Over the last couple of weeks I built a large sled for the AZ shop. The old sled was getting loose in the miter slots and fence and base slots were no longer zero clearance.
The base is 23” x 40” x 3/4” BB plywood. The push fence is laminated mix of Maple and Cherry. The back fence is BB.
For runners the 18” Rockler Aluminum Miter Slot bars were used. They are adjustable for width with nylon tipped Allen set screws. Very easy to adjust to the slot and slide freely.
Link to runners: https://www.amazon.com/Rockler-36-Aluminum-Miter-Bar/dp/B0052KF7LA/ref=asc_df_B0052KF7LA?tag=bingshoppinga-20&linkCode=df0&hvadid=80607997944701&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584207577420554&psc=1
The fence was locked in position to hold the base in the correct relation to the blade. (2” to the right of base center). The runners were shimmed up with a 1/8” thick strip of wood so they were above the table saw top. They are attached to the sled with a full length strip of double backed tape which is cut out at the three tapped screw holes. Three 1/4-20 x 1” SS Flat Head SS Allen Socket screws were added to permanently secure the runners. The procedure follows below:
To drill accurate holes through the plywood base a Drill / Tap was turned by hand using a tap T handle, Do Not use a Power Drill. Drilling through the Rockler runner first, the lead end drill bit cut about 1/2” into the BB base while still leaving tap threads in the runner. A #7 drill was carefully aligned to drill the rest of the way through the plywood base utilizing a drill press, the middle runner holes had to be drilled by hand after the drill/tap started the hole. The base was flipped over and the top holes were counter bored. On the Amazon site where the drill / tap was obtained most of the one star reviews warned that the Dewalt bits had a nasty habit of breaking.
The sled was dialed in using the 5 Cut method to square a crosscut sled per William Ng’s YouTube Video which is revisited every sled I build, a link to Mr. Ng's video is in my other sled built for the box swap, linked below. A 1/2” x 20” square of MDF was used for the 5 cut strips. This sled’s current accuracy is very good.
Initial fence alignment was set using a Wixey Digital Protractor between the blade and push fence. Two fence adjustments were made. Final accuracy was 0.0000292 “/“. I am sure a bit of luck was involved.
The aluminum runners will be able to be readjusted to take out future sled “wiggle”. When DW & I return to AZ I will verify whether the fence needs to be readjusted.
I hope this write up helps others to build a crosscut sled.