earl williams

My Feedback: (27)

Has anyone found a truely "striaght" straight edge. I have used metal rulers, but the edge is not truely even. Any suggestions?

fredscz

My Feedback: (47)

Hi Earl, A few years ago I bought a nice table saw and the aluminum rip fence[I think thats what it is called] was damaged on the very end. The manufacture sent me a new one and I cut the damaged end off and it works great as a straight edge. At the time it was not very expensive for just the aluminum part without the end fittings.
I also use pieces of steel strapping. It can be had for nothing and is amazingly straight but very thin.
Fred

Charlie P.

I've got a couple carpenter's squares that are true.



Try a better grade of metal ruler. Mine are straight. One is from an old drafting shop (before CAD there was pen and ink). Try a piece of extruded aluminum angle or "U" channel. The bends hold it to shape better than a simple flat run. Places like Lowe's or hardware stores carry it. Chect two pieces against each other and then flip one and check again. You'll be able to confirm the edge that way.

Edwin

My Feedback: (2)

No problem with my metal rulers either. I also use a 36" and a 60" I got from Home Depot. They are 1/8" thick. Easily straight enough for my work.
Edwin

Dr1Driver

I've never found a metal ruler, yardstick or straightedge to be more than a couple of thousanths out unless it's been run over by a car. Geez, what do you hope for? However, if you buy your metal rulers at Big Lots...well...

Buy quality tools and take care of them and they will last forever.

Dr.1

Scar

My Feedback: (3)

If you're really picky, get a Machinist's straightedge. It's for checking the flatness of cylinder heads & blocks. Mine was about 42" long, a quarter inch thick, and about 2.5 inches across the sides. One edge was hardened & ground straight. If a cylinder head was 0.001" out of flat, you could slide a .001" feeler gauge between the straightedge and the head.

I bought mine in about 1977, about $20 as I recall. It had a hole in one end, and it spent all its time hanging on a peg (unless I was using it to check a head.) I'm sure they're still available from machinst's supply places.

Personally, I use a long carpenter's level (aluminum, about an inch thick) for a guide, when cutting covering. Works good for me.
Good luck,
Dave Olson

Jigley3

Hi all..
I have several of the type mentioned, rules squares etc … but the one I use most is 3’6� length of aluminum 1�1/4 angle. I most often use it V side down especially when using a hobby knife. It is easy to hold, and your fingers can be away from the knife. The one I have is dead straight but the angle itself is not quite 90 degrees …go figure! .... bert

dmcmike

My Feedback: (14)

I've got one from a buddy of mine who hang drywall. it's a 5 footer, about an 1/8" (maybe a shade more) thick, aluminum, and dead straight. I've seen 'em in contractors supply stores, but not at Lowes, or Home Depot, at least not over 4'.

Prop Nut

My Feedback: (3)

If you really want a "true" straight edge, you can buy them here at this web site. They are called "Pinske-edge" and are very expensive. I have a custom cabinet shop and also do Solid Surface countertops. I use these to route my edges and my seams for joining them together. You can get many sizes, 24", 36", 48", 96" etc and 45degree bends, 22.5 degree etc. I spent 500.00 on a basic set, if that gives you any ideas. What I do though, is I take one of the perfect edges and make several straight edges from them. Clamp a long piece of solid surface to the "perfect edge" and then router along it. Giving me a straight edge that is just as....well, perfect. Saving me from nicking my expensive tools. If you know anyone in the area that does solid surface these type of tools are a must so they will have them. You might get them to make you a set of straight edges from these.

http://pinske-edge.com/catalog/catalog.htm

TexasAirBoss

My Feedback: (22)

Measure with a micrometer.

Mark it with a crayon.


Then cut it with a chain saw.

Prop Nut

My Feedback: (3)

Hey! Who has been giving away my shop secrets PilotFighter?!?!

Electriceddie

Earl,

What are you planning to do with the straight egde that it needs to be so perfect? Just curious what job your doing that a reguler good metal ruler which most guys use now would not work for. If your just on a quest for a good metal straight edge, then a good quality metal one should suffice. Remeber you get what you pay for!


Ed

RVM

I've never seen or had a straightedge or ruler longer than 24" that I could not see some run-out in. I either have really good eyes or everyone makes really bad straightedges. It is irritating, but something we have to deal with without going into some really expensive, precision scientific instruments. I simply picked out the straightest one I could find out of a bunch at Lowe's.

Prop Nut

My Feedback: (3)

I actually use a rather cheap straight edge myself (for RC), its a 6 foot metal ruler from Menards (Lowes, Homedepot also carry them). It does have a very slight bow, about 1/16th inch in the middle, but is good enough for building a wing. I checked it against my really really really expensive straightedges. It was 10.00

vicman

My Feedback: (10)

I believe ol Earl has put you guys onto a goose chase as he hasn't replied.

Prop Nut

My Feedback: (3)

Great thing about forums, no matter how old they are, or if the thread starter ever replies...everyone gets to put thier .02 cents in. The information gets to help someone. There is a thread for a kit manufactures certain plane. The thread starter hasnt been seen on it for years but there are at least half a dozen completed planes (build threads) on there. Tons of info and good tips.

jetpack

My Feedback: (1)

I bought an extruded aluminum yardstick thats about 2" wide and 1/8" thick. I checked the pile and picked the one with the cleanest edges. You can butt one against the other and check for light and keep rejecting till you have the one with the least problems.

Afterwards, I checked the one I picked with a dial indicator on a granite table and the strightness was within .007" and parallelism was withint .003". Good enough for straightening stripwood for pinning. I keep it hung on its own nail on the inside door jam of my storage closet.

You can check with paper and pencil also, just by drawing a line and flipping it end to end and compare lines.

scratchonly

Amazes me that in 2006 no one can make a straight straightedge?????

RVM

Your eyes are good enough to see a .0001" difference over the length of a 36" straightedge. I guess it's just not cost-efficient to produce straightedges for the common guy who doesn't need .0001" or better accuracy.

Time Pilot

I don't know if this helps or not, but here's a straight edge that's "machined flat to within 0.003" over the entire length".

http://www.leevalley.com/wood/page.a...at=1,240,45313

bps

My Feedback: (3)

Just like propnut said, we have fun even when (or if) we get sent on a wild goose chase! Kinda like getting old (I speak from experience), just what was the question? I FORGOT!!!

I have built models for over 40 years and hardware store rulers 12, 24, 36, 48 are plenty good enough. With temperature, humidity, balsa sealers, covering...... Point is the balsa moves a bunch after construction. Or at least the balsa I can still see!

JEB

Newc

Well stated, bps. In addition, unless one is to use a very slow moving planer/shaper/etc. sort of machine taking a really small cut with each pass, to cut the balsa, I'm sure that the cut will be less accurate than the straight edge used for the cut.