When I made this height-adjustable wooden fence for dog jumps, I tried to adjust the measurements of the groove where the tongue-and-groove boards fit and the length of those boards too much. The result was that when I wanted to assemble the fence, once it was finished and the protective stain was dry, the boards were very difficult to insert, getting stuck halfway in the grooves.
Apart from the fact that applying two coats of stain means eight coats of stain narrowing the groove (two on each interior face of the slats and another two on each side of each board), I noticed that the top of one of the slats seems to lean inward (this is part of the problem of buying wood that has been standing in a DIY center for a while, it always comes somewhat warped and that makes it difficult to work with).
So using a straight router bit, I trimmed the inside of that slat. The only problem was that I had to put the router’s side guide on the small ledge left between the other slat and the post, so the router base was elevated, but with a piece of marquetry under the base, I practically solved that height difference.
Once the routing was done, I was left with only a thin strip of slat at the bottom of the groove, but I easily cleaned it up with the chisel.
I also cut the boards just two or three millimeters shorter than the length of the wooden beam that joins the side supports at the bottom of the fence, so when inserting them into the grooves, as soon as I tilted them a bit, they got stuck on the sides and did not drop into position. But with the template for 90-degree cuts with the circular saw, it is very easy to trim a few millimeters off one end of the boards. Just by removing a slice of wood equal to the thickness of the saw blade plus the thickness of those scraps you see in the photo was enough. I sanded the cuts a bit, applied the two coats of stain to them, and the fence was ready.
How to make a height-adjustable wooden fence:
Odd way to make 30 and 60 degree cuts in wood
I make the lateral supports for the wooden fence
