28 June 2008

Fabricate - crimper

To attach the lugs to the ends of the 2/0 welding cable I need some kind of crimper. It is possible to solder them on, but solder is not really that good of high current joint. I asked the EVDL what crimp method is the best and eventually it came out that either a hex crimp or a stake crimp would suffice.
I found a pair of 36" bolt cutters on sale for $13 at Harbor Freight. I'm not sure I would use them for very long as bolt cutters, I think the "blade" would get dull quick. After thinking for a while, I thought it would be easier to make the stake style crimper than the hex type. I used an angle grinder and rotary tool to cut the half round (more of a hex really) into one jaw. Then I used the rotary tool to cut a tooth into the other jaw so that it lined up with the other jaw.
My test crimp looked pretty good. I still need to add a little more metal on the end of the stake so it is not so narrow. After making the test crimp I attached it to the ceiling and put all my weight on it. Then I had my wife put her weight on it with me (about 300lbs together). The insulation jacket started sliding so we stopped, but the crimp held! The next thing to do is cut it apart and look at the insides. I used a cutoff blade and cut the lug in two in the midle of the crimp. Then I filed and sanded down to 800 wet/dry until is was fairly clear what was going on. It looks like the crimp is sufficient, but I want it tighter. The dark spots in the photo are from the wet sandpaper. I left it in there to provide more contrast.
I call the crimper a success. With just a little larger stake it will be perfect. To make it easier to use, I have replaced one handle with a new link. Now I need to make a bench mount and possibly make the handle shorter, it doesnt take that much pressure to crimp. I may grind off the tips of the crimper that are not used, if I feel like it.

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