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I don’t trust the miter gauges they sell with table saws. Both of the ones I’ve had have been frustrating, requiring frequent checking to ensure they were perpendicular to the miter slots on the saw table. When I bought my Unisaw, which seems like a really long time ago now, I was reasonably happy with the miter gauge but it has hung, largely unused, from the hook they supplied to store it since I bought the saw. I simply don’t use them. Why? There is a better solution to crosscutting that, if you haven’t already tried, I urge you to explore.
Why use crosscut sleds?
For making crosscuts there is no better jig than a crosscut sled, which is nothing more than a platform with a fence to guide the wood that runs in the miter slots of your saw. It is superior to a miter gauge for two reasons. First, the fence against which the wood rests is generally much wider thus holding the stock much more securely. Second, and probably most important, there is no friction between the piece being cut and the saw table. You are probably wondering what I’m talking about.
Most people never explain crosscut drag. If you use your miter gauge to crosscut, as you guide the wood through the blade, the bottom of it is gliding along against the top surface of the table saw. So what? It isn’t a big deal if you are squaring the end of a six inch bench dog but if you’re cutting a table leg to length, the friction between the table and the leg can create a problem. The friction at the outboard end will want to slow that part of the leg down creating drag that you can feel as you make your cut. That drag imparts rotational force to the leg and, should it rotate as it’s being cut, you can end up with a poor cut or worse, a kickback. The crosscut sled base keeps the wood being cut off of the saw top so it won’t try to rotate on you, and the base is usually lubricated to reduce friction. That’s something you wouldn’t want to do with your project wood lest it ruin the finish later. But not all sleds are the same.
There is a third reason why sleds are superior to miter gauges, however it doesn’t apply to all crosscut sleds. Double runner sleds, which straddle the saw blade having runners in both miter slots, provide outfeed support for the scrap being cut off. On single runner sleds, as with miter gauges, the offcut is left to fall free and sometimes it gets caught in the spinning blade which may shoot it toward you. That is dangerous, but what is more so is the operator’s tendency to try and catch that offcut before it is kicked back. More than one finger have been lost that way. And that is the reason why this article is about a Mehler-esque crosscut sled.
Looking for a better design.
I’ve made many sleds over the years. My first was after watching the very first episode of The New Yankee Workshop. I had never seen one before and it was really a revelation. For years I built and rebuilt those single runner sleds until I read about the double runner version in Kelly Mehler’s The Table Saw Book. All the things I didn’t like about the NYW version seemed to be fixed in Mehler’s version. That still didn’t keep me from experimenting. In fact one of my more recent sleds was a slab of plywood with a groove underneath that ran on a piece of square, aluminum tubing that fit snugly in the saw slot. What a piece of garbage. You will be happy to know my piece of aluminum has put to good use - as a stick. I wedge it under the rear door of my truck cap to hold it up for loading.
I used to hang on to things too long and at one time still had every jig I ever made. When you make a big move you have to make decisions so one I had to make was to throw or give my old sleds away. When I moved into this shop all I had was the fairly new, aluminum tube under slab sled, thus I had to start from scratch. By Summer 2003, I needed a new sled so I decided to do a little research and see if there was a better design lurking out there.
I watched some new episodes of The New Yankee Workshop, and looked over David Marks’ design from DIY TV’s Woodworks. I went through all my magazines and found an excellent article in the October 1999 issue of American Woodworker. Lastly, I scoured my library, finding an interesting section in Ian Kirby’s Accurate Table Saw. In the end I concluded that the sleds I found were either not an improvement over Mehler’s sled, or they were basically the same thing – perhaps with some questionable refinements. I like to keep things simple so I opted to leave well enough alone.
Making the Sled
Mehlers’ design is very simple. There is a rectangular base attached to two runners. On top of that are two fences; the rear one is perfectly square to the blade and is where the stock being cut rests. The front fence just adds stability and keeps you from cutting the jig in half. Last, there is some kind of guard to keep your fingers out of the blade’s path. You could do a lot of things to this basic design but I decided against that. In fact, as you’ll see, I was rather lazy.
First, I cut a scrap piece of ½ inch plywood to size for the base. (Click here to see a diagram of the sled showing it’s dimensions.) I tried to stick closely to the diagram in The Table Saw Book but the resulting sled is not quite the dimensions advertised in the book (or on my drawing for that matter). This isn’t really important. You can build this crosscut sled in a variety of sizes (and many do) but the one I describe is good as a basic, all purpose sled. The only other one I will build, if I need it, is a much larger version for large panels or long boards. Right now I don’t need it for the projects I am making so I haven’t got around to it.
The next step was to take a board approaching the full width of my jointer and flatten it. After that I jointed one edge square to the flattened face, then I ran it through the planer. I mention this because I thicknessed that board to fit snugly in my miter slots. Once the right thickness, I only needed to rip off two runners on the table saw, the thickness of each not being that important as long as they are not quite as wide as the miter slots are deep. That left a pre-dimensioned board from which I could continue to cut more runners for future jigs.
I placed the runners in the miter slots and set the base on top. It’s not necessary to be overly fussy but I do like to keep the back side of the sled even with the edge of the saw table. After clamping the base to the saw I drilled holes for screws through the base and into the runners. Do this without measuring because it’s best if they aren’t all in a straight line. If I had drawn a straight line down the center of the runner and lined up all the screws, chances are I would have split that runner in half requiring me to start over. I did make sure to countersink the heads and use screws that were the correct length. Once finished, I slid the base back and forth in the slots to make sure there was no side to side play.
If the sled base is a little tight, there is an easy fix. Tight areas show up as black smudges on the side of the runners. These can be trimmed by scraping the black areas off with a sharp chisel. It is important that the sled slides free but no play should occur that would allow side to side movement.
Once I was satisfied with the sled base I lubricated it liberally with several coats of paste wax. I swear by paste wax as the only lubricant necessary to keep cast iron free of rust and lubricated. I wax any jig that comes in contact with my cast iron, as well as any surface I need to keep water off of, or friction to a minimum. Paste floor wax won’t harm finishes like other chemicals will. It’s easy to use and found in any grocery store.
The front and rear fences were laminated out of two slabs of ½ inch plywood as per the instructions in Mehler’s book. In previous incarnations of my sled, I was lazy and used pieces of hardwood that I had lying around. When I build the next sled, I’ll do that again. It’s easier than you think to get a wavy surface when laminating ½ inch plywood. A good stable hardwood, like maple or tulip poplar, makes a much better fence. It is important to make sure that it is at least a strong inch thick – thinner lumber may warp. Another mistake I made was to follow Mehler’s dimensions (for height) knowing that my jointer was not wide enough to flatten the face if necessary. I don’t like the way plywood can be torn when jointed – yet another reason to use hardwood for the fences.
I got lazy again by leaving the fences at their full height instead of cutting them down to their outlines as prescribed in the plan. That was a big mistake. The rear fence height is something over six inches tall. I have big hands but holding on to a piece being crosscut on the other side of a six and a quarter inch fence is hard to do. That’s’ without mentioning the reduction in visibility. Needless to say, I may be writing this article now, but when I am back in the shop I have plans to cut the fences down to increase safety and visibility.
One thing I don’t like about Mehler’s plan is his blade guard. You will notice in the pictures that my sled has no guard. NO, this isn’t for photographic clarity. I just haven’t found an alternative yet that I like. I will update this page when I do.
After the fences were glued, shaped and sanded, I mounted the front fence by anchoring it with countersunk screws from underneath. Then I turned on the saw and ran the jig through the blade, stopping about four inches shy of cutting all the way through the base. The saw kerf was used to square the rear fence. I anchored both ends of the fence from underneath with countersunk screws, one end of the underside having an oversized hole reamed out so that there was some play. Using the play in one end I wiggled the fence into square, then tightened the screws. At that point I removed the jig from the fence and added a couple extra screws in the rear fence, from underneath, to secure it.
The next time I build one of these, I will use two pocket hole screws (with flat bottoms) in the ends of the rear fence for squaring. The countersink for these would be made with a Forstner bit so that it has a flat bottom. I would have done that for this sled but I shopped around and couldn’t find the screws locally (or any other type of flat bottomed screw for that matter). I live in a real woodworking black hole. Thank God for mail order and the internet! Why would I do this? The cone shape of a regular countersink, regardless of the amount of play you have in the main hole, will always tend to draw the screw head back into one place, making it almost impossible to adjust the fence. It can be very aggravating.
The last step (that I did) was to glue a piece of 2 by 4 dimension lumber behind that part of the rear fence where the blade would come through. This allows you to cut through the piece to the full height of the blade and still cover any part of the blade that comes through the fence.
I never have added the triangular braces behind the rear fence, but I have never needed them. As I mentioned before, I haven’t yet added a saw guard. I don’t particularly care for Mehler’s use of the guard as a hold down with small stock. I prefer to use a pencil as David Marks does on DIY’s Woodworks. Despite these omissions, my fence is rock solid and square. The only thing I complain about is that I was too lazy to cut out the rear fence to the outline in the plan. I’ll remedy that shortly.
In the end, I can’t say enough about this sled. There is no side to side slop like you get in the single runner versions. The offcut is supported from behind so you don’t have to worry that it may become a permanent part of your face – or worse. Where single runner sleds can be very hard to keep square, this sled is very solid and provides an excellent base if you need to temporarily attach extra fences, stop blocks or guides. Most of the time, unless I am ripping a pile of stock, it just lives on my saw top, although staying there too long may promote the collection of moisture which is not good for the saw or the sled.
If you skip the laminated fence part, which I strongly recommend, you can easily put one of these together in an hour or two, depending on your skill and the speed at which you work. It isn’t hard and you’ll be very happy with the results. If you find a better way to attach a guard, please let me know. Then I can start thinking up something else instead of staring at the sled with a blank look. Happy woodworking. Hope you enjoyed the article.
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