A what is it and how are they used?

[Snaparxon]

Found these at a garage sale in a box of welding stuff, they were with set up tools, measuring tools and levels.

No markings at all.

 

[The Cobbler]

look up trammel points

 

[Snaparxon]

Thank you ! Took two minutes

 

[Milton Shaw]

Most sets have a slot to hold a pencil to mark circles and arcs. Most of the ones I have seen fit on a yard stick or similar piece of wood. Both sets I have hold a pencil and the best pencil is a flat carpenters pencil, round #2's don't fit as well.

 

[Snaparxon]

I'm going to use them with a piece of thin wall square tubing to make a tool for checking toe in on vehicles

 

[WoodsTruck]

I'll be darned.
I needed to mark out some large circles on some coated vinyl material for water cooler covers.
Printed out a pivot and a clamp block. Used to tape to mark center then taped the pivot down given I printed an open 90° on the bottom to match center, then measured the distance needed and clamped the marker. Didn't know there were fancier versions.

 

[RoninB4]

Didn't know there were fancier versions.

-Trammel points were/are commonly used for layout work by (machinists, sheet metal, wood workers, etc.) scribing thin lines on surfaces. Creating reference points or geometric shapes (half-way location, perpendicular lines, tangency points, etc.) can often be done without measuring. They're very handy for point-to-point measuring (center-to-center or edge) minimal weight, and can use whatever shape/length contact probe as needed. Need more/less length? Use a different beam. They're often cheap and often only limited by your imagination.

 

[Beerhippie]

-Trammel points were/are commonly used for layout work by (machinists, sheet metal, wood workers, etc.) scribing thin lines on surfaces. Creating reference points or geometric shapes (half-way location, perpendicular lines, tangency points, etc.) can often be done without measuring. They're very handy for point-to-point measuring (center-to-center or edge) minimal weight, and can use whatever shape/length contact probe as needed. Need more/less length? Use a different beam. They're often cheap and often only limited by your imagination.

I used to have a set of stair stops for my steel lay-out square that could also take points. Uber handy!

I can't count the number of field-expedient trammels I've made on the jobsite. Usually two nails and a two-by, but sometimes for a pencil or saw. Need to trim a 24' radius arc on a round deck? No problemo.

 

[OccupantRJ]

A precision type of trammel point such as Starrett has one attachment with a fine tuning screw for more precise adjustments.

 

[RoninB4]

Usually two nails and a two-by, but sometimes for a pencil or saw.

-Necessity is .......

 

[Beerhippie]

-Necessity is .......

And the two by was still usable as construction lumber.

 

[NUTTSGT]

I used to have a set of stair stops for my steel lay-out square that could also take points. Uber handy!

I can't count the number of field-expedient trammels I've made on the jobsite. Usually two nails and a two-by, but sometimes for a pencil or saw. Need to trim a 24' radius arc on a round deck? No problemo.

I suppose a couple of plastic wire staples would work too.