Hey Guys: Just set up a cool jig for squaring the ends of v-slot and c-beam. A while back, I was looking at a "calibration disc" for my table saw. It's basically just a saw blade sized disc with no teeth, the idea is it gives you a nice flat surface to calibrate your fence, miter gage etc. against. Easier than using a saw blade cuz there's no teeth to get in the way. But, the better part of all this is that they make sanding discs that fit this device, so you can turn your table saw into a disc sander. This got the gears grinding, and I decided to get one. $30 later I had the disc and a pack of 100 grit sanding discs to go with it. I installed the disc and used a nice little machinists square to set it square to the table (vertical) and square to my miter gage. Then I took it back out and applied the self adhesive sandpaper disc to it, and reinstalled it. I set up my miter gage (I know it looks weird, its an Osborne miter gage that is kind of triangular in shape) and locked it into the slot by tightening the setscrews in the slide. These are normally used to take up the slack in the miter slot so there is no side-side play. Here it is all installed and calibrated Works like a ****! After a little fine tuning, it makes a perfectly square end on V-slot in seconds. Just put the piece against the miter gage, slide it up to the sanding disk, and apply a bit of pressure. It also works really slick for taking off that last half mm to tweak the length of a piece. I thought about doing this with a regular disc sander, but I would have had to fabricate a bunch of stuff to hold the v-slot square to the disc. This setup took a few minutes, uses stuff I already had laying around, and produces great results! MG PS Both Freud and CMT make these, mine was a cheap Chinese knockoff. Also InfinityTools.com and EagleAmerica.com.
@Metalguru I lack both a disc sander and a table saw and have been looking for the best way to square up and finish my beams better after they are cut with my miter saw or horizontal bandsaw. Can you comment on whether this is a better solution than getting a dedicated disc sander? I realize that for you it was cheaper as well since you already had a table saw. But if you suddenly got disc sander as a gift tomorrow, would you give this up and use the disc sander? Or would you stick with this setup anyhow? -D
Jonathon Duerig, I would definitely stick with this method. It is possible to do this with a disk sander, and in fact I already have one. But it would require quite a bit of work to build a support to hold the v-slot perfectly square to the disc. It would have to be perfectly square in both directions. Typically, the tables on disk sanders are poorly constructed and flimsy as well. You need the support for the piece well out from the sanding disk. That's why the table saw works so well, I have 24" or more of flat surface to lay the work on to keep it aligned, and my miter gage is about 20" long as well, so its easy to keep the piece perfectly aligned to the blade in both planes. Also, you have the advantage of a perfectly parallel miter slot and a cast iron table to keep its position over time. The table saw is already made to be highly accurate in the first place. Not saying its not possible, but its a lot more work. Also, you would have all the same problems as you do with a chop saw that caused me to come up with this method in the first place. MG
Just a few more tips/observations after using this for a while: Wear a dust mask! This thing generates a ton of fine aluminum dust, which I surmise is bad to breathe. I have a dust collection system on the table saw, but it still gets fine dust everywhere. Clean off the saw table frequently to keep dust buildup from reducing your accuracy. I keep a small brush handy to sweep dust into the saw slot where the dust collection will pick it up. Keep a garbage can nearby to tip out the dust that collects inside the extrusion. The thing will fill up with aluminum dust very quickly, and if you don't get rid of it it ends up all over the floor. You can see your progress by looking at the sanded end. It is easy to tell a saw cut finish from the sanded finish, so it's also easy to tell when you've removed enough material. Replace the sanding disk regularly. When the sandpaper gets dull, or clogged, you start to get aluminum rolling over the edges which affects the accuracy and leaves hard to remove rolled over edges. Couldn't think of the right word... Swarf? Wear gloves. The aluminum gets hot fast near the end being sanded. Wear safety goggles. I shouldn't have to say this. Other than the above, it works great. I keep a 10" machinists square nearby to check the ends once in a while. Built several machines with this and love it. MG
I might suggest too that if you have compressed air in the shop it's great for blowing the particulates out of the channels.
no, 'swaged' is the word, bent to a new shape without cutting. swarf is 'metal sawdust' , I make a lot of it with my lathe (-:
I'm not sure I would want to blow that dust all over the shop. As I said it is pretty fine and would not be good to breathe.
A further word of caution - Aluminium dust can explode! see http://www.aluminum.org/sites/default/files/Safe Handling of Aluminum Fine Particles.pdf
It has to be really fine to be flammable, like flour. The dust off an 80 grit sanding disk is coarse by comparison. Not making light of your warning, it's good to be safe, but trust me, in my younger days I tried and failed many times to make flash powder using aluminum dust. Never got it to work. MG
