marc:the wood whisperer is sponsored by: powermatic, the goldstandard since 1921 and by rockler woodworking andhardware, create with confidence. without a doubt the handiestjigs and fixtures in the workshop are the ones youmake yourself, and the one that should be top on yourlist is a cross-cut sled. (groovy jazz music) the cross-cut sled is anincredibly simple device. it consists of a platformand two hard wood
runners that go intothe miter slots as well a front and back fence thatholds everything together. the idea is this movableplatform is fixed at a perfect 90 degree angle so you coulduse it to make little cuts on pieces like this, youcan get a stop block, clamp that to the back fenceand you can make repeated cuts, so you can have reallyprecision accurate milling if you want to batch through something. one of the things i find it handiest
for is trimming larger pieces. you know how if youhave a long piece that's longer than it is wide, let's say you're cutting book shelves or something, you never really want tocut that and make that cross-cut at the table sawbecause it tends to move and rack on you and you're going to havea really dangerous kickback. on a cross-cut sled it'sreally not a big deal at all. you put your work piece on here like so.
you can clamp it in place if you want, most of the time it'sstable enough as it is. and you could have apiece that's pretty long. as long as the workpiece itself is supported all the way out there you could just push right through and cutand it's perfectly safe. part of the reason isbecause the work piece is now travelling on the platform itself, the work piece is notgoing to have any issues
with friction like it wouldif you were moving it across the table saw surface, wherethe actual metal of the table saw wants to resistthe motion of the work piece. it's a very safe way todo these things and it's just nice to know thatyou've got something that no matter what you knowit's always cutting at a perfect 90 degree angle,that's very important. when i first started woodworkingthe cross-cut sled was one of the very first thingsthat i built for myself.
at the time i was watching a lot of woodworks with davis marks and he used a cross-cut sled in justabout every episode. i was fascinated with how simpleit made things and the fact that i can get a dead-on 90degree cut every single time, it seemed like it wouldopen up a playbook of opportunities for me thati didn't have at that time. i immediately built one and it served me well for a couple of years.
since that time i gravitatedaway from it a little bit, using my sliding compound mitersaw for a number of tasks. then once i got the festoolmft that really was a game-changer for me interms of cutting panels that are a little bitwider, like this one. and frankly at thatpoint my cross-cut sleds were a little bit beat up and they needed to be replaced at that point really. i was just a littlebit lazy and i figured,
"you know what, i'm justgoing to use these other "tools that i have toaccomplish those tasks." i've been doing that now forthe last five or six years and i didn't think i wasmissing anything until i took a couple classes atthe william ng school. william has all his table sawsset up with multiple sleds and it really is incorporatedwell into the lessons. it made a light bulb gooff, like i'm really missing out on some simple techniquesand great things that
you can do with across-cut sled in the shop. i promised myself that i would come back and i would build one, and then of course showyou guys how to build it, and we'll use it onprojects going forward. here's my design, and it'sfairly simple to build. let's review some of thematerials and we'll dig right in. all you need to makethis sled is a piece of half inch plywood for the base,
two pieces of thick plywoodor hard wood for the fences, and two hard wood strips for the runners. my fence pieces are going to be made from inch and an eight hdo plywood. this is like regularplywood but on steroids. the outermost layers featurea resin-impregnated fiber that provides a smooth,consistent reference surface. the only reason i'm usingthis stuff is because a friend gave me some scraps, so feelfree to face glue a couple
pieces of plywood togetherto get the thickness you need or simply use a stableeight quarter hard wood. i'll be using purpleheartfor the runners simply because it's the toughestwood that i have on hand. oak and maple would also be good options. take a close look at the grain here. wood expands most dramatically across the grain so if we wantthe most stable runners possible we should orientthe grain vertically.
that way if there's any wood movement it shouldn't affect the fit of the runners. i'll be cutting myslices like you see here. the first step is to make sure the runner stock is nice and square. exercise caution if yourpieces are thin like mine are. using a bandsaw i cut each strip to just over 3/4 inches wide by3/8 of an inch thick, and that's the roughdimensions of my miter slot.
although most miter slots are similar measure yours beforeyour making your cuts. i then test the pieces tosee how much stock i need to remove so that it fitsin my miter slot perfectly. the drum sander is my tool ofchoice for getting a snug fit. it removes minute amounts of wood with each pass so it's ideal for delicate work. if you don't have a drumsander you can carefully dial in a fit with yourtable saw or power planer.
if you're of the galoot persuasion a few passes with your jointerplane or smoothing plane should get you where you need to be. the ultimate goal is arunner that is flush or just a hair under thesurface of the saw top. in terms of width youshould be able to push the runner back andforth relatively easily. the ideal gap here should bea few thousands of an inch. to attach our runners to theplywood i drop the runners
into the miter slots and placethe plywood right on top. notice that the plywood is offset so that there's more room to theleft side of the blade. this gives me more clampingsurface for stop blocks and it's just a personal preference thatworks well with my workflow. i make sure that theplywood is flush with the runners at the operator's side of the saw. the runners will be attached to the plywood using countersunk screws.
a large square helps me draw reference lines so i know where to drill. i'm going to configure acountersink bit for a relatively shallow hole, using thesled itself for reference. i don't want the screw topunch all the way through the runner so i set the depth andthe stop collar appropriately. now it's time to drill. i drive the screw in by handto maintain absolute control, we don't want to crack the runner.
once the first runner is secure i repeat this process on the other runner. now that both runners arelocked into position i can proceed with the installationof the rest of the screws. install at least five per side. after the runners aresecure be sure to test the sled for binding,although there really shouldn't be any problems at this stage. using a long straight edge i find the
flattest of my two pieces of fence stock. hopefully they're bothflat but honestly the only fence that trulyneeds to be perfect is the one that the work registers off of, and that's on the user's side of the saw. you can attach yourfences as they are but it can be difficult to putpressure on work pieces with your hands if your fence is too tall. i use a french curve to createa small cutout on each end
that effectively lowers the fence height where i'm most likelyto position my hands. the curve here is just decorative. using a chamfer bit i put a small chamfer on all the edges of the fence. this not only eases theedges for comfort but also produces a little dustchannel that helps prevent dust from skewing theregistration of your work pieces. back at the table sawit's time to cut the kerf.
turn the saw on andslowly raise the blade. once a full tooth height isexposed push the sled forward and extend the kerf, but don't goall the way through just yet. with the saw off place one of the fences on the sled and clamp it in place. you want the fence to be flushwith the edge of the sled. countersink and pre-drill and then drive a single screw throughthe sled into the fence. to make sure that the fenceis as square as possible
i insert an eight inchthick piece of scrap into the saw kerf that i justcut and use the largest square that i have onhand to square it up. i can't seem to find my plastic drafting triangle which would be perfect for this so i use the largest square that i have. once the fence is as square as you can get it secure it with a clamp and double check to make sure nothing has moved.
make any last adjustments with a few taps from a hammer or deadblow. countersink and drive another screw to lock the fence in place. at this point it's safe toattach the other fence as well, only this one doesn'tneed calibration so i lock it down completely withsix countersunk screws. now using a 24 inch by 24 inch piece of plywood scrap i'm goingto make a test cut.
cutting one piece andchecking it for square will get you pretty close butwe can do better than that. i'm going to use thefive cut squaring method. the idea is to make four cuts, one on each side of a test board. after each cut i rotate theboard 90 degrees clockwise, putting the fresh cutedge against the fence. by the time i make thefourth cut any error in the squareness of the sled willbe four times as great.
to measure how far out it isi setup for the fifth cut, removing a small strip of wood. save that off cut and keep inmind that this is the side of the board that we originallymade our very first cut on. it's important to keep the orientation of your off cut straight so i mark one side f for front and one side b for back. in the perfect world thatoffcut would be exactly the same width at thefront as it is at the back.
what we have here is .8inches at the front and .82 inches at the back, for atotal difference of .02 inches, which is just overabout a 64th of an inch. frankly that's not too badconsidering this number represents the errorover a 96 inch distance. let me explain. each side of the board thatwe cut was roughly 24 inches, so after four cuts thetotal distance is 96 inches, so the error we measured on that last cut
is four times the actual trueerror. the true error would then be .02 divided byfour, which is .005 inches. in real world terms we'resaying that the error is approximately fivethousandths over 24 inches. frankly that's close enough for me, but i wanted to demonstratehow to make an adjustment so i'm going to try toget even better than that. here's how we make an accurate adjustment. since my cutoff piece wasthinner at the front and
thicker at the back ineed the left side of my fence to come backtoward me just a hair. i start by clamping a stop block to the sled base right up against the fence. i loose the fence screwand completely remove it and then inset a fivethousandths feeler gauge in between the stop block and the fence. this is essentially going to push the fence back five thousandths of an inch,
which is the amount of errorthat we calculated earlier. i use another clamp to make sure that the fence is fully secure to the stop block and then drive a new countersunk screw. note that this is a new screw hole, you do not want to reuse the first one. i remove stop block and the feeler gauge and repeat the five cut test. this time we have .648 at thefront and .653 at the back,
for a difference of .005. remember we have to divide this by four and the resulting trueerror would be .00125. now that sled's error is effectively about one thousandth of an inch over approximately 20 inches or so. that's what we call crazy good. remember, i would havebeen perfectly happy with the initial results sothis is just a nice bonus.
don't go nuts chasingdown perfection here. get it as close as you canwith no more than three rounds of this five cutmethod and you'll be fine. with the fence dialed init's safe to drive some more screws and completely securethat fence to the base. after firmly attaching therear fence here you may find that things havemoved a little bit on you. the runners may feel alittle bit tight now and that's just because as youdrive these other screws
things just may move acouple thousandths one way or the other and that couldcause it to be a little tight. it's very difficult tolook at it and figure out which part of the runneris causing the tightness. it may just be one ofthem, it may be both, it could be one side of the other side. what i like to do is use a sharpie marker, you could also use apencil or a piece of chalk, and i will mark each side of the runner.
both sides of each runnernow have a good marker line. and we can put the sled rightback into the miter slots. mine is doing just fine atthe front, it's toward the back where i'm getting justa little bit of rubbing. you can see i can push easilywith my fingers to right about this point here andthen it starts to tighten up. i can still push it through but i want it to be a little bit more relaxed than that. i'm going to push it forward and back,
i don't know, maybe ten or fifteen times, just enough that some of that marker is going to start to rub off. let's see what we can see. it's not going to be very easyto see but right along here, right in the middle ofthat marker line i've got an area where it'sstarting to rub away. it starts about here andends right about there. that seems to be the biggest offender.
i'm going to grab my card scraper and remove a little bit of that stock. i also see a little spot right up here. (scraping) not too bad, a little bit should do it. let's test the fit now. much better. that one little fix was all it took. there were a couplesmall points where it was
rubbing and that was justenough to cause it to be a little bit moredifficult to pull back. you want to be prettycareful with that because if you have to pull reallyhard to bring it back to you that's reallygoing to stress the screws that hold this fence inplace, and eventually it may come loose or it mayknock it out of calibration. (squeaking) getting alittle bit of noise there. the wax will probably take care of that.
but the point is there's no slop and it's fairly simple to push forward and back. keep in mind there are seasonal movement issues that may occur here. if it gets really humidyou may find that those runners swell up a littlebit and you have to decide whether or not to take alittle bit of material off. the drawback being thatwhen the humidity goes away those runners canshrink down a little
bit so they'll go back to where they were. that's one of the reasons why we want to use quarter sawn stock. that's very stable sohopefully we won't have that problem and even if it movesjust a couple thousandths here or there it's not goingto be that big of a deal. (ragtime piano music) now i think we can take amoment to review some of the basic operations that we canperform with a cross-cut sled.
of course you could makea very simple cross-cut on a piece like this, arelatively small piece. if you have a pencil mark onthe work piece you just line that up with the kerf cutin the back here and you should be able to fairlyaccurately cut to your line. nice simple cut, perfectly square. of course you're also going to want to use this setup to cut larger panels. it's really no different, you just line
up your pencil mark with the kerf cut. let's say it's right there. turn on the saw and go. let's say you want to batch outa bunch of parts and they're all exactly the same size,so you need a repeated setup. a stop block is what's reallygoing to make that possible. you could simply clamp thestop block to the back fence. now we know that every time weput the work piece up against the stop block we're going towind up with a piece that's
exactly the distance betweenthe stop block and the blade. generally how you woulddo this is of course a work piece needs to besquared on both sides. in order to have a good squarereference to put up against our block we need to have atleast one side square first. i put it on the right side,make that cut real quick. now i could put that nice square side up against the stop and make my cut. now no matter how many ofthese i have to cut they're all
going to be exactly the same length because of the stop block. there are going to be timeswhere your work piece exceeds the fence capacity so if iwanted to cut a piece that was, say 17 inches long for instance, i won't be able to do that in a setup that involves the stop blockbeing on this back fence. here's the great thing. we could use our tablesaw fence as a stop.
let me show you how we dothat. take your stop block. attach it to the fence. you want to keep it backtoward the front here because ultimately we don'twant the work piece to be in contact with the stopwhen it hits the blade. just adds a little extra safety here. of course we need tostart out with one square edge so i'm going toput it on the left side and just trim it so thatit's nice and square.
assuming that i havemeasured this distance and i know that this distanceis exactly the repeated cut i want to make icould take that fresh cut, put it right up against the stop ... once again i can batch out asmany of these as i need to. here's a quick tip for you.if you make your stop exactly one inch wide then all youneed to do is set your fence based on whatever the readingis and just add an inch so that you don't have to worryabout doing any odd calculations
and you won't even have tomeasure when a time comes. if i want to cut a 17 inchpiece i need to set my fence for 18 inches to account forthis extra one inch stop. if you can get this to beexactly one inch you're going to make your lifea whole lot easier. there may be a time when you need to cut really tiny pieces likethis little strip here. the problem is as you makethis cut, you can hold it with an eraser like this and steadyit but it's a little bit
scary to think of this littletiny piece sitting between the stop block and the blade onceit's cut all the way through. there is a littlemodification you can make to your stop block that makesthis a whole lot safer. i can use this extra piece that i cut. you can see i just removed material here so that there's a little stop on the edge. what will happen is it will fit right under my regular stop block.
notice i cut this so that it's just protruding a little bitfrom the stop block. i'll show you why in a minute. let's say we want to makeour cut right about here. clamp the stop block in place.tighten it down real good. this then becomes my stop,i'm not actually using the face of the stopblock. i want to set it so that my cut length isbased on this bottom stop. once i'm lined up, i'vegot my work piece in place,
i can actually remove thisso that once i go through and make the cut this off cut isgoing to float in free space here and not be wedged betweenthe stop and the blade. then when you go to make yournext one bring the stop back in, line it up again and make your next cut. let me do a couple test cuts this way. you still want to becareful because these are little pieces and theycould certainly vibrate back into the blade but it's a heckof a lot safer than having
that piece wedged betweenthe stop and the blade. those are just a few thingsthat you could do with a cross-cut sled and that's reallyjust the tip of the iceberg, there's a lot of tricks and tips. search on the internetand you'll find a lot of great ideas for not only what to do with a sled but also how you can really trick it out and make it thatmuch more useful for you. hopefully this starts as a nice
template that you could build upon. of course, send me yourpictures and your ideas. i'd love to see what otherthings you do with your jigs to make them work that muchbetter for you in the workshop. we'll share them with the community. i certainly plan to usemine on the show a lot more so you'll be seeing this thing again. thanks for working. (woman singing)