Five Router Difficulties and How to Avoid Them
Any woodworking tool that spins at 25,000 rpm presents both great potential and great pitfalls, and that’s certainly the case with routers. Check out my video on router bit options here to learn the basics of router bit choice, then come back and read on to learn how to overcome five challenges that every router user faces.
Pitfall #1: Routing the Wrong Way
You’re not likely to make this mistake often, but it does bear mentioning for beginners. Wood must always encounter the bit traveling against its direction of rotation. And since all routers spin the same way, success boils down to a simple rule: move all hand-held routers from left to right; feed wood across a table-mounted router from right to left. Get this wrong and the router bit will grab the wood and fling it instead of cutting cleanly. “Climb cutting” is a specialized operation where wood is intentionally fed in the same direction as bit rotation. Though this technique has some benefits, it’s also tricky and unnecessary. Don’t bother attempting it.
Pitfall #2: Biting Off Too Much
You can buy a brand new 3 1/4 hp router for $100 any day of the week, and with this much power in your hands, it’s tempting to rout too deeply in a single pass. But ease up, even if your router has the power to leap tall buildings in a single bound. Don’t cut anything more than 3/8”-deep in multiple passes – less if the profile is wide or your router is smaller than 2 1/4 hp. Your router and bit will last longer and the quality of cut you achieve will be better, too.
Pitfall #3: Don’t Rout Too Slowly
Cutters on a typical router bit hit the surface of routed wood about 800 times each second, and the potential for friction and heat build-up on the surface is high. Heat can cause burning, especially when you’re putting decorative edges on hardwoods like oak, maple, ash and beech. The solution is to reduce the number of cutter impacts on a given section of wood by moving your work piece across the bit more quickly. Tip: Rout all the wood off the edge profile except for about 1/32”. Extend the bit enough to take this final, very shallow pass, then complete the cut quickly. The wood won’t even have a chance to get warm, let-alone burn.
Pitfall #4: Beware the Warped Router Table Top
A flat router tabletop is good and a slightly crown one is fine, too, but a dished tabletop is bad news indeed. That’s because it causes the location of routed edge profiles to vary along the length of each workpiece. Here’s how: Imagine you’re milling a Roman ogee profile on the edge of a 36”-long drawer front and your router table top is dished just 1/16” in the centre. As the leading end of your drawer front hits the bit, it’s more-or-less tight to the table. But as you continue to push the wood farther along, the leading front end of the wood rises as it climbs up the dished shape on the other side of the table. And as the wood climbs higher and higher, it raises the middle part of the board in the process. This action causes your routed profile to shift 1/16” further down along the edge of the wood than at the ends. The more intricate the profile, the worse this shift looks.
Pitfall #5: Beware the Bearing
Many great router bits include bearings that guide cutting action, but these often leave track marks behind on soft wood. Some marks only show up while staining, when it’s too late to eliminate the trouble easily. Avoid marks altogether by using a fence on a table-mounted router, even when a bearing alone would do the job. Besides yielding mark-free results, a fence boosts safety by covering most of the bit so your hands and fingers are less likely to run into it.