If you don't have the money or space for a large planer, a router flattening sled is a great option for you to be able to plane large slabs without having to spend too much money to make this. I provide tips on how to build it and obtain a smooth finish, along with a link to the free plans!
Step 1: Make Your Cuts
Free plans can be found here.
The bottom of your sled should be the width of the base of your router, plus 1/4". The plans I made fit my router, but you can modify to fit your router.
Cut a rectangle out of the middle of this piece so the bit will fit through. The width of the rectangle should be wide enough for your bit to fit through. I used this bottom cleaning bit. I found it easiest to make this cut by drilling a hole on either end and using my jigsaw to make the remaining cuts.
Step 2: Assemble the Pieces
Assemble all the pieces according to the plan using wood glue and screws. After assembly, attach these casters to the bottom of the feet.
You can then assemble the whole piece with the bolts, washers, and nuts. The router should now slide freely within the sled.
Step 3: Plane the Slabs
You can now plane the slabs. A couple tips to get a smooth finish:
- Go with the grain. This will make a huge difference!
- Clean your work area often. And debris that the casters roll over will cause the finish to not be as smooth.
- shim your slab so that it is stable. Shim from all sides, not just one.
- Wear a mask and eyewear - this will make a ton of sawdust so do your lungs and eyes a favor and protect them.
Now you are ready to plane down some slabs!