# Fence height for Table Saw sled?



## Sleeper (Mar 24, 2009)

I’m building a new cross cut sled for my table saw and from what I’ve seen on YouTube everyone seems to be using 3 ½” fence height. I’m using 5/8” MDF for my sled and I’m afraid that 3 ½” would make it too weak although I would like to keep it as small as possible for storage.

Should I go 5 ½” or would 3 ½” be OK?


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## pineguy (Feb 26, 2012)

I think 3 1/2" would be fine!


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## Sleeper (Mar 24, 2009)

pineguy said:


> I think 3 1/2" would be fine!


Thanks. 3 1/2" would actually be better for me.


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## Steve Neul (Sep 2, 2011)

I also thing 3 1/2" would be fine for a sled however I would not make one out of mdf unless you are going to cover it with formica. mdf is a little too soft for that purpose. I would either make it out of solid wood or plywood


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## Sleeper (Mar 24, 2009)

Steve Neul said:


> I also thing 3 1/2" would be fine for a sled however I would not make one out of mdf unless you are going to cover it with formica. mdf is a little too soft for that purpose. I would either make it out of solid wood or plywood


 Thanks, I used MDF for the table, but I was planning to solid wood for the fence. The reason I mentioned the 5/8 MDF was that I was concerned about the saw blade cutting the fence in half when fully raised. I can’t measure the blade height right now because I have it all set up on top of the TS to route out my slots for “T” bolts and don’t want to upset anything. My daughter sleeps above the garage and I have to wait before firing up any power tools. :no:

I originally did not want to use MDF for the table, but I found a piece that was almost the perfect size in my wood shed and most everybody on YouTube was using it. I already glued on the miter rails and drilled my pilot holes for the “T” bolts so I don’t want to change right now, but I wish I would a have used particle board with the vinyl coating on it. After I started I remembered that I have 2 - 3/4”x4x8 sheets that someone gave me. 

Anyway back to the fence, since you brought it up I was wondering if I should glue 3 1x4 together and straighten one side with my joiner instead of using a 2x4 or something, And also would fir be OK for the fence instead of hard wood?


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## Hammer1 (Aug 1, 2010)

Technically, the fence doesn't need to be any higher than the thickness of the stock you are cutting. You want something stable for a sled, that won't expand and contract with changes in humidity. MDF is fine. Your fence needs to be flat and straight or the work won't register to it accurately, therefore your cuts won't be accurate. Since the blade will cut into the fence, fences up on edge may need to be wider to maintain integrity. A 2x4 laid flat will work and you won't need to cut all the way through it to finish a cut. In circumstances where you need a taller fence, you can add something to that. A lower fence can also be handy for adding toggle clamps. You certainly don't want the work moving during a cut. Too tall a fence makes holding by hand a real challenge. Anything on your sled that can move with humidity is something to avoid or it may not stay the way you made it or work smoothly.


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## woodnthings (Jan 24, 2009)

*I'd go hardwood*

Not pine, not MDF and a nice straight length of hardwood 3/4" x 3 1/2" tall and 30" or so long to match your sled dimension. Reason is it provides a little height for clamping stops and such. Also if you cut at full height it will not be weakened much since the work is already off the table 1/2" or so, and the blade only cuts 3" at full height, so that makes a maximun cut of 2 1/2" above the sled. Screw the fence(s) up from the bottom of the sled and countersink the screws which should not be in the path of the blade...just sayin' :wallbash:  bill


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## Sleeper (Mar 24, 2009)

Hammer1 said:


> ..........A lower fence can also be handy for adding toggle clamps. You certainly don't want the work moving during a cut. Too tall a fence makes holding by hand a real challenge.


 Oh yes the clamp issue. I had forgotten about that. I’m always fighting that issue with my miter saw. Not a problem for long pieces, but a real pain in the neck for short pieces. Thanks :thumbsup:


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## tcleve4911 (Dec 16, 2006)

Hammer1 said:


> Anything on your sled that can move with humidity is something to avoid or it may not stay the way you made it or work smoothly.


I've always had concerns about using MDF for jigs and sleds.
Maybe I don't use it properly.
I just know that the few times I tried, it blew out when I used thin pieces, or screws stripped out or sharp corners broke off.

I really haven't had much luck with it.
Now multi-ply baltic birch is another story.....


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## Sleeper (Mar 24, 2009)

woodnthings said:


> Not pine, not MDF and a nice straight length of hardwood 3/4" x 3 1/2" tall and 30" or so long to match your sled dimension. Reason is it provides a little height for clamping stops and such. Also if you cut at full height it will not be weakened much since the work is already off the table 1/2" or so, and the blade only cuts 3" at full height, so that makes a maximun cut of 2 1/2" above the sled. Screw the fence(s) up from the bottom of the sled and countersink the screws which should not be in the path of the blade...just sayin' :wallbash:  bill


 Just a single piece of oak? 



I have some 3/4” x 3 ½” red oak that’s for another project and I guess I could borrow that until I get to the store. I don’t know I just have a mental block about combing fine wood with MDF. It’s almost Sacrilegious or something. :blink:


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## Sleeper (Mar 24, 2009)

tcleve4911 said:


> I've always had concerns about using MDF for jigs and sleds.
> Maybe I don't use it properly.
> I just know that the few times I tried, it blew out when I used thin pieces, or screws stripped out or sharp corners broke off.
> 
> ...


 I feel the same way and I hope I didn’t make a mistake. That’s kind of why I was thinking of using Doug Fir for the fence just in case I have to do it all over again.


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## tcleve4911 (Dec 16, 2006)

Sleeper said:


> I feel the same way and I hope I didn’t make a mistake. That’s kind of why I was thinking of using Doug Fir for the fence just in case I have to do it all over again.


Not sure about doug fir...or any wood really. 
The potential for it to split along the grain line is what concerns me.

I like the strength of multi-ply plywood for most of my jigs and sleds.


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## woodnthings (Jan 24, 2009)

*this is your first sled...*

It won't be the last. :laughing: You'll learn somethings here and make the next one better. MDF is OK as long as you are screwing through the thickness like when attaching your fence. It's No Good for screwing into the edge, so avoid that. :yes: Take photos as you go.....OK?  bill


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## Sleeper (Mar 24, 2009)

I just got finished with the slots. This was the very first time I ever routed MDF and I think it will be the last. I cannot believe the mess. I had to immediately grab my dust mask as soon as I turned on the router. It was horrible. I’m not sure if I’ll continue with expensive materials like the hard wood because I’m having second thoughts about the MDF. 

I don’t know, I have to look through my wood shed to see if I have some scraps that I don’t care much about. But the fence is next and I’m thinking about ripping a 2x4 in half and gluing it back together with the grain running in opposite directions.


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## tcleve4911 (Dec 16, 2006)

Sleeper said:


> I just got finished with the slots. This was the very first time I ever routed MDF and I think it will be the last. I cannot believe the mess. I had to immediately grab my dust mask as soon as I turned on the router. It was horrible.


One more reason I don't like working with it.:thumbdown:


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## woodnthings (Jan 24, 2009)

*Yep*



tcleve4911 said:


> One more reason I don't like working with it.:thumbdown:


WE forgot to mention that part :thumbdown: :laughing:
I slotted several hundred feet of MDF for splines for underlayment years back. It was outside thankfully and I prayed for more wind. I used a router with a slot cutter. :blink: bill


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## tcleve4911 (Dec 16, 2006)

woodnthings said:


> WE forgot to mention that part :thumbdown: :laughing:
> I slotted several hundred feet of MDF for splines for underlayment years back. It was outside thankfully and I prayed for more wind. I used a router with a slot cutter. :blink: bill


Still blowin' your nose from that one I bet!!!!!:laughing:


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## Sleeper (Mar 24, 2009)

I found a couple of 4’ 1x4 poplar boards that I’m going to use for my fence. The only problem is that my jointer is out of commission right now because the knives don’t look so good. I ran a scrap piece of Fir through and it’s just not that great and I don’t want to take a chance ruining the poplar. I ordered new knives, but that’s going to be a week or so.

So anyway one of the boards is pretty straight and flat already. It does have a very light twist on one end and I think most of it will be cut off. I was thinking of using it for the fence and ripping a straight piece about 2” wide and gluing it on edge to the back. I’ll be using the factory edge of the MDF as a straight edge and temporary clamping the fence and 2” piece while it glues to ensure it is straight. I’m hoping that any small discrepancies will come out any and stay straight. What do you think will it work or should I wait for the jointer knives? 

I’m not real sure about the small twist in upper corner on the end, but I’m not sure it will be a problem. I suppose if I turn the piece so that the high side is one the table side I could hand plane it if it became a problem.

Here is a photo illustrating what I mean. And before anyone asks, I’m only used the table edge as a straight edge. I’m not gluing the fence to the edge of the MDF. :smile:


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## Sleeper (Mar 24, 2009)

I’ve spent some time looking sled fences and from what I see everybody has at least 1 ½” thick. Most look like regular construction lumber that was run thru a jointer. Some are two ¾” pieces glued together and then run through a jointer. I saw one that was two pieces of Poplar (I think) with a ½” piece of Oak for the fence surface and I’m not sure why that was, but it looked interesting. 

Anyway I’ve decided to wait for the jointer and I may try to sharpen the knives myself. Then instead of only one ¾” piece I’m going to glue two pieces glued together and joint it.

The other thing I didn’t think of was having the blade coming out the front at the end of the cut, so I ‘may just glue on a block of wood where the blade comes out and add stops for safety.


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## Lola Ranch (Mar 22, 2010)

I make my sled fences out of 5/4" straight grained fir or hemlock. The height of the fence depends on the height you cut through it. You want to leave enough so that it is structural which IMO is at least 2", so I make the fence 5" - 6" high in the middle but taper it down on each side both to cut weight and to make it easier to hold the work piece.

One very important feature I always put into my sled fences is a small, 1/8" x 1/8" rabbet at the bottom to give a place for the sawdust to go so you will always be able to get your work piece tight to the fence for maximum accuracy. 

Bret


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## Sleeper (Mar 24, 2009)

Lola Ranch said:


> ....One very important feature I always put into my sled fences is a small, 1/8" x 1/8" rabbet at the bottom to give a place for the sawdust to go so you will always be able to get your work piece tight to the fence for maximum accuracy...
> 
> Bret


Oh wow thanks for the info! :thumbsup: This is the first I've heard of this and it sure sounds like a good idea. The saw dust actually did occur to me and I thought I would have to leave the insert off when using the sled.

I am still thinking about the height. most of the sleds I saw had a high spot where the blade passed through and they specified 5 1/2" high. I don't know if i will ever have the blad up all the way, but I'd like to be prepared. 

I ordered an aluminum "T" slot for the top. so I guess i gould use a 3/4"x3 1/2" for the front face with the T slot on top and a 3/4" x 5 1/2" for the back of the fence for the handle and angle it down to 3 1/2".

I could use the poplar for the 3 1/2" side of the fence and Fir for the 5 1/2" side


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## Sleeper (Mar 24, 2009)

*Can’t decide on Fence thickness*

I bought a 5 ½” board today for the back piece and I don’t have my “T” slot yet to mount on top of the fence.

I’m going to taper off the top of 5 ½” board down to the 3 ½ on each end after I joint it.


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## Sleeper (Mar 24, 2009)

*Are my TB sled Slots too short?*

My slots end 2 ¾” from my fence. It works fine for Miter Cuts, but not sure if something else may come up


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