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I'd like to make a few straightedges, and I'm thinking about what material to use. I'm thinking aluminum or plastic, but I'd appreciate suggestions from people who have more experience and knowledge with materials - especially specific types of plastics and aluminum alloys - than I have (which is very little, really). The properties I figure I need are:

Easy machinability, and easy to do the final abrading of the edge to near-perfect straightness by hand
Dimensional stability
Fairly light weight

One of things I don't like about my steel straightedges is that they mar fret tops, so I want to use a softer material. I also want to make a few of my own notched straightedges for various scale lengths.

Thanks in advance for any help you can offer!

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Todd Rose
Ithaca, NY

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I use acrylic and different size color plexigless often in projects. Plexiglass comes in different colors and thickness for multi use applications. Worth checking out a plastic distributor.
Basic clear 1/8 Acrylic can be purchased at you local hardware or lumber yard as window replacement material. Might be a bit flimsy for a long straight edge but maybe OK for 24"or less and a 3" minimum width for edge stability.. Any downward pressure on acrylic will distort your straight edge...so finding that stabile width and milling it straight will be a challenge.
Plastics and acrylics also have BAD fumes when cutting....so ventilate well.
kent

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Drafting T squares make great straight edges with the t removed, they are relatively low cost and seem quite stable. I use a 24" one I found in someones trash I checked it against my surface plate it was real close. A little work with some fine sandpaper on the surface plate and it was real good. I am thinking of notching one edge to clear the frets for checking the fretboard for level on finished guitars.

Fred

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Fred Tellier
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I have some phenolic resin straight edges from when I worked as a glazier. Metal on glass is a bad idea, so that is the industry standard. They are 10 years old now and still straight.

This is the distributer I got mine from, the prices are not listed though I remember they were reasonable. I also see they have aluminum available. You may want to check with some stained glass suppliers or even a regular glass shop can order through CR lawrence.
http://www.crlaurence.com/crlapps/showl ... delID=2310

Most aluminum extrusions are pretty straight, I have a nice 2" x 2' square aluminum extruded thing I use as a router guide.

I got to play with a real 6' straight edge at one of my jobs, easily heavy enough to crush a guitar, but I would have loved to set up my home jointer with it.
Rob

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Todd: I have two 24" and 36" aluminum ones from Lee Valley. They also have a scale on one side. Purchased them a few years back so I forget the price and not sure they still have them. Think they are will worth a look unless you have machine shop access.Don't think plastic or wood is a suitable straight edge for finger board purposes, but that is just the old machinist coming out of me. You no doubt will get varying opinions. Good luck.
Tom P.S. See Mr. Stock knows how to check the accuracy of the straightedge. Why should I be surprised, this gentleman has a very very impressive data bank between his two ears . Nice going....! Tom

If it can be thicker than a steel straight edge, you can make one out of wood. Take straight grained hardwood, saw it in half, then flip the pieces & glue together. Make about 1/4" thick, & true one edge on the jointer ( a traditionalist or true old timer would do this by hand). I believe the traditional height on the ends is about 1", but I don't think it would matter, to a slight peak in the center of the back. Mine are sealed with either wax or shellac (maybe both, I truly don't remember), but I don't know if it's needed. I know it sounds crazy, but I have 2 of them that are still true after 5 years.

Thanks, everybody, for the ideas and information. Much appreciated.

I found an online "gage house" that carries lots of Starrett stuff at what appear to be wholesale prices. http://www.msi-viking.com/

http://www.msi-viking.com/search_result ... fromSearch

I ordered a package of 5 Starrett 24" "aluminum straight edge rules" for $3.79! I suspect they'll meet my needs, and I'll just cut them up and notch them as needed. To meet the $25 minimum order, I also got a Starrett 500mm steel rule, which I had been looking for as well - $53.21 for that, which, I think, is also a very good deal.

I'll let you know what the aluminum rules are like - how straight they are, etc - when they arrive.

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/