 how to flatten your workbench using a router sled. You can use this technique to flatten your new workbench or more important to re-flatten your workbench after every couple of years. Let's start with a discussion of the sled. I use three-quarter inch plywood. The base is one and a half inches wider than the width of the router. That way the base can accommodate two rails. When I get it all put together, as you can see here, I wax it up. Now in that base, before you put the rails on, you want to cut a slot down the middle that is about four inches from each end and sufficient to accommodate the width of your router bit. You may want to make it a little bit wider so that you have some vision of the workbench. Now I just marked it off as a rectangle with a magic marker and then I drilled with a drill bit in the four corners and then I used my jigsaw in order to cut out the slot. And it doesn't have to be precise. It's just something to allow your router bit to get down to the work table or workbench. As for the length of the base and the two rails, make sure that that's a good four to six inches longer on each end than the width of your workbench. So here my workbench is 26 inches wide so I made my base 34 inches. That's to make sure you can get all the way to the edges as well as not have your router sled drop off of the rails as you're pushing it forward that you've got plenty of extra room to support on those rails. Make sure the height of your rails does not interfere with any handles on your router when you are going to have your router plunged. In his video on the same subject, Mark Spagnola, the Wood Whisperer, said to build four-inch rails but that might work for his Festool router but that did not work for my Bosch. And so I had to go to two-inch rails that way when I plunged a good quarter of a half an inch below the bottom of my sled. I still had clearance over my handles. I definitely wanted the handles to push onto and to hold the router in place. As shown earlier, wax the sled. Make sure it slides easily and then test it for a folding. Make sure it's not getting hunked up anywhere while you're running your router. All right, sled done. Let's now turn our attention to the rails that are the key to making your workbench level. The first thing is to get some really straight sacrificial boards from wherever, Home Depot or your hardwood store. Make sure that the tops are perfectly flat with each other to do that. I put them together and I used my number seven plane in order to make sure that they were flat and totally equal to each other. Then I used two-sided tape and put those temporarily up against the edges of my workbench at about a quarter of an inch above the surface. I had marked a quarter of an inch line all the way along that helped me line that up. That was just temporary. I then took a Bessie clamps or parallel panel clamps and I attached those underneath the bench to hold those sacrificial pieces in place. Now, the next step was to go to three edges. So I went over there, here and here, and I set a quarter of an inch on my combination square and I made sure that each of these in those three locations were precisely or as close as I could make it of a quarter of an inch below the sacrificial bar here. Then I got my clamps on there, pretty awfully, fairly tight. Then I screwed some clothesline. This is just plastic covered wire that was sold at Ace Hardware at clothesline. I screwed that to the four corners. I got the three really tight and then actually they're all tight. And the idea here is to align these so that these touch each other. Now, you'd like them to pass through each other to compensate for the fact that one is on top of the other one that therefore can't pass through. You put a piece of the wire underneath the edge of the top one. What that does is it raises it up the width of one wire. Now, when you adjust, let me get this out of adjustment to show you, how the theory is that these have to be parallel to each other when these two lines just barely touch each other. You can tell they touch each other by checking, pressing down on one and seeing if the other one drops. In other words, if this one was down on this one, then when I pressed down, that would go down. If it's too high, when I press up a little bit, the top one doesn't move. In other words, I'm not touching. So I want to get this to where it's precisely touching the other one. And then that should tell me that I'm parallel because I've adjusted for the fact that one width. All right, that's the best I can do. I go back and I check to make sure these haven't changed at my three basically fixed points. I failed to capture it on camera, but the next step is to slide your sled all the way along the bench and find the place where the workbench itself is the deepest or the lowest in comparison to your sled. You will then want to set your plunge router bit so that it plunges to that point, if not slightly below that. And then you can start routing the entire length of your workbench. The other thing you want to make very sure is that your bestie clamps or parallel clamps are really tight and that those guide rails are not going to push down at all as you exert pressure with your router. Using a sled like this with a router is going to create the most debris that you'll ever create in your workshop. So you may want to do some precautionary stuff. I wasn't smart enough to do it and cover up some things like your computer or some of your different power tools. Otherwise, they're going to get debris all over them. It's going to be more time consuming to straighten, clean everything up. A few words of caution. Making very sure that you keep the router sled up on the rails and that you don't let one end accidentally get off of the rail and on to your workbench. Otherwise, you'll be plunging too low and then you'll have to plunge everything to that height. And then I think it's a good idea not to end up with a lot of little debris along the edge of your real workbench to go ahead and cut into your sacrificial rails. In other words, you'll hear the difference when your router hits those rails. Go ahead and plunge into that rail a little bit so that you've gone all the way over the edge of your workbench. That way you won't leave a lot of little triangles as you have to clean off. Your router bit will leave a lot of little ridges all across your workbench. Some people recommend just leaving those so the workbench will be a little better to hold the devices on it or work pieces on it. I prefer to get rid of them and so I use the lowly card scraper, one of the most effective tools in my workshop. So enjoy flattening your workbench and have a good day.