

Now I can fit a M10-1.5 bolt as the tension bolt and mark where the dies are going to be cut. 

I poked all the holes in this with the same tool. I just drove it a little deeper for the hinges so I could use a more substantial bolt. I may take a file to it so I can jump to 1/2" stuff on both ends, but I'm going to try it like this first. 

Then I put it in a vise and cut a small groove with a hacksaw to use as a depth guide for cutting (filing) the notches. 

I'll be cutting multiple notches so it will crimp various sizes. I took a wild guess and started with a 10mm "hex". 

It got too dark to continue, but I'm going to test it on an old cable and decide if I need a larger or smaller die. 

I'm excited to try it. ​​​​​​

Wow. Cool!

Yeah, seriously cool!

I'm apparently still 12. Your first post had me laughing like Bevis and butthead.

Otherwise, awesome!!!!

wtf.

.

.

.

This is so awesome.

Cool Beans dude,

I'm going to ask the wife to drop me off at Cracker's place, he's got all the cool, or in this case, hot toys.

Thanks guys! I'm really happy with how it's turning out.  

Dusterbd13 said:

I'm apparently still 12. Your first post had me laughing like Bevis and butthead.

I don't follow...

Read the middle of the first post with a dirty mind 

Regardless, blacksmithing is something that i know NOTHING about.  So incredibly interesting to read! Please continue and I'll try to refrain from being juvenile. 

Lol

Ok. Sorry......

Im socially incompetent in real life too!

Alright, so I did a test crimp with the 10mm die and that was a hard fail. Just too big. So I made a smaller 8mm die. Shown here with the lug from the failed crimp. 

Testing.

Looks like we have a winner!

It did however give my little 1/4" impact driver a run for the money. 

The long term plan is to make the dies on the hinge end for more leverage. I cut them on this side so I didn't have to worry if I screwed them up. Once the new dies are cut it will pretty much make crimping new lugs trivial. 

So now I need to source a longer grade 8 bolt so it can open up like this. 

While that mild carriage bolt would shear off pretty much immediately, you can see there why having a tapered hole was so important.

Hoping I can find something with lots of threads in a 3/8" fine or M10-1.5. 

Total investment would be about $5, and 3 hours. $2.50 of that was for propane to run the forge. 

Although I had all of this stuff laying around. Challenge rules would have this $0.50

So I just found out hydraulic crimpers are in the $50 range on eBay.

Everything I saw originally was closer to $200 for anything with jaws wide enough for single crimp capacity. 

Not that I regret making these, as tool making is one of my non-car hobbies, but I probably would have just bought a set had I known they were available that cheap and used the time for something else. 

Although, I did save almost $50, and got to spend some time participating in a hobby I don't have a lot of time for lately. I'm also 99% certain these will last forever, same can't be said for eBay Chinesium. 

In any case, I found all this out because I'm shopping for some new lugs and cable, as the stuff on the truck has a fair amount corrosion invading the cables. 

For now I'm just gonna slap on some lugs because I need to use the truck. I borrowed the battery to test another car and both of the cheap bolt-on terminals broke when I tried to remove them. 

GRM Advertiser HF's solution

$55.  It works great.  I use it for all kinds of things that need to be much flatter. 

Dusterbd13 said:

I'm apparently still 12. Your first post had me laughing like Bevis and butthead.

Otherwise, awesome!!!!

 same here I was wondering if it was on purpose lol