A) One piece of Melamine covered particleboard shelving ½" x 18" x 22" (approximate)
B) One 3’ length of 2"x2" oak stock (straight as possible)
D) 18" metal machinist rule preferably with 1/64" graduations ( for accuracy)
E) ¾" x 4" x 2" hardwood scrap block
F) 3/8"brass insert with 1/4"-20 hex bolt to fit about 2" long and a 1/4"-20 nut to fit bolt.
G) One small hold down clamp that can be screwed onto fence (Rockler item #53439)
H) One 2 1/2" machine screw with 10-32 threads and two 10-32 nuts (replaces arm on clamp)
I) One hardwood mitre runner cut to fit table saw slot SNUGLY, add 1/8" to height above table saw table and a least as long as shelf material is wide.
J) Eight #6x3/4" wood screws
The instructions listed below are for a sled that fits into the left mitre slot of the table saw and is for a blade that tilts to the right AWAY from the sled. If your saw has a left tilt arbor, reverse all the directions and drawings mentally to build a sled that fits into the right mitre slot. Easiest way to look at this to build the sled so that blade tilts away from sled. Shall we begin?
Measure the distance from the left side of the TS blade to the right edge of the left mitre slot as you are standing in front of (cutting position) of your saw. Position one of the shelf pieces in front of you so the long edge runs left to right. Measure from the right edge the same distance as noted and add ½". This ½" will be cut off the first time the sled is used to provide a zero clearance next to the blade. Cut a dado parallel with the right (short) edge along this line the EXACT width as your Mitre slot. Most saws have either a ¾" or 5/8" wide slot, measure it to be sure. Use either a router or a dado head in the saw to a depth of about 1/8"-3/16".
Use a piece of scrap hardwood at least as long as the length of your dado and cut/plane it down to fit SNUGLY in your mitre slot. Allow it to stand above the surface of the table about 1/8", this portion fits into the dado we just cut into the shelf material. I used Hard maple for mine.
Insert the runner into the mitre slot of your table saw, then slip the sled’s dado over the runner and seat it firmly. This keeps the whole thing from moving or sliding around on you. Pre-drill, countersink and screw through the sled into the runner with five or six evenly spaced #6 x 3/4" wood screws. Do not use glue! At some point later on, the runner will become sloppy in the mitre gauge from use and wearing down and will need to be replaced. Create alignment marks on the runner and sled, and remove the runner. The marks allow you to place it back on later exactly the way it came off.
With the dado down and sitting on the table. Place a small brad 2 ½" up from the edge closest to you and 2" in from the right edge. (lower right corner) Drive the brad all the way through to the other side, and drive as straight and square as possible to the sled’s surface, this will be used in a moment. Clip the head of the nail off. Using a string and pencil, mark an arc about 14" to18" in Radius around the nail. Vary this length so your arc remains on the sled and gives at least a couple of inches near the top and bottom for support (see picture). This gives you a basic idea of where your fence’s arc bolt will ride. Measure an approximate 45 degree angle from the nail to the back edge and stop your arc a little beyond this mark and a little below the 2 ½" line.
Once the arc length is determined, measure from the nail, along the horizontal line on the bottom, to the arc line. Note this measurement. Create a temporary circle cutting jig for your router from a piece of ¼" plywood, hardboard or other thin sheet material about 6"x 18". If you want to use it for other projects, a piece of ¼" clear acrylic works really well. Remove the original router base plate from your router, and place it on one end of this jig. Trace the mounting holes onto the material, the drill and countersink to accept the original screws. Locate the center point between these holes where a bit from the router would protrude and using a forstner bit or hole saw, cut a 1 ½" hole. This allows the bit to come through, and lets you see where the bit is cutting. Mount the new jig onto the router, and insert a ¼" straight cutting bit into the router. Measure from the edge of the bit along the CENTER of your jig exactly the distance we previously noted. Mark this point, and then move the mark CLOSER to the bit exactly 1/8". On this mark, drill a 1/16" hole all the way through the jig. If you measured correctly, the distance from this hole to the CENTER of your ¼" bit should be the exact distance from your nail to the starting point of drawn arc on your sled. Place the hole in your jig over the nail in the sled, and cutting in ¼" depth increments, cut a ¼" wide groove all the way through the sled. Be sure to go past your 90 and 45 lines about ½" or so. This allows for fine tuning of the angles later. Also make sure you clamp the sled down before routing and have a piece of scrap under the sled or the bit will cut into your workbench when you finally cut all the way through the sled.
Turn the sled over, chuck a 5/8" mortising bit into the router and set the depth for 3/16". Place the hole in the circle cutting jig over the same brad that was driven all the way through, and route an arc along the ¼" groove you previously routed. This is the recess that allows the carriage bolts to rest below the surface of the sled. Once complete, a ¼" carriage bolt inserted from underneath should ride smoothly along this arc and the head should be below the surface so it does not touch the table saw surface. Pull the brad we used to route with, and using a forstner bit, bore a 5/8" hole about 3/16" deep using the brad’s hole as the center. Then turn the sled over top side up, and bore a ¼" hole all the way through using the brad’s hole as a reference on the top. This becomes the fence pivot and a ¼" carriage bolt should be able to recess from the bottom through this hole and not rub on the table.
Using your 3’ piece of 2"x2" stock, measure 2 ½" from one end and dead center of the stock. Drill a STRAIGHT hole right through (preferably with a drill press) using your ¼" brad point bit. Using one of your 3" carriage bolts, place it into the pivot hole from the bottom of the sled, and using a hammer, "seat" the square shank nearest the head of the bolt into the ¼" hole. Turn the sled over, and insert the remaining portion of the bolt into the hole we just drilled into our fence. Place a washer and wing nut on the bolt and finger tighten, so it does not move.
Turn the sled back over, and looking through the groove cut into the sled, scribe BOTH sides of the groove onto the bottom of the fence with a sharp pencil. Once the fence is removed from the sled, bore a ¼" hole dead center between both faces of the fence and dead center between the 2 lines you just scribed, make sure it is as straight as possible. If it is not right in the middle, the bolt you insert will rub on one of the sides of the groove.
Test fit it onto the sled with both bolts, washers and wing nuts. It should operate smoothly and lock down with no movement using the wing nuts.
Turn your sled back over, and using the alignment marks you drew on your mitre runner, reattach it. Make sure that the heads of the screws are countersunk SLIGHTLY to prevent stock from catching on the screw heads.
Now, lay the runner in the mitre gauge slot (left of blade), and lower the saw blade all the way below the table. You should have a really snug fit with no "play" in any direction. Check to see that the surface of the sled is in full contact with the saw table, if it isn’t, the runner it too thick and needs to be sanded or planed down. With the fence tightened down and using it as a handle, rub the sled back and forth in it’s slot a few times to loosen it up. You may want to use "Slipit" or paste wax on the bottom of the sled and the runner to get it to glide along the slot. Once smooth motion is obtained, raise the saw blade to its full height and check that it is perpendicular (90 degrees) to the saw table. Turn on the saw and run the sled all the way through the blade to cut off any excess of the sled and fence.
Using your ¾" x 4" x 2" scrap block, Drill and insert your brass insert in the center (draw diagonals from the corners to find center) Clamp this block’s edge to the lower left hand corner of the sled. Pre-drill, countersink, and screw from the underside of the sled into the block with a couple of 1" drywall screws. Place the nut on the bolt that fits the insert, and run it down to the head. Screw the bolt into the insert and run it down until it barely touches the fence. Mark around the diameter of the bolt onto the fence’s back face where the bolt will make contact. Pre-drill and sink a #6 screw flush to the surface at the place where you marked. This will be the striker plate for the stop bolt (see picture). Without this, the bolt will eventually divot into the wood and your fence will not maintain 90 degrees at it’s stop. Back the bolt out to get it out of the way for now.
Using a fairly accurate framing square, lay one side along your fresh cut and the other along your fence. Once you think it is square, tighten down your wing nuts. Grab a piece of scrap lumber about 12"x 6", mark an "X" on one face, and crosscut it in your new sled. Pick the cutoff piece up off the table, flip it over so the marked face is down, and butt it up against the fresh sawn piece still on your sled (cut to cut.) make sure long edges are butted flush against the fence. If the cut widens, or narrows, your fence is not set to 90, readjust the fence, and make another test cut until you have a perfect joint between your test pieces. Take the time to do this to perfection!!! Every other angle is based on this 90, if there is ANY error here, it will show up on ALL your other mitres as well.
The wider the board that is crosscut, the easier it is to see the error involved.
Once you have a PERFECT 90 on your test pieces. Lock those wing nuts down good and tight. Using the bolt on your stop block run it down until the end of the bolt is just barely touching your "striker plate." It is best not to use tools to run it down, since there is a HUGE mechanical advantage and the bolt could push the fence out of 90, even with the wing nuts holding the fence. Just "finger tight" should do it, just enough to let the bolt touch the plate. Now, run the nut down until it makes contact with the brass insert. Holding the bolt in place so it does not turn, tighten the nut ½" turn against the insert to lock the stop bolt in place. I actually cut the hex head off my bolt and cut a groove with a hacksaw to accept a flat tip (regular) screwdriver. It acts just like a set screw (see picture). Make one last test cut/flip/butt to check the alignment and make any necessary adjustments for a perfect 90o cut. When you want to return to 90 on your sled, simply slide it back until it makes contact with this bolt, tighten the wing nuts and you are in business!
Awright, now comes the precision stuff. No protractors necessary, I have already done all the work for you. Open the ANGLE.XLS file and take a look at it. (Click the spreadsheet below to download this file.)
You need Microsoft Excel 6.0 (Win 3.1), 7.0 or Excel 97 (Win95/98/NT) Since this contains mathematical formulas that Excel is designed to do, no other spreadsheet can read THIS particular file.
If you don't have it, ask around and find someone that does. Anyway, if you have Excel then download it and open it. The headings look like this:
COLUMN A= angle this is the actual angle that is to be cut. The fence is at 90 degrees to the blade so 90=0. So, row #2 states an angle of 1 degree above 90. The real use comes into play later. 0-45 should be enough.
COLUMN B= # of sides Theoretically you could cut a frame with 180 sides if you were to set your jig at 1 degree. But, that is a lot of cuts and leaves a LOT of room for error, so we will stick to frames within easy range to begin with, then as your skill level picks up, you will be able to make more complex shapes, sizes and with more sides. This scale is set up or a minimum number of 4 sides, or a simple picture frame, all the way up to 180 sided frame.
COLUMN C= Adjacent length This is the length of one side of a triangle using trigonometric function. You will notice that this number (Highlighted in yellow) can be changed. I recommend that you stick with WHOLE inches and change the number in this yellow highlighted box ONLY!!!! All the rest of the numbers in this column will change automatically to whatever you enter here, and of course the formulas will change the values in all the other boxes as well according to what you enter.
COLUMN D= ½ fence thickness This number equals exactly ½ the thickness of your fence along the face that makes contact with the sled table top. In a 2"x2" this would be 3/4" or 0.75 since a 2x2 is actually 1 1/2"x1 1/12". The spreadsheet is setup for 3/4" already, but if your fence thickness is different, change the Green highlighted box ONLY to exactly 1/2 the thickness of your fence. All the rest of the cells in this column will change with whatever you enter here.
COLUMN E= xx/64" opp. Is the length of the opposite side of the triangle in 64th's of an inch. For instance, Row 4, Column E in the example above shows 12/64… this is actually 6/32" or 3/16". Trust me, just keep it simple, use your 64th's graduations on your ruler, and don’t try to reduce these fractions. You will give yourself a headache, and may end up erring and placing your marks someplace they ought not to be. Accuracy at this point is of the UTMOST importance to a good mitre cut. Even a little bit off, and you will have gaps in what you cut.
COLUMN F= xx/128" opp. Is the same thing as the
previous column only more accurate as it is in 128th's of an inch.
If you have a machinist ruler that shows these, I would like to see it…
COLUMN G= opposite This is the most accurate of all and shows inches in decimal format to 9 decimal places. If you can use it, then do so. You math wiz’s will be able to tell me how many thousandth’s this goes out to. I stuck with the 64th's and did just fine.
Now it is time for a trig lesson. Don’t worry, I hated it too and still do, but it was necessary for me re-learn part of it so I could write this formula and build the sled. Look at the triangle and follow along in your textbook.... This is Soooo much easier with the computer doing ALL the calculations for you!!
All we need to know here is the adjacent length, the little formula sheet we have will spit out all the other information. All we do is transfer those dimensions onto our sled, and we have it made! The angle of interest is located in COLUMN A of our spreadsheet. For simplicity, say our 4 sided frame needs 45 degree angle cuts. The very pointy end of our triangle (Angle of Interest) is the very center of our bolt that is the pivot point of our fence. Our adjacent side is the length from the center of this bolt to the very left edge of our sled. Mine is 18 inches and that is what remains in the formula sheet. If yours isn’t the same, then change it in the sheet, but change ONLY the highlighted box, all the rest will change too since the distance from your bolt and the left edge of your sled will NOT change. (until you build a new sled of course) Like I said before, try to keep this number in this column a WHOLE number, no fractions, though the sheet can handle decimals (tenth’s, hundredth’s, or thousandth’s of an inch.) IF you can’t convert 17 3/4" to decimal (17.750) then just round the number down to a whole inch. For example, if the distance from the edge to the CENTER of your bolt is 17 ¾" then round it down to 17". Enter this number in the highlighted box, the measure 17" from the center of your bolt (16 7/8" from the edge of a ¼" bolt) and make a mark. Then lay your framing square on the face of your fence, and draw a perpendicular line up from the 17" mark you just made. This line should be parallel to the saw blade. If we overlay our triangle onto our sled you can see what we are dealing with.
As you can see from the drawing, the adjacent side of our triangle will be the very CENTER of our fence, not the face of it. This is because with a 1-½" thick fence, the face is actually ¾" further up than the center. Since our fence does not pivot on the face, and if we used the face of the fence as the adjacent side, then the triangle would constantly change. From the center of our pivot bolt which is in the center of our fence, this point never changes, so we have to take into account half the thickness of the fence to get accurate measurements. With the fence locked down at our perfect 90, and using the measurements in our spreadsheet, we can measure up from the FACE of the fence and mark off every point listed in the OPP/OPPOSITE columns (columns E, F or G). The spreadsheet takes into account half the thickness of the fence that we supplied and subtracts this number to mathematically reach the center of the fence. Simply butt the ZERO end of your 18" machinist rule up against the fence, and lay the 64’ths graduations along the edge of the sled (or the perpendicular line you drew) and mark off each point going down the list for the angles you require (see picture). I used an exact-o knife and split the graduation mark on the rule, then rubbed it with a pencil to show the mark, the finer the line here, the more accurate it will be. Also, I do not expect you to mark off all 45 degrees, though you can if you wish to. I know that I will never make a 180 sided frame, nor a 90 sided. Though the spreadsheet listed all the measurements for all angles, I have highlighted only the pertinent (most used) one’s in light blue. If you mark off just these, you will be well on your way to the most versatile sled. Besides, every single angle marked off would clutter the sled, and make it easier to make a mistake by setting your fence to the wrong mark. This is up to the discretion of the builder. Just use caution, check and recheck the measurement to what you are marking. There is very little margin for error here!
You may have noticed by now that if your sled is longer than it is wide, you can’t mark up to the 45 degree line along the left side of the sled. At some point in your marking, you run out of edge to mark! This is easily rectified by placing another piece of the same thickness sheet material along the top edge and in line with the left edge. Make sure it does not move, or create gaps while marking by placing a piece of masking tape along the joint, this can be taken of later after all the marking is done.
Leaving the spare board attached, take off the fence and remove the pivot bolt from the pivot hole. If your fence is 1 ½" square, find a piece of scrap lumber that is exactly ¾" wide. (I used a small cutoff piece from the mitre runner when it was trimmed to length.). You will also need a short ¼" wooden dowel that fits tightly into the pivot hole. Pound the dowel in flush to the sled surface, and visually mark the dead center of the dowel with a pencil. This mark will be the pivot for making the final marks for the angles. Now, lay the edge of your fence that we removed (or other perfect straight edge) across the 2 points. We are connecting the dots. The first point will be the mark in the center of the dowel, and the second point will be, say, the 45 degree mark. Lay the piece of scrap up against the end of the fence where the angle mark is, and run a pencil line along it’s edge. The reason for the spare block is because the measure marks drawn on the sled with the ruler is based on the center of the fence. If we were to just pivot the fence up to this mark and draw a line all the way down our edge of the fence, it would not intersect the center of our pivot bolt. This would be at an angle other than what we want. If we could see through our fence and line our mark up to the center of the fence, we could do this, but most of us can’t. So we line up the marks, and offset half the thickness of the fence with the scrap piece, make our final mark, and do the same for all the other angles we have marked. Right now we are marking this in pencil, our permanent marks will be placed on in a minute. Once you have the marks drawn in, be sure to LABEL each mark. It is helpful to write the actual angle, i.e. 45o. below the mark, and to write the number of sides of a frame this angle will produce above the line, i.e. 4 sided. Do the same for all marks you made for easy reference later when we actually cut some frames.
Guess what! The sled is ALMOST finished! Reattach the fence using the bolts, washers and wing nuts. Swing the fence through it’s arc to view each of the lines you made. Each line should be parallel to the face of your fence. To align the fence perfectly with a mark, tighten the pivot bolt down, and loosen the arc bolt a little bit. Swing the fence to the 45o or Four sided line. You want the edge of the fence to barely touch the line, not split it, and not eliminate it. The scrap block we used to draw this line was just below the line, and the pencil lead could not write under the scrap's edge. So you want the fence face in the exact same position as the scrap was. Now is the time to attach the hold down clamp. Since very few of us will be cutting 3 sided frames, this is the furthest our fence will swing. Attach the clamp between the pivot bolt and the right (blade side) of the sled (see picture). You don’t want the clamp to interfere with the wing nut, and you don’t want the arm to extend out far enough that it hangs over the edge of the sled. If it does, then there is a possibility of the saw blade hitting the arm. (NOT GOOD!) once you have it in a suitable position, mark the mounting holes, pre-drill and attach it to the fence with a few more of those #6x3/4" wood screws. With this clamp, you can cut pieces VERY short (less than an inch) and do it safely. It keeps fingers away from the blade.
If you really want to get fancy with finishing touches on the sled, you could route a "T" groove in the face of the fence for easy use of a stop block (production cuts of pieces) I took the easy way out with mine, and just use a small scrap piece of wood and a 6" quick clamp. Either way is fine, builders preference.
Cutting the Test Frame
Now comes our first frame and test of the sled. Just a piece of 1"x2" stock about 3 feet long will work. Nothing expensive or fancy…..yet. With your fence at 45o, and the blade raised to completely cut the stock through, cut 4 pieces of about the same length (4" or so). Remember that the FINISHED cut is the one that remains on the sled after you complete the pass, mark this in pencil with an "F". For every piece that falls off the other side of the blade, the far right hand cut will be a finished cut. Keep all four pieces in the same orientation as you cut them by marking the visible side with an "X."
Without changing the fence setup, attach a stop block to the face of the fence with either your "T" slot system or using a piece of scrap and a clamp. Now we cut the opposite angles on the four cutoffs we have to complete a frame. By flipping the pieces over with the "X" we marked facing the sled top, and rotating our finished cuts "F" and butting them up against the stop block, we can pass these through the saw for the opposite finished cut on each piece, make sure you adjust the hold down clamp to firmly hold the piece to the sled for each cut. The key to a good finished frame is good angles AND all the pieces of EXACTLY the same length. By not changing our fence setup we get the same angle on both ends of each piece and the stop block provides us with each piece the same length.
Now butt all your mitre cuts to each other and check for gaps. If you measured and marked everything correctly, you should have 4 perfect joints. If it looks like the gaps are all parallel to each other and not wedge shaped, then your saw blade is not perpendicular to the sled top. If they are wedge shaped, determine if your fence has too much angle or not enough angle, and micro adjust it, cut another test frame, and readjust as necessary. Same hint as before when we cut our 90o crosscuts. The wider the stock you use, the easier it is to determine errors in the angles. Once you get your perfect 45’s, use a permanent marker and the face of your fence as the reference to scribe the permanent alignment mark. Mark thickness is not a factor, visibility and a sharp edge are. When you move the fence up to the mark, place the face of the fence right to the lower edge of the mark and it will be in the same position as when you marked it. Also, be sure to permanently label them as well.
Once marked, swing your fence out of the way, and look for your initial pencil marks to see how far out of true you were originally. You can use the distance between your permanent marks and your pencil marks as a reference for how far out all your other angles will be. But to be sure, cut test frames and try them out, then permanently mark them on the sled. If you make a mistake in marking with a permanent marker and want to erase it, the ink will easily come off with a light application of Denatured Alcohol (Shellac Thinner). Isopropyl (rubbing) Alcohol will take off some of it, but not all.
Congratulations! You have just finished an invaluable tool that will get a whole lot more use than your old mitre gauge ever did!
Since each piece has to flipped and laid on it’s face to make the second mitre cut, this face HAS to parallel with the back or the joints will not line up. For instance, a piece of molding from the hardware store can’t be used because of the profile of the cuts on the face. The back is nice and flat, but the visible face would rock and not sit flush to the table top along it’s width. This does not mean that you can’t make some pretty fancy frames, you can! And there are ways around the parallel rule. You can use the same procedure as we did to build this sled to make a sled for the RIGHT side of blade. One that rides in the right side mitre slot. Everything is reversed and the fence will swing the opposite way. Make all your initial cuts on the left sled, then switch to the right sled for the opposing cuts. Or, you can create your own custom moldings for use as frame stock. Route some profiles in the edges, cut a groove/flutes in the middle of the stock, cut a rebate/rabbet in the back for the picture etc. to recess into, then cut your mitres. There is no limit to what you can do.
Frame "A" is a standard 8 sided frame. Set the fence to 22.5o. Cut 4 short pieces at this angle, then cut 2 medium length pieces, then 2 longer pieces. Without changing the fence setup, clamp your stop block close to the end of the fence, flip and rotate to place the finished cuts up against the stop and cut the 4 short pieces to their finished lengths. Move the stop a little further away, and cut the medium length pieces, then move the stop further yet, and cut the last 2 pieces. Butt the mitres together and that is all there is to it. No problem. (see picture of completed frame here)
Frame "B" uses 2 different angles. Every one of the 16 pieces has a 45 on one end, a 22.5 on the other and all the pieces are the same length. Cut all the 45’s, then move the fence to 22.5 and without flipping the pieces (just rotate so the finished cut is against the stop) cut all the 22.5’s. Then rotate and flip the finished pieces until they get into this configuration. The real trick is gluing something like this up, but I assure you that it IS possible. If the stock used to make this particular frame is profiled, and not just plain 'Ol square, it will take a little more practice to get the orientations right to get all the profile edges where they need to be. Experiment, have fun and let your imagination go wild!
Once you have the basic idea down as to how to cut different frames, the advance stuff comes into play when we do COMPOUND mitre cuts on the sled, WITHOUT changing the angle of your blade! But first, we have to create a wedge of 22.5o (or any angle really) by tilting the blade on your table saw to the correct angle and ripping a 1 foot length of 2"x4" through on edge. Make sure that all the edges are planed and square to each other.
Reset your Saw blade to 90, lay your wedge against the fence on your sled, and make your first initial cuts to any angle you desire, cut just as if the stock was sitting flat on the sled. Be sure to butt the edge of the stock against the fence, and clamp it down good and tight. It is okay to overhang the wedge initially and cut through the wedge to make the first cut in the stock. Can you say, "Zero Clearance?"
Once the initial cuts are made, flip the wedge around so the pointed end is up against the fence. To keep it in this position without moving, I use a couple of pieces of carpet tape to stick the wedge to the sled. Position your stop block to the right length, flip/rotate your pieces so the previously finished cuts are against the stop, clamp the piece down, and run it through the saw. Complete for all pieces.
Test Fit and Glue Up
A hint when gluing these pieces together is to lay all the piece out flat, mitre cut to mitre cut on a length of masking tape, you can test fit the mitres this way AND glue them up this way as well. This works for the regular flat frames and the compound cuts. The following drawing is the 8 pieces of the 8 sided frame labeled "A" under the "Starting Off" section. Once all the pieces are in line and the mitres butted together in the correct format, grab both end of the tape and wrap them around each other. The frame will magically fall into the proper shape. Have fun with your new toy!
Other sites by me
Couple of other things I have built
Jake's Chair View 2 (as modeled by my buddy Eryn)
Learn how to build a Jake's Chair HERE!
Comments or Suggestions?
Robert J. Hoppe
Orlando, FL firstname.lastname@example.org