How to Turn a Cylinder with a Router

When you see a cylinder like this one you are probably thinking lathe then, you know what? It's crazy, but I'm thinking router, I have got a shot made jig here that makes it absolutely dirt simple to make a perfect cylinder like this, massive thing that it is using a router. Now let's say you've got a couple of things going on here. Maybe you don't own a lathe at all, or you own a mini lathe or the limited spindle capacity and you need to do a table leg that's 27 or 30 inches long or maybe you own a full-size lathe, but your turning skills are such that you're not quite confident. You can make a perfect cylinder or for tables four that are identical.

This router base jig is a great answer for this. Let me describe how this works so you can understand that, and then I'll talk about what it takes to make it. We're going to take a rough blank like this get it inside the box. So it has to be suspended on centers in there kind of like a lathe would hold a piece of wood. Once that's set a router is going to sit on top, travel back and forth.

So as we turn that blank by hand, the router is taking off the waist and leaving a cylinder behind. So here's what we've got. Let's talk about the box first. I made this one out of plywood. Very, very simple construction dimensions are, it's five inches by five inches inside 36 inches long.

I did 36 because 27 to 30 inches is a very common table leg length. So this gives you plenty of capacity to do table legs. Now I use plywood so that it'd be nice and durable and everything would be very, very straight. On the ends, I've got a series of holes drilled. Now what's important is that both ends have holes and they both have to be perfectly located relative to each other.

So the way I did that was I cut the two end pieces and I stacked them up and I drilled the holes at the same time. So that as I was drilling this one, this one and this one, it went through both pieces. So they have to be located the same. I've got the holes five, eight, seven inch apart and center. So this one is in the very center of my piece, this one five eights up, this one five eights up.

So that gives me a variety of applications I can use this for, while I'll talk more about these upper holes in just a second. On this part of the jig, I've got a flange that projects out that way when this is down on the table I can get a clamp on here that holds everything securely. On this side of the jig I've got a hole drilled, that'll take a vacuum hose so I can run dust collection on this while I'm doing the routing. So that parts very simple. Now, in order to drive the cylinder for the turning process I had to make up some hardware.

I'm using three eight strip threaded rod for this, so I've got three eight inch holes drilled in my piece. Let's talk about the tail end first, this is very simple. Six inch piece of threaded rod it's sharpened on this end, so when I had my blank prepared, I'm gonna dimple the end of the blank with a scratch hole and that sharp tip is going to go into that dimple. This washer is going to be on the inside of the box with a nut holding that in place, this washer and wing nut on the outside of the box. So I can advance this threaded rod, kind of like a tailstock on a lathe against my blank.

Once it's in the right spot I can lock it in place with the wing nut. So that side's real simple. This is the drive end of it. The handle is very simple, just a piece of material, piece of wood with a dowel screwed onto it so I can spin this by hand. Now this part is the drive end of it.

So I've got a washer which has actually been epoxied onto a nut. So those two parts are stuck together it's important that you have that. When this is in place, I can pull it up onto the threaded rod like this and lock it in place with the second nut. The threaded rod that's sticking out is going to go into a three eighth inch hole that I drill in the headstock end of my blank. So I'm going to drill a hole, then I'm actually going to use hot glue on this little flange to hold that against the end of the piece.

So that as I spin this I can drive the cylinder. On the other end, this large fender washer is going to go against the inside of the box. That's going to help secure everything this way so that it doesn't just fall out the box. So it's going to end up looking just like this on the inside of the box with the majority of this six inch piece of threaded rod sticking out. So that's the hardware part, simple to set up once you understand it.

Now let's talk about the router setup and what I had to do there. The router needs to be able to bridge the box. So I made a wooden base for this. That's big enough to span the box. It's got two runners on the outside edge, so that limits the travel this way.

Underneath I have to drill a hole for the bit to come through. I commonly use a three quarter inch bit for this, so I drilled a one inch hole. I've got stops here so that when I get to the end of the travel, the stop limits the travel of the router so the router bed can't cut into the box. So that holds it in that direction. The other stop stops it in that direction.

And then of course these runners limit it this way. So there's no way that I can accidentally run that router into the plywood box. So that's the setup. That's the stuff that you need to build in order for this to work. Once you've got that set, now we're ready to actually get our spindle blank mounted inside the box.

I've got the hardware re-installed in the jig, I've got my vacuum hooked up here but let me talk about some preparation on this blank I've got ready. This is a big chunk of Walnut. I actually glued it up from three individual slabs in order to make such a big piece. It's three and a quarter by three and a quarter. The other thing I did up to this point was cut the corners off.

We could do the whole thing on the router here but it's just a lot easier, it's going to go a lot faster if you start by taking the corners off very similar to what you'd follow if you were working on a lathe. On this end which will be the drive end of this setup I've drilled a three-eighths inch hole about an inch deep. The threaded rods is going to go in there, then remember that big fender washer, the fender washer is going to get hot glued to the end grain here that's going to let me spin this and drive it. On the opposite end. Once I found center I used a scratch hole and I made a small dimple, the tail stack end of this with a sharpened end is going to seed into that dimple and support it there.

So now that we've got the blank ready to go we can actually get this inserted right in the box. Now notice that when the drive into this goes in there's a small wooden space right here, and that holds everything the correct distance off it's just a piece of three quarter inch plywood. On this end the drive end of my cylinder, I can apply hot glue, and then that'll seat against that flange. And that's going to hold everything together for the drive end to the box. on the other end of the cylinder, I'm going to advance the threaded rod so that the sharpen point goes into the dimple I made with the scratch all, then move that nut, So it bears against the plywood box.

I'm going to give that a turn with a ranch. I want to make sure that I've got a good squeeze on that cylinder and it's going to stay held between centers. Then lock everything in place by advancing the wing nut on the outside. Now the cylinder is secure and can rotate freely inside the box. Now with the cylinder mounted in the box, we can set up the router, got this unplugged.

Here's what I'm going to do is, I'm going to set my depth of cut on the router bit so that it just kisses the top of one of those flats. That's going to be first pass. So I'm going to do that by just putting the router on there, and then I'm going to dial that down. That's right there at the top of the flat. Now I can come off the end of my cylinder, turn the router on and then at the same time, I'll start turning the cylinder, work the router down the length.

Now, if there's spots that you missed, just like I did you can come back and you can cut those. Then come back to this end of the cylinder, increase your depth of cut a little bit repeat the process and keep doing that over and over again until you get the finish you want and the diameter of cylinder that you're trying to produce. So I can keep going now on this one. In order to get the best possible finish on your cylinder. You want to travel with the router slowly while turning this fairly quickly.

So it's a little bit like rubbing your hand and patting in your stomach. It takes a little bit to get used to doing those two actions together, but do that as best you can to get your optimal surface finish. The good news is we can easily get a perfect cylinder. I guess the bad news is that this does require some hand sanding when you're done to even out the high spots and get the best possible surface on the cylinder. When I talked about making the box, I was mentioning there are three holes on each end.

So let me explain that to you. A couple of applications for those three holes, one would be, if you're just planning working on a smaller diameter cylinder, having holes up from the center will allow you to move the cylinder up. So you don't have to try to project the router bit so far out of the base of the router. The other thing that we can use those holes for is imagine what you'd have, if we use the center, the bottom hole on this end and the top hole on this end. It would allow you to create a tapered leg.

So it's a pretty cool approach. It's a pretty cool way to make a taper and because we're doing it in the box with a router every one of your tapered legs would be exactly the same. A little bit of experimentation of the length relative to the offset that you introduced from center to center but with a little bit of practice and a little bit of experimentation you'll be able to make very cool cylinders, tapered legs, lots of applications for this easy to make jig. You'll have lots of uses for it in your shop.