Precision straight edge

[charles Tauber]

Originally Posted by dekutree64

Only if you get lucky and get a flat one. I bought one with the intent to level frets with it, but it's pretty badly curved. I use a diamond stone for leveling.

If memory serves me correctly, a mill file has one side with a slight curve to it while the other side is flat. I use both sides, depending upon the task at hand. This is different than buying a badly made file that is "all over the place" in terms of flatness.

A diamond stone works well.

[Ned Milburn]

Originally Posted by charles Tauber

If memory serves me correctly, a mill file has one side with a slight curve to it while the other side is flat. I use both sides, depending upon the task at hand. This is different than buying a badly made file that is "all over the place" in terms of flatness.

A diamond stone works well.

I thought the term "mill file" referred to its single direction (angled) grooves...

[Howard Klepper]

While a mill file is usually (or always) single cut, it should be dead flat on both sides, while tapering in width. There was a time when you could just go buy one in a hardware store and not worry about it being off from flat. Now that the American makers have offshored their manufacturing, that's not always the case. Swiss files are still reliable, but I recently got a 10" Grobet to replace my old Nicholson and it was very close, but not perfect.

One does not need a flat tool to create a flat surface. It's actually easier to do with a slightly convex tool (this is why "flat" files are tapered in thickness--the name comes from their intended use on flat surfaces). Working a surface with a flat tool can easily create a convex surface, especially if the tool is longer than the surface.

IMO there is no need for a fret leveling file longer than 10", and disadvantages to using a longer tool.

[BradHall]

Took the morning consensus on how to level the frets. I bought a mill file at the box store for $7. I checked it as near as possible on my granite slab, seemed flat on both sides. I surfaced a piece of hardwood about 8"X2", used ca gell to glue it to the file and sandwiched with another block in the vice for 20 min. The actual leveling went pretty quick, with only one real high fret. I have a 6" radius block that I taped 150 grit sandpaper to and smoothed it all out. The real work was radius filing and polishing with steel wool. It came out nice. Very satisfying process. Thanks to all for the help.

[Sperry]

I'm a little late to the talk here . . . I use PEC seconds bought off the online auction site. Products Engineering Corporation.

google: ebay pec "blems"

[BlmJn]

Granite off cuts are cheap but also can be .010 off. That is acceptable to me. I have on that is 24"x24" that is .005 off and that is not acceptable for frets. Go to ENCO equipment/tools for straight edges. Also check steel suppliers for cold finished and ground bars and flats. See what the allowable tolerance is before purchase. Speedy Metals and Online Metals are 2 suppliers I would check. Also check MSC (Manhattan Supply Corp.)

[BlmJn]

Made in USA - 18 Inch Long x 1 Inch Wide x 1/4 Inch Thick,AISI/SAE Type 4142, Alloy Steel Pre Hardened Flat Stock - +0.125 Inch Long Tolerance, +0.005 Inch Wide Tolerance, +0.001 Inch Thickness Tolerance, 0.003 Inch Square Tolerance
Brand:
Made in USA
In Stock
Price:
$26.20 ea.


MSC LISTING

[stoneaxe]

A small surface plate, a good machinist square, and a good straight edge are very useful items for any small shop. Useful to check all sorts of stuff, including verifying other square and straight edges. And not very expensive, if you don't need top aerospace level accuracy. This is an area where the law of diminishing returns is quite obvious!

If there is a industrial sharpening shop in your area, they will likely have big grinding capacity for veneer knives, big planers etc- my local shop re-ground a worn 48" Brown and Sharp straight edge for me for a nominal cost. They won't get tool room accuracy but for any woodworking operations it is fine- it is primarily used as a jointer set up tool.

[Howard Klepper]

Originally Posted by BlmJn

Made in USA - 18 Inch Long x 1 Inch Wide x 1/4 Inch Thick,AISI/SAE Type 4142, Alloy Steel Pre Hardened Flat Stock - +0.125 Inch Long Tolerance, +0.005 Inch Wide Tolerance, +0.001 Inch Thickness Tolerance, 0.003 Inch Square Tolerance
Brand:
Made in USA
In Stock
Price:
$26.20 ea.


MSC LISTING

Notice that no claim at all is made for straightness. You can get a piece of flat stock that is straight, but you can also get one that is not, even when getting Starrett rather than "Made in USA". I do have a piece of 18" Starrett flat stock (2" wide) that is reliable as a straightedge, but another piece I bought (also Starrett) is a bit off from straight.

A good brand machinists straightedge is a valuable tool and worth the investment. The good news is that you don't need one longer than 12" for fretwork (you do need one or two shorter ones, though). Measuring tools in general are not a place to economize. Get a good precise tool and use it for a lifetime.

[BlmJn]

Yes, and I have # of lengths of straight edges and squares. Even find the plastic drafting angles of use at times. Especially when determining a "center Line" on a slotted fret board from suppliers that cut from a "center line" with CNC saws but fail to provide a reference.