Building a cross cut sled.....

[Corey Hallagan]

I will be starting a cross cut sled for the TS this weekend amongst a couple other jigs. The plan that I am loosely follow made an interesting comment with regards to setting up the front and rear rails on the sled. It states: " in location the front rails simply line up the fence with the edge of the front edge of the base, however, the rear rail needs to be perfectly perpendicular to the blade so you must line it up properly...." and it goes on to explain using a long bladed framing square to align the rear rail.

It seems to me that if this is a cross cut sled that it would be crucial that the front rail/fence be as perfect as possible, not the rear. Actually both should be as much as you can get it but the front is what will have the stop on it along with hold downs that hold workpieces up to the front fence. Just seems to me they have this backwards. Am I right?

Thanks as always,
Corey

[Don Baer]

Cory,
You are correct. Here is an article on buildind a sled that might be helpful.

http://www.canadianhomeworkshop.com/weekend/xcutting.shtml

[Michael Ballent]

The sled will only be as accurate as the square you are using to measure. What ever you are using to make sure that it is 90º it has to be very accurate. One other method to use is to take some plywood and cut it, rotate the fresh cut onto the fence, cut again, repeat until you have made 4 cuts. Measure the it for square and it will be 4 times greater than the amount the sled is off of 90º. I hope that makes sense. :D and yes the face of the fence has to be flat as well.

[Andrew Ault]

Corey,

One thing I like to do is to set the runner(s) into shallow dados to ensure that they are perpendicular to the fence.

-Andy

[Steve Schoene]

I think this is a matter of symantics. I'd bet the author was thinking of the rear fence has that closest to the operator. It does pass the blade last.

[Michael Ballent]

Corey,

One thing I like to do is to set the runner(s) into shallow dados to ensure that they are perpendicular to the fence.

-Andy

That is too much measuring for me :cool: I am not sure that would really buy you much... The dados are parallel, but you want the fence perpendicular to the blade. What I have done is to just place the plywood/particle board on the saw with the runners already in the slots. Then I screw them in along their length. I pull the assembly back to clear the blade, turn on the saw and advance the plywood into the blade cutting about half way into the ply. Then I get the fence perpendicular to the blade.

[Corey Hallagan]

Steve, I think you are right on that. Don, good article and thanks. In fact in the article the author refers to gluing up the front brace ( the part that goes to the back of the saw and then putting the fence on the sled, which would be what I call the front.

Thanks all,
Corey

[Roy Wall]

I think this is a matter of symantics. I'd bet the author was thinking of the rear fence has that closest to the operator. It does pass the blade last.

I agree!

Both Jim Tolphin and Kelly Mehler say the same thing..They "harp" on the exactness of the "rear fence"...or the fence you are pushing...the fence the stock is set against..

[Chris Giles]

It may seem a small point folks, but you actually want the fence on the sled to be perpendicular to the cut line of the blade, not the blade itself. Often, the trunnion is not set precisely parallel to the slots in the top. Unless you are positive of this parallel alignment, use the cut line through the sled as your reference. I find a reliable way to check square is to rip a piece of mdf to whatever the maximum capacity of your sled will be, then crosscut it on the sled, flip it over front-to-back, and take a 1/32" more off. As you push it through, observe the consistency of this cut. This will tell you how square you are.

[Corey Hallagan]

Chris, my plans do say to square the fence to the kerf as you say, not the blade as I said in the post. Makes sense.

Thanks,
Corey

[Corvin Alstot]

Corey/

FWW magazine had an article on building a sled awhile ago. I used it and have been please with the results. By the way, I square front and rear fences. Ping me if you need a magazine date.

[Jim Becker]

I believe that on a sled with both a front and rear fence, they BOTH need to be accurately indexed to the cutter. My cross-cut sled is a-la Norm and only has a front fence. I find that format most convenient for the way I work as well as being less sensitive to maximum panel width, but it is only one way of many to build one. It also only sits on one side of the blade. For a sled that straddles the blade, both fences are best so you can also do a guard over the blade path.

[Corey Hallagan]

Jim, it sounds like you are referring to the original one that Norm made and what he refers to as his panel cutter. I built that as a downsized version for my very first jig many years ago for a small 8 inch bench top. I used the heck out of that and when I sold the saw the guy wanted it too.

Corey

[Jim Becker]

Yes, it's the same as both his original and his updated version done in the "Jigs" episode. I use it for panel cutting. For sticks I use one of my miter guages (OEM with a short MDF sacrificial fence or my Incra 1000) For 45º miters I have a custom sled I made that spans the blade so I can make opposite cuts from either side for an exact 90º mating.

[Norman Hitt]

Chris, my plans do say to square the fence to the kerf as you say, not the blade as I said in the post. Makes sense.

Thanks,
Corey

Cory, there was a Really good Video, (that I "thought" was on the Taunton Site), and I used to have it bookmarked, but I guess I lost it when the old "Confuser" went down and had to be rebuilt. I looked on the Taunton/Fine WW site, but couldn't find it. Maybe someone else remembers this VIDEO CLIP, and knows where it is, (or maybe it's just no longer there OR, It was on some other site and my CRS just kicked in). :D

If you can find it, it is very helpful for Making, and Setting Up Cutoff or Panel Sleds and their Fences.

[Corey Hallagan]

Thanks Norm, I wil see if I can locate it. As it stands now, I probably won't get much done on the sled this weekend. Probably just going to get parts cut. I have two other jigs to build first, the adjustable Dado jig I will use on the sled to cut the miter bar slots. The sled is quite involved for a sled. It will have a slot on the rear fence for attaching stops and hold downs and Tnuts on the field for additional hold downs and a swing arm miter fence as well.

Corey

[Kelly C. Hanna]

I built two double fenced sleds for my old saw.....only drawback was panels size limitations of 20" wide. Next time I build one like Mr Marks has....

[Mark Singer]

I have made several using this basic technique:
This is for a zero clearance sled...A seperate dado/angle sled should be made and a seperate miter sled

1. Cut runners from hardwood...Paduck, Maple, the size of the miter slots. Sand or plane until they slide easily , but are not loose.

2. Cut a rectangular piece of 1/2" Baltic Birch plywood...make sure its prety darn square.

3. Lower the blade and put the runners in the miter slots place the plywood on top. Position the plywood square with the saw....use the fence.

4. Glue and screw the plywood to the runners while it is on the saw....use wood screw and make sure they will not go through the runners and into the saw table. Counter sink the screws.

5. Install the front fence. Mine is high in the center and rounds down on the sides like David Marks sled. The front fence is lower than the rear.

6. Install only 1 screw on the rear fence....square the rear fence as accuratley as possible then cut a board exactly the distance from the rear to front fence and use a bar clamp and clamp across the rear and front fence with the board in between. This will hold the rear fence in place so you can make a trial cut.

7. With the saw running raise the blade and slide the sled making a cut throug the bottom and both fences.

8. Place a edge jointed piece of wood in the sled about 8" wide and make a cross cut. With your most accurate square check the cut. If it is not absolutly perfect....loosen the clamp and shim the spacer board or trim it to adjust for square.

9. Retry the cut. When it is 100% square ...with the bar clamp on....flip it over and install a second screw in the rear fence.

10. Try another cut to test for square. When it is perfect add several screws.

11. Wax the runners with paste wax..

12. The rear projection of the blade should be capped with a block for safety.

[Christopher Stahl]

Thanks for these instructions Mark!

chris

[Kelly C. Hanna]

No doubt...much better than my way. Thanks Mark!

[Hank Knight]

Corey, I tried several methods for getting my crosscut sled fence square, starting with a carpenter's square. Nothing worked very well until I tried this one posted on Wood Central by EagleSC back in February. It works much better than anyhting else I've tried. My fence is now dead-on square. Here's Eagle's desciption:

Easiest way is using the 5 cut method.
Use a piece of stock that is"about" 12 inches(or longer) square and fits on your sled.
1.SCREW one end of the fence down.
2.After getting it "eyeball" square using any method you prefer, square, 3,4,5, or winging it.Secure the other ens with a screw through an over sized hole in the sled.I like to make my sleds wider than the saw top so I can use a clamp on one end.
3.Mark the corners 1-4 of your test piece far enough in that you won't cut your marks off.
4. place your test piece against the fence and cut one side.
The cut doesn't have to be too wide, but you need to straighten the board for a reference side.
5.Rotate the test piece 90? and cut it again.
6.keep rotating and cutting until you have cut it 5 times total.
7. measure the diagonals.If they are not equal(they never are for me) adjust the fence one way or the other and repeat the sequence again until they are.
(I can never figure out which way to "bump" the fence so it's usually hit or miss.)
Eventually you will get equal measurements on the diagonals.
Scribe a line as a reference for the fence and add glue to the fence sparingly.
(I never remember to do this but I always intend to make a saw kerf at the base of the fence in the sled for saw dust accumulation, may be you will)
repeat the test one more time,It's a good idea i have found to use a glue with as much open time as possible.
If you pass the test the final time,pull the sled back, clamp it down and run a few screws up from the bottom.
I leave a few in but make sure you don't leave one in the blade kerf,(DAMHIKT)
I know it's as clear as mud and maybe some one else has a link to a method with a better description.
I tried using just a framing square, but never got it "DEAD ON"
I got this method from a wood working video and my sleds have been true ever since.

[Corey Hallagan]

Thanks Hank. Yes, that is the ultimate test for squareness in any project, cabinet etc. I think the biggest problem people have with using any kind of a square is that so many just are not accurate. I never realized this until the last several months. The best one I have is a 6 inch speed square that is bang on. I paid about 15.00 for it. And I have a rosewood handled square that is about 40 years old that was my wifes uncles. Problem is both are 6 inch. Neither are very long. I have two budget "engineer" squares that were a waste of money even at the low price i paid for them and they were 20.00 from "shop fox" from grizzley. I will use my best squares and then my long bladed framing square to see how I fair. My test cuts will be the 5 cut method.
Thanks,
Corey

[Bernie Weishapl]

Corey,


I am building a sled out of MDF like Mark was talking about with the fences higher in the middle and the sloped off. I am going to use the 5 cut method even though I have 3 machinist squares that were tested to .0005.

One thing Corey that I saw the other day was a friend of mine in Denver had made a sled out of plywood. On his rear fence or the one closest to him he put a T-Track on the inside. He made a stop block that moves from one side to the other. He also mounted some straight line toggle clamps on 3/4" plywood block and put two T-bolts in each block. He has two of them mounted which clamps the piece down being cut. Really works well especially when trying to cut real small pieces. I'll send you a picture when I am done.

Bernie

[Corey Hallagan]

Hi Bernie, thanks for the info. I am building mine out of birch play and the rear fence will have the higher profile like Marks does. I just received in the mail today a 4 foot section of Rockler T-Track and hold down set. I will put the ttrack on the rear rail like you said your buddies is and the field of the sled will have 2 rows of Tnuts that I can use to screw the hold downs into. With about 5 in each row that should give me the ability to hold down about any length of board I want to. I will make a stop block to put into the Ttrack with a Tbolt and a piece of oak. Yes, I will use a square to get it close, use marks method to hold it together with the board and do the 5 cut test until perfect.
Corey

[Norman Hitt]

Cory, the 5 sided cut is fine, but I use the simple/lazy :rolleyes: method, for checking for square. To do it, make a test piece by jointing one edge of a piece of 3/4" wood about 2' long, then rip it so it is 4" or 5" wide and the sides are now straight, AND parallel. Place it flat on the sled against the fence with the middle of the test piece straddling the sled's kerf, and cut through the test piece. Now, keeping one of the pieces in place against the fence, turn the other piece over and slide it back up against the other piece with both pieces held snugly against the fence. It will be readily apparent if the cut is square as they will fit together perfectly. If there is a gap, then you need to correct 1/2 of the gap. If the V shaped gap is on the fence side of the test pieces, then the left end of the fence needs to come back towards you, and conversely, if the gap is on the blade side, then the left end of the fence needs to go foreward, (away from you).

To test again, flip the piece you turned over, back over again so the original face is up and with the pieces pressed together and against the fence, resaw through the kerf, and check again, and keep repeating and adjusting as necessary until it's dead on.

If your sled is long enough that it hangs over the side of your saw's extension wing, then just put one screw through the sled into the fence on one end fairly tight, and then just clamp the other end of the fence to the sled, then use another clamp going across from the front fence to the rear fence to move it in small amounts and don't put a screw in that end until you test square. Glue can be applied at the start of this procedure, if you work quickly. (Maybe make a few dry runs first)........this procedure was what that video that I mentioned was about. (still can't find it, and I'm surprised someone else hasn't chimed in about it, as it was mentioned several times here in the past).

Note: One other thing in the video was that nearly every saw's miter slots are 90* to the front (I call it) operator side of the saw, so to get real close to start, lay your miter bar/bars you are going to install on your sled into the saw's miter slot/slots, and then lay the sled base on the table, centering it as you like it, and use a flat board held against the front edge of the saw slide the sled base against it, and then insert the screws through the sled base and into the miter bars. You can then start your fence installation by referencing that edge of the sleed and be pretty close to square from the start.

Note 2: When the front fence is installed and square, I just cut two identical 1 x 4's (cut at the same time, one on top of the other), and place them against the front fence close to each end of the sled, and then press the rear fence up against them and install the screws and that makes the rear fence square also, (but you can check it for square if you like).

You can see a Simple sled I made at http://www.sawmillcreek.org/showthread.php?t=21335

[Scott Donley]

Hi Corey, just in case you have not seen it, Highland Hardware (http://www.tools-for-woodworking.com/)has a library, a number of home built jigs and info there. Their crosscut sled is worth a look, an interesting way to square it to the blade is also shown. Take care!

[Jeff Sudmeier]

That is a great step by step tutorial Mark, I think it would make a great article!!!