parallel rule

[Vinko]

I just got a replacement pair of parallel rules -- 24" acetate from a Marine store. Good for lining up some work I do.

My father was looking for something like 24 or even 36" in stainless.

See through acetate is there because of map reading, and I don't know if someone makes a quality parallel rule in stainless? Anyone know.

I guess you make one....

 

[RbrtAWhyt]

You went to a store that sells Marines?

 

[Mike83]

Probably a store that sells boating stuff. These sound like navigation tools.

Although, when I saw parallel tool I immediately thought of "parallel axis theorem." Oy, I've been working too much.

 

[Richard Givan]

Parallel rules are indeed marine navigation tools (pre-GPS). You lay one side on a course and "walk" the rules over to a compass rose on the chart to read what bearing it is.

I kind of doubt you will find them in 24" or bigger sizes. A work around is to use two 30-60-90 degree triangles with the hypotenuses (no, not a large African water-dweller) in contact and sliding them sideways to the proper spacing, but good luck coming up with triangles that large, too.

Option three, and probably most practical, would be to take two framing squares with the ells nested together and slide them apart to your desired spacing.

 

[Vinko]

I kind of doubt you will find them in 24" or bigger sizes.

I just got a replacement pair of parallel rules -- 24" acetate from a Marine store. Good for lining up some work I do.

I've seen them longer -- 36".

Seen them in brass as well, though shorter

Two straight edges given to a machinist buddy with more skill then me might be the way to go for precision, which is what I really want.