Does anyone know of a source for steel 72″ precision straight edges without bevels? I just got one at an auction for next to nothing, but I’d like to get a sense of the replacement cost. As near as I can ascertain, Starrett doesn’t make one with these specs. This thing came from Weinig (I’ll call them tomorrow), and it’s a full 1/2″ thick. I guess I’ll use it to set up a 14′ long jointer in case I ever come across one…
Thanks!
Visit me at The Wood Mechanic site!
Replies
Closest I came was on amazon.com....they've got a 72" Starrett for $487.17 but it's got the bevel.
http://www.amazon.com/Starrett-385-72-Bevel-Straight-Edge/dp/B0006J4FT2
charlie -- "Count your blessings....it could always be worse!"
Starrett certainly makes a straight edge without bevels and last I knew they were going for maybe $375 or so but they are about 5/16" thick. Suburban Tool sells a similar one for around $300. I bought my Starrett 72" square edge straight edge years ago for setting jointers professionally and it was a square edge one. I have a source to get 72" straight edges for around $70.
Rule of thumb is straightedge should be 2/3 the length of the combined jointer tables so a 72" is good for an 8 or 9 ft bed.
I have no idea.. More that several years ago I authorized a purchase of a steel precision rule for checking LASER mounts across a stone table about 12 feet long and 12 feet wide. That table was about 3 feet thick as I remember.
That hunk of steel had bevels though and cost about $12,000. I do not remember who made it but you could send it back for 'truing' if needed at no cost except shipping!
Wow! $12,000? That's amazing! What kind of laser mounts were being checked with this hunk of steel? What industry was involved. That's SO interesting!
Visit me atThe Wood Mechanic site!
Details.. I have no idea because it was made to our optical engineering departments specifications. It was engraved (like a ruler) but with special horizontal and vertical markings.They used the tool for setting lens distance and height (I think).
I was working in the printing industry at the time with engineering on developing new products.
McMaster-Carr: http://www.mcmaster.com/
Part number 19295A54
Page 2171
Almost $700 for a rigid one, half that for flexible.
Good luck.
EW
Part number 19295A54
Page 2171
Almost $700 for a rigid one, half that for flexible.
The number you are referencing to is a sq. edge at $580 and stainless. How do you read $700 into that. More of the misinformation highway.
Mcmaster carries the Suburban tool line which is typically less than the Starrett line but just as good. The tool steel sq edge is $308.
Sorry, was looking at the price line for beveled -- $645.
Nice catch; though the "misinformation highway" line was unnecessary.
EW
A $700.00 straightedge is a $50.00 piece of steel that has been machined, tested, and certified as being true to a certain degree of accuracy.
If you don't know the tools history, it only needed to be mishandled once, you have a $50.00 dollar piece of steel that may, or may not, still be straight.
John White
Yestermorrow School
Contributor, FWW Experts column
John,How can I best test the straight edge? I though that if I laid it on a piece of white cardboard, scribed a line, then flipped it I'd get a decent read. If I had a reference surface large enough, I could test it with feeler gauges, but I don't. What would you recommend?For what it's worth, it appears to have been handled well. It's in a wood, padded case and appears to have been sold by the Michael Weinig company, I'm guessing for moulder calibration.Thanks for posting!Best,Tim
Visit me at The Wood Mechanic site!
The scribe method for testing a straight edge would be fair at best. It certainly wouldn't give you down to .0001"The only way to tell for sure would be to reference it to a straight edge you know is correct. The only other way is to send it out to a company that makes such tools for calibration testing. I'm sure Weinig and don't know if Starrett or Suburban tool would test another makers tools. It's probably fine and if it was that cheap you shouldn't loose any sleep over it. Mostwoodworkers don't need fine tolerances.
Find a local machine shop with a large granite plate and see if they will let you have a go with some feeler guages or at best it shouldn't take more than a few minutes to give you the answer. You might get away with six pack or something for the the cost.
It's still probably more than close enough for your use. A groung piece of precision tool steel is more like $150.
There are machinsts forums out there...
http://www.chaski.org/homemachinist/
You could use the three-point method described in John White's book to check. ALot more work than checking against a surface plate, but if you can't find a shop with one, it's an option.
Oh, and don't let anyone sell you the "wood moves, so you don't need precision" argument. There are plenty of places where one needs better than 0.004" precision in woodworking; e.g., getting the proper fit on a M&T joint, setting a jointer, etc.
Re: testing a straight edge.Have you tried getting your eyeball REAL close to one end and looking down the length of the edge? : ) He he heRed Green once said the most accurate tool in the handyman's pouch is his eye.peace, mark
How much precision do you really need? I often get the impression that some woodworkers think that they need machine shop precision to work on a material that will never be as stable as steel. Good setup is definitely necessary, but chasing that last few thousandths of an inch is often overkill.
For my setup work, I use 1" aluminum square tubing. I have an 8' piece and a 4' piece that I got at the hardware store for ~$25. Each piece was checked for straightness by clamping it to a sheet of plywood, drawing a line along the edge with a 0.9 mm mechanical pencil, flipping it over and drawing another line. For each piece, the two lines overlapped over the full length and that was good enough for me.
I drilled 1/4" holes in one end, and they hang from nails in a stud bay so that they won't take a set, or get dinged because they're leaning against the wall.
They would never work in a tool and die machine shop, but they work fine for a wood shop.
Dave,Your point is well taken! I mostly just want to know about the big straight edge I got a) because I need to know its replacement cost and b) because I have a mild fetish for precision measuring instruments. Does anyone know how best to assess this tool's straightness?Thanks!
Visit me atThe Wood Mechanic site!
"Does anyone know how best to assess this tool's straightness?"
In general, you need a reference that is bigger and better than what it is you're trying to measure. So, in your case, you need either a reference plate or a reference straightedge (or an optical interferometry setup) and the best that you'll be able to do is to say that your test piece is at least as good as/significantly worse than that reference.
-Steve
I must have overlooked the part about you already having the straight edge. Sorry 'bout that. - lol
You might try using something like a chalk line to check the straightness. Lay it on something that supports most of its length, and stretch a string from end to end. You may need some backlighting, but any gaps along the string should be visible. You may not be able to quantify them, but their existance should indicate the location of any deviations.
A machine shop may also be able to check it for you. I'm no expert, but a couple of months ago, I helped a machinest friend set up a metal lathe. It took quite a bit of fussing around to get set up, but when he mounted a workpiece and ran a dial indicator along it, we could see deviations in the 0.0001" range.
Fantastic, Dave --thanks!
Visit me atThe Wood Mechanic site!
Dave I fully agree with you. You mentioned using tube stock which is more rigid but I find that 'L' shaped also works well and a 'bit' less expensive.
Well, in the interest of full disclosure, I suppose that I have to confess that I intended to get the angle instead of the square. Their stock of angle was pretty well gone, but they had a good selection of the square. Jeez, a guy can't keep any secrets around here. - lol
I got the angle cus' I'm cheap!
So am I, but I just don't talk about it much - lol
To anyone who has been following this discussion, I just got an answer from Weinig's parts department. They sell this straight edge in its nice, padded box for a whopping $874.75. At that rate, maybe I'll just frame it and hang it on the wall!
Visit me at The Wood Mechanic site!
This forum post is now archived. Commenting has been disabled