I recently completed a project that required a massive amount of kerf cuts to bend a lot of 1"x12" boards. the cuts had to be repeated 90 times per board across the entire length. Far too much to even think measuring each one so I made a crosscut sled with a stop pin to speed things along. I also included adjustable options for the distance between repeated cuts.
Step 1: Measure for Guide Rails
Get an accurate measurement of the space between the guide rail slots and where to position them.
I chose oak for these rails to run on the underside of the sled. I milled them to 1/16" less than the width of the slots 1/16" less than the height so they would slide freely through the guide slots.
Step 2: Cutting the Base and Attaching the Rails
There are three critical steps of making the sled a worthwhile tool:
Cutting the base square, attaching the rails perfectly parallel to the blade and attaching the rear fence perfectly perpendicular to the blade.
If the base is square then attaching the rails properly is easier. I chose 3/4" MDF for the base. It's stable, cheap and I had some readily available. I'd recommend a higher grade plywood for durability though.
I measured it to fit the top of the table saw with just a little overhang. Cutting the base to the size of the table made it easy to get an accurate read on where to glue the guide rails. (It's made for me and my saw so please think about what suits your needs)
GET REALLY ACCURATE MEASUREMENTS AND PUT THE RAILS IN THE RIGHT PLACES! If they are not attached in perfect alignment with the guide slots on the table top you will bind the sled and make diagonal cuts. Take your time, be precise, however you get there. I measured everything off of the right side of the sled base and stayed consistent with it as my starting point. Using marks on the front and rear of the base I lined the rails up and carefully glued and clamped them. You could easily screw them on for a quicker assembly but screws will eventually loosen and lead to slop in your cuts down the road. Be ready to clean up any excess glue seepage with a wet rag and be careful you don't nudge anything out of alignment.
Once everything is dry, clean up your inside corners with a chisel or similar square blade. Make sure the bottom side of the base is clean and slides smoothly across the table and through the guide slots.
Step 3: Slots for Every Occasion
Next, I cut a shallow slot in the top of the base where the blade would run so I had a mark where the stops could be measured from. These slots were measured at 1" increments but I wish I would have done them at 1/2" increments instead. I only needed one slot on either side of the blade but I put more in because I might want larger increments later on for other projects.
Set your fence and be super careful pushing into the blade just enough so you've got a long enough slot to put your stop pin in. This might be tough on a smaller saw if your rip fence can't be pushed out that far from the blade.
Again, be careful. You'll be pushing the board the wrong way to use the rip fence. You could set up a router guide to do this too. I had a table saw so I used a table saw.
Step 4: Front and Rear Fences
Pick a nice thick board to use for the front and rear fences. These things will be what holds your sled together and give you the ability to push the sled forward and pull it backwards as needed. If they are skinny and weak you will break them or break your sled base. The thicker they are the more surface you have to glue them to the base. More = better. I went with 2" x 4"s and a lap joint to make it as sturdy as possible.
Glue it up as square as you can. This is one of those critical steps in making an accurate and worthwhile tool.
Step 5: Stops
For the stop and pin, I cut a piece of oak 1/8" thick x 3/4" tall. It serves as a stop of the first cut and accepts that slot t repeat the cut at consistent interval.
Make it out of whatever you like.
Step 6: Cut and Ready
Set your sled in the guide rails with the blade down and make sure everything is running smoothly. You've probably done this already but one last time to make really sure. Pull the sled off the table and raise the blade. Run it through to remove blade's path through the base and fence.
Step 7: Cut & Cut & Cut & Cut & Cut & Cut & Cut & Cut & Cut
Test out your new system. .
It functions as a regular old crosscut sled too.
Here's to your continued safety, versatility and consistency!