45-degree reference tool

[Larry Fox]

Guys - wondering if anyone can recommend a fairly large and accurate 45-degree reference / setup tool. I frequently find myself having to cut this angle and always seem to struggle to get things aligned properly and am getting a bit tired of the test / adjust / test / cut cycle. I have a sliding table saw and want to add solid attachment points to the wagon for the fence to cut the angle. I recently bought 2 large heavy squares with the short side being somewhere in the 12" range and the blade being around 18" and I have found them to be extremely useful. I would like to find something similar for 45-degrees -- the larger the better.

Thanks in advance for your time.

[Bill Huber]

I have and use all the time a 16" drafting triangle (45°/90°), you can get the like up to 24".

http://www.cutting-mats.net/2340.html

[Mike Henderson]

Yep, a drafting triangle is very accurate.

Mike

[Myk Rian]

+2 on the triangle. Craft stores carry them.

[Larry Fox]

Interesting - thanks guys. Question - do you find the 90-degree side to be sufficiently accurate for your needs? I guess I had imagined the responses sending me off to look at some super-heavy metal monster like some squares I have seen.

[Myk Rian]

I use them to setup my RAS for frames and such. They always come out right on.

[Lee Schierer]

I agree with the others, drafting triangles are very accurate. Just be sure they are drafting quality, not kids toys.

[Sam Murdoch]

Also, you might consider a Swanson 12" speed square - http://www.swansontoolco.com/s0107.cfm

or maybe try to find one of these - http://www.woodpeck.com/carpentertriangles.html Ask Woodpecker to do another run.

[David Hawkins]

Plastic is better than wood or metal. Wood changes with humidity and metal changes with temperature.

[Stew Hagerty]

It's too bad you just missed these, they're fantastic!

http://www.woodpeck.com/carpentertriangles.html#2221

[John Lanciani]

Plastic is better than wood or metal. Wood changes with humidity and metal changes with temperature.

And some plastics change with both. Metal in a typical wood shop environment will not suffer from any measureable movement. Metal would be my first choice for durability, these look very nice for the price; http://www.cutting-mats.net/stainless-steel-triangles.html

[Myk Rian]

For the cost of the fancy dancy ones, you could buy 20 of the plastic ones.

[David Hawkins]

Draftsman grade plastic triangles are stable, no need to worry there.

I once worked a a factory where someone got the bright idea to use aluminum gauges to verify lengths at the double end tennoner, they lasted about a month and the mill was in chaos. The longer the gauge the worse the problem. They ended up going to wood as wood changes very little over it's length, much less than aluminum in any event.

[Stan Calow]

Larry Highland Woodworking sells a granite 45-degree angle set-up tool that looks pretty hefty. I have one on order so don't know if its any good. Other companies probably have similar. I have trouble setting up miter saw with plastic drafting tool.

[pat warner]

"Guys - wondering if anyone can recommend a fairly large and accurate 45-degree reference / setup tool.
************************************************** ****
Whilst there are no substitutes for precision measuring tools, measurement is the final arbiter. Do the inside & outside measurements of your assembly prove parallelism?
Can you measure close enough to prove it (parallelism or orthogonality)?
I don't know why but there are very few precision 45 degree miter squares compared to the 90's.
But because the 90's are a dime dozen and good to 4 places (precision machinist's squares) why not use a cheap 45 for a rough set up and verify with a 90?
Assemble a corner and inspect with a 90 then adjust your fixturing to create the inside or outside 90. You say you're blowing a lot of time making the adjustment.
Do it on the assembly (scrap but similar parts); it may save time.
Moreover, an assembled corner takes the machine and handling kinematics into account.
A single slice does too, but an assembly takes more stuff (L & R e.g.) into account and is ultimately, what you're after anyway.

[Bill Huber]

While we are on the subject of drafting squares this is what I did with one of mine. The problem is when you lay it on the table saw it is hard to pick up. I do have one with little bevels in the center but I always for some reason put down wrong.

I milled some strips of maple to 3/8" thick and used double back tape to attach it to one side of the square and it makes it so much easier to pit up.


275588275589275590

[Derek Arita]

I have to +1 on the Woodpecker triangles. They are big and very, very accurate. You may be too late to get one new, however I'll bet if you look hard enough, you'll be able to find one used and most people don't abuse these, so most will be in good shape.

[Keith Outten]

My triangle was machined on my CNC Router. Made from 1/2" thick Corian it is stable and easy to pick up. This one is a 16" triangle but they can be made just about any size up to the maximum table dimension of the router table and the 30" width of Corian sheets. On second thought these would be easy to create from Corian scraps glueing the pieces together then machining the finished piece to size so a 48" by 48" triangle and larger would be possible.

There is a large group of CNC owners here, any one of them can make these, its more about who has project scraps to use up because Corian is a bit pricey.
.

[Lee Schierer]

One additional thought. It isn't large, but it is pretty accurate. Get a Beall Tilt Box or other digital angle gauge. I recently made an octagonal box that was 12" across the flats. I set the bevel angle on my TS using my Beall gauge. I then cut the eight side pieces about 1/8" long and test fitted them. I noted a slight gap on the inside edges of each joint. One half turn on the tilt knob to correct for the gap and a quick trim of all 16 edges resulted in a perfect fit of the corner joints. One additional quick trim to get to he final length and I was done. When I was done, I used the same angle gauge to return the blade to 90 and a quick cut and check with my precision square showed the cut to be true. Best $40 I spent for a tool.

[johnny means]

You could make a very large one from a sheet of MDF. Lay it out with the pythagorean formula and it should be plenty accurate.

[David Hawkins]

You could make a very large one from a sheet of MDF. Lay it out with the pythagorean formula and it should be plenty accurate.

MDF is a good reasonably stable material

For a 45 you just need the diagonal of a square which would give you 45-45-90. I understand the Pythagorean formula to be a 3-4-5 triangle which contains no 45 degree angle, but does have (if I remember correctly) 30-60-90 degrees.

[glenn bradley]

I agree that given your requirement the plastic version would be your best bang for the buck. The thicker offerings have a hole chamfered from both sides which creates a lifting area/edge that allows the square to set flat on the surface and still be picked up without issue. Professional grade versions can be had for around $40 and are made to be handled. They are fairly resilient but, will not stand dropping or other abusive treatment. Of course a $150 aluminum version converts quickly from tool to trash with a 1 meter drop-test as well. Once you have a good triangle, you could make yourself a few expendable ones from MDF and not be so concerned about shop "incidents". Keep the original as a guide for making "users". Spend your money where you will ;-)

[Larry Fox]

Thanks again for all the great reply guys - I really appreciate the time. I think a large plastic one might do what I need.

[johnny means]

MDF is a good reasonably stable material

For a 45 you just need the diagonal of a square which would give you 45-45-90. I understand the Pythagorean formula to be a 3-4-5 triangle which contains no 45 degree angle, but does have (if I remember correctly) 30-60-90 degrees.

Actually, the pythagorean formula is aa+bb=cc, which happens to include the 3, 4, 5 rule. Even using the 3, 4, 5 measurements one only has to measure and mark two for foot legs to make a very accurate and quite large 45 degree jig.

[Michael Dunn]

Actually, the pythagorean formula is aa+bb=cc, which happens to include the 3, 4, 5 rule. Even using the 3, 4, 5 measurements one only has to measure and mark two for foot legs to make a very accurate and quite large 45 degree jig.

A 3, 4, 5 triangle does not have a 45 angle. For a 45 you need two legs of exactly the same length.

[Mark Bolton]

+1 for Johnny's method. Just make one in house if you have a slider already. No need to buy. I have a couple hanging next to our slider that i use to super accurately swing the slider fence. If your slider is cutting dead square at long lengths it should be about a 5 minute job.

[Greg Hines, MD]

Richard is good about taking orders for all of these one-time-tools and eventually rerunning a series. It does take time, however, so a drafting triangle would be available immediately, and if you find that time allows, order one from Woodpeckers.com. They make great layout tools, I have several, though not one of the triangles.
Doc