KundoBlack
[Purchased in the late 1970's, from the Dahnken Catalog. They had a showroom in Orem.]
- Uses 0.0032" suspension spring
Regulation Screw:
- Clockwise = Slower
- Counter-Clockwise = Faster
2013-12-09
This clock has suffered from poor running for years. I suspected that the pivots had dried out, but there was more! I disassembled the entire clock, removing all wheels and the barrel. I popped the barrel cover off with a small screwdriver and that the mainspring was corroded and green, and completely dry. In fact, the mainspring was somewhat gummed up with the old dry lubricant.
2014-02-04
After building my spring winder, I was able to remove the mainspring from the barrel and clean it. I used acetone to remove the gummed up stuff, but there was still discoloration in places on the mainspring that seemed to be permanent. I was not able to remove the greenish color. I re-oiled the spring with new synthetic oil by drawing an oil soaked piece of tissue paper down both sides of the mainspring. With that completed, I reloaded the mainspring into the barrel.
I checked each of the pivots, cleaning them as I went, and each pivot hole on both the front and back plates. They all looked good. I reassembled the movement, and oiled each pivot and the winding arbor. I attached the dial and mounted it back on the vertical pillars. I reused the original suspension spring assembly. It looked in fine shape and though it may not include a Horolovar temperature compensating suspension spring, I thought I go with it anyway.
After reassembly, I set the it in motion, and lo!, it kept running! The beat looked good, though I needed to adjust the regulation screw, which was off quite a bit with my fiddling over the years.
2014-02-10
After getting my computer regulation apparatus set up, I fine tuned the regulation and the beat. I am geting slightly more than 270-degrees of swing on the pendulum. After a day or two, the clock shows to be running a bit slow, about 1/2-minute per day. Hmm, I thought I got the regulation dialed in quite well with the computer. Something to note. Nevertheless, the clock is running reliably, after many years of poor performance.
2014-03-09
Adjusted for Daylight Savings. For some unknown reason, after simply changing the time on the face, the clock ran down and stopped in about 45 minutes. After two more attempts at restarting the pendulum and having the clock stop, I re-wound the mainspring fully and tried again. Since then, the clock is running again.
This clock has always been difficult to keep running. I was hoping that the cleaning and oiling would solve the problem, but not necessarily so it would seem. I wonder if the factory original suspension spring is just a tiny bit too 'heavy', and not allowing the pendulum enough swing. I might try to thin it a bit, or at worst I could replace the suspension spring with a new Horolovar spring (.0032").
2014-10-28
In the past week or so, the clock stopped running, after about 10 months of good performance, and a rewind would not get it going again. At first I tried about a 75% wind-up and the clock would not run. I wound the mainspring 100% and still the clock would not run.
Today I took a closer look and it appeared the the wheel pivots were dry. I was surprised by this since I didn't expect the purpose-made clock oil to disappear so quickly.
I disassembled the movement, to the point of removing the barrel. I had to go this far because while I was letting down the mainspring, it got away from me and in the process the click spring was compressed so far that the click would no longer engage with the ratchet wheel, so I had to remove the barrel to correct that.
With the barrel out, I re-oiled the barrel arbor pivots, click and click wheel. I then reassembled the wheels and secured the backplate. Then, re-oiled each pivot on the front and back plated, reattached the dial, and hands, and reassembled the clock as a whole.
Yes, it is now running again, with about a 280-degree swing of the pendulum.
2014-04-21
Last night the clock stopped. Without wanting to dig any deeper at the moment, I simply rewound the mainspring, set the time, and restarted the pendulum.
2016-11-14
The clock is still temperamental. Since the last change from Daylight Saving Time to Standard Time, along with a full wind of the mainspring, the clock will not continue to run. At last I decided to rework the suspension spring. It is still the factory suspension spring and I've long suspected that it is too stiff, probably too thick. Knowing that the thinner-than-appropriate spring allows the clock to run fast (too fast if the spring thickness is too thin) with a large pendulum swing, thinning this spring seems like a good experiment. If all else fails I can install a new, known thickness spring from my spares.
First, I removed the suspension spring + pendulum assembly from the clock. I had to knock out the pendulum retention pin, which is driven into the suspension spring's lower block. Using my tiny jewelers hammer, and a 'punch' (a simple square-ended rod) I quickly removed the pin. I filed the mid-way bumps down on the pin to allow simple re-insertion by hand, without needing to 'knock' it back in with force.
With the suspension spring free of the pendulum, I used two manicurist's fingernail files to thin the spring. I used the coarse side of both files, and gave the spring six strokes, three up, and three down.
I reinstalled the pendulum on the suspension spring, easily re-inserting the retention spring, and re-hung this assembly on the clock.
After fine-tuning the 'beat' I let the clock run to observe it. If I need to thin the spring further, it will be easily removed and given a few more strokes with the nail files.
...
After about 15 minutes, I didn't see any change in the length of the pendulum's swing with less than 270-degrees of swing, and the escapement was just barely operational with such short swings, so I removed the suspension spring + pendulum again and gave the spring about 8 strong strokes between the two nail files. This time I was not timid in my use of the files.