So I’ve been thinking over how I use my router for pattern routing and though I have been pretty successful thus far I know for fact that I have actually wrecked more projects using the router than I have created. You see a router is a very violent tool. Spinning at 10,000 RPM, on the low end of my variable speed model, its great for long, straight cuts, or even for wide arcs or circles. Where you run into problems is with cutting around thin parts of a pattern or cutting narrow arcs or circles. That carbide blade isn’t forgiving and even touching part of your work-piece the wrong way can be catastrophic. I can’t tell you how many times I have moved a work-piece into the blade and within a split second and with hardly any resistance at all a piece has been snapped off and is flying across the room. Naturally experience is a big, big piece of the puzzle, but every pattern cut is different because the wood grain is different on every board. Combine that with gluing up different sized boards to get what you need and it can be frustrating as now your dealing with the grain of three or four different pieces of wood.
One area I have seen trouble with time and time again is the hilt of the Curtana. Both the main body and the side scales are thin and even if I am making the cut just right it can still end up snapping off, ruining a perfectly good work piece and wasting the time spend edge gluing everything up the night before.
Recently I ran across an interesting little tool called the Robo-Sander. This ingenious little device is a pattern SANDER that is used in a drill press. It works much like a pattern bit for a router: The bearing on the bottom of the sanding drum rides along the pattern your following while the sanding drum removes material from your work-piece to create a perfect duplicate!
Intended for instrument makers, it seemed like a less violent and more controllable alternative to the router, as it works at a paltry 2,000 RPM max and doesn’t chop away at material the way a router bit does. Even though my spiral cut bit uses more of a slicing action instead of a chopping action the speed of the blade makes it just as likely to break something, while sanding is much more gentle.
I have a couple of issues with the Robo-Sander, though, and they are strictly personal in nature. First the smallest size you can get the tool is 1″ diameter, which is double the diameter of my straight edge router bit. Not a huge deal until I need to work on a narrow space. If I needed to I could still use the router for those cuts, but I run the risk, again, of breaking something. Second is the drill press setup. It’s probably ideal for making instruments but for making a four foot long sword, or longer, the column holding up the motor is bound to get in the way at some point. I considered trying to use it in my router table, but at 2k RPM max, spinning it at five times greater is likely to tear the thing apart.
A bit bummed I did some online searching and found an interesting alternative!
So these are the plates for my oscillating drum sander, a sander that is very much like a router table except the sanding drum spins while also moving up and down to remove more material. (see below)
Though you can’t see it in the picture the plate goes underneath, or rather, around the bottom of the sanding drum so that different sized drums can be accommodated. This eliminates the gap between the edge of the hole around the drum.
I found a guy on YouTube who custom made his own plates out of MDF, but in addition he added a small lip around the inner edge of the plate, around the hole the sanding drum protrudes from. Using this lip similarly to the way the bearing gets used on the pattern bit, he could ride the pattern along the lip, preventing it from touching the sanding drum, while his work-piece, stuck on top of the pattern with double sided tape, gets sanded down into the shape of the pattern! The finished piece would end up being slightly larger than the pattern, but that would be inconsequential in my case!
Rather than trying to make a plate out of MDF on my own, which would require a lot of large hole cutting, I opted to create new plates in my 3D program and see about having them 3D printed!
With accurate measurements it’s a fairly simple thing to add a quarter-inch lip around the inner hole for multiple sized rings, and then send the files to a 3D print service and have them printed and shipped for around 20$ a piece. I’ll look into ordering one here soon for testing and, if it works, I’ll be sending in other sizes for printing as well!
This could be a fantastic discovery and a great help for me! Not only that, but if it works well I can make up some files for different models and brands of drum sander any maybe print and sell them for a small profit. Not much, but at least enough to help me buy more materials.
I’ll keep updates posted as the process moves along!