Straightedge for jointer setup?

[roger wiegand]

Is a moderately priced 8 ft level from the Borg likely to be flat enough for jointer setup? Is a long Festool saw track stood on edge accurate? My new-to-me jointer is bowing boards pretty badly. I don't think it's technique as I haven't had such a problem on multiple other jointers over the decades. Near as I can tell using a variety of things around the shop that should be flat the tables are not currently coplanar, but neither of my current (ancient beaten up) 4ft masons levels are straight to within an eighth of an inch and I'm not sure what else I have that I can trust as a reference. Being able to measure over the whole ~7 ft length would make life easier I think. The 6 ft straightedge from Starrett is $600, I'm hoping that's way overkill!

[glenn bradley]

A decent straight edge (not a level or a rule) is a good investment. For as often as I use one I kept the price under $100. I've always gotten by with a 36" steel from Lee Valley but, there are some nice aluminum ones around now. When you say "bow", do you mean thinner at each end and fat in the middle? This would imply tables that are high at the tips. I've seen this when ham-handed helpers lift the jointer by the table ends.

Oops. the Lee Valley is now well over double what I paid but, it has been a while. However, a quick look around shows the $122 price to be in line for steel in that size today. I have no fault with aluminum. Just take very good care of it as one good bump turns a costly tool into a candidate for the recycle bin.

[Mike Kreinhop]

When I finally got around to setting up my jointer/planer, my "precision" carpenter levels weren't up to the task. There were too many variations along the length of the level that I couldn't rely on it when aligning the infeed and outfeed tables. They work great for drywall installation, but not so good for the J/P.

I bought the Veritas Aluminum 50-inch Straightedge, which worked perfectly. At $122, it is less expensive than the Starrett straightedge and is easy to use on the flat surfaces.

Here is one video (there are many) showing the setup using the Veritas straightedge.

[Mark e Kessler]

How long are your tables? Mine are about total 90” x 16” and I used a 50” alum straight edge like the Veritas with pretty good results, you will also need a dial indicator and holder like the oneway which I have or lamb tool works version.
The festool track may work but I found it too difficult to deal with because of the marrow edge, some do use levels, you need one with a machined edge like a Stabile. And Yes the Starrett would be nice but overkill.

Is a moderately priced 8 ft level from the Borg likely to be flat enough for jointer setup? Is a long Festool saw track stood on edge accurate? My new-to-me jointer is bowing boards pretty badly. I don't think it's technique as I haven't had such a problem on multiple other jointers over the decades. Near as I can tell using a variety of things around the shop that should be flat the tables are not currently coplanar, but neither of my current (ancient beaten up) 4ft masons levels are straight to within an eighth of an inch and I'm not sure what else I have that I can trust as a reference. Being able to measure over the whole ~7 ft length would make life easier I think. The 6 ft straightedge from Starrett is $600, I'm hoping that's way overkill!

[Robert Hazelwood]

Some levels might be good enough, but you can't count on it and there's no good way to check at the store.

I have the 36" steel straightedge from Lee valley and it is very accurate but a bit short to check the tables on an 8" jointer. What I ended up doing was making a pair of straight edges from scrap hardwood, each about 5' long. Used a Stanley #8 to create straight edges on both pieces simultaneously. Then check against each other to confirm straightness, also test against 36" steel straightedge.

With the extra length of the straightedge I was able to detect a bit of misalignment and correct it. After doing that the accuracy of workpieces coming off the machine improved, so my wooden straightedges seem to have done the job. It's nice to make a pair of them because you can set one on each side of the table when doing your checks, so you aren't constantly moving one straightedge from one side to the other.

[Aaron Rosenthal]

I made a straightedge using oak and a string edge to edge.
When I look at the time it took me to set it up, and then tweak it every season, it's cheaper to buy one.

[johnny means]

I've always been able ro check and adjust all my machinery with rudimentary measuring tools. When I set up my jointer all I used was a 4" rip of MDF. You'll be fine with an undamaged level.

[Howard Pollack]

Take a look at John White's book on maintaining and setting up shop equipment. He gives clear instructions on how to make a fixture that involves 3 points and is dead straight. Apparently an old machinist's solution. -Howard

[Doug Dawson]

Is a moderately priced 8 ft level from the Borg likely to be flat enough for jointer setup? Is a long Festool saw track stood on edge accurate? My new-to-me jointer is bowing boards pretty badly. I don't think it's technique as I haven't had such a problem on multiple other jointers over the decades. Near as I can tell using a variety of things around the shop that should be flat the tables are not currently coplanar, but neither of my current (ancient beaten up) 4ft masons levels are straight to within an eighth of an inch and I'm not sure what else I have that I can trust as a reference. Being able to measure over the whole ~7 ft length would make life easier I think. The 6 ft straightedge from Starrett is $600, I'm hoping that's way overkill!

I have that Starrett straightedge, NIST traceable (although I don't remember paying $600 for it, it's been a while.)

I also have an 8 ft level from the Borg (the level is orange too.) I just tested it, and it's straight to within around 6 thou along its length, which as I recall is within its spec. This is with it laid on its side. With it laid along its edge, which is how _you_ would be using it, sag starts to become a major issue, and the error is approaching fractions of an inch. It's a level, not a straightedge. :^)

I also tested my 55" Festool track, and it looks to be within a thou or so along its length, opposite the "cutting edge" . Surprisingly straight, but I guess that's part of what you're paying for. That would probably be good enough, if yours spec'ed as well, and you didn't have a problem with shining the light at that oblique angle and having it be useful.

[Tom M King]

The few times I've done it, a good, long level was plenty good enough. If you can straighten two long boards after adjusting a jointer, and they fit together perfectly, that's a good enough test for me.

[Mark Daily]

I’m getting ready to buy this 50” straight edge for myself. It’s a great value at $44.99. I’ve bought several tools from this eBay vendor and have been very pleased. A lot of his tools (new) have only cosmetic defects and sell for quite a discount.

https://rover.ebay.com/rover/0/0/0?m...2F151867626327

[Mark e Kessler]

I have had no luck with Taylor tool and their seconds or customer service or even firsts of the PEC squares. The rules are ok but the squares are terrible, if you take the rules out you have to fight to get it back in as there is no anti rotation on the clamp post and the machining of that part is low quality. Additionally the biggest annoyance on the squares as they won’t clamp the blade tight enough so it won’t slip, I thought to was due to ordering a second but it happens on a new one as well

I probably have early onset old fart syndrome as I have been using Starretts for 30 years and their is no comparison...

[roger wiegand]

Thanks for the ideas! The jointer is 220 cm (~87 in) long. Using what I think is a straight board it seems that the cutter is lower than at least one end of the table. Probably a sensible first step is to correct that and see if the problem disappears. I'm loathe to invest a lot in a tool I may only use once. My previous 6" Delta jointer got set up when it was new and stayed adjusted through the 25 years I used it without further intervention.

[Brian Holcombe]

I would want the straight edge at least as long as one table, use it to check each table for flatness. If they’re flat then adjust them according the available length.

Trouble is when the tables aren’t perfectly flat.

Read the straight edge tolerances carefully, often enough they’re called out per inch or per foot. I have an aluminum straight edge that is called out at .0005/inch, over 96” that is .048” which isn’t very good for machine setup.

My favorite straight edge is a Camel back type, scraped accurate. It agrees with my new (to me) Starrett A grade surface plate. Long camelbacks are hugely impractical but shorter ones are very useful for machine setup. The camel back offers a lot beam strength not available to bar stock type straight edges.

[Brian Holcombe]

Before you adjust the tables by tilting them, make sure the cutter is just a touch proud of the outfeed. I like to adjust it until it just barely begins to grab a piece of wood resting on the outfeed when rotated by hand.

This is probably around .002” proud.