I'm in the initial build stages of the C-beam XL, and am squaring the extrusions. To make one, just one, totally square took at least a couple hours. I have the extrusion clamped to my bench, and I'm using a file to remove metal. I'm checking for square with a Moore & Wright engineer's square. Should it be taking this long? Also, how square does it need to be? Am I looking for perfection here? I did see a clever idea on squaring with a table saw from @Metalguru and may go that route, but I'd like to get some input on using a file first. Thanks in advance.
I'd say it needs to be as square as you can get it. Imperfections will affect your machine's performance If you have a lot of shaving off to do with a metal file - consider going back to your table/miter saw and recalibrate that. Get that to cut as good as it can and there will be less work to do with the metal file later. Have not tried it but perhaps you could save some time using a disc sander if you devised a way to hold the extrusion in place?
Yep it is a pain..., it was put in the manual for those that don't already have a drop/table saw and aluminium blade with some lube. Took me about a day, that I will never get back from memory. So if you know someone with a drop saw and a suitable blade, square up their saw and do it that way. As you said give Metalguru table saw method a go if thats all your got. Glenn Weston has some great suggestions with his build using a drop or compound saw "The Moagie Mill" My C-Beam XLarge ; as Bad Sequel suggests squareness and exact lengths will save you a lot of sadness when you start to make some cuts latter down the line, as it will tram squarely, which is a good thing. Good luck @Aeneas.
Guys: I've found that it's extremely difficult to get my miter saw perfectly square. And then get that perfectly square with the supports. And then get that perfectly square with the extension fence. I got mine as close as I could, but it took a lot of time and if you ever touch anything, you have to do it all over again. I considered using a disc sander, but it would have taken quite a bit of time to build some kind of support to hold the piece perfectly square. This is where the table saw method works great as the table has lots of support, it's cast iron so not likely to move once you have it set, and it takes minutes to get it square. I've even taken the miter gage off, and put a blade back in to cut wood, and then replaced the sanding disk and everything was still bang on. The other big advantage is it's easier to cut your piece a red hair longer than you need and sneak up on the measurement. Now if I only had a caliper that would measure 1m+ lengths... Somehow I think something is lost using a tape measure... MG Edit: Using this method, I don't get it square to within .001", at least not that I know of. It's square enough that I don't see any gap on an 8" machinists square, which is good enough, I think, but it's still just using a calibrated eyeball. The best way IMHO would be to square the ends off on a milling machine, but I don't have one.
No matter how hard I tried I couldn’t get my miter saw perfectly square either. However, using a cross cut sled, the 5 cut squaring method, and a precision square for the blade tilt I can get a perfect cut every time on my table saw. Also great for shaving a hundredth of an inch or so of an end for a perfect fit too. Note: I made a cross cut sled just for the aluminum extrusion, using a length of confirmed flat aluminum (hollow 2x4.5 in rectangle with 1/8 thick walls) for the back fence/brace and HDPE for the runners, then took extra care to get it truly square.
Yeah I agree getting square cuts can be tricky. Even on my table saw I was few thousands out over some odd inches ( would need to check my notes to be sure. ) I built a cross cut sled and used the 5 cut method as well to get it as close as I could, But I am not much of a wood worker. Then cleaned up the ends on my 12in disc sander (Made a temp jig). Next batch of cuts I do for the up coming project. I plan on giving your idea a go Metalguru. Dealing with long lengths on my disc sander does not sound like fun jig or not. Not ideal given price or lengths over 1m. But A Mitutoyo 530-502 or 534-116 would be sweet
Kyo, I actually found a 1m caliper for a decent price - $332 CDN, that's about $19.95 US https://www.amazon.ca/HHIP-4100-000...9495&sr=1-7&keywords=vernier+caliper+0-1000mm Hmmm, very tempting...
Amazon US has them all the way up to 2.5m but at $3116.74 they seem a bit high for not even being digital. https://www.amazon.com/HHIP-4100-0012-Vernier-Caliper-2500/dp/B01BHHFVOY
Very nice discussion. Thanks for all of the input. I like the table saw idea, and I may try it depending upon the capabilities of my table saw. It's a Ryobi, so I'm not sure if it will be able to be squared accurately. I'll see if it works, and if it won't I'll be using the file method. If that's the case, I'll let you know how it went in a couple of weeks
I still find the best, and easiest way, to square an end, is to get it almost there, and then clamp an engineers set-square further down the piece, and use it to guide a router to trim the end square. Works every time.
That sounds interesting. I think I know what you mean, but are you able to elaborate on your process?
Well, there isn't much to elaborate on, which is the whole point. Do I have to say, "Using all the necessary safety gear!"? You initially cut to length with a chop saw, or whatever is your choice of weapon, leaving a couple of mm too long, enough to accommodate any error in that first cut. Sit your router on the aluminium with the raised cutter initially 1mm or so from the line. Slide your set square, along with a straight piece of timber, up the aluminium until it touches the router, and clamp well. That's about it. The first cut will show the square, and the degree of error. Then gradually move the square back until it is absolute. Do cut in small increments, don't be greedy! I use a two flute cutter designed for cutting worktops. The cuts are so minimal, that any aluminium that sticks to the cutter can be removed before each cut. I like this method because it removes that dreaded thing, I am very susceptible to, called, "Human Error". Gray
