Rewiring Anne: A 1953 Necchi Nova Part 3

With all the decisions made, the tools lined up, the work bench clean and a spot chosen carefully for the hot soldering iron, it was time to get down to business.

Cutting the old and new wire.

This requires more sharp cutter than practice.  It can take formidable pressure to get a clean cut. More often than not I end up with one or two little strands that I have to carefully snip to length.

Stripping wire

is one of the things that a wire multi-tool is supposed to do. Getting it just right is a trick unto itself. I have to be careful and watch what I'm doing. My issues may have more to do with having an older multi-tool and it could be a tad dull, but being older and a tad dull is something we share, so I don't ever complain.

The wire stripping part of the tool is labeled per gauge. I'll insert the wire and press down allowing the jaws to just cut into the insulation, then I'll or push the tool away from the cut in the direction of the intended bare wire section (still closed) and the insulation should slide off. Sometimes I have to place the wire in the slot, pinch, and then turn the tool on the wire and pinch again. just to make sure it's cutting into the outer covering, and I have to be careful pushing/pulling. More than once I should have allowed a little more free space for what can be a rather sudden follow through.

One wire seems to always be different from another wire, and the longer it's sat around... the more resistance there can be to the insulation. For me, it's good to have new wire and enough of it for a mistake.

Since I now know the length of new wire that I want, I'll go ahead and cut those. Then, I'll strip the insulation off one wire end: between one half an inch and three quarters an inch in length.

Here's the new wire being held up against the old leads of the motor. ^

After a very careful examination of the old motor leads I found the last bit of insulation to be very good. Apparently being encased in the safety of the motor kept them in great shape. I rolled, and pinched, and the material was not dry and it did not crumble.  So, instead of having to take the new wire all the way down to tiny little original leads, I chose to save what I could and leave a little room for future maintenance.

I cut the old motor leads so that the bare wire before the good insulation was a length equal to the new wire end I just stripped. These two will be braided together.

Wire Braiding 

Is simply that. Two ends of wire twisted together in a braid. Wire isn't the friendliest of mediums to manipulate for me. Single strands can be rebellious and want to wander away from what everyone else is doing. It's like getting everybody on board for a perfect family photo. Sometimes it happens quick, other times there's considerable fidgeting.

Since I did have a length of the old motor wire and plenty of new wire, I did do a couple of test braids just to make sure I was up to the task.

 

Soldering

Before I even tried to solder once, I read several blogs and watched youtube videos. Even then, my first test attempts were sloppy. After awhile, I began to understand what a good solder looked like, and noted what mine looked like... and went back and practiced more until I got better.

When a 'good' solder happens for me... I can watch the solder turn liquid and 'flow' throughout the wires - even on the inner strands. The fluid literally runs as if it's being piped from one place to another. It's fun to watch when it happens the way it's supposed to.

It was time to set up the helping hands and figure out access to the wires with one hand holding a hot soldering iron, and the other holding the roll of solder.

This is also when the helping hands don't just provide a prop for the wires, but perform the very important roll of a heat sink. I had to attach the clip on the bare braided wire section as far off to the motor side as possible. That placement should be ideal to allow the clip to pull heat away from the soldering process and then dissipate that heat through the helping hand structure.

I got lucky here and my neighbor was walking by and I asked her to take a quick picture since I couldn't. This shows my route into the fray with the soldering iron, and the solder which is rolled out about half a foot with the reel of it in my right hand.

Here's a photo of the set-up on the second wire, this time with the clip as far to the other motor side as possible.

Going back to the first I had the new wire on one side and the old on the other. I had braided them together. the next step was to wipe some flux across the braid with a cotton swab.

It was time to plug in the soldering iron and allow it to heat. To be honest, I allowed it to heat twice. The tip of the iron was dirty and once it was first warm, I ran it across the damp sponge to clean the tip, then allowed a few more minutes for the iron to regain heat.

Carefully then, with everything set, I reached in with the iron so that the tip touched the braid from below. As the iron heated the wires the flux began to run and there were a few whiffs of smoke. Shortly after that I moved the solder into place from above and upon touching the braided wire it became liquid and flowed through the braid. When it appeared as though solder had run throughout the braid I removed the solder and the iron and waited.

It takes several minutes for the solder to cool and I did not want to disturb the process. Before the soldering the wire was somewhat malleable, but the solder will stiffen the union. Any bumps or movement between hot and cool could crack and break the joint.

After about five minutes or so I removed the one clip (which can get rather warm) and then the other and went about arranging the helping hands and motor for the other wire to be soldered. The entire process took less than twenty minutes. Once the wires were cool it was time to cover the unions in shrink tube.

Since shrink tube reacts to heat... all the wire and soldered area really does need to be cool. I needed lengths of shrink tube to cover not just the soldered area, but to be long enough to shrink around the new wire for about a half an inch.

When the first tube was in place, I used a disposable lighter flame back and forth across the tube until it reduced in size. After the first shrink tube cover had set and cooled, I added a slightly larger diameter tube to cover the a part of the old wire insulation and the union. I'm double layering to ensure no gaps in insulation. Then, on the second wire, I repeated the process.

Here's my final product laid out across the motor cover awaiting the Underwriter's knot. This knot is tied with the two strands of wire to be located inside the motor assembly. It's not tricky to do on a flat surface with all the room in the world, but here with the extra thickness of the shrink wrap, knowing it's all going to have to go into the housing... it might get interesting.

(Great video on tying the knot: https://www.youtube.com/watch?v=jpdTG1-YJpM)

The reason for the knot is so that it is larger than the access hole of the metal cover of the motor. This way any external force that may tug or pull at the wire will not yank directly on the leads. The knot is supposed to take the strain allowing the wiring inside the motor beyond the knot to remain in place. Without this, or some other form of restraint, it might be possible to yank wiring right out of a motor - even if it was running.

What it comes down to is that it's a little crowded in the back end of the motor. The available free space was designed for the original wiring. The shrink tube doesn't exactly make the underwriter's knot any smaller, so I really had to very careful slipping everything back inside the housing.

This is when I needed that reminder photo:

Carefully... the end of the new wires were routed through and out the access hole, and I began to slowly nudge the motor back together. I made sure the other two original wires returned to their routes and then tucked and edged the new wires into a position where all was clear.

It was at this point, when I began to relax a little. The procedure from here on was one of reassembling.

Try as I might, I could not get that darn little pin back into the name plate. The same thing happened to me on the BU and my solution for that was to replace the soft metal headless pins with real, although tiny, screws. I may have to do that here as well. If it's my only real error in the entire process... I'm okay with that. I'll find a fix later.

Once I returned the long case bolts securing the two halves of the motor I carefully returned the springs and caps by hand. I can twist them back on holding them down with a finger and turning the motor. It's almost easier in that I can feel the threads and tension a lot better.

Then, the bracket screws and washers and bracket and I'm almost back to the beginning. The pulley will wait until everything else is back on the machine, and there will be a few new things:

When I brought Anne home the wires to the motor had not been routed correctly. They should have come out of the motor and then passed through the hole in the deck. That's the correct route. To do this, I would pass the wire ends through the deck, then attach the motor bracket with motor to the machine body.

Then I carefully marked the place where the motor wires were going through deck passage on the gold wire (It's Pittsburgh, ask for two different colors of wire and I get black and gold...). Since I have not yet attached the plug to the wires, I removed the wires form the passage and slipped a piece of shrink wrap over both wires, centered the wrap on the mark, and shrank the tube. This gives the wires a layer of extra protection from the metal edge of the deck as the wires will move a little each time the machine is pivoted.

The added bonus was that the shrink wrap gave me an anchor point to lightly twist the two together before attaching the plug. Two became one. With all of this out of the way, I could go back and make sure everything was ready for a test. I slipped a belt on, adjusted the pulley position before securing the set screw, tightened the bracket to the body and it was ready to test.

Out came an extra pedal and Mercury box I just so happened to have, and the fused power strip... and within minutes I pressed on the pedal and the motor spun to life! It sounded great! I tightened the hand wheel nut and threaded the machine.

So there we go. Just as I believed. Anne would run. She would sew. Everything appears to be working as it should, although... the material isn't feeding quite right when asked to zigzag (it's drifting a little). I may have some things to do there, but I'm adjusting the final list: new screws for the name plate, new belt, find a light cover. I'll continue with more detailed cleaning now that I'm convinced she's going to be okay and hopefully I'll have Anne back in her cabinet shortly.

She sounds good too! There's a little more noise from the front end than on the BU, but I'm betting it's some thing I have overlooked, or maybe she's just finally able to tell her story.

So it's not all over yet. I'll need to replace the original junction box, and find a pedal of choice, but now at least I know that my efforts were worth it. That pretty, green and original motor was salvageable, just some little details left. My work here is certainly not any where near some full-on museum piece redo, but that wasn't the goal. The goal was getting Anne back to the sewing room and doing what she does best: sewing all the youngsters how its done.