How do you use a plumb bob like these?

[AndyT]

Over in another thread, Wolfgang Jordan kindly posted a link to this catalogue page on his excellent website:

It shows two plumb bobs which were available with an optional square brass or steel plate ("Messingplatte" or "Stahlplatte").

I've never seen that on a plumb bob before. Does anyone know exactly how it would be used? Or seen one anywhere else?

 

[doctor Bob]

Its a spacer, slightly wider than the Bob, if you drop a line without this spacer, down from the top of a wall the bob would sit against the wall and not give a true vertical, however if you push the spacer to the top of the line and put it against the wall the bob will sit just off the wall and give a true vertical.

 

[DTR]

Its a spacer, slightly wider than the Bob, if you drop a line without this spacer, down from the top of a wall the bob would sit against the wall and not give a true vertical, however if you push the spacer to the top of the line and put it against the wall the bob will sit just off the wall and give a true vertical.

Why did the plates disappear from common use? It sounds like a great idea! #-o I think I'll have to make one for my plumb bob

 

[dickm]

My german isn't up to reading the caption, but is item 1386 at the bottom of the page made by the UK Record?

 

[MusicMan]

it says "Revolution counter for use in the hand, with zero-torque-position". From this and the item above it appears you push them onto a centre in a rotating shaft and it counts revolutions. Dunno why one would want that!

It does say Record on it.


Keith

 

[bugbear]

it says "Revolution counter for use in the hand, with zero-torque-position". From this and the item above it appears you push them onto a centre in a rotating shaft and it counts revolutions. Dunno why one would want that!

In conjunction with a watch (or stop watch) it allows the RPM of a lathe, drum or shaft to be measured. Important information to a millwright.

BugBear

 

[AndyT]

Bob, thanks for the explanation which fits with what I had deduced.
But as Dave said, it's odd that a useful method is not more widely known - unless everyone else knew it!

 

[doctor Bob]

But as Dave said, it's odd that a useful method is not more widely known - unless everyone else knew it!

I was only allowed this knowledge from "the secret woodworkers club" after the initiation ceremony, bye heck that was a big goat.............. anyway shhhhh don't tell everyone about it.

 

[J_Cramer]

Andy, if you google

wooden and metal spacers for plumb bobs

you'll find a pdf by Wolfgang Ruecker from plumbbobcollectors with some additional information.

(My post count still doesn't permit me to post links, hence the google ref.)

Jürgen

 

[AndyT]

Andy, if you google

wooden and metal spacers for plumb bobs

you'll find a pdf by Wolfgang Ruecker from plumbbobcollectors with some additional information.

(My post count still doesn't permit me to post links, hence the google ref.)

Jürgen

Brilliant, thanks! That's exactly what I wanted. A good description of usage, confirmation that spacers were not common in England, and lots of pictures.

The link is http://www.plumbbobcollectors.info/media//DIR_42117/DIR_42126/27370a50d48b95cdffff868cac14422e.pdf.

 

[Billy Flitch]

Been meaning to make a post on this thread for some time but life gets in the way. Sorry Andy I carn`t add any thing to the plate on the plumb line, never really came across it. Wolfgang Jordan Has really made a great job of his site and is a credit to any one studding a subject.
What really drew my attention was the level at the top of the page of tools in Andy`s first post, I thought it would be interesting to some but maybe not to all. The level has a adjustable foot on one end and can be raised up to 150 m/m to measure the incline over the full length of the level we used to do the same thing but use a declivity stick. I didn`t fancy explaining what a declivity stick is so I went looking on google and found a guy doing a very good job of explaining it, check the link.http://lumberjocks.com/GnarlyErik/blog/33307

I must say I never set a boat or ship up using a declivity stick that's a job for Dumphy levels, theodolites and sight boards , the stick was usually used foe beds for machine, you can also see in the guys link that declivity is not only allowed for in the level but also in the plumb. In the plumb maths would come into play, if the declivity was say 50m/m and you wanted to plumb something up that was say 10 MTRS tall you would have to set the plumb bob up 500m/m away from the object.

Planing the mahogany to make the levels and declivity sticks was how I was taught how to use bench planes I could go into the way they where tested when I thought they were finished but you may not believe it.

 

[MusicMan]

Billy, I'd be very interested in how you tested them.

Keith

 

[AndyT]

So would I!