Resurrection of a CFEI 100 KVA Induction Furnace

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awemawson:
I've rather come to the conclusion that I need to do away with the crimped lug entirely, form a cup shape from the 3/4" pipe to receive the 12.25 mm diameter of the 70 mm copper wire, and directly braze the wire to the cup / pipe.

This actually is as I thought that I had done it years ago, and maybe when I open up some more 'ends' that will be revealed, but the lug on the outside of the copper tube is too big and needs to go.

I've had one of the brand new short driver cables on the workshop floor for a while - these are the ones with the wrong conical ends fitted. So I decided to butcher one to see how it was done. Turns out that basically they also have formed a cup in pipe, but it's apparently thick enough to be crimped.

So I'll be doing much the same but brazing not crimping.

The internal 19 mm bore of the pipe gives 283.5 square mm and 12.25 mm diameter of the copper wire gives 122.7 sq mm, so the copper takes up 43% of the bore, and the water 57%

WeldingRod:
I've got to say, I like the short hose version a lot better!

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awemawson:
Sadly not easy to replicate though I wish that I could.

You’ll notice that the cable is a flat plait, and the tube forming the crimp is very thick wall, neither of which I have

awemawson:
What I do happen to have though is eight 70 mm 'Butt Splice' crimps that I maybe can modify.

Objective is to modify half the butt splice to be able to encircle the 3/4" copper pipe, but leave a gap for water to emerge and use the other half to crimp the 70 mm welding cable.

So, cut half way through in the middle, slit half the length and form the resulting mangled bit of copper round a steel bar held in the vice. Then trim off corners, a bit of filing, then a run through the sand blaster.

Looks like it might work :thumbup:

awemawson:
So now it's a case of cleaning up the welding wire by immersion of the end in phosphoric acid followed by a good rinse, crimping the modified butt splice, cleaning any flash from the crimping to save tearing / cutting the hose as it enters, and pushing it in.

. . . and in it went - easy peasy :clap:

The other end isn't going to be quite so easy. The rubber Brewers hose needs pulling back about five inches, gripping while the cable is gripped and cut to length before crimping on another modified butt splice brazed to the copper pipe. Once cut if the Mole Wrench gripping the cable lets go you are up the Swany as the cable will retreat back up the Brewers Hose never to be recovered :bugeye:

Once the first crimp is made things can relax a bit - I made a total of three crimps each end to reduce the entire length of the butt splice to 'crimped diameter, and had to tidy away quite a bit of crimping flash.

After that it was relatively easy to push the fitting into the hose once the Mole Grips were released, as the compression of the hose was helping this time !

So that is one hose assembled bar the Band-It clamps and serving with heat shrink.

. . . one down three to go and at least now I have a process that seems to work :thumbup:

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