Seth Thomas 89 rack and snail

[chezwilly]

I have a Seth Thomas 89 movement. There is no letter on the movement like 89c or whatever. It is the type of movement where the front plate is in two pieces and the rear plate is in two pieces. It is a rack and snail movement. The snail has slots of varying depths for a pin on the rack tail to fall in. I think I remember reading there is a certain relationship between the snail, rack tail and the cam on the center wheel arbor and that these items need to be set up in a particular manner upon reassembly. Any comments about this would be appreciated. Thank you.
Willy

 

[Jay Fortner]

I don't think you have an 89 movement,those are count wheel movements. You're going to have to post some pics for us to figure out what you have. The only relationship with the star cam and rack and snail is that they're both part of the strike train. The star cam starts the sequence and the rack and snail counts the number of strikes and tells the train when to stop.

 

[Patch]

I have the 89L. (I believe.) It has the rack and snail that makes it a quarter hour striker. (bim-bam-1/4 hr. bim-bam,bim-bam-1/2 hour. Three bim-bams for the 3/4 hour. Cam on the back of the center arbor, lifts one hammer, for single strikes of each hour.) I'd take a photo of mine. But, it's currently being used.
The snail will have four plateaus' for each hour. I found it easiest, to adjust it to the hour. Rack tail falling into the 11:00 slot, worked the best for me. Either way, it's not difficult, to set up. Then, test it to the hammer operation. Sorry about the photos. But, it's technically, the wife's clock.
I hope, that this helps.

 

[Tom Kloss]

Jay

Willy has an 89 there. Sort of a hybrid. It's an 89 but it is rack and snail. It's a bim bam that strikes on the quarter hour. It has an odd looking snail. I've attached a pic. I've had one come through my shop.

Tom

 

[chezwilly]

Tom,
That is exactly what I have. Is there any special tricks in reassembly?

Willy

 

[Jay Fortner]

Thanks Tom,I've seen these here on the MB but never had the pleasure(or displeasure?) of working on one myself. I personally am not a big fan of bim-bams,having one that went off on every quarter may suffer lead poisoning.

 

[Bruce Alexander]

I've worked on one of these 89Ls. The rack tail on the movement I worked on was unusual in that it had a flat spring applying force to the back of a pin base (the pin that falls on the rack). I found that the spring has to exert enough force to the pin base to hold it securely otherwise the quarterly and hourly strikes would not be consistent. I think that it was spring loaded in this manner to allow the time train to continue operating in the event that the strike train ran down first or was not wound by the owner. There are a lot of deep and narrow hourly slots in the snail which might cause the time train to stall if the rack is not being gathered. In this manner the spring-loaded pin can deflect under the force of the rotating rack/canon. That's my theory anyway....I didn't test it out. The photo I have does not show pin detail, but it does show the top of the flat spring that I'm referring to. The pin has a hemispheric base which fits into a mating, slotted socket within the rack tail. If the spring lies flat against the rack tail, you should be fine, but test the pin to make sure that it doesn't move easily. If it doesn't fit tightly, you'll have a very hard time getting your rack to fall consistently with precision. There was a slight gap between the spring and the rack tail on my movement with just enough slop to cause intermittent problems. Hope that makes sense...

 

[harold bain]

Tom,
That is exactly what I have. Is there any special tricks in reassembly?

Willy

Spend enough time studying the movement to be totally familiar with it's operation. Make notes and take lots of pictures.

 

[chezwilly]

Thank you, Guys. I think I can take it from here.
Willy

 

[ahemsley]

I've worked on one of these 89Ls. The rack tail on the movement I worked on was unusual in that it had a flat spring applying force to the back of a pin base (the pin that falls on the rack). I found that the spring has to exert enough force to the pin base to hold it securely otherwise the quarterly and hourly strikes would not be consistent. I think that it was spring loaded in this manner to allow the time train to continue operating in the event that the strike train ran down first or was not wound by the owner. There are a lot of deep and narrow hourly slots in the snail which might cause the time train to stall if the rack is not being gathered. In this manner the spring-loaded pin can deflect under the force of the rotating rack/canon. That's my theory anyway....I didn't test it out. The photo I have does not show pin detail, but it does show the top of the flat spring that I'm referring to. The pin has a hemispheric base which fits into a mating, slotted socket within the rack tail. If the spring lies flat against the rack tail, you should be fine, but test the pin to make sure that it doesn't move easily. If it doesn't fit tightly, you'll have a very hard time getting your rack to fall consistently with precision. There was a slight gap between the spring and the rack tail on my movement with just enough slop to cause intermittent problems. Hope that makes sense...
View attachment 206392

Hi Bruce,

I'm working on one of these movements which would only strike 2 times, no matter what hour it was. I haven't been able to remedy irregular chiming and striking problems. I've read your post here, and note from the photo that I need to do more disassembly before all parts are clean, since a few threads in the Forum suggest that thorough cleaning can solve some problems. What must be done to get the gathering pallet off the maintenance cam pivot, and is it critical that it should go back on in a particular orientation? I've been reluctant to try anything there for fear of never getting things realigned.

 

[Bernie Mercury]

I have worked with an Ansonia rack and a snail that is very similar. I share your frustration. As Bruce indicated, the gathering pinion with dowel pins must engage properly. It's a slow process but I had great success by filing the rack with a file on the tooth to allow the rack tail to consistently engage with the rack. Happy New Year.

 

[ahemsley]

I have worked with an Ansonia rack and a snail that is very similar. I share your frustration. As Bruce indicated, the gathering pinion with dowel pins must engage properly. It's a slow process but I had great success by filing the rack with a file on the tooth to allow the rack tail to consistently engage with the rack. Happy New Year.

Hi Bernie,
I'm new to this and my vocabulary is sometimes a bit shaky, so I just want to make sure I understand your advice. You're suggesting that reshaping the teeth on the rack so they mesh better with the three gathering pallet pins will align the rack tail better? I have cleaned the teeth much more carefully since reading this post, and will check individual tooth movement once I get the clock going gain today. I've also fashioned a "rack tail spring clamp" from brass wire to try if all else fails, but I'll try your suggestion first. Happy New Year to you as well, and thank you very much.

 

[Bernie Mercury]

Hi Bernie,
I'm new to this and my vocabulary is sometimes a bit shaky, so I just want to make sure I understand your advice. You're suggesting that reshaping the teeth on the rack so they mesh better with the three gathering pallet pins will align the rack tail better? I have cleaned the teeth much more carefully since reading this post, and will check individual tooth movement once I get the clock going gain today. I've also fashioned a "rack tail spring clamp" from brass wire to try if all else fails, but I'll try your suggestion first. Happy New Year to you as well, and thank you very much.

Thank you. Yes, I believe that you understood my advice correctly. From my experience, due to the age of the movement and parts, soft brass will eventually wear and deviate from its original design specification tolerances. It is usually just one or. two teeth on the rack gear. The right file can work wonders. But don't be too aggressive. Thank you and Happy New Year to you!

 

[ahemsley]

Thank you. Yes, I believe that you understood my advice correctly. From my experience, due to the age of the movement and parts, soft brass will eventually wear and deviate from its original design specification tolerances. It is usually just one or. two teeth on the rack gear. The right file can work wonders. But don't be too aggressive. Thank you and Happy New Year to you!

Before I tacked the tooth filing, I tried this alignment tip from YouTube, accredited to David LaBounty. I'm surprised that the information wasn't mentioned in any of the threads I searched, and I'd never have seen the set screw or ventured to mess with it because I had to use brute force to separate the snail from the cannon tube once I removed the set screw because of oil, debris, etc. Now the clock chimes the quarters perfectly and seems to strike reliably as well. There might be a stutter on the 2 o'clock strike (I heard only one strike) but chiming perfectly 47/48 times in 12 hours will satisfy me for now! Hope this is educational for others:

 

[Bernie Mercury]

Before I tacked the tooth filing, I tried this alignment tip from YouTube, accredited to David LaBounty. I'm surprised that the information wasn't mentioned in any of the threads I searched, and I'd never have seen the set screw or ventured to mess with it because I had to use brute force to separate the snail from the cannon tube once I removed the set screw because of oil, debris, etc. Now the clock chimes the quarters perfectly and seems to strike reliably as well. There might be a stutter on the 2 o'clock strike (I heard only one strike) but chiming perfectly 47/48 times in 12 hours will satisfy me for now! Hope this is educational for others:

Great job! Happy New Year!

 

[Bruce Alexander]

Glad you got it worked out ahemsley. Sorry for the delayed response but I've been on vacation with family. Happy 2023!

 

[ahemsley]

Glad you got it worked out ahemsley. Sorry for the delayed response but I've been on vacation with family. Happy 2023!

Thank you Bruce and Bernie for the advice, hope 2023 is starting well for you and yours. After a week of good performance, the clock began giving irregular 1/4 hour bim-bams again and is back to striking 3 o'clock at every hour, rather than 2 o'clock as it did originally! I've gained an hour through cleaning. I scavenged another 89L movement on EBay and I'm experimenting with a flat spring retainer clamp repair fashioned from brass wire and will go back in and file the teeth as you suggested Bernie. I don't think that it's the set screw slipping because it was ridiculously tight when I cleaned the clock and the problems were there at that time. I'll get to this one by next week and post on how the filing goes.

 

[Bruce Alexander]

Hi ahemsley.

Before you make any irreversible changes, I strongly recommend that you ensure that the Strike Train timing is properly adjusted.
As you're undoubtedly aware, the Strike Train has three settings/states, namely: Lock, Warning and Strike. As it goes into a "Warning" state before it is released into Striking the Hour, there is necessarily a slight advancement of the entire Train. If the transition from Lock to Warning is excessive, one or two undesirable things can occur. The Strike Hammer(s) may begin to lift early, which puts the Strike Train under load when it is in Warning. This means it must begin Striking with the Hammer(s) already lifted a little. Ideally, the Strike Train can get fully up to speed before it has to go to work lifting the hammer(s). Something else that could go wrong is that the Gathering Pallet might engage/foul the Rack and prevent it from falling onto the Snail as the Strike Train goes fully into Warning. When this happens, only a few teeth can be "gathered" when the Strike Train goes from Warning into Strike. This may be what you're experiencing. It's often seen with Movements which use 3-Pin Gathering Pallets, as they can be a little tricky to properly adjust. Of course, once a Gathering Pallet is properly adjusted, one must make sure that it can't slip out of adjustment.

Just a couple of things to consider if you haven't already done so.

Good luck,

Bruce

 

[ahemsley]

Hi ahemsley.

Before you make any irreversible changes, I strongly recommend that you ensure that the Strike Train timing is properly adjusted.
As you're undoubtedly aware, the Strike Train has three settings/states, namely: Lock, Warning and Strike. As it goes into a "Warning" state before it is released into Striking the Hour, there is necessarily a slight advancement of the entire Train. If the transition from Lock to Warning is excessive, one or two undesirable things can occur. The Strike Hammer(s) may begin to lift early, which puts the Strike Train under load when it is in Warning. This means it must begin Striking with the Hammer(s) already lifted a little. Ideally, the Strike Train can get fully up to speed before it has to go to work lifting the hammer(s). Something else that could go wrong is that the Gathering Pallet might engage/foul the Rack and prevent it from falling onto the Snail as the Strike Train goes fully into Warning. When this happens, only a few teeth can be "gathered" when the Strike Train goes from Warning into Strike. This may be what you're experiencing. It's often seen with Movements which use 3-Pin Gathering Pallets, as they can be a little tricky to properly adjust. Of course, once a Gathering Pallet is properly adjusted, one must make sure that it can't slip out of adjustment.

Just a couple of things to consider if you haven't already done so.

Good luck,

Bruce

Thanks, Bruce, I'll observe the transitions again more closely. I don't recall whether the warning transition was clunky in this clock. But the fact that it ran with all Bim-Bams right as they should be and almost every hour strike perfect for a week before the problems crept back in does suggest that the clock is being disturbed while operating. That's a great suggestion because I truly would rather not file on the teeth for fear of making things worse, not better. The clock does have the three-pin gathering pallet. It doesn't seem detachable from one of the wheels, the maintenance cam wheel is on one side of the plate and the gathering pallet is on the other side. I left them with the plate still between when I disassembled and cleaned the parts because I did not think they should be detached by someone who doesn't know what the alignment should be. (photo is from before disassembly)

 

[Bruce Alexander]

Sometimes one has to "dress" parts or make adjustments for wear and tear. As you suggest, watch the interaction of the Rack, Rack Hook and Gathering Pallet through the entire Warning/Strike/Lock cycle. If you would like further suggestions or input it might be helpful to all if you could post a video link of the Strike Train's action when it fails to operate properly.

The Gathering Pallet should be removable unless some has done something unusual to lock it in place. If you have not removed the Gathering Pallet, "tweaking" the Strike Train's timing can sometimes be a little difficult. It's been a while since I've worked with one of these movements. Does it have separate Warning and Lock pins within the Strike Train or does the Lock Pin also serve as the Warning Pin?

Thanks

 

[ahemsley]

Sometimes one has to "dress" parts or make adjustments for wear and tear. As you suggest, watch the interaction of the Rack, Rack Hook and Gathering Pallet through the entire Warning/Strike/Lock cycle. If you would like further suggestions or input it might be helpful to all if you could post a video link of the Strike Train's action when it fails to operate properly.

The Gathering Pallet should be removable unless some has done something unusual to lock it in place. If you have not removed the Gathering Pallet, "tweaking" the Strike Train's timing can sometimes be a little difficult. It's been a while since I've worked with one of these movements. Does it have separate Warning and Lock pins within the Strike Train or does the Lock Pin also serve as the Warning Pin?

Thanks

I took the movement back out of the case yesterday. I'm starting to suspect a time train issue. The time-side mainspring had a tendency to want to balloon out to the sides when I was cleaning it and as it unwound this got worse. It was sitting cock-eyed between the plates and when i realigned it correctly, the clock ran again, briefly. I originally ran the clock through the hours by hand-turning the main arbor for a test strike/chime assessment. I noted that all the bim-bams were in correct sequence and the movement struck the hours correctly. So I wound the clock fully on both sides and put it into the case. I wound it again fully two or three days later, on the day I give all my 8 day clocks their weekly winding and time checks. So, I think it might have taken three more days for the time-side mainspring to start causing some type of drag. When I just rotate the main arbor now, the bim-bams and strikes still seem good. So, I'm going to order two new mainsprings for this clock, and I'll see what I can find to try a slightly better spring in the meantime. I should have tested the time side for longer than I did, I'm still impatient for results and probably rushed through the part that did not seem likely to be causing strike problems.

 

[Bruce Alexander]

Okay, but it’s not clear to me why you’re planning to replace the mainsprings. If the clock was In my hands I would test the movement on a stand for one complete winding cycle. You generally can’t inspect it while it is installed of course. If it runs for 8 days without any surprises, only then would it go back into the case for another week-long test run (at a minimum). If you rush through the testing routine, sooner or later you will miss something. Replacement of a mainspring is not trivial so be sure that it is the answer and not part of your testing. That’s my opinion anyway…
Good luck,
Bruce

 

[ahemsley]

Okay, but it’s not clear to me why you’re planning to replace the mainsprings. If the clock was In my hands I would test the movement on a stand for one complete winding cycle. You generally can’t inspect it while it is installed of course. If it runs for 8 days without any surprises, only then would it go back into the case for another week-long test run (at a minimum). If you rush through the testing routine, sooner or later you will miss something. Replacement of a mainspring is not trivial so be sure that it is the answer and not part of your testing. That’s my opinion anyway…
Good luck,
Bruce

Thank you for the time frame advice. I didn't observe the clock for an entire winding cycle, just a day or two. Clearly not long enough. I'm testing with a different mainspring on the time side to see whether the time side will run better and not bind up between the plates as the spring unwinds in a distorted manner. I'm doing this because the strike side still proceeds without problems on the test stand when I manually rotate the center arbor through the quarter hours, just as it did before I thought all was well and put the movement into the case. Trying to go back to basics with everything. This is going to take a while

 

[ahemsley]

Thank you for the time frame advice. I didn't observe the clock for an entire winding cycle, just a day or two. Clearly not long enough. I'm testing with a different mainspring on the time side to see whether the time side will run better and not bind up between the plates as the spring unwinds in a distorted manner. I'm doing this because the strike side still proceeds without problems on the test stand when I manually rotate the center arbor through the quarter hours, just as it did before I thought all was well and put the movement into the case. Trying to go back to basics with everything. This is going to take a while

I ran the time side for a week and did discover some issues there. But now that I've placed a better arbor and mainspring into the time side, the clock still chimes and strikes poorly. It strikes 3 times only and chimes irregularly. I'll try to create a video of what happens at each 15 minute interval.

 

[ahemsley]

I ran the time side for a week and did discover some issues there. But now that I've placed a better arbor and mainspring into the time side, the clock still chimes and strikes poorly. It strikes 3 times only and chimes irregularly. I'll try to create a video of what happens at each 15 minute interval.

Ok, I have a video with the hammer action and snail/hand position side-by-side for a sequence from striking the hour, 1/4, 1/2, 3/4 hour times and a second hour strike. I left the clock running overnight, and now it seems to strike several different hours, but not in correct sequence. The hour hand should be ignored. The video was to large to load, so here is a link to YouTube where the file has been uploaded:

 

[ahemsley]

Ok, I have a video with the hammer action and snail/hand position side-by-side for a sequence from striking the hour, 1/4, 1/2, 3/4 hour times and a second hour strike. I left the clock running overnight, and now it seems to strike several different hours, but not in correct sequence. The hour hand should be ignored. The video was to large to load, so here is a link to YouTube where the file has been uploaded:

Sorry, production took longer than expected, and I was timed out.

 

[Bruce Alexander]

Hello ahemsley,

Your video is good and thanks for taking the time to post it (videos should be hosted on 3rd party sites like YouTube btw).
Others will weigh in. It looks to as though the strike train timing needs to be retarded a little. It is "skipping" lock at the 15 and 30 minute marks and also at the 1:00 mark. The issue with just one set of strikes at the 45 minute mark suggests to me that the Snail/Rack Tail may slightly be out of adjustment. Either that, or perhaps your finger is getting in the way of the Rack drop in the video.


I would expect the mechanism to strike the two note sequence four times with the Strike Train timing set as it currently is. I would also expect it to continue striking an "extra" hour for a number of hours (It seems to have transitioned from an accurate 12:00 hours to 2:00 in your video.

Others will weigh in with their observations and suggestions.

Bruce

 

[ahemsley]

Hello ahemsley,

Your video is good and thanks for taking the time to post it (videos should be hosted on 3rd party sites like YouTube btw).
Others will weigh in. It looks to as though the strike train timing needs to be retarded a little. It is "skipping" lock at the 15 and 30 minute marks and also at the 1:00 mark. The issue with just one set of strikes at the 45 minute mark suggests to me that the Snail/Rack Tail may slightly be out of adjustment. Either that, or perhaps your finger is getting in the way of the Rack drop in the video.


I would expect the mechanism to strike the two note sequence four times with the Strike Train timing set as it currently is. I would also expect it to continue striking an "extra" hour for a number of hours (It seems to have transitioned from an accurate 12:00 hours to 2:00 in your video.

Others will weigh in with their observations and suggestions.

Bruce

Hi Bruce, I'm too inexperienced to know what you mean by retarding the strike train timing. I thought I saw the clock go into warning at each stage, so I don't think that's what you're referring to.

 

[Bruce Alexander]

Well, the Strike Train "tries" to lock but it skips once, except when it struck 12:00. See timestamp 0.51 and 1:07 (approximately). The Rack Hook bounces up allowing the Train to strike one more time before locking That often means that the lock pin is too close to the Lock Lever or Locking Detent and needs to be adjusted, retarded or set back a couple of gear teeth. It might also mean that the Maintenance Cam is out of adjustment. Your settings are close or the Train wouldn't go into Lock. These 3-pin Gathering Pallets don't leave much room for error. From what I can see, I don't think that the main issue is with the Rack and Snail, but likely arises from the Lock Pin and/or Maintenance Cam timing between the plates.

I'm not certain, but you may be accidentally "gathering" a tooth or two with your finger when you advance the minute hand to the 45 minute mark. You can confirm or rule that out quickly of course. If that's not the case then something more complicated may be going on with the Rack and Snail setup. It may be a combination of issues.

If the Gathering Pallet was loose enough to adjust/rotate on its pivot, you might be able to make minor adjustments to the Lock timing more easily, but since you didn't remove the Gathering Pallet during the servicing of the movement (because it was too tight with the tools you have to work safely on it with), I don't think you should attempt it now. You might bend or break the Pivot if you do.

Before you attempt to make further adjustments, please wait for others to weigh in. No doubt there are some folks out there with more experience on this type of Movement. I've worked on a few, but it has been a while.

Good luck,

Bruce

 

[shutterbug]

You have a rather complicated "bim bam" movement. It should strike one double sequence at the 1/4, two at the 1/2, three at the 3/4 and only one hammer should count the hours. I can't tell for sure from your video, but it looks like the hammers might be touching each other. Do you see that? And based on this sequence, what do you see the problem as being? Incorrect counting?
When the rack falls for the hours, there should be a pin that enters the deep slot. That controls how far the rack falls, hence the number of counts. What do you observe there?

 

[ahemsley]

You have a rather complicated "bim bam" movement. It should strike one double sequence at the 1/4, two at the 1/2, three at the 3/4 and only one hammer should count the hours. I can't tell for sure from your video, but it looks like the hammers might be touching each other. Do you see that? And based on this sequence, what do you see the problem as being? Incorrect counting?
When the rack falls for the hours, there should be a pin that enters the deep slot. That controls how far the rack falls, hence the number of counts. What do you observe there?

The bim-bam sequences are off . I get two at the 1/4 hour, three at the 1/2 hour and one at the 3/4 hour. The hammers don't touch. The hour hammer counts the hours, but in the video one hour was skipped, possibly because I moved something with my finger. I cleaned this clock, aligned the snail at the hour mark ( with one hammer raised as shown in the video posted on January 2, and the clock worked as it should with strike and chime all good as I manually rotated the hands through the hours. I thought this was good enough and put the movement back into the case. It ran fine for a few days, then went back to irregular patterns. The pin enters all the deep slots. I need to observe more closely at every hour. I miss the observation sometimes because the setup has no chime to alert me, just hammers striking at air. Will try to get more observations today.

 

[ahemsley]

Well, the Strike Train "tries" to lock but it skips once, except when it struck 12:00. See timestamp 0.51 and 1:07 (approximately). The Rack Hook bounces up allowing the Train to strike one more time before locking That often means that the lock pin is too close to the Lock Lever or Locking Detent and needs to be adjusted, retarded or set back a couple of gear teeth. It might also mean that the Maintenance Cam is out of adjustment. Your settings are close or the Train wouldn't go into Lock. These 3-pin Gathering Pallets don't leave much room for error. From what I can see, I don't think that the main issue is with the Rack and Snail, but likely arises from the Lock Pin and/or Maintenance Cam timing between the plates.

I'm not certain, but you may be accidentally "gathering" a tooth or two with your finger when you advance the minute hand to the 45 minute mark. You can confirm or rule that out quickly of course. If that's not the case then something more complicated may be going on with the Rack and Snail setup. It may be a combination of issues.

If the Gathering Pallet was loose enough to adjust/rotate on its pivot, you might be able to make minor adjustments to the Lock timing more easily, but since you didn't remove the Gathering Pallet during the servicing of the movement (because it was too tight with the tools you have to work safely on it with), I don't think you should attempt it now. You might bend or break the Pivot if you do.

Before you attempt to make further adjustments, please wait for others to weigh in. No doubt there are some folks out there with more experience on this type of Movement. I've worked on a few, but it has been a while.

Good luck,

Bruce

Thanks, Bruce!

 

[shutterbug]

Your phone makes a good alarm system. Use the timer feature to alert you to watch the movement.
Depending on the type of hands you have, you might just be able to take off the minute hand and move it 15 minutes to get the bim bam strikes right. The hour is probably the biggest challenge. Let us know what you observe. Make sure that pin is in the fully down position before every hour.

 

[ahemsley]

Your phone makes a good alarm system. Use the timer feature to alert you to watch the movement.
Depending on the type of hands you have, you might just be able to take off the minute hand and move it 15 minutes to get the bim bam strikes right. The hour is probably the biggest challenge. Let us know what you observe. Make sure that pin is in the fully down position before every hour.

I've been making 15 minute observations for 5 hours now, using the timer on my phone. Here's the data. The Number on the left is the strike position on the snail. Next to it, the number of observed strikes. Then the number of Bim-Bams; eg. 1/4 2BB would mean at 15 past, the were 2 sets of Bim-Bams:

2:00 2 strikes
1/4 1BB
1/2 3BB
3/4 3BB
3:00 2 strikes
1/4 1BB
1/2 3BB
3/4 5BB
4:00 3 strikes I noticed the rack pin was not going to the bottom of the snail groove, pushed it down a bit and got three strikes
1/4 3BB
1/2 3BB
3/4 3BB
5:00 5 strikes by pushing the pin down again. The set screw was still inaccessible.
1/4 1BB
1/2 3BB
3/4 3BB
6:00 When the rack pin fell incompletely into the slot I stopped the clock and readjusted the snail position so the pin was not touching the sides of the groove. Started it up again and got 6 strikes.
1/4 2BB
1/2 4BB
3/4 3BB
7: 00 7 strikes, no assistance needed.

 

[Bruce Alexander]

Your Strike Train is failing to reliably go back into Lock when it should. As mentioned earlier, "Skipping" is noted in your video. I think that your timing (lock pin) is too close to the lock detent when the Rack Hook drops off the end of the Rack (Lock). Either that or perhaps the maintenance cam needs to be adjusted. Another video showing what's going on between the plates at the top of the Strike Train might help. We would need to see what's happening when the train skips instead of going into Lock. As mentioned earlier in your thread, there could be other causes such as wear or a bent pin. It's interesting that the movement was working properly for a period of time before it became unreliable. The bottom line is that we need to see more of what's going on to be of much help.

 

[ahemsley]

Your Strike Train is failing to reliably go back into Lock when it should. As mentioned earlier, "Skipping" is noted in your video. I think that your timing (lock pin) is too close to the lock detent when the Rack Hook drops off the end of the Rack (Lock). Either that or perhaps the maintenance cam needs to be adjusted. Another video showing what's going on between the plates at the top of the Strike Train might help. We would need to see what's happening when the train skips instead of going into Lock. As mentioned earlier in your thread, there could be other causes such as wear or a bent pin. It's interesting that the movement was working properly for a period of time before it became unreliable. The bottom line is that we need to see more of what's going on to be of much help.

I have 5 hours of data now (shown directly above) and have corrected the strike problem, at least for the last 2 strike sequences (6 and 7 o'clock) observed since I made a snail position adjustment. The Bim-Bam sequence seems to be the problem.

I'm only familiar with some terms (those I learned first), some of yours don't register:
Is the timing/lock pin the small pin that goes into the grooves of the snail?
What is the lock detent? Not the cam lever notch? Do you mean the deep groove in the snail?

 

[Bruce Alexander]

Okay. See this link for some of the terminology that I've been using: Rack Strike Elements

The Bim-Bam sequence seems to be the problem.

The Train is not reliably going into Lock when it should. As detailed in Post #34, your Bim-Bam sequences are all over the map with no real discernible pattern.

When the strike ends (either the hour strike or the quarterly bim-bams, three things need to happen at once: (1) the rack hook drops off the end of the rack (2) the maintenance lever must drop into the slot of the maintenance cam and (3) the locking lever (or detent) falls into the path of the warning/locking pin, which stops the wheel from turning and puts the Strike Train into lock. The failure of 2 or 3 is often the cause of failure to Lock or Lock reliably. When the rack hook and maintenance lever drops, it appears to me (from what little I can see) that the warning/lock pin skips the locking detent, so the wheel keeps turning. And with it, the strike train keeps running, so that excess bim-bam strikes can and do occur..sporadically. I think that this can also happen on the hourly strikes. I believe it happens in your video (before you latest adjustment) at the 1:00. Correct me if I'm wrong but I think the movement struck 2:00 instead.

IF this is the cause of the failure to go reliably back into Lock, the fix would be to adjust the maintenance cam so that the maintenance is in the middle of the maintenance cam's slot and adjust the warning wheel so that the warning/lock pin is about 1/4 to 1/2 turn away from the locking lever/detent. The warning wheel spins very fast, and needs some lead time/distance to make sure the locking lever/detent is down before the warning/lock pin gets to it.

I think you are close but an adjustment is needed to make the Strike Train go reliably into Lock when it is supposed to.

Again, please exercise patience and wait for others to weigh in.

I am making assumptions based upon an incomplete "picture" of what's going on. You can clearly see the Maintenance Cam (or Wheel) in David LaBounty's video at about the 1:40 mark. There is a cut out in the front plate above his finger. The black Maintenance Lever is also part of the Rack Hook assembly. He is talking about alignment of the Snail which is what you are focused on. While that is critical in these movements, there's more to it than that. The Maintenance Wheel/Cam and Lever are basic components in most Strike Train designs be they Rack and Snail or Count Wheel.
David's video assumes these adjustments have been made already.

Making the wrong adjustment(s) could simply compound the problem.

I hope that helps.

Bruce

Edit: The Maintenance Wheel and Lever are clearly visible in your Post #19 photo.

 

[ahemsley]

Okay. See this link for some of the terminology that I've been using: Rack Strike Elements



The Train is not reliably going into Lock when it should. As detailed in Post #34, your Bim-Bam sequences are all over the map with no real discernible pattern.

When the strike ends (either the hour strike or the quarterly bim-bams, three things need to happen at once: (1) the rack hook drops off the end of the rack (2) the maintenance lever must drop into the slot of the maintenance cam and (3) the locking lever (or detent) falls into the path of the warning/locking pin, which stops the wheel from turning and puts the Strike Train into lock. The failure of 2 or 3 is often the cause of failure to Lock or Lock reliably. When the rack hook and maintenance lever drops, it appears to me (from what little I can see) that the warning/lock pin skips the locking detent, so the wheel keeps turning. And with it, the strike train keeps running, so that excess bim-bam strikes can and do occur..sporadically. I think that this can also happen on the hourly strikes. I believe it happens in your video (before you latest adjustment) at the 1:00. Correct me if I'm wrong but I think the movement struck 2:00 instead.

IF this is the cause of the failure to go reliably back into Lock, the fix would be to adjust the maintenance cam so that the maintenance is in the middle of the maintenance cam's slot and adjust the warning wheel so that the warning/lock pin is about 1/4 to 1/2 turn away from the locking lever/detent. The warning wheel spins very fast, and needs some lead time/distance to make sure the locking lever/detent is down before the warning/lock pin gets to it.

I think you are close but an adjustment is needed to make the Strike Train go reliably into Lock when it is supposed to.

Again, please exercise patience and wait for others to weigh in.

I am making assumptions based upon an incomplete "picture" of what's going on. You can clearly see the Maintenance Cam (or Wheel) in David LaBounty's video at about the 1:40 mark. There is a cut out in the front plate above his finger. The black Maintenance Lever is also part of the Rack Hook assembly. He is talking about alignment of the Snail which is what you are focused on. While that is critical in these movements, there's more to it than that. The Maintenance Wheel/Cam and Lever are basic components in most Strike Train designs be they Rack and Snail or Count Wheel.
David's video assumes these adjustments have been made already.

Making the wrong adjustment(s) could simply compound the problem.

I hope that helps.

Bruce

Edit: The Maintenance Wheel and Lever are clearly visible in your Post #19 photo.

Thanks Bruce, now I think I know what you're referring to. Here's a quote from the link you sent (clock similar to mine):
"Things are properly adjusted when...
1. When the rack hook is fully dropped beneath the rack,
2. The warning pin is resting against the locking stub; and
3. The projection on the rack hook is nestled in the dent of the bean cam.
That means the rack hook is synchronized with the warning wheel.

The cam is a pressed fit on its arbor. It can be adjusted either by twisting it on the arbor, or by prying it off and repositioning it with its dent against the rack hook pin. Do this while the warning pin is against the locking stub, and it should be good to go. "

I know the warning pin is resting against the locking stub, I watched it about 25 times yesterday! I'll check the position of the rack hook at that time and ponder the bean cam issue. I think my clock is using the three pin gathering pallet instead. I just ordered a crow's foot, and I could try to loosen the gathering pallet and reposition it. Although I don't know which way I should turn it, I could aim to have the pins to either side of a rack tooth if that's not what I observe.

 

[Bruce Alexander]

3. The projection on the rack hook is nestled in the dent of the bean cam.
That means the rack hook is synchronized with the warning wheel.

The cam is a pressed fit on its arbor. It can be adjusted either by twisting it on the arbor, or by prying it off and repositioning it with its dent against the rack hook pin. Do this while the warning pin is against the locking stub, and it should be good to go. "

I think that what bangster is calling the "Bean Cam" is what I am referring to as the Maintenance Wheel or Cam. You adjust that when the plates are separated, of course, by rotating the wheel (or gear). There should be no need to remove the Cam. That would be a bad mistake.

When the Rack Hook falls off the end of the Rack, that black tab (let's call it the Cam Projection) must fall as far as it can go towards the bottom of the slot in the Cam. If it is not down, the Warning/Lock Pin may slip past the Detent (which is also not fully down) and the Strike Train can fail to go into Lock until the cam slot comes back around. Since, at that time, the Rack Hook has already fallen off the end of the Rack, the Cam Projection should be able to drop towards the bottom of the Cam Slot. (The Gathering Pallet is still doing its thing, but it should be irrelevant at this point.) This would result in an extra Bim-Bam, or Hour Strike. You might get more than one as you've detailed here:

3:00 2 strikes
1/4 1BB
1/2 3BB
3/4 5BB

(emphasis mine)

I think that your timing is pretty close. I would probably try to make adjustments by rotating the Gathering Pallet on its fragile Pivot. The direction of rotation depends upon what you observe as the Strike Train fails to go into Lock. The timing may need to be retarded (Gathering Pallet rotated clockwise) or advanced (Gathering Pallet rotated counter-clockwise) depending upon what you see. Keep in mind that much depends upon the position of that fast rotating Warning/Lock Pin. If it is too close to the Lock Detent, you probably won't be able to reliably "catch" it the first time regardless of whatever Gathering Pallet adjustments you make. Again, the Gathering Pallet's Pivot should be considered fragile. Much better to split the plates and adjust the timing of the wheels, especially if you're not yet ready to re-pivot an arbor.

Also keep in mind that any adjustments to the 3-pin Gathering Pallet must be kept very minor. Three Pins do not leave much room for error. The Gathering Pallet must not engage the Rack teeth when the Strike Train goes into Warning. If a Gathering Pallet Pin "fouls" the Rack, it can't drop fully onto the Snail. As a result, one can get all sorts of strange strike counts!

This all assumes that the Strike control levers have not been "adjusted" (bent). One never knows what has previously been done to a movement. They've usually been on several benches before they land on yours. You should be able to tell when something has been bent. It's usually pretty obvious once you've disassembled a movement and focused on each part.

I hope that makes sense. Try to visualize what is happening vs. what needs to happen to get your Strike Train to go reliably back into Lock.

Good luck,

Bruce

 

[shutterbug]

I may be wrong, but it seems that there is evidence of proper sequence, i.e. there are three bim bam sequences followed by a strike sequence. So the process is correct, but the numbers are wrong. The locking pin is a likely suspect, and equally suspect is the rack itself. I think both need to be observed to find the issue.

 

[ahemsley]

I may be wrong, but it seems that there is evidence of proper sequence, i.e. there are three bim bam sequences followed by a strike sequence. So the process is correct, but the numbers are wrong. The locking pin is a likely suspect, and equally suspect is the rack itself. I think both need to be observed to find the issue.

I saw that when the warning pin was against the locking stub, the black rack hook was not resting under the rack tail, so I took the clock apart and reassembled it. Now, after going into warning, I have bim-bams that wont stop. the rack hook doesn't seem to want to go under the rack tail again. You predicted I might make things worse. So it would seem. I'll try another reassemble tomorrow.

 

[Bruce Alexander]

I saw that when the warning pin was against the locking stub, the black rack hook was not resting under the rack tail, so I took the clock apart and reassembled it. Now, after going into warning, I have bim-bams that wont stop. the rack hook doesn't seem to want to go under the rack tail again. You predicted I might make things worse. So it would seem. I'll try another reassemble tomorrow.

The "Rack Tail" is the part of the Rack that drops against the Snail. What are you referring to?

When you reassemble, I find that it helps to make sure all three conditions are clearly met for the strike train to go into lock. The only exception is that you'll want the warning/lock pin to be approaching, not at, the Locking Detent. About 1/4-1/2 turn away. Remember that the Warning/Lock Wheel (gear) turns very fast and everything has to be in place to catch it. If not, as you've discovered, you'll have a runaway Strike Train. You must visualize and understand what needs to happen when the Strike Train transitions from Lock, to Warning, to Striking, and back into Lock. Seems like you're getting pulled in too many directions at once, and I'm just starting to repeat myself. I'll let Shutterbug take it from here.

Good luck,

Bruce

 

[ahemsley]

The "Rack Tail" is the part of the Rack that drops against the Snail. What are you referring to?

When you reassemble, I find that it helps to make sure all three conditions are clearly met for the strike train to go into lock. The only exception is that you'll want the warning/lock pin to be approaching, not at, the Locking Detent. About 1/4-1/2 turn away. Remember that the Warning/Lock Wheel (gear) turns very fast and everything has to be in place to catch it. If not, as you've discovered, you'll have a runaway Strike Train. You must visualize and understand what needs to happen when the Strike Train transitions from Lock, to Warning, to Striking, and back into Lock. Seems like you're getting pulled in too many directions at once, and I'm just starting to repeat myself. I'll let Shutterbug take it from here.

Good luck,

Bruce

Sorry, rack, not rack hook. Thank you for your help.

 

[shutterbug]

The rack hook falling under the rack should happen just before the stop. You'll get it with patience Another video might help.

 

[ahemsley]

The rack hook falling under the rack should happen just before the stop. You'll get it with patience Another video might help.

I've gone over everything in this thread again. I noticed that the maintenance lever was not sitting absolutely dead center of the cam slot during operation, and put C clamps on the main springs to tweak the gear positions again. What I saw this time was that I do have everything precisely aligned as I've been advised when the C clamps are on the clock and the mainsprings are not providing any power. But when the clamps come off, it's all a bit different. Not sure how to safely get around this issue.

 

[shutterbug]

You can wind it with the clamps in place to test it. If it needs more tweaking, just let the power down into the clamps again. A couple of turns should be enough.

 

[ahemsley]

You can wind it with the clamps in place to test it. If it needs more tweaking, just let the power down into the clamps again. A couple of turns should be enough.

That opened up a new can of worms, or possibly another way to look at the irregularity. I did another tweak, left the clamp on but wound a few turns and physically held the spring plus clamp out of the way of the hammers. Upon rotating the minute hand I got 2 correct strikes at 6 and 7 o'clock with a 1BB, 2BB, 3BB sequence between on the 1/4, 1/2, 3/4 hours points. Then I took the clamp off, since all seemed good. The BBs went back to being irregular. Then it was the end of the day. Should be interesting to see what the clock has reverted to overnight.

 

[Bruce Alexander]

Still lurking here. What "tweak" did you make? As suggested by SB a few posts ago, I think another video could be helpful. At one point it sounded like an issue with the timing of the maintenance and lock wheels between the plates, but you've been changing things and so I'm not so sure anymore...just curious as to what's causing your peek-a-boo issue

 

[ahemsley]

Still lurking here. What "tweak" did you make? As suggested by SB a few posts ago, I think another video could be helpful. At one point it sounded like an issue with the timing of the maintenance and lock wheels between the plates, but you've been changing things and so I'm not so sure anymore...just curious as to what's causing your peek-a-boo issue

The tweak was to the position of the maintenance cam lever since it sat back too far from center, still following your advice . Adjusting it yet again got me some good timing yesterday with the clamp still on the strike mainspring and that continued into today. After two hours of absolutely correct striking and Bim-Bams, which had gone on all night I think, I decided to add the hammers onto their levers, to test it closer to how it would be in the case. When I attached them I caused the mainspring to lurch open a bit and I also bumped on the strike levers some when attaching the wires and hammers. Now the clock runs on again with too many strikes and BBs. So, back to tweaking the timing of the maintenance and lock wheels between the plates , but those hammers are staying on this time. The clock seems to be more sensitive to movement than I could ever have foreseen.

 

[Jeff T]

check the lever that rides on the maintenance cam if it has groove worn in it that will sometimes cause a run on check the maintenance cam that the stop slot is not worn at an angle should a right angle before it meets up with the curve the leads to the edge where lever rides