Help Identifying Suspension Spring for Kundo clocks

barriebarry

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Apr 13, 2021
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I have 2 Kundo clocks that require new suspension springs and I have attached the photos of the clocks. Is that sufficient to identify the suspension spring size? The length of the spring for both is just over 7 inches.

Also, any additional information you can provide about the clocks would be appreciated. "clk1" was from my grandparents I expect from the late 60's or early 70's. Made in "West Germany". I did have it operating up to 9 months at one point but it likely needs a good cleaning and oiling to make operate again.

Clk2 I picked up at a garage sale in the mid '90's and is made in "Germany" and has a plastic base and dome. I am using this one to practice restoration before working on my grandparents. I managed to strip down, clean, and rebuild (including the main spring) but it won't run beyond a few minutes. The suspension spring is holding a twist and so was likely over spun at some point.

So before I spend much more time on either for them, I'll order new suspension springs but without the famed book on the subject, I'm cannot be certain which to order.
Clk1-left_Clk2-Rightx.jpeg

Clk1a.jpeg Clk1b.jpeg Clk1c.jpeg Clk2a.jpeg Clk2b.jpeg Clk2c.jpeg
 

Roy

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Sep 25, 2009
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All full sized Kundo's used 0.0032" suspension springs, but I don't see anything wrong with yours. A twist should not be problem as long as it is not near the top. Did you put your clock in beat? That's critical!
 

barriebarry

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The one clock has about 3 or 4 full 360 degree twists in the suspension spring evenly spaced over its length so I wasn't sure how that can impact operation. As for in beat, think so, as I desperately tried to make the swing overshoot equal on both ends of the swing. But it takes so very very little adjusting the rotation at the top to go too far one way, then too far the other. Maybe I don't understand what in beat means.
 

Roy

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Sep 25, 2009
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The one clock has about 3 or 4 full 360 degree twists in the suspension spring evenly spaced over its length so I wasn't sure how that can impact operation. As for in beat, think so, as I desperately tried to make the swing overshoot equal on both ends of the swing. But it takes so very very little adjusting the rotation at the top to go too far one way, then too far the other. Maybe I don't understand what in beat means.
Well, that's a lot of twists. Not sure if that will have an effect, I would guess not, but might be good to get a new sus. spring. It takes some patience to get the clock in beat. You need to mark each end of the swing and where the beat occurs and get them reasonably close. Don't need to be perfect though, but once the clock is running on its own you need to have adequate overswing between the beat sound and the end of the rotation.
 

Wayne A

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Sep 24, 2019
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For the twisted suspension spring, you may be able to remove the twist by keeping tension on it and winding the opposite direction. Probably take a few trys to slowly unwind those set twists.

Could be the picture angle but the clock on the rights mainspring cover looks to be not pressed in fully.
 

Darrmann39

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Dec 6, 2020
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Someone might correct me and say this is wrong but I've gotten 6 400 day clocks that I've set the beat on in minutes. Not marking anything.
I spin the pendulum until it just bottoms out on the escapement. Then let it swing. If it doesn't touch the escapement or bottom out on the other side when it swings it needs to move that way. If it bottoms out with a bit of over swing then move it the other way. Small small movements.
I get it at almost everytime on the first try
 

KurtinSA

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Nov 24, 2014
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So you turn the pendulum so far that the pallet begins to touch the valley between the teeth on the escape wheel? Seems like that is a little hard to find the exact point where the pallet hits the escape wheel. I only turn the pendulum until the pallet just falls off one escape wheel tooth...then I let the pendulum go and swing the opposite direction. Watch for the other pallet to fall off tooth. If the pendulum doesn't make it so it falls off or if it falls off and goes much further, then the beat needs to be adjusted. If the pallet just falls off on the other side, I'm good to go. It's easier to see these precise situations IMO.

This test for the beat is also a good point to see if your clock has sufficient power. If you have the beat such that a tooth just barely falls off each side, let the clock continue on its own. If the over swing builds over the next 10-15 minutes, then there is sufficient power to run. If the clock stops, then there's something wrong with the escapement or too much friction in the train.

Kurt
 

Darrmann39

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Dec 6, 2020
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So you turn the pendulum so far that the pallet begins to touch the valley between the teeth on the escape wheel? Seems like that is a little hard to find the exact point where the pallet hits the escape wheel. I only turn the pendulum until the pallet just falls off one escape wheel tooth...then I let the pendulum go and swing the opposite direction. Watch for the other pallet to fall off tooth. If the pendulum doesn't make it so it falls off or if it falls off and goes much further, then the beat needs to be adjusted. If the pallet just falls off on the other side, I'm good to go. It's easier to see these precise situations IMO.

This test for the beat is also a good point to see if your clock has sufficient power. If you have the beat such that a tooth just barely falls off each side, let the clock continue on its own. If the over swing builds over the next 10-15 minutes, then there is sufficient power to run. If the clock stops, then there's something wrong with the escapement or too much friction in the train.

Kurt
I'm not sure why it's harder to see what i do compared to what you do. Your looking thru the holes at the same thing.
You watch it on the tip of tooth i watch it at the valley. It's actually very easy to see.
 

Wayne A

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Sep 24, 2019
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Someone might correct me and say this is wrong but I've gotten 6 400 day clocks that I've set the beat on in minutes
Your still using the anchor as a timing marker similar to watching or listening to the drops. Only down side is having to wait for the swing to decay to get an idea on size of the over-swing and having to closely watch the anchor. I use a amplifier so I can hear the drops and not have to look at the escapment at all. This way I can focus on watching a degree wheel to get the beat set and measure over-swing with precision. Most often theres more than one path to get a job done.
 
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barriebarry

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Apr 13, 2021
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Thanks for the comments and descriptions for setting the beat and this all agrees with what I thought "setting the beat" meant. I have been very careful to adjust the beat such that a tooth just barely falls off each side but the clock never lasts much more than a few minutes, i.e. I've never seen the over-swing increase. So the logical conclusion is that it is lacking the power due to friction somewhere in the train or there is something wrong in the escapement. Or can a weak suspension spring contribute to this? If it has lost it's temper or "springiness" (is that a clock term!), can I also experience this lack of increase swing?

If the suspension spring is unlikely the cause, then I'm back to investigating the power train or the escapement settings. The clock has been disassembled, cleaned, and oiled including the main spring and I did not touch the escapement settings except the fork: I did adjust the fork position on the spring so it might not be at the 3.5 or 4mm distance from the top. Does raising or lowering this position help in a particular way?

I suppose I should purchase the Horolovar book so I wouldn't have to ask all this but I don't see myself attempting another 400 Day clock once I get these 2 going. Maybe in retirement if that every comes :)
 

Wayne A

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Sep 24, 2019
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So the logical conclusion is that it is lacking the power due to friction somewhere in the train or there is something wrong in the escapement. Or can a weak suspension spring contribute to this? If it has lost it's temper or "springiness" (is that a clock term!), can I also experience this lack of increase swing?
All power comes from the mainspring, lots of ways to loose power in the train. Also often a problem is friction at the pin and fork, check that its not binding at the end of rotation. Also check for notches in the fork or pin, I like to have the fork mirror smooth with the smallest gap that will run.

As long as the suspension spring is spinning the pendulum at the proper BPM its fine for the clock. Have you tried lowering the fork to increase the overswing?
 

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