Not what is it but how you use it.

[formariz 12,019]

These are plumb bobs. A tool that I always use rather than a level.The one on the left belonged to my great grandfather. The one on the right I use and it’s a relative “modern “version . Some here will say that they are used by a specific trade and in a way they are right. However where I am from basically all plumb bobs are like this with no point.

I can transfer a line from the floor to a ceiling by myself as far as the length of the line and my eyesight will allow and do it quickly. Can anyone tell me how that is done? It’s actually very simple.

Edited April 26, 2020 by formariz

[JAinVA 4,636]

You could use a square to mark 4 points on the diameter at roughly 90 degrees and connect the marks to form an x.That might not be the answer you are looking for but you could do it that way.

[formariz 12,019]

Clever but no. Plumb bob may keep turning. It would be virtually impossible to line up those two points with the line on the floor and definitely not alone. Then how would you transfer those two points to the ceiling?

Edited April 26, 2020 by formariz

[JAinVA 4,636]

Is the plumb bob supended from a point on the ceiling?

[formariz 12,019]

It’s used together with block. Remember I have to transfer line on floor to ceiling alone.

 

In reverse , transferring a line from ceiling to floor it’s actually easier. I don’t have to go off ladder to mark line on floor, I can do that from top of ladder.

Edited April 26, 2020 by formariz

[SylvanLakeWH 28,183]

Chalk or a light casting a shadow of the string on the wall. Take your pick.

[Ed Kennell 41,578]

57 minutes ago, formariz said:

It’s used together with block. Remember I have to transfer line on floor to ceiling alone.

Place the center of the block on the line.   Then suspend the weight from the ceiling over the block.     Do this at each end of the floor line and connect the two ceiling points.

 

57 minutes ago, formariz said:

 

In reverse , transferring a line from ceiling to floor it’s actually easier. I don’t have to go off ladder to mark line on floor, I can do that from top of ladder.

Suspend the weight from a end point of the ceiling line allowing the weight to set on the floor.  Draw around the OD of the weight.    Repeat from the other end of the ceiling line.   Then connect the centers of the two floor circles.

[formariz 12,019]

Remember ,there is a line on floor. I have transfer that line to the ceiling by myself. 
 

The other way, there is a line on the ceiling already and I need to plumb it to floor. This one is a little easier  because it’s next to me I can see it clearly since I am on top of ladder. I can transfer that line to floor with this plumb bob without going off ladder to mark floor.

 

 Take a good look at all the parts of this plumb bob.

 

Edited April 26, 2020 by formariz

[formariz 12,019]

51 minutes ago, SylvanLakeWH said:

Chalk or a light casting a shadow of the string on the wall. Take your pick.

Shadows are never accurate and we are not dealing wit a wall nearby. Merely a floor and a ceiling.

[8ntruck 7,703]

Is the wooden block the same diameter as the bob?

[Ed Kennell 41,578]

I can see the block being used as the anchor for the bob  with the side of the block where the string exits being on the ceiling line.   But I can't see how the bob marks the floor.

[formariz 12,019]

38 minutes ago, Ed Kennell said:

 

Suspend the weight from a end point of the ceiling line allowing the weight to set on the floor.  Draw around the OD of the weight.    Repeat from the other end of the ceiling line.   Then connect the centers of the two floor circles.

Hint. Part of the answer is the fact that plumb bob has no point. Another part of answer is that one has to take into account all parts of this plumb bob. 

[formariz 12,019]

11 minutes ago, 8ntruck said:

Is the wooden block the same diameter as the bob?

Wooden block is not the same diameter. On my grand fathers block is a cube. I prefer mine a cylinder which is much more accurate.

 

 

Edited April 27, 2020 by formariz

[formariz 12,019]

6 minutes ago, Ed Kennell said:

I can see the block being used as the anchor for the bob  with the side of the block where the string exits being on the ceiling line.   But I can't see how the bob marks the floor.

Care to elaborate on first part of your answer? What happens when there is no line on ceiling?

 Yes bob does not physically mark floor but it tells me where point needs to be marked when I go down the ladder.

[Ed Kennell 41,578]

      It is clear the side of the block would be held on  the ceiling line with the block groove placing the center of the string and bob on the ceiling line.   With the block held in position on the ceiling, the string is pulled thru the block lifting the bob and letting it settle with out swinging to the floor.   The center of the bob is one point on the ceiling line.

[formariz 12,019]

21 minutes ago, Ed Kennell said:

      It is clear the side of the block would be held on  the ceiling line with the block groove placing the center of the string and bob on the ceiling line.   With the block held in position on the ceiling, the string is pulled thru the block lifting the bob and letting it settle with out swinging to the floor.   The center of the bob is one point on the ceiling line.

This bob does not have a center one can see, much less alone on top of a ladder. Regular bob on left has a center.

 

Edited April 27, 2020 by formariz

[Pullstart 66,295]

Are you using the edge of the plumbob?  It looks like the distance from the center hole to the edge of the block is the radius of the weight?

[formariz 12,019]

54 minutes ago, Ed Kennell said:

I can see the block being used as the anchor for the bob  with the side of the block where the string exits being on the ceiling line.   But I can't see how the bob marks the floor.

Although it really would not work without a line,in this case with this type of plumb bob , line has really no bearing on the process besides being the carrier to keep the system together or rather being the gravity connector. Reason why also line is so thick, since it is usually not used to measure to for checking for plumb, although one could. For that I use a different plumb bob with very thin squid fishing line that can be anchored using a multitude of possibilities.

Edited April 27, 2020 by formariz

[Ed Kennell 41,578]

To transfer a line from the floor to the ceiling.       The free end if the line could be anchored to one end of the floor line (north).    The block could be held against the ceiling near the middle of the floor line with the bob suspended.   The block could then be adjusted   (east and west) to align the two string lines with the floor line.  When all three lines are on the same sight plane, the block is plumb to the floor line.    Two or more of these points could be marked on the ceiling.

[formariz 12,019]

14 hours ago, pullstart said:

Are you using the edge of the plumbob?  It looks like the distance from the center hole to the edge of the block is the radius of the weight?

Exactly. In this system the block is as important as the actual plumb bob. Block length is the same as bob's diameter and it is drilled exactly in center matching therefor bob's center. It is however the end of block that allows one to mark ceiling on the right spot.  From the top of the ladder one aligns the very edge of the bob by moving the block left to right to achieve the alignment. Flat bottom allows you to place bob just above floor. That also allows you to roll the block back and forth ( with the round block that I prefer) placing bob gently on floor and raising it smoothly making it stop from swinging very fast. Shape of bob also does not make the top of it swing like a regular bob that it is top heavy. These are also hollow and are filled with lead. Once it is in line with line on floor one marks the end of cylinder in the ceiling. Again here the cylinder is more precise since only one very small point contacts the ceiling unlike the square block.

 

In reverse, transferring a line from ceiling to floor one aligns block with line, stops bob from swinging in the same manner as above and and when that is achieved gently place bob on floor. You can then go down and mark that edge of bob. Again since it is a circle  it is a very small point so its accurate. Do a second point like that and snap the line. One man can do it this way without having someone else on bottom stopping bob and telling the other guy where to move on top.

 

Checking a wall for plumb same principle by holding end of block against wall on top and checking edge of bob. It will be either perfect with side of bob just touching it or off in either direction by bob just leaning against wall to leaning away from it. No need for a second man on bottom again measuring to line.

 

I never liked regular plumb bobs, even the ones I have with a point are custom made for me like the one in the photo above. I have them made like that because weight distribution is much better when they have straight sides and are long.

On an interesting note,I worked numerous times on the top floors of the now gone World Trade Center buildings. It was before lasers were really around. Using plumb bobs there was a difficult task because buildings moved so much. A plumb bob left alone would be swinging like a clock pendulum within five minutes swinging as much as a foot each way once it picked up momentum. We had to place plumb bobs in a container with water so it gave us time to use them accurately. Although it was not really evident just walking around, one could also just stop at the windows stay still and eye the the edge of another building for a little while noticing then that we were moving. On a really windy day there was no missing that.

 

Edited April 27, 2020 by formariz