What Happened To My Table Saw Sled?

[BadgerDave]

Awhile back I made a very basic table saw crosscut sled out of ¾" ply and I used oak for the runner. It worked just as it was supposed to for months without any issues. Today, I went to use it and it no longer sits flat on my saws top. The wobble is very noticeable and I feel uncomfortable using it.

I'm looking for some ideas on what not to do when I make another. Should I have used a different material instead of ply? I can't remember for sure but I think I made this based on a design from WOOD Magazine or Shop Notes and it called for using ply.

I'm also wondering if possibly I didn't store it correctly when it wasn't being used. For those of you who use a sled, how do you store yours during downtime?

[Pipestone Kid]

I made one after first reading about them and after a while, I decided it worked best in my wood burning stove. :D

[cpw]

Is the wobble in the ply, or is it somehow in the runner?

[VASandy]

If you lay the sled on the saw with the blade all the way down and the runners up does it still wobble? This will tell you if it's a problem with the runners alone. The oak may have swollen/shrank unevenly. This could cause the ply to warp. Try taking the runners off and see if the ply is warped.

To alleviate the problem in the future, you can purchase aluminum rails from Woodcraft or Rockler. Using those runners, you shouldn't have any more warp problems. Remember to store the crosscut sled flat.

[BadgerDave]

As Sandy suggested, I removed the runner and it appears the ply is where the issue is. I'm also leaning towards the way I stored the sled as the cause. As is the case with many of us, I just don't have a lot of storage area so I was storing it standing up on end and not laying flat. Being fairly small I really didn't think storage would be an issue but live and learn I guess. If I make another one I'll have to figure out a way I can store where it would be laying flat.

Maybe PK can use the warped one for making a little heat. :D

[CCusson]

I've got the same shop-space situation as Badger Dave, and am planning on making a sled out of ply over the weekend (just cut the runner last night out of maple).

So, what about hanging the sled from one end of the ply, do you think this would cause it to warp also?

Thanks!

[FINER9998]

what about making the sled base out of MDF? flat, stable, reliable. use hardwood for runner and rear/front fence.

[Tom5151]

what about making the sled base out of MDF? flat, stable, reliable. use hardwood for runner and rear/front fence.

That's what i did and it has stayed perfectly flat........1/2 inch MDF for the sled and oak slats for the runners

[cpw]

That's what i did and it has stayed perfectly flat........1/2 inch MDF for the sled and oak slats for the runners

I also used 1/2 inch MDF and I store it leaning against a wall. Still flat. I used a strip of 3/4" ply for the runner.

I think that 1/2" is better than 3/4" just because it doesn't raise the table height so much.

[Pipestone Kid]

"Maybe PK can use the warped one for making a little heat. "

BD, I could use it for smoking Walleye if it is clean wood.:D:D

[Bob D.]

Try MDF and put a hang hole in it . Gravity will keep it flat then
instead of warping it as it did when leaning up against something.


cpw wrote: "I think that 1/2" is better than 3/4" just because it doesn't raise the table height so much."

I agree with the 1/2". It's also not much trouble to make the opposite half to compliment your sled.
I made my sled for use on the right side of the blade. And I made a piece that has a runner on it to
keep it positioned to the left side, and a piece 24"w x 48"d(front to back) that slides up along the
edge of the left wing. There I use a c-clamp to secure it from moving. The sled (36"w x 24"d) then
travels on the right side of the blade. Any offcuts do not fall as they are supported by the other half
on the left.

Next time I use it I will try to remember to take a photo.

[BadgerDave]

.............
BD, I could use it for smoking Walleye if it is clean wood.:D:D
Now that's hitting below the belt. :bash::bravo:

[RevEd]

As Sandy suggested, I removed the runner and it appears the ply is where the issue is. I'm also leaning towards the way I stored the sled as the cause. As is the case with many of us, I just don't have a lot of storage area so I was storing it standing up on end and not laying flat. Being fairly small I really didn't think storage would be an issue but live and learn I guess. If I make another one I'll have to figure out a way I can store where it would be laying flat.

Maybe PK can use the warped one for making a little heat. :D

If you built it from ply bought at HD that is your problem. That Ply comes from China and is about as stable as jello. It warps, shrinks, delams, cracks, and has been found to have metal imbedded in it on occasion.
I wouldn't burn it because none of us know the glue formula remember these are the people that cut their baby formula with wacked chemicals to get more profit.

[Bob D.]

...I wouldn't burn it... [plywood]


I never burn plywood no matter what the source. Too much glue.

[darius]

So would there be general agreement that MDF would be a better choice for a crosscut sled?

[cpw]

So would there be general agreement that MDF would be a better choice for a crosscut sled?

I usually think ply is better for everything as far as stability, but I think MDF is likely to be smoother without the need for wax etc. It is cheaper, but it doesn't take a screw as well, which I think does matter, because it is nice to be able to screw things onto your sled so that you can hold down "interestingly" shaped workpieces safely.

[VASandy]

I made my first sled from MDF. I couldn't get the runners to attach well, unless I used superglue. No screws I have would properly hold into the MDF. It's stable enough, but you still have to store it flat or hang it (the runners can get warped otherwise). I think ply is much better suited for this task than MDF.

I do use a lot of MDF in the shop for things like temp fences for the drill press and band saw, as well as router guides. MDF works great as a router guide since you can easily shape it any way you want using standard tools.

[BadgerDave]

I knocked out another sled this AM. I was able to reuse the runner and fence from the other sled and I had a piece of scrap ½" MDF laying around so I used that. I found a spot in the furnace room(basement shop) where I can hang this one on the wall.

I know I'll probably regret this and have to make another one but this time I made the sled so that I can use it on the RH side of the blade. I know that this will be a problem if I use a blade with a different kerf but as that is seldom the case it shouldn't come into play very often if at all.

[CWSmith]

Hey BD,

I think I'd stick with ply, but perhaps a better grade than from HD. Then, I think I'd give it a good coating or two of poly to seal it. I'd also go with the previous suggestion to drill a couple of holes in it so that it could be hung during storage.

CWS