Odd observation when trying to square up cross cuts via 5-cut method

[Roy Wall]

here is a link to an excellent video from William NG that explains the 5 cut method in great detail and also a great way of squaring up your sled.

http://wnwoodworkingschool.com/5-cut...ross-cut-sled/

Larry - this William Ng Video is superb! But it does take some tinkering to get it dead square..... not as easy as William Ng makes it.....he has serious skills!!

Shoot me a PM and let's catch up......long time been off the grid!!

[Phil Thien]

I'm with you Von. I think we can get too anal about accuracy. On the other hand, when I use my crosscut sled, I know the cut is good without ever picking up a square because I took the time to make it dead accurate and very stable in the first place. By the way, I have several framing squares but only one that is accurate enough for furniture work. I was surprised at how difficult it is to buy a framing square at a big box store that is actually square. I have compared several new ones right there in the store and they are not the same.

Add me to that list.

I've got good squares (including a trusted framing square for larger cuts). If they say the piece is square, that is good enough for anything I'm making.

[Larry Fox]

I seem to have it sorted out. Fiddled with it again today and was able to get it to just about 0 deviation on a 23x23" piece. This should be close enough for anything I will be doing. Others have mentioned squares - I recently bought 2 16"x12"-ish metal machinest squares and they come in VERY handy. Can't see any light at all on any of the corners. Thanks again for the time to look and respond.

[Metod Alif]

OK, it is not about 5 cuts. I cross-cut a straight piece of stock (parallel edges a must). Flip one piece and butt it to the other. If I get a straight alignment, I am good enough. I saw this idea mentioned in several places, it made sense, and I started using it.
Best wishes,
Metod

[Ole Anderson]

First problem I ran into with my track saw was making a good 90 degree crosscut on a piece that had already been ripped. Neither my carpenter or drywall square met the flip test. So I took a piece of 1/2" ply, prefinished one side, and cut it square on my sled, (which was previously shimmed to cut within a thousandth over 12" using the five cut method) added a fence and I had a sturdy guide I could square my track to. Went prefinished side down so I would slide easily on the unfinished ply. As stated, by measuring each end of the offcut on the fifth cut, you know your error on one cut is one fourth the difference.

[john bateman]

I have quit worrying about "Super Accuracy"..... If I make a cut on a board or piece of plywood, I will hold it up to my tri-square or framing square, and if I don't see light, it's close enough for me.

Try making a 6 sided box sometime, with all edges of all sides being beveled at 45 degrees so that no plywood edge shows. You will appreciate having dead-on crosscutting capability.

[Phil Thien]

Try making a 6 sided box sometime, with all edges of all sides being beveled at 45 degrees so that no plywood edge shows. You will appreciate having dead-on crosscutting capability.

I have made six sided boxes to conceal plywood edges.

First, let me say, I don't think your picture shows one, does it? That loudspeaker has four beveled corners, and front and back are fitted into a groove. And the rolled front profile makes me think it is vinyl-wrap (probably cut via a CNC-controlled beam saw), although hard to tell by the picture.

Let me point-out some possible issues w/ the 5-cut method:

First, in order for the five cut method to work well, there can be no (none, notta) slop between the sled's runners, and the miter slots on the table. Otherwise, you'll end-up chasing your tail (you may achieve a perfectly parallel cutoff on your final cut one instance, but the next instance you may get a cutoff w/ convergent lines). In this case. 001" of slop in those runners can throw the entire process off.

Second, the amount of movement required (of the fence) to get to these minute adjustments people are trying to achieve are not easy, especially when we're working w/ hardwood, plywood, and MDF.

Third, in order for this to work, your fence must be (and remain) dead-nuts flat. Otherwise you will get different results, depending on the side of your test piece.

Fourth, any error the user introduced by not placing the test piece perfectly against the flat, on just one cut, tosses off the results.

Fifth, blades (especially thin kerf) can deflect during the cut. And they don't always deflect the same direction. Differences in material thickness, and blade tilt, can effect the deflection of the blade.

Sixth, many saws, due to their trunion design, may introduce geometry problems when you tilt the blade. This can be adjusted-out on many cabinets saws by shimming the table to the cabinet, but not many people do this.

I use a plastic triangle to check my cuts. I was making some wrapped-up subwoofer boxes yesterday, and they wrapped-up perfectly (this is sort of a five-cut method, if you think about it).

To get there, I did have to make an adjustment or two to my fence after tilting my blade to 45-degrees. I made a couple of test cuts while adjusting my fence, and was able to dial it in perfectly.

I find that, for me, this results in far more precise output from my saw.

[john bateman]

more info

I have made six sided boxes to conceal plywood edges.

First, let me say, I don't think your picture shows one, does it? That loudspeaker has four beveled corners, and front and back are fitted into a groove. And the rolled front profile makes me think it is vinyl-wrap (probably cut via a CNC-controlled beam saw), although hard to tell by the picture.

Actually that is walnut veneered mdf which I cut on my tablesaw. The front has a solid piece in order to put a round profile on it. But the other 5 sides are all beveled. It doesn't take much misalignment to get a box where none of the corners will come together tightly. And the box plus the baffle board must be very square or the joinery will look quite poor...maybe .01" out of square looks terrible. But my earlier post was in response to the guy who just holds a framing square against the cut and moves on.

[Chris Fournier]

Your point is well taken John, sometimes perfect is "good enough". I've made similar items and there really isn't room for error is there. Very nice work!