I recently rebuilt my sled (switched to thin kerf blades). I was not really happy with the selection of sheet goods at the home center. I've seen a couple of videos calling for 1/2" base, but neither the 1/2" ply or the MDF was flat.

I ended up going with 3/4" ply, just because it was the only thing that was reasonably flat. I used 3/4" for the base, and laminated 3 plys of 3/4" for the front fence and 2 plys for the back rail. I glued them up all together with a top caul and clamped them to my bench to dry. They came out nice and flat on the faces. I jointed the bottoms and verified them with my jointer plane. They helped pull the slight bow out of the base, and the final sled was flat.

 

I used 3/4" melamine for my sled base. It seems to me that the melamine on both surfaces help keep the material from acquiring much of any bow, and the material is not so rigid you cannot easily push out whatever little bow it may have.

Incra uses a 1/2 melamine-over-mdf material in its Miter Express and Miter 5000 sleds which is great stuff, but I have no idea where you can get something like that.

Are you planning your sled to extend to both sides of the blade? I see that a lot and even did it myself on my first sled, but I much prefer the sleds that extend to only one side like mine, the Incras, the Dubby, etc.

 

I was planning on it taking up the entire space of the table saw with about a foot of it hanging over the left edge.

My primary use for it would be to cut down square panels (up to 24" wide) for cabinets and built ins, with the occasional use to crosscut smaller pieces for doors and drawers that aren't quite long enough for my miter saw's stops.

I'm definitely open to any frugal suggestions on materials and design.

 

Tuba fours are gonna give ya grief until they fully dry. My sled is 1/2" ply with doubled 3/4" fences. Its flat after I let it sit in the shop and acclimate.
Remember that ya don't have to go nuts tryin' to get flat within .0000?
Just tryin' to ease the pain as well as the cost.
The MDF base will work as well. Melamine will too. Both will degrade on edges or corners if treated roughly.
The well designed fences will certainly help keep the base flat enough.
Bill

 

That Incra Miter 5000 looks interesting, BTW. Tempting…..

I need a flat piece for my fence. Do I have to fork out the bucks for some phenolic plywood from woodcraft?

What can I scrape together from Home Depot? Hmmmmmm…

 

My next one will be entirely MDF.

 

I used 3/4" mdf for my base and kiln dried 2/4s from HD as my fences. It's a small sled though, about 24"x12" which really covers about 90% of what normally gets crosscut. It's more for dados/rabbets and any crosscut I cant do on my 10" mitre saw. Cut a rabbet out of each 2×4 and joined them to the mdf base with glue and screws. The proper rabbet helped a lot with geting everything squared up nice. It's held up pretty well so far but it's only been over a month and less than 100 cuts.

 

Just finished packing up the Incra 5000 miter sled. I really wanted that beauty to work out for me, but I could not get the miter bar to slide smoothly even after messing with it for 3 hours. I must have adjusted all those nylon washers a million different ways and I still could not get that bar to slide smoothly without "bumping" as the bar entered the slot at each point where the washers were on the bar. Very disappointed.

I could have built a sled with the time I spent f'ing around with this.

I guess I'm back to square 1 where I will use a phenolic flat piece of ply for the fence and either 1/2"mdf or 3/4" melamine for the base.

Or maybe some S4S oak from HD?

 

noone, any chance the problem is with your miter slots? Often they are not perfectly uniform along the entire length from the factory. I used a 3/4" block and some sand paper on mine to widen the narrow sport to get any bars to travel cleanly. As I remember the tightest spots were at the beginning and the end. The Incra bars should be pretty darn uniform (not impossible they were machined badly, but not terribly likely), so maybe it's your slots.

Just a thought.

 

John got it right for cleaning up the slots. Use emory sand paper.

For a sled 1/2" is what you want. You want it to be light weight and as little height reduction as possible. For the fence glue up a plywood lamination then joint it flat. I found that the Sandeply at home depot is very good for jigs and would be excellent for this.

Do not beat yourself up on thinking it has to be dead flat. Virtually flat is flat enough. Been doing this along time with jigs and slides that look like they have been to hell and back.

The key is that you fence is perfect a 90 to the blade and that your runner slides tight and smooth. Paste wax works great. Lube up the bottom of the sled and the runner.

Good luck and do not sweat the small stuff.

 

It did seem like the very front of the slot where it begins was tighter. Enough to make it bump so slightly. The only way to keep it from not 'bumping' was to make it loose. Too loose to the point it would wiggle slightly. No matter how I adjusted it. I tried expanding one side's washers more on one part to make it bump less but then it made the other side bump. I played around with it for about 3 hours and finally decided that it wasn't worth the time and the money when all I really need is a sled that cuts square stock up to 24". No angles needed here.

Rawdawg-

I totally forgot about that Sandeply stuff at HD. Good call!

I'd love to be able to joint my fence flat, but how do I do that if I don't have a jointer?

Are you talking about just gluing it up and clamping it to my mdf workbench flat while it dries?

 

I got a phenolic plywood at rocklers when they were on sale, I think woodcraft sells those as well. they are flat, 3/4" and have super smooth surfaces on both sides which helps with the SLIDING action of the sled.

a day after I bought it I found an INCRA MiterExpress on craigslist that uses similar material (only with MDF as the substrate and not plywood) and have been happily using this ever since… one of the best thing I ever got for the shop.

I was planning on replacing the INCRA factory sled base with the phenolic board I got as it is bigger (for a bigger sled) and I might do that at some point, but for now I don't see a need as this sled just does everything I need and is not 'broken' so no need to fix.

 

If the bar was only binding in certain places, it was most definitely your slots. If you have a caliper you should be able to measure the narrow spots. Another method is cut a block an inch or two long that barely fits in the slot (could also use a narrower pieces with a screw in it to allow easier adjustment) and run it up and back in your slots; areas where it binds are narrow and need attention. Do some light sanding (don't go crazy, you can remove metal faster than you might think) and keep testing. Once you get a uniformly tight fit you should be good. And I'll be those Incra bars will work great.

This is something that should really be done to all table saws as part of the initial setup and tuning. Once it's done you should never have to worry about it again.

 

Hmmmm. The sled is still packed up in my car ready to go to UPS. Maybe i'll pull it out and give it another try. I measured the width of the slot with my digital caliper and it was .755" wide. I measured it in several spots along the slot, but I did not measure the very front where the slot first starts.

 

If you liked the Incra enough to buy it, I'd try it again. Even if you cut your own hardwood runners you'll have the same problem if the slot is not uniform. You'll have to either accept sloppy runners, or tune up your slots. No good way of getting around it.

If you decide again to send it back, it only cost you some tape, right?

 

Well it's going to cost me another night of f'ing around when I need to really be finishing up my project that has dragged on now for 3 months.

But at least the return to Amazon will be free (if needed). Gotta love Amazon.

I'll measure my slots as soon as I get home.

 

Here's one for you.

http://www.incrementaltools.com/default.asp

 

Yeah, but it's going to cost you another night of messing around with it no matter which way you go. The good news is that you've probably got it figured out now. This is a learning process; shame some of the lessons are painful (and often expensive.) I think we've all learned many the hard way, I know I have.

Good luck

 

JOHN, THAT SOUNDS LIKE A GREAT IDEA FOR A NEW THREAD!!! Might save some of us greenhorns some grief down the road.

 

First one used MDF two layers of 3/4". To heavy. Now use 9-ply, very accurate square, and a deck of cards. Even the new one seems to move. Check the setup before each use, and in midstream of longer run. Add a playing card on either side. I think the problem is in the slots or sawdust/splinter-next runner will have adjustments built into slot rails, and either side of stock support. Did the Table Saw Tuneup - on either this forum or another. At least I have a chance to know and do something about the sources of error. s

 

There is a good video on tuning table saw miter slots at Newwoodworker.com . Click on tips and tricks and scroll down til you find it.

 

Absolutely Scot. Here's a link - video at the bottom of the page. Probably where I read about it. Tom's got a nice site there.

http://www.newwoodworker.com/tunemiterslots.html

 

Great link. I'm curious to see if I am going to end up having to keep this $233 cross-cut sled…....

 

I used 1/2" baltic birch plywood for the "bed" and some pieces of Maple I had laying around for the front and rear fences. I also made the slot for the saw blade adjustable. If and when the left (in my case) side of the slot wears too much, I will install another piece of hard maple as a refurbish. I like it but I have only a 16 inch or so capacity and I wish I had more. More, however, will create even more problems with the sled tipping off the front of the saw. Maybe I can make a support to take care of that roblem.

 

I measured my slots with a digital caliper and they were uniform in width from front to back.

I still could not get that Incra miter bar to work correctly without it bumping slightly at the washers in 2 places, no matter how hard I tried.

Maybe i'm just being picky, but I didn't like feeling 'bumps' in the $233 sled while sliding it back and forth…...

So I packed it up and sent it back today. I'm only interested in square cuts anyways so the 5000 was pretty much overkill.

My new plan is to buy some 1/2" Sandeply from Home Depot, laminate up 3 layers of it and clamp it flat to my granite countertop bar while it dries.

I was going to use MDF, but I know that i'll be crying when I start screwing things to it and the screws keep twisting…...