5 Cuts To A “Perfect” Cross Cut Sled
February 28, 2012 by William · 76 Comments
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.
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″
William Ng comes from an engineering background and uses a similar approach in his woodworking. Precision, accuracy and efficiency are emphasized in his teaching. His sense of humor, combined with his passion for woodworking makes for an enjoyable learning experience.
Nice video
Thanks.
William, will you make plans available on your site for the sled?
Great job, very educational.
Thanks John.
Great video…really enjoyed your work!
thanks,
TD
Thanks for the support
Judging from your comment at 13:40, I’m guessing Rodney Dangerfield has been a student of yours. Nice video- full of info.
Ha Ha Love Rodney! You’ve got to be able to laugh at yourself. Thanks for watching.
William, seeing this video reminds me how much i miss the two classes (bench and cab.) i took from you. As always, great explanation of your thought process and the reasoning for each step. Gosh, an engineer that can actually communicate to us non-technically inclined dreamers; what a pleasure. Hope to be back down there early this summer.
Like the comment above, appreciated the self-deprecating humor . . . but think i heard that one before (wink). However at 14:40 I had to back up several times and still am undecided if you got a haircut or if the make-up artist did a touch up.
Best regards, Patrick
Patrick, yes I remember, We had many laughs when you were here. So even when I said “you’re going to need two promotions before you make moron” you’re still planning to come back early summer. Ha Ha … I’ll be waiting.
As for as the engineer part… I guess my Mama didn’t wastes her money putting me thru college huh?
At 14:40 It’s call editing and photoshop. Look forward to our next meeting.
Oh yes, I am a glutton for punishment; so I will be back. Plus, you need a student like me to make the other ones look good!
My wife wants to come too, apparently suspicious about what actually went on since for weeks afterwards I kept smiling and grinning about having such a good time at your shop.
My Best regards, Patrick
Ha Ha Ha Ha! That’s too funny!!! Don’t worry about your wife. What happens here, stays here. I got your back!
Great Vid. as always. I have learned so much from you in these past few years. Can’t wait till the Blacker Chair Table class (wink wink). Down to my last Blacker side chair, photos coming soon. See you soon.
Ok Jim. I get the hint. We’re working on it. I wouldn’t recommend holding your breath. hee hee.
William, great video. Yesterday I just finished making a sled. It took me forever to get it almost sq. I did not look at my email the last couple of days to get your video. I should have. I guess I will start all over again. I will give the sled I made to my grand kids to use in the snow. Ha Ha!
Hey Frank, nice to hear from you. You might want to double check before your give it away. You never know, it might be square.
This is exactly what I need to do. BUILD A CROSS CUT SLED. Thank you so much for posting this. And I love the 5 cut method. Learn something new every day. (I know how to use the 4 cut method, this seems to be just a little bit better…ie, it should only take 1 adjustment, instead of the 3-4.)
Thanks again,
Jerry
Thanks for the visiting to our website, best to you in making your sled.
What an excellent video on cross cut sleds. I love the way you adjust the fence so accurately. I downloaded all your video’s. You are an excellent teacher.
Thanks again
Leon
Leon, Thank you for watching and your comment. Are you the same Leon that email me about the big daddy bit? Give us a call and we can help you out. Thanks again.
Hi William,
Yes i am the same Leon that e-mailed you . I have applied for a job in Tx . Waiting for the paperwork- i have the job but paperework takes very long . Hope to be in Tx by the end July. Will buy some stuff from your shop then
Regards
Leon
Very informative. I enjoyed your video presentation on your table saw sleg
Thank you
Mike, Thank you and thanks for watching.
Great video. Thanks for taking the time to educate. I was wondering though, why after cutting the fifth cut and measuring for your error, why you would not divide that by five instead of four.
Thank-you again.
Hey Domenic, I divide by 4 because there’s only 4 angles in a square not by how many cuts I make. Starting at 3:37 on the video I show why. The fifth cut does not introduce any more error. Hope that helps.
Thanks for the explanation. You have a great web site and keep up the great work. You have great teaching skills. I would love to be able to attend one of your classes someday.
I just finished y crosscut sled this morning and thanks to your method I was able to calibrate it well.
Sincerely,
Domenic
Great video, 5 cut is simple and the way to go. Not sure where I saw it first. Seems like the formula can be simplified greatly if your 5th cut is length is equal to the distance from pivot to point of adjustment?
Bob
Hi Bob, That is true. The only problem is the board won’t fit between the sled.
Let’s see, if the 5th cut is made on the sled, it has to fit. My suggestion is to do the adjustment measurement with the feeler gauge at that distance from the pivot point. I am not a machinist, so I am willing to be wrong. But it does not seem like you would gain much by mathematically extending the distance where you measure with the feeler gauge much beyond the length of the last cut?
Bob, We are talking about the same thing. Yes, you can make the adjustment the length of the fifth cut. It falls into my formula. After the fifth cut you take the error divide it by the length of the fifth cut multiply the distance between the pivot point to point of adjustment. It’s the same thing. What I’m trying to do is make it easy to get the best results. Like I said in the video, the farther it goes out the bigger the error ratio which is easier to adjust. If my fifth cut is 17″ and that’s the biggest board I can find.. and my base is 34″ wide. That means I have to make my adjustment almost in the middle of my sled. I would have to find a deep throat clamp to be able to reach that far in. Also if I clamp my stop block and for some reason I’m off by 1/1000 of an inch that would be twice the error if I adjusted twice as far from the pivot point. It’s easier to clamp a block right at the edge of the sled at the end of the fence as long as the error ratio is an even number. Like I said if you get an error of 10-1/5 thousands you have change your calculation until you get rid of the 1/2 thousands. If you follow the formula, it really doesn’t matter where you make your adjustment, it’s what ever is easiest and convenient.
Ooops, I meant the error should be calculate to get a “whole” number not an “even” number. My bad.
Really enjoyed this as I really need to make one of these to help get better cuts on the table saw my little mitre gauge just isnt cutting it!
This is the first time I have seen anyone put a box on the back of the sled. What is the purpose of this additional piece? I apologize in advance for my noobness!
Hi Justin, The box is added protection when the blade comes thru the fence when you cut. It’s a blade guard. Some people push the sled way pass the cut, so I put a stop in my miter slots so you can only push so far.
Excellent video – I went right out and measured my sled… which needed a bit of adjustment. I can say you made it easy to correct. I went from .0025 to <.001 which is great.
You mentioned a video on a mitered sled. Would you post a step-by-step process to fabricate this jig? I have a project coming that needs precise miters.
Hi Skip, Glad to hear it worked for you. Less than a thousand… impressive. The reason why I made the sled video was because we were replacing all our sleds. Every 2-3 years we change them out to make sure they’re at optimal performance. I’ll see if our miter sleds need replacing, if it does I will have my cameras ready. Thanks for watching and hope you visit back soon.
Looking forward to future content!
FANTASTIC……The best sled I have seen.
William,
This was the most in depth video i’ve seen on how to properly construct a crosscut sled and accurately square the fence. Thank you so much for all the hard work that went into creating this video. I have a couple of questions.
First, i notice that all the cuts you made on your sled were done on the left side of the blade, even during the five-cut process. When i use my CC sled I almost always place the work piece on the right side of the sled/blade and the cutoff ends up on the left. Is that just a matter or personal preference or are there some mechanics/accuracy reasons behind it?
Second question relates to the measuring formula. When you use the dimension of the board as 24″ is that the beginning measurement of the long(#1) side of the board, or the final dimension? The reason i ask is because each time you do a cut in the five cut method you are reducing the dimensions of the board. So even though you may start with a board that has a 24″ long dimension, you may end up with 22″ or less depending on the width of your cut. This begs the follow up question, how much material do you cut off of your larger board with each of the first 4 cuts?
Hi Chris,
I use the left side of the sled because the fence is longer and the base is wider which give me a bit more support. It’s a matter of reference. When I cut long pieces using the left side gives me more room and I don’t have to move the fence. After the cut my out fall is on the right side of the blade and I just stack it on the table saw table on the right. If I cut on the left and it’s a long piece, I have to move the fence all the way to the right, sometime I have to take it off. My cut offs will be on the left and have no where to store it, because my stock will be on the right side of the blade and I need the room to move it back and forth for the cuts.
As for the formula, you are correct stating that each cut will remove material. Because of the length of the video, I edited close to 17 minutes out. It’s hard to cover every detail. So my formula says divide the error over the length of the fifth cut, which means whatever is left. How much do I cut off each cut? About 1/16th of an inch. Hope this helps and Thanks for watching!!
This was the most useful woodworking video I have watched/used in a long time. I already had 4 sleds that I use for various applications, but I built your version anyway and finished it out at .002 of an inch over 28″ I was so excited that I disassembled all of the others and set them up using the 5 cut method. Got one at .001. How cool is this method!
I canned my old wide panel cutting sled and am buildling a new one from scratch and am planning on setting up the one fence with the 5 cut method. I got so excited with the new precision that I removed my Incra TS III fence from the saw and completely reinstalled it and recalibrated everything. I have always been partial to Incra tools because of their repeatability and accuracy, but I must say, the 5 cut method is amazing. Now if my patience could only stay as precise as my TS. Thanks William. Keep up the great work.
Hi Bob, Thanks for sharing that with me. It makes me feel good that people get excited with precision. You’re getting some great results with your sled and fences. I am a huge fan of Incra tools. I use them and love them. Thanks for watching.
Very Nice. Going to start working on my sled
William – Thank you very much for doing this video. I really appreciate it.
Hi Rob, If you’re referring to 13:45 in the video. The purpose is to avoid kick back. When you have a piece of wood trap between the fence and the blade it can become hazardous. If for any reason your work piece comes off the fence, it has nowhere to go but into the blade. Depends on where your cut is, it will ruin your piece or worst yet, you’ll get a kick back. Watch the video again starting around 13:00. I explain it there. Thanks.
William
hi William – I noticed that you used a large rectangular wood box (up against the fence) when you were cutting the rails. Would you mind explaining what it’s purpose is?
thx
Hi Rob, If you’re referring to 13:45 in the video. The purpose is to avoid kick back. When you have a piece of wood trap between the fence and the blade it can become hazardous. If for any reason your work piece comes off the fence, it has nowhere to go but into the blade. Depends on where your cut is, it will ruin your piece or worst yet, you’ll get a kick back. Watch the video again starting around 13:00. I explain it there. Thanks.
William
I should have been more specific. I was referring to the wood box that you placed between the fence and blade at 16:45. (Thank you for your answering!)
rob
William,
Rob is asking about the box that you placed around your Beismeyer fence before you ripped the rough stock for your sled runners.
Hi William,
Watched your video several times and actually made a computer model of it in order to build the sled. I would like to ask you if you used a plywood/plastics cutting blade to cut the acrylic sheets for the blade guard? I don’t usually work much with acrylics and I’m not sure about sawing the material using an 80 tooth carbide tipped blade.
Best regards and Happy Holidays!
Ed
Hi Ed, I don’t work much with acrylics also. You’re probably right about using a special blade for plastic but, because I’m only doing a few cuts I just used my regular woodworker II 40 tooth blade. Probably not the best thing to do. It doesn’t hurt the blade and I’m sure with the proper blade I would of gotten a cleaner cut. Thanks for watching and Happy Holidays to you.
William
Dear William,
By far, this is the best instructional woodworking video I have watched in twenty years. Your treatment of the theory and how to implement it is excellent. In my line of work, dentistry, 0.001″ is considered large. I delighted to find someone who appreciates accuracy in his work and has the talent to pass it along. When are you going to do the video on the miter sled? Soon, I hope.
Thank you,
-jtj
New to wood working-I believe I really need this sled.Thanks for a great video!!
Great video. Thanks for the hard work!
They showed your video at our Woodworker’s Guild Meeting last week. I made a table saw sled using your method over the past two days and it turned our great. It will be wonderful using it to make square cuts for a long time. Thanks so much! In the video, you mentioned another video for cutting 45′s. Is it available for viewing?
Hi Bob, Which woodworking club do you belong to? The miter sled video is on my list of videos to make. I just have to find time between my classes. Thanks for your comment.
Our local guild is the Lees Summit Woodworkers Guild located in Lees Summit, Misssouri (a suburb or Kansas City, Missouri. Our new website is http://lswoodguild.com/
Hi.
Finally in Texas and setting up shop. On my first attempt to make the crosscut sled i managed to get it 0.000316 of an inch . Thank you William for an excellent video
Leon
That was after the calculation tough
Wow! that’s rocket science close. Better than what I can do. Again, welcome back to the states.
William
Hi;
Great video for the sled. I have searched the web looking for a reliable 45 degree miter sled. There is NOT any designs out there that will give you an exact 45 degree cut. I sure hope you will find the time to make your video very soon. I am in great need of one as I am going to be making a wood floor medallion with many 30, 15, and 45 degree cuts.
by the way, after finding your school two days ago this is the first time I wished I still lived in southern Cal.
hey will great great great video
what material did you use for the base?
Hi Nathan, I use Baltic Birch for the base and all my jigs. Thanks.
William
I never knew how much fun precision could be!
So, theoretically, if I glue a strip into the slot of my awesome new crosscut sled, move my blade to 45 degrees and make a new, angled slot, would I have a perfectly dialed in sled for miters?
Thanks again!
Hey Brian, I would make a separate sled dedicated to miter cuts. I have multiple sleds for each saw. One for cross cut, dado, taper and miter. Thanks for your comment and for watching.
William
Thanks for the quick reply. I will definitely be making more sleds! But just to clarify, to make a sled for mitered edges using your method would be very hard -the fifth cut would be (if I remember my high school geometry correctly) a parallelogram. And the calipers would squish the pointy tips.
So, I guess my question is, would my method in the comment above result in a perfectly dialed in miter sled? (I actually tried it last night and it seems to be working great so far, but I have a degree in music so I just wanted to make sure I wasn’t losing any accuracy in the process.)
Thanks!
Brian
Brian, I don’t use the 5 cut on miters. All you have to do is take your bd make your first cut (A) then flip the bd and make your second cut (B). Your cut off should look like a triangle. Take your measurements. If A square + B square= C square then you know your angles are 45, 45 and 90. If you’re off by a bit, use inverse trig to calculate angle error. The adjustment is a little tricky. The inverse Trig formula is Sine Theta = Opposite over hypotenuse. For this to work one angle has to be at 90 (right angle) Start by squaring off your 6″ board. Take it to your angle jig and make a cut, the cut off should be a triangle. The side that got cut is the hypotenuse, the side against the jig is the opposite. Take your measurement. To eliminate sine, use inverse sine on both sides which results Theta = inverse sine opposite over hypotenuse. This will give you the 45 degree angle. You’re going to need a scientific calculator for this. If you’re off by one tenth to two tenth of a degree, I think it’s acceptable. Hope this helps. I will put the miter sled on my list of videos to make. Using a miter sled is a lot easier to calculate and adjust. Thanks for watching.
Did mention I was a music major?
) I think I got it, though measuring sharp edges with calipers still seems less than accurate. So, my calculation was arcsin(1.010 / 1.426) = 45.0947 which means my error is just under a 10th of a degree. If that’s correct, I guess I’m pretty happy! Thank you once again for taking the time to share your wisdom!!
Hahahaha Yes, you did mention you were a music major, but that doesn’t mean you have a low I.Q. In fact as an musician myself, I like to think the opposite, that music increase ones I.Q and creativity. You are proof, you’ve figured it out and a 10th of a degree? Awesome!
Hello William;
The weather here in up state New York finally got above freezing so I could work in my basement without the worry of getting froze bite. I made the sled and after making the adjustment to the fence my error was .00033. Thank you so much for the video.
Now I need to make a mitered sled. I am want to make one like the one in the video for Mitered Mortise with Yeung Chan. If I set it up like that one and have 2 screws for ajusting the angle, can I use the same method as in the sled video to get a perfect mitered cut. A-b / 3 / The length of cut X The length of the piviot Point.
Wow! .00033 that’s better than my sled. The calculation for the miter is a little bit different. You cannot use A-B/3 because the 3 angles are not equal. You have to use basic trig for that. If I have time, the miter sled is on my list of videos to make. Thanks for watching,
William
there are so many cookie cutter sleds ,all seemed to leave me looking.Then I found Mathias,then through the next door,then you. Whooie,then I read your bio,yah, said to myself,there you have it,the guy is an engineer.. how good does it get.What a great short cut. William there is an a fine watercolor artist living in Toronto,Can. , Alfred NG, how do you pronounce your last name?,forgive me for presumptiousness, I mean if I get a reply. Truly wish I could be living near your school.
Glad you’ve found me and hope the video will benefit you. My last name is pronounced ing or eng. Thanks for watching and comment. Thanks
William
Hello William,
I just purchased your CD on G&G joinery details and somehow got hooked into you Web site. Thanks for the great video on the Cross Cut Sled. I have used a cross cut sled for a couple of years now. Believe I found the plans and procedures on the Fine Woodworking Web. Long story short my sled never cut with the precision I would have liked. More than likely it has been operator error on my part in the construction and operation.
Using the techniques in your video I did a tune up on my existing sled. First, I made new runners that fit snug. Second, I flattened and squared up my rear fence. And lastly I did your recommended five cuts and calculation. After the first adjustment I had a positive 0.00147l. Initially I thought hey good enough for government work, but had some time to kill so I made another adjustment. Well the fifth cut Delta came out “nuts on” — 0.000. Hey I am not that good so as they say “I would rather be lucky than good”
What is the cost of the class on How to Properly Chuck a Drill Bit?
Thanks again Bob
Bob, Thanks for purchasing my Greene and Greene Joinery DVD. Your support is always appreciated. As for your sled I would have let it go at .00147 you are a patient man and it payed off. Yes, I rather be lucky than good. As for the Chucking the drill bit class, I’ll see what I can work out.
Thanks for watching.
William
Thank you for the video on mak