# 5 Cuts to a "Perfect" Cross-Cut Sled

5 Cuts to a "Perfect" Cross-Cut Sled

The cross cut sled is probably the most important jig in your shop. Here, William will explain the theory and calculations to enable anyone to get a sled dead on square. He will show his tips and techniques for constructing the sled.

Formula for calculating Error: (A-B) ÷ 4 ÷ Length of 5th cut x Distance between pivot point and the point of adjustment = Error

Material List:

Runners: 5/16″ x 3/4″ x 30″

Base: 1/2″ x 34″ x 30″

Front Fence: 1-1/2″ x 5″ x 30″

Rear Fence: 1-1/2″ x 5″ x 26″

Great instructional video! I sure hope you continue to create these videos. You have a knack of explaining things, not alot of people do.

This worked perfect and awesome! Thank you so much for this video. It was very easy to follow and thanks to the clear instructions was able to get to .001 with only one adjustment.

Great video made simple to understand!

I have tried unsuccessfully to find an answer to this question. Is the material at 34:15 acrylic, polycarbonate, or something else? It seems to be polycarbonate, but I’d love to know before spending the money. I still come back to this one repeatedly, as well. William is my hero!

Awesome job and superior craftsmanship.

….” As you know , my face can’t stand another hit…” that’s the best part! How can you be so serious and so funny? 👏👏👏😂😂😂😂

Outstanding. When I get around to building a crosscut sled, I’ll know how to to make it as square as possible. Your simple and clear explanation of the 5 cut method answered the “why” (theory) behind the steps and really reinforced the elegance of this method.

Thank you, I now understand the 5 cut method.

Dang Chinese people and their math… Oh wait, I’m Chinese, and I used to win math competitions, dammit… Guess I’ll be using this method when making my first sled then. 🤣

Hi people. It’s 2022, I built my sled from pure diamond. Milled from one single huge mega nugget…. It was cheaper than the ply and that maple glue up bench was over twenty million pounds. That’s actual pounds, not those Micky mouse dollars you foreigners use. Also what the hell is a 3 8ths of a inch? You know the only thing measured in inches in the developed world is male genitals. You fellows from the colonies always make us chuckle.

You’re the absolute best I have found. Thank you for sharing your knowledge

Just started watching your videos. Really enjoy them and will use your lessons to make me a better woodworker. Thank you

Super cool!!

I’m working on adapting your technique to my radial arm saw.

It would have been 10 times simpler to follow if you had just made a new sled a d explained as you went.

With the verbal explanation, it’s a bit like going down the white rabbit’s warren as you have a tendency to double and triple down your original explanation to such an extent that I needed to go back and see if the qualification of your original comment has the same value as before.

Thank you!! I really enjoy your videos and please don’t be discouraged by the haters. It is very important to understand the math behind anything that we try to do. I really like your teaching style. I am fairly new to woodworking and your videos are a great help!!

Worked like a charm!

It’s sad that I can’t give this video a new like every time I come back to reference.

this is thee best video I have seen on making a crosscut sled

Excellent teaching of the math and the process needed to apply this technique. Well explained with examples and illustrations to take the sting out of math that intimidates many when it shouldn’t.

At 12:45, why is that off centre?

I have come back this video a second time to review the five cut method.

Mr. Ng’s instruction is concise, explaining how and why.

I hope , with a few more viewings of this video, I will completely absorb the method as well as related information on building functional and accurate table saw sleds. Thank you for this video !!

i can do everything except math 😢

Your calm and stright forward method of presentation is most welcome.

32:42 the best moment

Hi William

How can we exactly measure the distance beetwin pivot and adjusting point?

Thank you

Very well articulated lesson. Your student are very fortunate!

I just built a crosscut sled using your method. Even though this video is 10 years old, this is still the best method I’ve found for squaring up a sled. Thanks for taking the time to put the details out there. You’ve helped a ton of woodworkers!

Where or how did you get the templates for making the front and back fences of your cross cut sled?

I just completed building my first cross cut sled and I’m going to try your method to see just how square or unsquare mine is.

Thanks Chris

🙂 Thank you very much, don’t know why I watched it again after many times and still happy and I like the way you teach, very nice way

I’m just starting out working with wood in my 40’s lol. Always wanted to and I’m finally in a position to afford it. So much knowledge and wisdom, thank you. Wish I we were in the same area so I can take your classes.

Mr. William Ng, the man, the myth, the legend! I love the dedication to precision and repeatable excellence that your methods strive for. Thank you for sharing and keep it coming! Just made cross cut sled IAW your video. Having a solid proven method to dial in a jig is invaluable. Thank you sir!

The plexiglass cover and rear guard as well as the calculations…Awesome…..Math that is actually useful and important…this is how geometry should be taught…all things learned must be applied in real life, otherwise they are forgotten. Thank you so much…(old lady learning how to build).

I need to make a sled soon. I will re-watch this video and make it along with you then.

https://youtu.be/UbG-n–LFgQ?t=799 Love your humor 🙂 haha thanks for your videos!

Very helpful and really love they way you explain things. Wish you had been my math teacher!

Very nice method. Thank you very much for sharing this!

I was wondering why this works with all kinds of dimensions of the piece of wood. This is because the error ANGLES add up. For the same reason the formula is actually an approximation…

sin( arcsin( (A-B) / Length of 5th cut ) /4 ) x Distance between pivot point and the point of adjustment = EXACT error

For small values both sin and arcsin can be replaced by its arguments. You can still use the approximation, because the error is insignificantly small. (In my case it was less than 0.001%.)

Thanks William. I recently built a crosscut sled after watching your video several times. It is great. I do have a question. After my fifth cut, the rip I have is two thousandths out in about 18 inches. Do you think that is close enough to perfect or should try to adjust it?

Way too much information and now gets too confusing.

Thanks for a great video, William. I finally made my "Perfect" crosscut sled, thanks to you. I simplified your method, however, and hope you will not mind.

Before I attached my 2nd fence, I marked the location of its pivot point so I could locate it after the fence was attached. After cut number 5 I placed the cut off strip along the fence with one end at the pivot point, and marked the location of the other end along the fence line. Then I measured both ends of the strip, and divided by four, as per your method. Then, I made the "pointed stick", and clamped it to the sled at the distance meaured and calibrated, using my feeler gauges, again, as per your method. My next (5th) cut was within one one-thousandth of an inch! Yay!

The proof of the pudding was measuring the diagonals of a 38 by 20 inch coutnertop extension I made for my wife after i cut it to final length on my new sled. Absolutely dead on.

By laying out the exact distance from the pivot point using the cutoff from the 5th cut, I eliminated a lot of math. The variation there is the same as one fourth the variation after the fifth cut. Maybe the trolls who gave you such a hard time will be able to use this variation.

Hope you don’t mind my rambling, and thanks again for the inspiration.

Thank you for the great , easy to follow instructions. I now have a crosscut sled that will make a ninety degree cut within .001. Outstanding

I watched many cross cut sleds built I like yours best I plan on making yours, also I like the way you explain yourself got a lot out of the video thanks. MS wood working.

Thank you, GOAT!

This may be a dumb question, but how do you get the materials square without being able to use the sled to measure the error?

If your fence is not perfectly straight. How do you square it?

25:27 You definitely need more clamps!

Wow this dude goes beyond I thought I was bad but holy cow man is he good he’ll I’m proud to say that I just watched it hands down one of the best I need to start over on all my thinking 🤔

I will never make a sled without using this method. Thanks for sharing

Great video William – thanks! One question – since your last cut to get the strip to measure also adds any error, should you not divide the error by 5, not 4?

A logical and well thought-out sled. I have a junky one I built years ago; I think I will build yours for better precision and safety.