Spiral Router Bits
George VondriskaDescription
Spiral router bits have numerous uses in your woodworking projects. Master woodworker George Vondriska shows the two types of spiral router bits and the advantages of each over traditional straight bits. A WoodWorkers Guild of America (WWGOA) original video.
Router Bit technology has really come a long way, and even what used to be just simple Straight Router Bits have progressed a lot. Let's have a look at a couple different options you can use in your router. This bit is simply a Straight Bit with carbide fastened to the cutting tips here and that real big news there. But these two are very cool, these are both Spiral Cutters. Those are the ones I really wanna talk about.
Now what's the deal with a spiral. When you are cutting a piece of wood, if you can shear it at an angle instead of cutting it straight on, you're always gonna get a better surface finish. back in the day when you were first learning to use a Hand Plane, somebody may have told you, "Hold that Hand Plane at a little bit of an angle as you're cutting the edge. And by shearing it like that, you're gonna get a better surface." Exact same thing here. So the spiral helps provide better cut quality.
Now think about the technology we would need to try to attach carbide to that spiral cutting edge so that we had the same where resistance the straight bit provides. In other words, we wanna get a carbide cutter here. How the heck do we do it? Well, the easiest way to do that is to simply make the whole bit out of carbide. That's what's happening here.
Both of these cutters are solid carbide. Couple impacts of that, one is that you got to watch the impact especially if you have a concrete floor in your shop. If you drop this bit, it's quite likely it'll break into two pieces. So you do wanna be careful handling them. Make sure you don't drop them.
A bit like the first one we looked at, would probably withstand a drop like that. You might the cutter a little but it probably wouldn't break. So we do wanna be careful about that aspect of the solid carbide bits. Now we can take this a step further. We've actually got these wound in two different directions.
This cutter is what's called an Upcut Spiral. Now I need to actually hold it in the direction that you would use it. Think about this being in your handheld router, and when the router spins, in its normal direction this router bit and Upcut Spiral is working like a Drill Bit does. The flutes are actually evacuating material out of the cut, helping lift them out of there so that it clears the cut. The other bit next to it is what's called a Downcut Spiral.
Now that's not a Southern hemisphere bit, it's got its own application. It's gonna spin of course in the same direction. You never reverse a router, but what's happening is this one spins is that it's pushing the fibers down into the cut. Why would you do that? Let's say that you're cutting a through a really delicate surface.
It could be that if we use the Straight Bit or the Upcut Spiral, it'll actually lift the fibers and it'll lead to chipping on the surface of that material. A great example would be something like Birdseye Maple. With this cutter, as the bit goes through the cut, the spirals are actually compressing the material and pushing them down into the surface to reduce or completely eliminate chipping that we get on the surface. So all of these bits have their place in your shop. The benefit of the Straight Bit, it's the least expensive of the three.
The Upcut Spiral clears material out of your work may cause a little bit of chipping. The Downcut Spiral is your go-to bit, if you wanna make sure the top corners of that cut are as crisp as they can be. So like I said, technology has come a long way. It's good to know about the different things that are available to you in router bits.
Funny they look surprisingly like the fluted end mills I used for decades as a machinist. Which I always thought would work just fine in wood.
George, I am going to cut a table top from heart pine. It is 3/4" thick, actually heart pine flooring that has been glued together to make 45" square. Using a Rockler circle jig to cut the circle which has a pin to hold the center. Will be cutting from the bottom side. What is best router bit for job, straight, spiral upcut, downcut? I am thinking after watching video sprial upcut since I am cutting from underside. Appreciate your advice. Thanks you
One type you didn't talk about was the combination spiral bit.I hope you'll redo this video to include the combination bit. One quick note, it's a bit annoying not to end the ad after the 1st 4-5 seconds like we can with the Titebond ads.
George...It may just have been light reflection on the bit but, it looked like the spiral bits had serrations similar to a metal milling machine bit. Additionally, do they make a router bit with serrated edges for use in mortise machines for hard wood?
It works fine for me.
George, this is (only half) funny - idk if u r aware that this video u posted is incomplete. Ive seen a few vids of yours end abruptly like this, but this is my first time commenting on one of them. I'd like to make the obvi request of u updating it, or enter in a new one, named part 2 or something. I know u wanna empower us w/this knowledge that u intended to convey to us, & we would like to utilize that knowledge just as much! Thank you... ;-)