Hi,
I’m having difficulty cutting hardwood runners for a cross cut sled. Any pointers? I started with a piece of maple jointed it and then planed it to size.. 3/8″ thick. Then I set up the saw to cut it to width ( just shy of the 3/4″ mark) But no matter how hard I try I just can’t seem to get the right fit. It either turns out too wide or too narrow. I can’t get a snug fit. (so it just slides without any slop in the miter slot.
Would oak work better than Maple. Maple seems to warp. At least the piece I had. Any hints on how to use the table saw so I don’t have to reset the fence position everytime I go to cut the 2nd runner. That’s probably why I can’t get 2 pieces the same width.
How about metal runners? at least metal doesn’t warp or cup. and would slide nicely inside the miter slots.
Should I use 3/4″ plywood for the base? Not sure if MDF would hold the #6 3/4″ long screws very well. I think 1/2″ material would be too thin.
Help please!!!!
Wanda
Replies
plane the maple to the width of the slot first (3/4 inch?)and after you are happy with the fit cut off two 3/8in pieces for the runners , maybe use cherry it is a little more forgiving than maple ,if using metal try brass i have used this on various jigs to good effect
Wanda,
As a general rule, I size the ¾ runner dimension in the thickness planer before ripping to 3/8. I then set the runners in the miter slots and glue/screw through the sled into the runners. The miter slots keep the runners straight. Any minor adjustments to the runners can be made with a scraper.
-Nazard
Thanks guys,
I'll pick up some material for the runners tomorrow at the Home Depot and try again. Seems I had it backwards.. planing to 3/8ths and then ripping to 3/4".
Wanda
If all else fails:http://www.woodcraft.com/family.aspx?familyid=3178********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Wanda,
I use aluminum bar stock for my runners, that I purchased at a local business that sells metal. The 3/8" by 3/4" size is a common bar stock size. It works well, lasts a long time and doesn't expand or contract like wood runners.
Danny
I used a 24" Incra miter slider for my recently-completed übersled. The best thing about this is that any slop can be adjusted out at any time (assuming you drill access holes for the width adjuster screws). It works beautifully. I highly recommend the thing.
did
Donate Online!
Wanda,
Buy a Dubby from Jerry Cole at In-line Industries. It's a great cross cut sled for about $170. It cuts accurately to all angles. The secret to its success is that it is adjustable for perfect squareness, just by turning a set screw. Homemade sleds do not have this option.
http://www.in-lineindustries.com/
I bought mine about five years ago. I just met Jerry at the woodworking show at Dulles Airport last weekend. Nice guy. Great product at a fair price.
Have fun.
Mel
Measure your output in smiles per board foot.
Wanda200,
Using 1/2" material for the sled is fine. I have both 3/4" and 1/2" in both MDF and hardwood plywood and they both work fine. You will gain a little depth of cut with the 1/2", and it's not so heavy to pick up and move around.
I did a little one with 1/4" ply once which also worked well until I left it in the back of my pickup (inside a canopy) on a rainy weekend. Monday morning and it wasn't very flat and it never recovered.
You have received a lot of great advice about making your rails fit. Another thing you could do is cut them on the tablesaw just a hair oversize, then hand plane to fit your slot.
The problem with your wood being squirrely is just a part of woodworking. Most of the time when you cut a small strip off of a wide board, the strip will not end up perfectly straight. In the good old days, when the trees were really old and we made things out of the trees that grew on flat ground, wood was more stable.
Hal
http://www.rivercitywoodworks.com
Hi,
I'm back from the Home Depot. Picked up a piece of 1X6X4 oak. Tomorrow when I get a chance I'll rip a few runners on the table saw. See how it goes.
If the wooden runners don't work out I'll try aluminum. But for now I'll try my luck with the wooden runners.
Wanda
Wanda,
You shouldn't try to make the runners fit in the slots so that both sides of the runners contact the walls of the slots. Working with wood, it can't be done.
It's hard enough to get that kind of accuracy in metalworking - to have 4 surfaces align like that. In woodworking, the accuracy is not in the equipment we use and the material won't hold that kind of tolerance.
I've given details here how to contsruct the sled so that the runners perfectly mate with the miter slots. Here's a previous thread in which we discussed this.
http://forums.taunton.com/fw-knots/messages?msg=30255.14
Rich
I am not intending to argue, but I don't get the problem with making the runners fit the slots. Just cut them the right size, or a little tight and plane to fit.
I have done them often, and I just cut them on the tablesaw 1/32" oversize, then joint the edges to fit. Make them plenty long so you can experiment with getting the jointer set perfectly prior to running the two strips. Or even cut a couple of extras for practice.
Also, isn't it just two sides that have to fit on each strip? Am I not getting something? I just run a small bead of glue on each one, put them in the slots, lay the sled on top, and tack a couple of brads into the strips. Then I take the whole thing off the table and clamp the strips firmly to the sled, or screw them on.
Hal
Hal, Wooden runners milled to fully fit the miter slots, then attached to the underside of the sled to run "perfectly," move and change size constantly due to all the factors of wood movement. It's a fact of machining and fitting that making 4 surfaces all align (both walls and both sides of both rails) is significantly more difficult than making 2 surfaces align. And for a sled, accomplishes nothing in increased performance. A rail has to fit tightly for a single rail miter gauge. And most people think the same is true for a 2 rail sled, but if you think about the design, it's not. The method I described is self-aligning and self-canceling for all the inaccuracies of the "traditional" method of fitting the rails to the slots, then fitting the rails to the underside of the sled, then hoping everything stays in the desired positions, then hoping that wood movement due to moisture doesn't affect anything. My method eliminates the effect of moisture-caused movement. Movement can still occur, but it won't move the mating surfaces from each other. So there will be no slop or no binding. If the whole thing were made of metal, on metal-working equipment all four surfaces could be accurately machined to fit, but it still would be unnecessary to do that for an accurately-fitting device. Rich
Rich,
If this is a stupid question, I apologize in advance. I read through your sled directions (after I had already made a sled getting all four runner edges tight) and thought, yeah that makes sense, runners tight to the miter slots on two sides rather than four would keep them from binding or getting loose as the runners change size with moisture content.Then the trouble starts because I couldn't fall asleep the other night and lay there thinking....wouldn't the moisture change in the runners still cause a loosening or binding against the previously tight two sides of the miter slot? The runners aren't going to know to expand or contract only toward the "loose" side of the runner and not the tight side. So as they expand and contract the distance between the inside edges of the runners is going to be changing, right?What am I missing?
bp,
There's no such thing as a stupid question, except the one that's not asked. Dimensional changes due to moisture won't affect the relationship of the wood runners to the walls of the miter slots. Or, more accurately, the changes will be no greater than the potential dimensional changes of the plywood or MDF sled body.
Plywood or MDF is as dimensionally stable as wood-based material can be. For a sled, we can assume it will not change size over the span of the sled body enough to be of any concern.
The runners are glued so that their inner-facing walls are against the inner-most walls of their respective dados in the underside of the sled. They don't completely fill the dado width.
The position of the runners, (actually, the inner walls of the runners) relative to the saw table miter slots is determnied by the stability of the sled body itself. Since that doesn't change, the runners always maintain their precision contact with the inner walls of the saw miter slots.
The runners can expand or contract with moisture. They can't move against the inner walls of their dado slots, so any expansion has to be into the extra width in the dado. That expansion is also into the extra space in the miter slot. It affects nothing.
When the runners contract, they're still held tight against the dado inner walls by glue. They simply shrink in width in that direction, leaving more room in the dado and in the miter slot, but still affecting nothing about the mating faces of the runners and miter slots.
Rich
So the key is the dado in the bottom of the sled being there and also being a bit oversized for the runner? I got the impression from the write up (which I downloaded and saved for future sled building) that the dado was a nice to have but the runners could just be screwed and glued to the bottom of the sled without the dado.Thanks for the clarification.
It sounds like all of this is being made to sound way more complicated than it really is. This is just a cut-off sled after all, so quit thinking so much and get a good night's sleep.
The moisture exchange swelling and shrinking problem really isn't an issue. Just make them fit, and if they get tight, scrape the edges a bit with a sharp chisel, lubricate and go back to work. If it gets sloppy, you can push it to the right when you cut and it will work just fine because it will still be guided by the slots.
I use both single guide and double guide and the wood works just fine whether you use maple or white oak.
Making the fence part absolutely square to the blade is often more difficult in a double guide sled than making the guides.
Sweet Dreams!
Hal
http://www.rivercitywoodworks.com
Believe me it wasn't the sled keeping me awake. It was the elephant sitting on my chest from eating pizza at 10 that night. Since I had already solved the worlds problems a couple nights earlier when I ate chinese food really late (no, I will never learn) I turned my cognitive powers (weaknesses) to the cross cut sled!I'll just buy another crossword puzzle book for the next time!
Hal,
I pretty much disagree with everything in that message.
A 2 runner sled is a must. Both runners will stay precisely in contact with the walls of their miter slots, not too tight, not sloppy, if the sled is made correctly. The back fence can easily be made square to the cut with a very high degree of accuracy (want to know how?).
There's certainly no reason to make this more complicated than it is. But there's also no reason to discourage easily-achieved accuracy and encourage a sloppy fit and work practices to live with that problem.
Rich
Ouch!
I guess we agree to disagree.
Hal
http://www.rivercitywoodworks.com
bp,
You're right. I had posted a link to an old message, and those points weren't clear.
Rich
Hi Rich,
I would like to see how you do your fence. Is it on your post about how to make the sled? I've been too busy this week to check it out, but I always am open to new ideas. I'm going to click on your link after this.
I reread a couple of your posts here though, and one thing I disagree with you on is your statement that it isn't possible to make wood fit a slot with woodworking epuipment due to the inaccuracy of woodworking equipment.
My comment about this is that it just ain't so. Wood can be machined accurately to fit those slots. It can also be shaved if necessary if it gets sticky, and carries lubricants well for sliding parts like sled runners. I agree that a metal runner could also be made to fit accurately, and also carries lubricants well, and could be filed a bit if necessary.
Both products work well enough that it is just a case of how much time does the woodworker in question want to spend on a project that will turn out well either way, and in both cases, the sled will cut just as well. After all, you are working with someone that is buying red oak at Home Depot. I doubt that they can work metal.
The wood movement issue isn't limited to the 3/4" wide runners either. MDF expands considerably with moisture vapor transmission and will change the fit of your two side only fit too. But really, we are talking about 3/4" x 3/8" sticks here.
Just trying to clear things up a bit.
Hal
"Just trying to clear things up a bit."Well, let me get them a little more clear for you.In the design I described (it's not my design, the details have been described many times, eslewhere) the distance between the the inner walls of the 2 runners is critical. That distance determines the fit of the runners against the outer-facing walls of the 2 miter slots. Not only is the distance critical, but the runners must be positioned parallel to the slots to a very high degree of precision so that the sled rides with the same degree of friction all along its trave. Any out of paraellel condition of the miter slots themselves must be matched. No binding, no slop. No change whatever in the action. The precicision needed is on the order of a few ten thousandths of an inch.The precision of these 2 facotrs is automatically achieved in the construction because the 2 halves of the sled are not attached to each other and are brought into alignment by pressing the runners against the miter slots and securing the sled parts in that configuration. This method of construction is inherently much more accurate than milling any part to fit. It's a basic reality when machining critical tolerances.It is not possible to mill a wooden runner to fit even one miter slot to that same accuracy. Wood simply cannot be machined to that accuracy (metal can) and it can't hold the machining. Wood working machinery does not prmit the settings needed, nor can it hold them.Even if one runner could be milled with enough accuracy, it would change size enough to easily destroy the fit. Even if the accuracy held long enough to glue the sled together, keeping all the relationships in their needed alignment can't be done. The need to hold 4 mating surfaces in precise position is beyond anything avaialble in a wood working shop.The accuracy needed for keeping 4 surfaces in precise relationship IS available when working in metal and using metal-working machinery (milling machines, drills). But while metal working allows the accuracy, it also compounds the problems should you not get the pieces sized properly. Then the binding and inability to bolt the pieces together becomes even more of a problem than when working in wood. And you quickly get to the point that you welcome the opportunity to only have to machine 2 surfaces to a "perfect" fit.You really ought to try the exercise in metal to understand the mechanics involved, or better yet, try the construction I recommended (in wood) to experience a perfectly-running sled, easily and quickly made, that won't develop slop or bind in the tracks, as long as you own it.Rich
Rich,OK, I'm going to ask the dumb question (my apologies if it's already been addressed)Why two runners? Most plans I've seen call for two, but that just seems unnecessary and adds to the difficulty of maintaining accuracy. As the portion of the sled to the right of the blade is just along for the ride, why give it a runner. Seems to me that if your left miter slot is parallel to the blade, that's all the reference your sled needs. A good miter gauge works just fine with one runner for many cross cutting operations -- why not a sled?I have a very crude, one-piece sled (early Norm) with one runner (oak) and an aluminum fence that is dead accurate. I've been thinking about making a new one for years, but this one works so well, I just never bothered.Mike
Just curious, but what did you use for your aluminum fence? Did you mount it at the back of the sled or at the front?I'm thinking about building two sleds, one a single runner that I can use for larger panels, dados, etc.
<<Just curious, but what did you use for your aluminum fence?>>I used a piece of right angle aluminum. It's about 45" long. Norm put his fence at the front, but that never seemed right to me, so I mounted mine at the back. Like I said, very crude, but it's also very accurate. Good luck with your sleds.Mike
Is the whole base 45" long?What do you consider to be the safe cross cut capacity of your sled?Thanks for the information.
<<Is the whole base 45" long?>>No, the base is about 24"square -- the size of the scrap I made it from. I don't use this sled to cross cut anything too large -- mostly door panels, small table tops, or things that would be awkward or unsafe to do using the saw fence.Mike
Mike,"A good miter gauge works just fine with one runner for many cross cutting operations"No, it doesn't. it absolutely does not.Have you acutally used a typical miter gauge for accurate work? I hate to overuse this term, but they are truly an exercise in fruustration. They bind, they wobble, they are full of slop and repeatability is terrible. The "base line" (the distance between the left side and right side of the runner - the width of the miter slot) is woefully inadequate to provide a stable perpendicular reference to the direction of travel. Especially for heavy pieces or pieces exceeding a couple of feet."the portion of the sled to the right of the blade is just along for the ride, why give it a runner."The cross cut sled, in utilizing both miter slots, increases the baseline of the device enormously over simply relying on the width of a single miter slot. And that is why it is such an improvement over a miter gauge.Unfortunately, it's hard to get most people to stop focusing on the way a single runner miter gauge MUST "fill up the slot" and accurately reference both sides of the single slot (the two necessary guide surfaces for a miter gauge).Once you use BOTH slots, you then reference to ONE side of EACH, either the 2 inner surfaces or the 2 outer surfaces. You don't carry the method from the single slot to the 2 slot configuration. The only reason the miter gauge's single runner fills the single slot is that's the only way to reference the needed 2 sides.If the 2 sides of the saw table itself were accurately milled smooth and parallel to each other, THEY would be the best surfaces for a sled to reference. Then we wouldn't need to have this continuing confusion about milling 2 runners to perfectly mate to both sides of 2 miter slots. There would be only 2 mating surfaces with which to be concerened.Rich
Rich,I can't argue that your design isn't a good one as I've never made a sled as you describe -- and it certainly makes sense in theory. Were I to make a sled based on your design, I have no doubt it would be an accurate saw accessory. All I'm saying is that my after market miter gauge and crude little sled produce dead on results for me. From my experience, even a standard issue miter gauge can yield acceptable results with a little tweaking.And, unless I'm confusing you with another Knots poster, haven't you just purchased a real slider. If we all had one, threads like this would not be necessary. I have pretty much every tool I need, but do lust after a genuine slider.Mike
Mike,If your miter gauge is giving you all the accuracy you need, nothing further needs to be said. Use your equipment and enjoy it.Yes, I am awaiting delivery of a Hammer "Combo" machine which includes a "real" sliding table saw. I am waiting for it to arrive in Sacramento, then it gets examined, adjusted and shipped to me. With any luck the ship has actually gotten through the Panama Canal by now, but I have no confirmation on that yet.Rich
Rich,Hope you enjoy your new Hammer Combo and that it arrives soon. Just took delivery on mine -- what do you think?Mike
Well, Thre are hammers, then there are hammers and there are . . .
I'm sorry you spent so much time explaining all of this to me because (this is the part I am sorry about) I don't really think any of it really matters. I really think that wood runners work well enough.
There were a few parts that I questioned though, like the part about "Any out of paraellel condition of the miter slots themselves must be matched." It seems to me that if the miter slots are not parallel, and you make the bars match out of parallel, the whole thing will either get tighter or looser when you slide it.
But even that doesn't really matter. It is possible to make wooden runners to fit, put them in their slots with glue on top, lay down the sled where one wants it, tack the runners, pull the whole thing off the saw, and screw the runners where they go.
I know it works and it isn't hard to do because I have many sleds of different sizes and shapes that all have worked pretty well. I bet I am not the only one. I would bet that there are hundreds, maybe thousands of them out there being used. I wouldn't think that many of them have metal runners. I'm not saying this is true, it's just a hunch on my part.
Norm is pretty well watched, and when he shows how to make a one runner sled that only takes 30 minutes to make that can accurately be used to cut sheet goods square, people pay attention.
I have double runner sleds and single runner sleds. The one I almost always reach for first is a single runner, similar to the old Norm sled, that I have used for probably 20 years which is made from 1/2" MDO plywood, a maple runner, and a cherry fence.
The second choice is a 3/4" thick cherry plywood, 2 runners sled. It's my oldest one, and has rift sawn white oak runners glued and screwed to the bottom.
I do know that what you are talking about is probably better than what I use, but my one point that I was trying to make is that it is not really necessary to have metal runners to have an accurate sled.
Hal
http://www.rivercitywoodworks.com
I don't think Rich advocates metal runners. In fact in the "other thread" he specifically recommends hardwood runners.
Oh!? I didn't know that. Are you sure? I didn't read the other thread.
I was just trying to help the person that wanted to make a wooden runner sled to know that it isn't necessary to make metal ones.
Hal
Hal,Here is a direct quote from Rich14 and a link to the post in question. It's a good thread and I enjoyed reading his posts. I recommend reading it."The trick is that the runners should NOT fill the width of the slots. Make them out of hardwood (yes wood!)and make them slightly more narrow than the slots."http://forums.taunton.com/fw-knots/messages?msg=30255.14
CJH,Well I didn't say NOT to use metal runners. Only that a hardwood runner sled could be made in a way to deal with wood movement and remove it from the equation.After all I AM getting a saw with the ultimate steel "runners," a sliding table model with steel roller bearings!Rich
Hi, Rich. I just went back and skimmed the original description you posted for Wanda in the other thread (wow, 90 messages total, 2 threads. Controversial subject?). I trust you when you say "fitting perfectly dressed rails to the underside of the carriage in such a way that they remain perfectly true to the miter slots is an exercise in frustration, despite all the clever methods developed to accomplish the job, such as gluing the carriage to the rails as they sit in the slots, then cutting the blade clearance slot." [emph added] Given this is exactly the kind of "clever method" I'd probably try, could you explain why it doesn't work? Seems on the surface like a slam dunk, but I've had those bonk me in the head more than once!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
fg,It's an exercise in frustration, because for that method to work, the rails must perfectly fit the miter slots, and remain perfectly fitting for all time. They must run with the degree of precision in the slots that the finished sled runs made as I described. (Remember, the "two half" method aligns the 2 mating runner-to-miter slot surfaces precisely and holds them there during critical glue-up.) It's simply not possible to mill the wood runners to that same degree of accuracy. It is MUCH more difficult to maintain 4 mating surfaces to the same degree of precision as it is to maintain 2 mating surfaces to that same accuracy.Then the sled must be attached to the runners, disturbing none of that accuracy. The runners ultimately change dimension as the atmospheric conditions change. Binding or slop, or both is inevitable. The basic fallacy is that runners should be made to perfectly mate to both walls of both slots. There is no truth to that assumption. But it's easy to fall into the trap of thinking that way. The precision surfaces to which the sled needs to be engineered are the 2 outer facing walls of the miter slots.The best illustration of the method I've described is in Taunton's "Tablesaw Methods of Work," edited and illustrated by Jim Richey. Page 146-147 describes a little sled made of acrylic with ball bearing guides rather than runners. (The size and materials are irrelevant) The bearings can ONLY be aligned against one side of the miter slots. There is no way they can be made to touch both sides the way most people think runners should. If you read that article a few times and wrap your mind around the method of constructing the sled (it's exactly what I have described), you'll realize that it doesn't matter whether we use roller bearings or runners, and that only 2 reference walls of the miter slots should be used. The result is a perfectly aligned sled that always maintains its alignment.What I have found is that most people mill the runners to be quite tight-fitting in the slots. Because, if they fit loosely enough to move with even a reasonable amount of freedom, there is already perceived slop. Then when the sled is finished, there is the need to trim the widths of the runners by sanding or planing. How is it possible to know if binding is the result of one runner being too wide in its slot, or whether the problem is the distance from the corresponding walls of the 2 miter slots? Trimming any one wall of either runner changes both relationships simultaneously. Even if one can tell where the actual binding is happening (it can't be done), the effort to fix one problem creates another.When only two surfaced are referenced, trimming one to relieve binding improves that problem and that alone. Nothing else is affected.Construct 2 sleds using both methods, then tell me which one is the smoothest, more precise tool.Rich
Richard,I'm a software engineer by training and inclination. I can fully understand your logic...requiring accuracy by referencing a non-stable material off 2 unchanging points (the outside of both miter slots) rather that 4 points is almost self-evident. However, I also remember an old professor of mine who started his first lecture with the statement "As is obvious to the most casual observer..." and I didn't understand anything for the next 6 weeks! It's also (possibly) interesting to relate that I'm the CEO of a company which developed a package of artificial intelligence software algorithms that works on principles completely different from most of the accepted norms. We developed a demonstration application based on the old game of 20 questions, called 20Q. It's now been licensed, and is a relatively successful product for Mattel. However, one of the interesting foibles is that most of the people playing the Web based version of the original game know that a dolphin is a fish, and they've trained the game so well that the game now knows a dolphin is a fish. I grew tired, long ago, of swimming upstream....we haven't tried to change the answer!Patrick Henry may well have said "The majority have no right to be wrong" but he wasn't dealing with anything as subtle as wood movement!
You're right, but everyone else will have to build a few sleds to discover what you already know.Regards,RonEdited 3/26/2007 8:00 pm ET by RonInOttawa
Edited 3/26/2007 8:00 pm ET by RonInOttawa
Ron, A dolphin ISN'T a fish? - just kidding! Of course, we all know it's a football player! I must have had your prof's brother. Mine would say, "It's intuitively obvious that . . ." And I didn't know what intuitively meant. Actually, we've been making a great deal about a pretty simple piece of equipment here. And a pretty simple concept for achieving accuracy. My only reason for continuing the discussion is that it is very easy to make a very simple device to achieve a very high degree of reliable accuracy, if you do it right. Rich
Thanks muchly for the detailed explanation, Rich. As to "Construct 2 sleds using both methods, then tell me which one is the smoothest, more precise tool." Not likely, LOL. Having enough trouble taking the time to make one sled -- tend to turn to my miter saw when something long needs to be cut, and haven't made anything that has absolutely demanded a cross-cut sled. I know I'm wasting time in the long run, though, by not having one.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
IMHO my sleds get me close, my shooting boards and planes get me there.
In my mind a homemade jig for a TS made entirely from wood is not going to be dead on accurate. What's more, does it need to be? How can you make wood more accurate than steel?
The question is: Given the application, how accurate does it need to be? In some respects the marriage of metal to wood allows the worker the flexibility to inject their own English to affect the ultimate goal.
Just my 2¢,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 3/26/2007 9:56 pm ET by KiddervilleAcres
I just finished building a small Mehler-esque sled this afternoon.
Maybe I'm lucky, but my miter slots take a 1x on edge very tightly. I used poplar for the rails cause I had it handy although oak or maple would be better. I seated a 3' poplar 1x6 into the miter slot on edge and ran a pencil along the table to mark the depth. I ripped along that line and cut in half for my 2 18" rails.
I used 1/2 plywood for the bed. Once the bed was screwed to the rails I turned it over and lightly shaved one edge of each rail by drawing a chisel toward me and rubbed some paste wax on the bed bottom and on the rails to make it slide without grabbing. Fits well & slides easily, no side to side play.
Ripped the remaining 3' poplar piece for the front (2") & back (3") fences. Got lucky with the back fence and had it square on the first try for a change, no adjustment necessary. I'll check it again tomorrow to make sure it wasn't "wishful thinking" that I had it lined up! Currently waiting for the glue to set up on the blade block on the rear fence. The blade guard will have to wait until I score some plexiglas later this week.
Edited 3/19/2007 5:12 pm ET by bp21901
Wanda,
Consider adding a wood screw spreader-adjustment near the ends of your sled runners. I did not and wished I did. Since I glued the entire length of the runner, I cant go back and add it (see the attached "drawing").
KB
where were you yesterday? ha!ha! I just glued one down for a shaper jig last night, man this would help. Great tip, thks.
We've got a sled in our shop that uses very high density plastic for runners. The plastic was bought already sized to serve as runners.
Sorry, but I have no idea where they bought the plastic.
Most likely UHMW strips from Veritas, Rockler, Woodcraft? Excellent runner material.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Wanda
One tip that I haven't seen in this thread yet is make sure that your runners are quartersawn so they expand across their height and not their width. There are several good articles and videos on FWW regarding crosscut sleds. I made mine last year from 1/2" baltic birch ply and used qs oak as the runnners. I applied wax to the bottom of the sled every so often and it works great. Good luck. Tom
Hi,
when I went to pick out the piece of 3/4" oak I was searching for Quartersawn. Think the piece I have is flatsawn or possibly Ripsawn. Certainly isn't q/s The growth rings are almost vertical but not quite ...more like at a 45 degree angle. Most of the boards I looked through were flat sawn with the growth rings more or less horizontal with a slight curve.
I discovered I have a slight problem with the sled. I cut a piece of pine for the fence but discovered that it wasn't exactly flat so I jointed one face and one edge. But for some reason I still couldn't get it lined up properly with the table saw blade. (I'm using my large carpenter square to square the back fence (one that closest to me) to the saw blade. I know that the fence has to be dead on ..90 degrees to the saw blade. Now I have checked to make sure that my table saw blade is perpendicular to the saw table. and the saw table is flat. So I clamped the sled onto the saw table and slowly raised the blade up through the 1/2" MDf base. but when I went to line up the fence with the blade using my carpenter Square(set flush against the saw blade.. I couldn't get it lined up properly although The fence was flush with the edge of the base.. Could be the square itself I suppose.
I'll have to try gluing up 2 pieces of MDF (because I know they are dead flat) and see what happens. Perhaps it's the piece of pine that isn't exactly flat on both sides. The edges of the base are square. I can see having to pivot the back fence a little to make is 90 degrees to the balde, but I think being out almost 1/4" on the rt side is too much.
wanda
WandaYou actually need the board you make the runners from to be flat sawn or rift sawn on its face and quartersawn on the 3/4" edge because you are going to cut across the grain, making your runner quartersawn. I used two layers of 1" MDF for my back fence and one piece for the front brace. There is a great article and video by Lon Schleining on FWW that goes step by step on how to make a sled. Gary Rogowski also has a good article and video on the site as well. My table saw blade is adjusted dead square to the miter slots, and making the sled was not as difficult as I had imagined. Rogowski recommends bolting the fence to a base of 3/4" MDF so that it can be adjusted and tweaked if necessary. I glued and screwed mine from the bottom of the base, and then made one slight adjustment after a quick test cut before the glue dried. I've made lots of cuts with it since. Great jig to have. Good luck. Tom"Notice that at no time do my fingers leave my hand"
Hi,
While searching through the F/W site last night I came across those 2 articles you mentioned. I like Gary Rogowski's idea of bolting the fence to the base. But for now I'll just glue and screw.
My miter slots are narrower towards the rear of the saw so I had use my chisel to make the runners fit. The sled seems to be sliding across the table ok. Should you feel a tiny bit of resistance as you slide the cross cut sled across the saw table? Is that normal? I don't want to have any slack. I've all ready coated the runners and the bottom of the sled with paste wax but I'll give them another coat later on.
Next sled I build I think I'll try using 3/4" material MDF. I went with 1/2" MDF because that's what I happened to have lying around the tool room. I must make some test cuts and see how the sled performs. Then I can get on to cross cutting the parts for my shop cabinets.
Wish I could find a copy of that FW mag. Issue #188 with Gary Rowgoski's article on how to build a cross cut sled. I could kick myself for not buying that mag. I'm not a paying online subscriber so I can't access all those wonderful online articles.
Wanda
WandaYou should feel a very small bit of resistance, but it should glide through the miter slots without binding or slop (side to side movement). I built my sled per Lon Schleining's article and used 1/2" birch ply for the base. The critical thing is the fence must be 90 degrees to the blade. Once you've got that angle set, you are done. Regarding FWW website, for $15 per year, you get a lot of information and access to almost all articles ever published in FWW. Too good for me to pass up. Tom"Notice that at no time do my fingers leave my hand"
"ripsawn".....riftsawnforestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Hi,
Leave it to you to pick up on that "error". :) Thanks for making that correction Forest Girl.
No flies on you hey!
When I get the back fence on the cross cut sled screwed in place I'll let you know how it works out.
I think a 2 runner sled is a lot safer than a single runner sled. Building a sled doesn't have to be too complicated. I'm hoping that using riftsawn lumber for the runners will avoid any problems with wood shrinkage and expansion in the miter slots. The shrinkage only being in the height and not the width so I've been told.
I purchased a piece of 3/4" thick oak for the runners. Planed it to fit the miter slots ( Miter slots on my table saw are a little less than 3/4" wide) then cut it to fit the depth of the miter slots using the table saw. Thanks to the people here at Knots who passed along that tip.
I like the method Rich described but decided to take the easy way out. If it doesn't work out I'll just build another sled using his method.
Wanda
Wanda,
I experienced the same problem...the solution that worked for me was to make the sled rails slightly undersize and use screws to tune the fit in the miter gauge slots. I don't have a picture of this but the screws are very small, are countersunk, and are installed 2 per rail parallel to the surface of the table saw. This lets me pick one side of the rail to use as a full contact reference (say the right side) where the wooden sled rail slides along the right edge of the miter gauge slot. The side-to-side movement on the other side of the slot is eliminated by backing out the 2 screws so that the heads just contact the left side of the slot. You lose precision when only one screw per rail is in contact with the edge of the slot but it's adequate for cuts I typically make and works like a champ. Also allows you to compensate for wear or wood movement.
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