Gilbert #23 Bim Bam Mantel Clock Not Striking on Hour

[mjrichard5051]

Hi,
I have a Gilbert #23 Bim Bam Mantel clock. It has 2 strike hammers. One hammer strikes on the half hour at the correct time (less than half a minute late). Both hammers strike in a Bim Bam pattern on the hour but they strike 3 minutes late (minute hand at 3 minutes after 12 at stike). I can also hear the Warning Cam trip 3 minutes late (assuming it normally sets at 5 minutes before the hour).
The clock keeps good time and was cleaned by a pro not too long ago. As you can see from the photo I don't mind "repairing" the clock. When the regulator's pressed components blew apart, I replaced it with a paper clip and an adjustable bob. Please be kind - it's not a real repair but it worked.
Is there any adjustment(s) I can make to correct the hour strike without removing the movement from the case? I don't mind using a mirror and making needed "adjustment tools". If not, I may just live with it versus causing further damage.
Thanks in advance for any advice.

 

[comet61]

I work on a lot of of these Gilbert movements. The passive strike is in a position in relation of the minute arbor and easily corrected on the back. The problem you may have is that the lifting J hook is slightly bent out too far causing the early strike. The J hook rides up the strike release pins on the minute arbor. If the tip of the J hook is bent too far out, it will strike too soon. This will also effect the warning as well. You have to slightly bend it in until the J hook drops at the top of the hour. Doing this disassembled makes it easier if you put on the miinute hand for proper indication when the J hook drops and the hand is straight up. There is a PDF file here that shows the procedure.

 

[Willie X]

Pretty sure you will have to disassemble this one. The solid plates won't allow access for what you will need to do. The "J" hook will need to have more curl, or less curl, at the hook. A few minutes studying the situation will help you decide what exactly needs to be done to the hook to correct the drop-off point.

There are several variations of this movement but I'm pretty sure yours is the one comet just mentioned. The half hour drop-off is easily adjusted and completely independent from the hour strike, which will be difficult to adjust.

Also, while you're at it, make sure the minute pinion is not cracked. This is a very common problem on Gilbert clocks.

Willie X

 

[Steven Thornberry]

I think this will do better in the Clock Repair forum.

 

[John P]

You could try flipping the minute hand over and re checking. could be that simple.

johnp

 

[mjrichard5051]

I think this will do better in the Clock Repair forum.

Thanks. This is my first post. Still in the learning curve.
I assume you have moved it to the Clock Repair forum? If not please let me know.

Mike

 

[R. Croswell]

You could try flipping the minute hand over and re checking. could be that simple.

johnp

Yes, do try flipping the minute hand. If the strike is still off in the same direction by the same amount you know the minute hand is not the problem.

The half-hour strike on this gilbert is independent of the hour strike. It is a "passing bell" controlled only by the position of the little lever on the back of the movement which lifts and drops a single hammer.

These Gilbert models typically do not have a "J" hook that can be adjusted but have a flat steel (or sometimes brass) lever shown in the picture here that serves the same purpose. The flat lever should not be bent, however, sometimes the tip of the lever gets "messed with" and may cause the strike to be early or late.

My diagnostic conclusion: Because the hour strike and the half-hour passing bell strike are totally independent of one another, but both the hour and half-hour are off by the same amount, my money is on a bent minute hand or a minute hand that the square hole wallowed out, or an improperly fitted minute hand. (Much less likely is that someone has moved the brass cam on the center shaft and failed to replace it properly and adjusted the half-hour lever "off" to match the hour.)

RC

 

[mjrichard5051]

I think this will do better in the Clock Repair forum.

Yes, do try flipping the minute hand. If the strike is still off in the same direction by the same amount you know the minute hand is not the problem.

The half-hour strike on this gilbert is independent of the hour strike. It is a "passing bell" controlled only by the position of the little lever on the back of the movement which lifts and drops a single hammer.

These Gilbert models typically do not have a "J" hook that can be adjusted but have a flat steel (or sometimes brass) lever shown in the picture here that serves the same purpose. The flat lever should not be bent, however, sometimes the tip of the lever gets "messed with" and may cause the strike to be early or late.

My diagnostic conclusion: Because the hour strike and the half-hour passing bell strike are totally independent of one another, but both the hour and half-hour are off by the same amount, my money is on a bent minute hand or a minute hand that the square hole wallowed out, or an improperly fitted minute hand. (Much less likely is that someone has moved the brass cam on the center shaft and failed to replace it properly and adjusted the half-hour lever "off" to match the hour.)

RC

View attachment 715147 View attachment 715148

Thanks RC,
Very helpful and appreciated. One correction. Both the hour and half-hour are not off by the same amount. Half-hour is on time while hour is 3 minutes late.
Thanks,
Mjrichard

 

[R. Croswell]

Thanks RC,
Very helpful and appreciated. One correction. Both the hour and half-hour are not off by the same amount. Half-hour is on time while hour is 3 minutes late.
Thanks,
Mjrichard

Understandable because the little half-hour lever on the back is easy to adjust.
RC