Mario Turcot
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- Nov 26, 2017
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- 1,288
Thought it was worth sharing.
3 Cut Method to a Dead-on Crosscut Sled with Tom McLaughlin
- Thread starter Mario Turcot
- Start date
Great share, Mario. A nice alternative to W. Ng's 5-cut method.
Since the initial fence setting is approx., I see no need to set the fence against a strip fitted into the sled's kerf slot at the beginning. Referencing against the saw blade itself should be good enough.
I like Tom's videos that are produced by Fine Woodworking (because they're professionally edited for their runtime up to 30 minutes per episode).
Since the initial fence setting is approx., I see no need to set the fence against a strip fitted into the sled's kerf slot at the beginning. Referencing against the saw blade itself should be good enough.
I like Tom's videos that are produced by Fine Woodworking (because they're professionally edited for their runtime up to 30 minutes per episode).
Mark Katz
Member
McLaughlin's method is so much cruder than the 5-cut method that it's just comical to watch him claim that it's so great. Pathetic, actually.
Firstly, his method is similar in concept to checking a square for accuracy by drawing a line, flipping the square and drawing another line. This doubles the error and makes the discrepancy more visible. That's basically what Tom is doing when he flips the board between cuts 2 and 3.
Then, he places his "measuring stick with a stop block" to figure out which end is wider, adds a second stop block, and uses a feeler gauge to figure out by how much. That's OK, but just not necessary with the 5-cut method. And various colors of masking tape instead of a feeler gauge? Yikes. And in the end. all that is being measured is twice the error.
The five-cut method doesn't need the "measuring stick and stop blocks". Make a few extra cuts which is no problem since you're already set up. Then on the last cut just cut a smaller slice. Using a dial caliper (who doesn't have one these days?) you can easily see what 4 times the error is.
I admit that his method of using the test piece to determine where to offset the fence to correct the error is clever. That eliminates to the need to adjust the offset amount by the ratio of the fence length to test piece size. but otherwise, the 5-cut method is really no harder that his 3-cut method and more accurate.
Whether you need the higher accuracy of the 5-cut method over Tom's 3-cut method is a whole different issue.
Firstly, his method is similar in concept to checking a square for accuracy by drawing a line, flipping the square and drawing another line. This doubles the error and makes the discrepancy more visible. That's basically what Tom is doing when he flips the board between cuts 2 and 3.
Then, he places his "measuring stick with a stop block" to figure out which end is wider, adds a second stop block, and uses a feeler gauge to figure out by how much. That's OK, but just not necessary with the 5-cut method. And various colors of masking tape instead of a feeler gauge? Yikes. And in the end. all that is being measured is twice the error.
The five-cut method doesn't need the "measuring stick and stop blocks". Make a few extra cuts which is no problem since you're already set up. Then on the last cut just cut a smaller slice. Using a dial caliper (who doesn't have one these days?) you can easily see what 4 times the error is.
I admit that his method of using the test piece to determine where to offset the fence to correct the error is clever. That eliminates to the need to adjust the offset amount by the ratio of the fence length to test piece size. but otherwise, the 5-cut method is really no harder that his 3-cut method and more accurate.
Whether you need the higher accuracy of the 5-cut method over Tom's 3-cut method is a whole different issue.
I, too, was puzzled by his unnecessary masking tape suggestion. Blue or green tape has many good uses in woodworking, but his example isn't one of them.
Edit: Regardless of what method is used to set the fence and verify squareness, the choice of runners matters equally if not more. Overtime, the fence will get out of square if play develops between the miter slots and runners. Every time the play is rectified, so should the fence be checked again. I've come across YouTubers gluing their fence to the sled, which makes retuning the fence almost impossible.
For the panel cutting sled which uses only one runner, I chose the Incra steel miter slide bar to keep the frequency of adjustments to a minimum.
Edit: Regardless of what method is used to set the fence and verify squareness, the choice of runners matters equally if not more. Overtime, the fence will get out of square if play develops between the miter slots and runners. Every time the play is rectified, so should the fence be checked again. I've come across YouTubers gluing their fence to the sled, which makes retuning the fence almost impossible.
For the panel cutting sled which uses only one runner, I chose the Incra steel miter slide bar to keep the frequency of adjustments to a minimum.
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usernumber1
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- Aug 7, 2018
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- 412
what a great video thank you for sharing. the method is simple and genius.
i dont have to use calipers, feeler gauges or even a measuring tape. 5 cut method is fine but this is better and less machine shop and more woodworking
i dont have to use calipers, feeler gauges or even a measuring tape. 5 cut method is fine but this is better and less machine shop and more woodworking
