repro banjo question 3 of 3 (weight/bob separation)

Jim Hartog

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Hello,

When the weight of this weight-driven banjo gets down into the lower box, there is a strip of wood held in place only by friction that is supposed to deflect the weight (it has a rounded front edge) back towards the backboard so that there is no interference to the bob. The classic time pieces had a piece of sheet metal that separated the weight from the bob.

Third question. Is what I have sufficient for the task of weight/bob separation or should I consider an upgrade? Since this is not one of the original classics, I have no problem with installing an upgrade to improve what the maker did. At least a better support for the strip of wood!

Jim

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Darrmann39

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Hello,

When the weight of this weight-driven banjo gets down into the lower box, there is a strip of wood held in place only by friction that is supposed to deflect the weight (it has a rounded front edge) back towards the backboard so that there is no interference to the bob. The classic time pieces had a piece of sheet metal that separated the weight from the bob.

Third question. Is what I have sufficient for the task of weight/bob separation or should I consider an upgrade? Since this is not one of the original classics, I have no problem with installing an upgrade to improve what the maker did. At least a better support for the strip of wood!

Jim

View attachment 662542
Your right about the metal but mine also has the neck pieces going all the way to bottom for the metal to attach to.
I'm not sure that's even needed , I can't imagine a thin piece of wood like that wouldn't bow a little from being pressure fit and hard to get exactly right without touching Bob or weight.
It's just something to interfere with the 2.
But I've not seen one like this so I don't say that from knowing for sure.
 

bruce linde

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will your weight slide behind that cross piece? hard to tell from the photos.

your pictures don't really show all that's going on... i would suggest photos from all angles that show more of the entire path the weight follows, dial, case, etc.

we can't see what you're seeing.
 

Andy Dervan

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Timepieces have either a wood or metal baffle that separates the descending weight from the pendulum bob.

Sometimes there are wooden strips at the top of throat to keep weight away from the pendulum rod.

Andy Dervan
 

Jim Hartog

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Hello,

The same YouTube video (shipping dis-assembly) shows that the throat sides pieces also extend into the bottom box and the sheet metal attaches to these extensions to separate the weight and bob. I could put a couple of pieces of wood in the bottom box and put some sheet metal across those. Painting the metal black would be a good idea, too, since there is a pendulum viewing hole (lenticel?) in the bottom glass.

The piece of wood that mine came with is about a cm thick. Sheet metal would take up a lot less space and be closer to "original".

Something tells me that whomever designed this case had no idea what the originals looked like.

Bruce, there is room for the weight, the piece of wood and the pendulum bob when all are at the same level in the lower box. But, not a lot of room since the stick is 1 cm thick and not held in other than by friction. It needs to change. it will be changed.

Jim
 
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Jim Hartog

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Hello,

In reviewing the video again (
), I noted that there is a crude "beat scale" on the sheet metal behind the rating assembly which can be used to plumb the case on the wall. But, there is no room for a central screw to fasten the bottom of the clock to the wall, though. The clock in the video has holes on either side for the stabilizing screws. Not so great for modern drywall-on-stud walls on which you attach the top and bottom of the clock case on one stud.

Jim
 

bruce linde

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In reviewing the video again I noted that there is a crude "beat scale" on the sheet metal behind the rating assembly which can be used to plumb the case on the wall. But, there is no room for a central screw to fasten the bottom of the clock to the wall, though. The clock in the video has holes on either side for the stabilizing screws. Not so great for modern drywall-on-stud walls on which you attach the top and bottom of the clock case on one stud.
i don't have a single banjo clock hanging from a screw into a stud... they're all hanging from 100lb hangers secured with three angled nails into the sheetrock.

i always have at least one additional screw helping support the clock (and preventing side-to-side movement) through the inside back of the case into the wall, but on either side of the weight channel. the total weight of these clocks is maybe 10lbs.
 

Joe Hollen

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It would be easy enough to take two pieces of wood and glue them into the bottom pendulim box. You would basically extend the throat pieces down to the bottom of the box. Get a measurement of the thickest part of the weight. I use a caliper. Banjo weights are usually 1 1/2“ thick. Take that measurement and extend it 1/8“ to 1/4” more than the weight‘s thickness. That will be the width of the two pieces. Make the pieces as thick as the throat pieces that extend into the top of the pendulum box. Carefully shape the two pieces to contact the backboard, throat bottom (which again extends down into the case) and the bottom of the pendulum box. Make sure the wood (in the case) where the pieces contact the case are sanded and free of varnish, etc. If it’s possible to clamp the pieces after they’re glued and put in place, that would be good. After they’re glued you can reinforce them with glue blocks, but DON’T put glue blocks where the weight comes down in the weight channel…. After the pieces are in place you should be able to shape a piece of sheet metal to fit. It will be trapezoidal in shape. You can spray paint it black. Tack it in place with small brass tacks. Drilling very small pilot holes for the tacks in the wood pieces you made would be recommended to preclude the wood from splitting., and of course, drill holes in the sheet metal large enough for the tacks. There’s a lot more that would be done if you were versed in making banjo cases, like fitting a pendulum tiedown, and slightly flaring the top part of the sheet metal so that the weight wouldn’t hang up on it as it descends. You should be able to do this work… If you’re not comfortable doing this, try to find someone who is versed in “small woodworking”. The results would be a lot better than what you have right now !
 

Andy Dervan

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Our basement got trashed due to a flood, so I had to remove all the paneling, but left most of the 1 x 2 inch wood strips nailed into the concrete wall.

I inserted 1 inch # 10 screws into the wood strips and hung all the clocks back up safe and secure and started running about half of the them.

Attached is photograph of lower box of a non-sophisticated early timepiece ca 1830 that has a simple wood baffle and a friend cut paper to form simple way to plumb clock on the wall.

It is not necessary to wood strips the entire length of the throat....

Andy Dervan

Haynes - lower box better photo.jpg
 

Jim Hartog

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Hello Joe,

I am fully capable of all that you suggest (copy the originals) and that is my plan. Integrating some sort of pendulum tie-down sounds like a good idea, too. Still have to think about that idea.

Jim
 

Jim Hartog

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Hello,

I went with parallel sides on the box just to make things simpler. The metal is aluminum and the top has a couple of folds to create a flare to catch the rounded bottom edge of the weight to deflect it into the box. That was tested last night and it worked well. The aluminum is screwed in so that the metal can be easily removed to access the existing hole in the center of the backboard to stabilize the bottom of the clock. I am contemplating putting a larger (one inch) hole in the aluminum behind the bob to access the screw without having to remove the aluminum (6 tiny screws). The marks on the brass beat scale are just scratched into the surface. I failed at trying to get some black into the scratches. The sides of the box are just screwed in from the back. The two pegs in the sides of the box will be the anchors for some kind of pendulum tiedown (bubble wrap and rubber bands?).

P1030014.JPG P1030015.JPG P1030016.JPG

Thanks for all the help on this.

It is now my opinion that this was not a factory case. Someone who got baffled by the taper of the throat and couldn't glue two pieces of wood together at 90 degrees built this. I corrected some of the errors but in doing so I was creating other problems so I have reached the point where I have quit trying to "fix" things. All my additions were solid mahogany in keeping with the builder's wood choice.

Tomorrow is strip-off-the-old-finish day. Then a re-stain and a new finish. A solid brass finial has been ordered from Timesavers. The old hole for the missing finial can't be re-used because it is 1/4" off center. Why am I not surprised?

I will post an all-done photo when I get to that point.

Jim
 

Andy Dervan

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The aluminum weight baffle looks good. I did similar thing with a number of my Waltham Willard banjo clocks as original weight baflles were discarded. I made two pieces ones out of aluminum and painted them flat black. One was in lower lower box and the other slid into grooves in the throat, so the weight and pendulum were completely separated.

Andy Dervan
 

Jim Hartog

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Hello,

The Timesavers finial arrived and everything got finished up. I did replace the 1.2 mm braided cord with 1.0 mm braided cord (still 300 pounds test) so there is more room on the winding drum at full wind. Things are getting "tight" here so I had to move a ST hanging "Eclipse" to a closet! The object in the plastic bag in the bottom is a spare suspension spring.

Jim

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Willie X

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Looks good. Willie
 

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