Spiling sticks, joggle sticks and a “digital” rule

[Philip Davies]

Vinyl layers use a similar technique, although ones I seen and used myself, are just a small rectangular block, running a line off the opposite to the edge.
Then use the same block to transpose back onto the vinyl...

Yes, here’s the little block I used to keep in my tool bag. I also used it to space nails or screws into corners

[hemmjo]

I have used them lots of times, but always called them tick sticks as mentioned above. Very handy. It is interesting how names of things change from region to region. The comments are interesting on this video.

[carloski]

I was selling the metal ones, as shown, in the early 1970's, made by General. Now they have plastic ones, and some people think they are a new invention.

[Peter Sanders]

I could not see the point in using such a spiling stick in your example. Why not just use a pencil to draw around the object's profile?
I assumed it could be used on larger (longer) items, i.e. boat building, where tracing a profile to a "template" is beneficial. This prompted me to look on Wikipedia spiling stick which shows the intended use, though with a different "stick".
I further assumed that the notches are more for creating a line or mark at specific distances from the edge being profiled. Hence the taper of the stick.
So, instead of using the point as an indicator of sorts, the "back" (unnotched) edge is moved across the board being profiled and the pencil or other marker placed in a suitable notch, is moved along/across the template. This generates an appropriate "cut" line for the template or the new board that fits against the previously "profiled" board. Obviously in boat building this is a useful tool, for smaller items, perhaps not so useful.
Best wishes...

[Philip Davies]

I could not see the point in using such a spiling stick in your example. Why not just use a pencil to draw around the object's profile?
I assumed it could be used on larger (longer) items, i.e. boat building, where tracing a profile to a "template" is beneficial. This prompted me to look on Wikipedia spiling stick which shows the intended use, though with a different "stick".
I further assumed that the notches are more for creating a line or mark at specific distances from the edge being profiled. Hence the taper of the stick.
So, instead of using the point as an indicator of sorts, the "back" (unnotched) edge is moved across the board being profiled and the pencil or other marker placed in a suitable notch, is moved along/across the template. This generates an appropriate "cut" line for the template or the new board that fits against the previously "profiled" board. Obviously in boat building this is a useful tool, for smaller items, perhaps not so useful.
Best wishes...

Yes, I take your point, Peter, ha ha. I could not think of anything else to use as an example. It was merely to show the technique. The last time I did this was to fit an oak window board into an irregular masonry opening.

Were you to fit a board to fit the bottom of this ( slightly tapering) chest I made, you might find the method helpful. While I might scribe using compasses, it’s never occurred to me before to move the spiling stick and pencil simultaneously

[hemmjo]

Peter, the video is not the best example of the process either. Imagine a much more complex shape. For example fitting a counter top into the galley of a boat. Or fitting a V-berth into the bow of a boat. You want it to fit snug against the side to things do not slip between it and the side of the boat. There are no straight lines. There is nothing good to use for reference points. You just have to "map out" the size and shape by creating your own reference points.

The scribing technique you describe certainly works in a lot of situations, but that is dependent on the angle of the stick, or scribe or compass, etc remaining constant to in relation to the surface being copied.