Another few days of work down, and we are steadily making progress on the media console. One aspect of this whole furniture-making thing that I did not comprehend previously: the importance of 90-degree cuts.
Sounds simple - make a cut here, make a cut there, screw a few boards together, and voila--you've made a box/drawer/cabinet/etc. As it turns out, even very slight errors make for very wonky, sloppy furniture and very frustrating afternoons.
So we spent several hours the other day constructing what is called a "cross-cut sled" to help us make perfect 90-degree angle cuts with the table saw.
The basic construct of a table saw is just a flat surface with a stationary blade that comes up through it, and then you run your boards across the blade to make cuts.

Do you see the 2 slots that run parallel to the opening where the blade comes up (above)? Those are "miter slots".
You can take advantage of the miter slots by making a sled with runners that fit snugly into the slots and then affixing a "fence" (described 2 posts ago) to the sled to hold the board you are cutting perfectly still and straight.
So without further ado, here are the steps we followed to make our cross-cut sled:
1. Acquire a big piece of plywood or MDF to be your "sled" (ours is 3/4 MDF, about 22 x 26")
2. Mark where the runners will go and get some appropriate length screws.
3. Screw the sled to the runners. (we made our runners from 3/4 inch plywood strips, but you can also order them online or buy aluminum ones from a specialty woodworking store)
4. Start the table saw and bring it up into the middle of the sled, cutting a slit in the sled to let you know where the blade is.
5. Measure 90 degrees from the blade cut, and place a fence there (click here to see how to make a fence).
6. Screw the fence into the sled.
7. Bring the blade up only high enough to cut through the rest of the sled, but not through the fence. Thus, the fence acts as a bridge, keeping the 2 halves of the sled together
We also affixed an additional bridge at the other end of our sled to provide additional support to the sled.
Now you can put your board right up along your fence and be confident that it won't move and you will get a nice, 90-degree cut; very important.

And that is all I know about making a cross-cut sled! And now you know it, too.




