Which came first?

[smorgasbord]

William Ng is famous for his "5-cut Method" for checking squareness of machine cuts. His video, dated Feb 2012, is here:

The Kapex KS-120 Supplemental Manual has the equivalent method, although called "4-cut" on page 24. The link to the PDF is here:https://www.festoolusa.com/-/media/...s/manuals/kapex-ks120-supplemental-manual.pdf

In the Feb 2012 video, Mr. Ng states he's been teaching this method for "5-6 years." So 2006ish.
The Kapex manual's copyright is 2008.

It would seem Ng came first, and indeed the Kapex manual references a “5-cut Calibration Method," but that would be before the YouTube video, so perhaps "5-cut method" doesn't refer to Mr. Ng.

On the interwebs, I found a 2004 reference to a "5 cut method" here:https://woodweb.com/knowledge_base/Setting_Up_Excalibur_Slider.html

The 5-cut method is the best one I know of and works for any sliding fence, with allowance for the mechanics of how the fence is adjusted, of course. I first learned of it from an owner of an Altendorf panel saw, who said this was the industry standard method of fine-tuning a slider.

It's also referenced in a Ryobi  BT3100 Tablesaw page which also dates from 2004.

The 2004 references would appear to predate Mr. Ng, but perhaps not. I couldn't find an old Altendorf panel saw manual online.

 

[Michael Kellough]

Pretty sure the method pre-dates the internet.

 

[Peter Kelly]

I had a tech from SCM show me both the 3 and 5 cut method for squaring when I got my first slider in the 1990s. It’s been around for a while.

 

[MikeGE]

I had a tech from SCM show me both the 3 and 5 cut method for squaring when I got my first slider in the 1990s. It’s been around for a while.

The Tech who commissioned my saw did both the 3- and 5-cut method.  I only use the 3-cut method now for the SCM slider.

 

[Peter Kelly]

For anyone interested, Sam Blasco demonstrates the three cut method pretty well here:

 

[Crazyraceguy]

That's what I was taught, when first using a big sliding table saw. This would have been '04?
Most people just use a square and look for a light gap with miter saws, but when you get into much larger panels, that's just not enough.

 

[Lincoln]

An Altendorf tech showed me the 3-cut, back in the 90's. Hadn't seen the 5-cut until the Kapex manual.
I've found the best way to confirm square, without resorting to measurement, is to cut two rectangular panels using the crosscut fence and stops, then put them face to face - very quickly shows if you're square or not.

 

[smorgasbord]

3-cut method pros:
• Faster
• Little math

3-cut method cons:
• Needs full size material
• Only doubles the error (5-cut quadruples it)
• Measurement prone to error itself (tape/ruler versus digital caliper)

One thing rarely talked about in both methods, especially for use in tablesaw sleds, is that the fence has to be dead flat. If the fence isn't flat you'll get different results with different sized workpieces.

 

[Mini Me]

• Measurement prone to error itself (tape/ruler versus digital caliper)

I am not sure about that but I too could be wrong. If I set up a panel to be square by Sam Blasco's 3 cut method and using the same tape the side to side dimension on each end of the panel is the same wouldn't that method be accurate? When I do it using the 3 cut method I measure the final dimension each end of the panel without moving it and if the trailing dimension is greater than the dimension on the fence face I creep up to that dimension with the fence fine adjuster until both are the same. This requires a lot of care as the test panel cannot be clamped but it seems to work. Here is another method for sled users.

Sled Sqauring

 

[MikeGE]

3-cut method cons:
• Needs full size material
• Only doubles the error (5-cut quadruples it)
• Measurement prone to error itself (tape/ruler versus digital caliper)

I disagree with each of these points based on my experience.  I have never used full-sized sheets for the 3-cut method.  Most of the material I use is about 500mm square, which meets my requirements.

Double, triple, or quadruple the error, and I don't care.  I'm using wood for my projects and wood has seasonal movement. I try not to spend any time chasing that last 0.05mm of deviation in a one-meter cut.

In my shop, I only use Class I tape measures or Class II folding rules.  For critical work, I use the same tape measure for all work.

I have no idea about the accuracy of the tapes in my saw fence, but they appear to be good enough for the distances I use.  I always double check any cuts with the Class I tape measure.

 

[Peter Kelly]

3-cut method cons:
• Needs full size material

I don't understand the "con" part? The assumption with the 3 cut method is that you'd be breaking down full sized sheet materials with the slider and would therefore already have them on-hand.

 

[smorgasbord]

Double, triple, or quadruple the error, and I don't care.  I'm using wood for my projects and wood has seasonal movement.

For me, the accuracy is needed for a number of things, including when cutting joints. If your tenon shoulder isn't square, there will be a gap, and if that gap is visible it will remain visible even as the wood expands/contracts. There are also mitered corners, or any mitered frame for that matter.

I try not to spend any time chasing that last 0.05mm of deviation in a one-meter cut.

Seems fair to me.

In my shop, I only use Class I tape measures or Class II folding rules.  For critical work, I use the same tape measure for all work.

The resolution of any rule/tape measure is far less than calipers. In the video, the guy is working with a tape measure that has a 1/16" resolution. He came up with a way to use calipers and a piece of steel with an attached stop and measured that he did really well for the tape measure only, then improved it with the calipers.

The assumption with the 3 cut method is that you'd be breaking down full sized sheet materials with the slider and would therefore already have them on-hand.

I was thinking of the SCMS's like the Kapex.

 

[Mini Me]

In my shop, I only use Class I tape measures or Class II folding rules.  For critical work, I use the same tape measure for all work.

As do I or better still a good steel rule if possible. Accuracy varies with different disciplines of work, building a house frame does not need the accuracy of a fine piece of furniture which is pretty obvious. I always think that the job is working under a handicap with me doing it so I try to be as accurate as possible but others more talented wouldn't think that way. What I did do was get a aluminium adjustable "stick" made that I use to calibrate all the fences in my workshop so a cut made on any of them will always be the same. I can't see any advantage in measuring something and depending on what saw I use to cut it will depend on how close to the measurement it is.

 

[smorgasbord]

I had a tech from SCM show me both the 3 and 5 cut method for squaring when I got my first slider in the 1990s. It’s been around for a while.

I don't doubt. But Mr. Ng himself implies that he invented it in a follow-up video building a miter sled:=lJLouejN5gLMTK86

Maybe if you listen to his words carefully, what was unique to him was the formula for calculating how much to move the fence. In practice, I expect some/many people to just nudge and 4-cut again.