Cutout Rebuild Question

[sethkestenbaum]

Does anyone have a good step-by-step guide to rebuilding a cutout? If so, please share. I have some old notes from the late/great Tom Wesenberg but I can't seem to find anything comprehensive.

[ndnchf]

I don't know about rebuilding them - do you mean rewinding the coils, replacing the points etc? I've never tried that. But I have serviced them. This includes cleaning and gapping the points, adjusting the air gap and point closure voltage. Tom's guidance is very helpful.

Here is a couple photos and a short video I made.

https://youtu.be/MbITShRm6W4

[sethkestenbaum]

Great video. Yes, I mean breaking the cutout down and rebuilding it if needed. I haven't tried it either but find myself without a working cut out and with the desire to drive my car tomorrow. I figured I would give it a shot on one of my two non-functional ones.

[ndnchf]

FWIW, the crusty one in the video didnt work at first. But after cleaning the points and adjusting, it worked fine. I think it very unlikely that the heavy coil wire would be bad. But the very small wire that goes to the base that creates the magnetic pull that brings down the arm when energized, could be broken. They are very simple with little to go wrong. They usually just need cleaning and adjusting.

[sethkestenbaum]

The one I was able to open so far had the hair wire broken at the base of the winding shaft as opposed to the base of the cut out... so this one might need to be rewound to work.

Now I am just trying my best to file off the welds on the second one so I can see what is happening with it. Whomever spot welded this one did a great job.

[ndnchf]

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Yeah, the spot welds can be a pain. Please post some photos of your progress.

[sethkestenbaum]

I can't get the dang housing off the cutout in spite of filing away at the welds for quite some time. I'll get back at it later this week and post some photos/videos. In the interim, I guess I'll order a replacement.

[ndnchf]

They can be a challenge. This is what I've found works the best for me after grinding/breaking the spot welds. I have an old generator body I use just to hold the cutout firmly in place. Then use a flatblade screwdriver. Place the tip under the edge of the cover. Using the mounting screw head as a fulcrum and the screwdriver as a lever, pry it up. I've also had good luck twisting the screwdriver blade from the same position. I've got everyone off doing it this way.

[sethkestenbaum]

I was able to force it open, clean some contacts, but wasn't able to get it to "click" right. It seems to be all intact. I am hopeful to borrow a soldering gun strong enough to help me refresh the connections. In the interim, I guess I will be buying a new cut out as I still can't find my back up. This stated, if anyone reading this has a good working original cutout for sale, please let me know.

[katy]

For temporary, just use a 30 amp diode.

[Ed in Maine]

I'm afraid there are parts on the Model A that just aren't worth the time to rebuild. What can you do with the pitted contacts. You can't replace those and this is the problem with most cutouts, the contacts are burned, high resistance across the contacts. Ed

[ndnchf]

Ed - I'm sure you are correct about many original cutouts. No doubt many were just burned up.

But in my limited experience, I have found quite a few that just needed cleaning and adjustment. This example I just did tonight.

First I tested it to see if it was functional. It was, but the points didn't close until about 9 volts. This cutout was virgin, never been apart. I carefully cut and split the spot welds, then pried the cover off as I described above. I found the points had some pitting, but not bad. They were also mis-aligned, the gap was too large and the air gap was too large. I gently dressed the points and reassembled, setting the closed air gap at about .010" and point gap at about .020" I tested it again and closure voltage dropped to about 8 volts - better, but still too high. So I lightened the spring tension a little and retested - the points closed at about 6-1/4 volts - perfect.

I know they cannot all be saved, but I think many can. It just takes a little effort.

Steve

[sethkestenbaum]

I ordered one of the lousy mechanical ones which will arrive in a about a week. Somewhere in my boxes of stuff I have a good solid state diode one waiting to be found and used.

Out of curiosity, how often do others end up replacing their cutouts? What would cause them to fail?

[ndnchf]

High current flow will cause faster point wear. If the generator's 3rd brush is set to high output for continuous use of headlights etc., then one can expect faster wear.

That being said, I have installed focused beam LED headlights, and LED taillights. The 3rd brush of my generator is set to its LOWEST output setting. This gives me a 4-5 amp output on the ammeter with headlights OFF. With the headlights ON, I still get a slight positive charge on the ammeter. So for either day or night driving, I never need to change the 3rd brush setting. For me, this is best combination. Great lights, minimal generator output, which means less heat and wear on components. Under these conditions, a cleaned and serviced cutout with good points should last for a long time.