I’ve done some searches and can’t really find anything that looks good to me. I’m looking for a straight edge to check my jointer and can’t justify the cost of a Starrett or Suburban. Have any of you used John Whites method of using 3 pieces of MDF to make a test bar? Has anyone used the long leg of a drywall square? Is it straight and long enough?
As always everyone’s thoughts and opinions would be appreciated.
Thanks,
Greg
Replies
A friend of mine who is an amateur machinist picked up a piece of tool steel from a machinist supply company that was about 3 feet long by 1 inch by 3/8 inch thick. The steel was remarkably straight and the cost was if I remember right about 1/3 the cost of a Starrett straight edge.
Lee Valley has some straight edges. You might also check e-bay as well for used ones..
Troy
Edited 1/14/2009 8:12 pm ET by troys
I have not used John Whites method, I recall reading about it and liked the idea. I just use an aluminum 2x2 angle or a jointed piece of lumber.I would not use a drywall square unless I could prove that the long leg was sraight.I would expect that a decent 4'-0" level would suffice.
mike
I have two of these.
http://www.leevalley.com/wood/page.aspx?c=1&p=50074
The 24" and the 38 " They are consistently bowed a microscopic amount. The machined straight side is convex ( bellied out ).
I have the Starrett steel that is longer, too lazy to go measure it but is about 48 ". I have had it for more than twenty years. Occasionally the Varitas gets me in trouble and wastes me time because I know I should be coming into or flat and the Varitas still pivots on the belly like a compass needle and I keep making adjustments and the feel of things do not add up if that makes any sense to you.
I could start spouting thousandths and ten thousandths but I the peanut gallery has settled down and I don't want to get them all riled up again.
I also have a Starrett Christal Pink granite surface plate so I can judge these "pretty darn accurately", that is a wood working technical measurement. That is how I know the Varitas are out and the steel starret is straighter and by how much.
Soooo. I like my Starrett ! If you divide up the cost over twenty years it isn't so bad. I bought mine when I was poor and do not regret it.
It is what ever you like. Some say wood is all squishy and this doesn't matter. I find it does. Different realities on the same planet; go figure.
I use the Veritas SEs but only to get in the ball park. If I drop them I don't feel as bad. That is a lye. I still feel bad. But the Veritas is light and easy to hang onto because it has the concave grip surface so that is nice to have.
Over all I absolutely recommend Veritas tools and for the price the 24 and 38 are great ! Just great.
But when I want it right, dead on etc I bust out the steel Sterrett.
I bet that doesn't help you at all but that is my experience with these straight edges.
roc
PS: drywall square. It depends on the particular object and how many times it got dropped off the conveyor or fell out of the truck etc. One needs to check the exact one you buy to tell if it is usable. You get what you pay for in this particular tool item.
If you got nothing but time and like to "save money" you could check into Toshio Odate's book Japanese Woodworking Tools: Their Tradition, Spirit and Use . Comes in paper back also
http://www.amazon.com/Japanese-Woodworking-Tools-Tradition-Spirit/dp/0918804191
he will show you how to make your own super accurate straight edges. They are used in pairs to refine each other. It will take a long time and you will need to tune them every time you use them because they are made from wood but that is another way to go. You could use them to judge your dry wall tool and if that is straight enough then keep it safe and just use that. Fascinating lore in any case.
Edited 1/14/2009 9:49 pm by roc
Edited 1/14/2009 9:50 pm by roc
Find a flooring supply company and order a straight edge intended for cutting vinyl flooring or carpet. These are steel, more than straight enough for a jointer, longer than your average straight edge, and reasonably priced. They're also straighter than the "precision ground" tool steel we buy on a pretty regular basis.
I have found that certain aluminium extruded sections are ideal for the purpose you talk of. If you are near a suitable outlet (such as building supplies) look at rectangular cross section hollow tube. Get say two pieces of 5 feet length and place them edge on edge- they are normally mighty straight. There are many extruded section shapes and designs and the ones with corners of minimal radius are best.Another section which comes to mind is tee section.
The advantage of this metal and section that it is light but rigid and a lot cheaper than anything labelled "Precision ground" .
Ofcourse, the easiest way for a woodworm to do what you want to do is to find a decent length of stable timber and shoot an edge or two straight with a hand plane. If you are not confident then prepare two lengths individually and test them by placing edge on edge.....
And I am assuming that you don't have a jointer with tables the length of a rail track- just a smallish one of table length six feet or so? (;)
You could check the drywall square, or any other piece, using a taught string or piece of thin wire.
When millwrights and machinists need to check for straightness, they sometimes use piano wire, pulled very tight. (A method that will soon be lost to lasers.)
>taught string or piece of thin wireI like monofilament fishing line. Not fuzzy like string. Never considered it for checking a straight edge. I have strung it along planks after resawing to watch how they move. Just as a learning process.HuummmrocPS: You are welcome Tbag good luck with jointer.PPS: String theory: ( sorry couldn't resist ) Sounds like it is possible to just use a string or two or three strung above the table with a known thickness spacer at the ends to make them all even amount above table like a nut on a guitar and then measure gap with feeler type gauge.
Edited 1/16/2009 12:34 am by roc
I do have a pair of machinist v blocks that would put the line at 1/2" above the jointer bed and a set of brass thickness gauges. I could then measure the difference between the brass and line at various points. Piano wire would have the least amount of sag across any distance and I happen to have a spool. Still, I wouldn't trust it beyond 4' because of sag and would have to come up with a way to put it under proper tension. Mount a guitar adjuster on the end of my jointer? :)
It occurs to me that I could use this setup to test a straight edge by placing it on top of the v blocks, with the wire in the groove, and measuring the difference at various points. The blocks could be moved any distance apart up to 4', the length of my jointer. I'll try to rig something up this weekend and post pics' if it works. Or of my injuries if the wire slips!
PS, I should try John White's method at the same time and compare the two for accuracy and easy of use.
Thanks,
Greg
Edited 1/16/2009 9:18 am ET by spindle
Great reply. I forgot about taught wire thing!
Wire is also good for..
http://www.wirelady.com/berrienwireprogpage.html
I have a piece of aluminum square tubing (1" x 1" x 72") that I got at a hardware store for just this purpose. While it certainly isn't a high precision calibration device, it's plenty good enough for aligning joiner tables, fences, etc in a wood shop.
To keep it from taking on a bend from leaning against a wall - or laying on a shelf - I hang it from a nail in a stud bay.
I have the two of the Veritas Steel Straight edges (12" and 36"). There is a big difference between them and their aluminum sets. http://www.leevalley.com/wood/page.aspx?c=2&p=56676&cat=1,240,45313
"...precision steel straightedges are ground flat over the entire
length on both edges, the 12" and 24" lengths to within 0.0010" and the 36"
length to within 0.0015". "... At $69.00, it may get the job done for you.
I hate to ask all of these questions but...
If you are confident that the table is the issue... look to the pro's for answers. I am not a pro... but there is no way I would rely on a drywall square to adjust my 10" X 84" jointer. I would first check the knives with the most accurate tool I had available (I have a OneWay depth gauge, accurate to .001"), take a good look at my technique (outfeed pressure... but not too much) and if I still had problems - I would check the tables with a machinist straight edge - equal, at a minimum to 1/2 the length of the jointer beds.
Oops, forgot a comma!
,
There:0)
Tbag,Questions are good. 1. Can you tell us what issues you are having with your Jointer?
I'm not having particular problems, but this a used "new to me" Ridgid 6" jointer that I want to ensure is correct. That way if I have problems I'll look to my technique.
2. What size/type it is (4"bench top, 6" Craftsman, 12" PM)?
See #1
3. Are you sure you've ruled out you knives?
These are new installed by me using a magnetic jig.
4. Is the Jointer new or used?
See #1
5. Are you trying to joint a board that is more than twice the length of your jointer bed?
Only 30% longer
6. Are you applying pressure to the infeed our outfeed side of the board?
On the outfeed side but not to muchWanted to say thanks for everyone's input!Thanks,
Greg
The method described by John White works fine. I would either buy a Starrett or use John Whites method and not waste my money on any possibly straight solution.
I have the Lee Valley 38" aluminum straight edge. I use it mainly for setting up saw and shaper extension tables.
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