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I'm planning to move my table saw fence guides over to allow suspending an extension table at one end for my router. I've seen plans for doing this on my Craftsman hybrid 22114 saw using 1-1/2" x 1-1/2" x 1/8" angle iron. I'm wondering whether the iron is particularly superior in this application to the much lighter and easier to handle aluminum? Seems that I'd need to coat the iron to prevent rust, not to mention the hassles of drilling and installing that heavy stuff. And I'm only shifting the fence guides about 9" over, plus adding a router table to the shifted end. What do you civil or structural engineers think? How about if I extended my mobile base as well, and put a couple legs from the base up to the ends of the aluminum?
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- David
“Be yourself; everyone else is already taken.” -- Oscar Wilde -
David, when I did my 1/2 rail wide table extension, I used aluminum with 2 T nuts on either side of the bottom and 2 T nuts on either side of the back. It worked great. I did fashion legs to help support the weight of the router table though, just a couple of poplar legs with levelers on the bottoms.
Served me well for a couple of years before I got my PM2000Keith Z. Leonard
Go Steelers! -
Aluminum would actually a superior material to accomplish what you want to do.
It's stiffer then steel which is what you want.
Signifigant weight savings is an added bonus.-John
"Look, I can't surrender without orders. I mean they emphasized that to me particularly. I don't know exactly why. The guy said "Blake, never surrender without checking"
-Henry BlakeComment
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Aluminum is stiffer then steel.
I guess I don't know for sure, but I don't see why the same wouldn't hold true for angles, so long as they dimensions are exactly the same.
Aluminum dosen't bend much at all - it just snaps. Steel will yield long before it snaps. In the true measure of strength, steel (I believe) is technically stronger (ie there is more area under the stress strain curve). But how many applications would you really want the material yielding a bunch?
Bike frames for instance are an interesting example - a steel bike frame with actually deform a little with every bump it hits, acting as "suspension" for the bike. Aluminum frames will not deform this way, and transmit these bumps directly to the rider. That's one reason steel is a much more common material for typical bike frames - although for "high end" riders, the weight savings and precision (yielding on a bump makes the handling "sloppy") of an aluminum frame is worth the extra punishment.
Steel is harder, cheaper and easier to machine. This is why it's much more common (or at least some of the reasons).
PS Aluminum is softer - therefore easier to drill, but will not hold the threads well at all.Last edited by Garasaki; 01-12-2008, 01:24 PM.-John
"Look, I can't surrender without orders. I mean they emphasized that to me particularly. I don't know exactly why. The guy said "Blake, never surrender without checking"
-Henry BlakeComment
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The biggest issue I find with aluminum, is finding it straight, not prebent, at my local suppliers. I tend to catch it AFTER people have grabbed the straight stuff.
It wouldn't hurt to grab some extra for other projects.She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.Comment
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Read this about bike frames, steel and aluminum stiffness.
http://www.sheldonbrown.com/frame-materials.html
Aluminum is about 1/3 as stiff as steel. it's the use of oversized aluminum tubing that makes an aluminum frame stiffer.Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas EdisonComment
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Ok looks like I'm totally wrong
I coulda swore aluminum was stiffer. I guess not!-John
"Look, I can't surrender without orders. I mean they emphasized that to me particularly. I don't know exactly why. The guy said "Blake, never surrender without checking"
-Henry BlakeComment
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Router Table Extension
I'm wondering how big your router table will be. I removed the small wood extention table that came with my 22124 and replaced it with an 18" router table extension. The extension is bolted to the fence rails, in thier standard position, using their factory holes. It has worked great for me without sagging to this point. I'm sorry I don't have a better picture to show you.Comment
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My 22114 didn't come with any wood extension table [nor Biesemeyer fence :>( either!]
Where'd you get the 18" router table extension? Sears or some 3rd party like Woodcraft?
Also, I think the 22124 has longer and stronger fence rails than the 22114.- David
“Be yourself; everyone else is already taken.” -- Oscar WildeComment
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Aluminum is strong enough if it is at least 1/8 thick and an inch and a half wide. Maybe if it is 1 inch wide.
You could probably cantilever an extension table 9 inches with no support if it is firmly clamped to the rails.
Aluminum yields a little under stress. Steel does not permanently yield until you go above the yield point. If you load steel below yield, you can do it nearly an indefinite number of times and it will remain the same strength (you have to also look at fatigue but that is a lot of cycles and for many applications you can't get there from here). Aluminum essentially does not have a load level where it does not weaken a little bit with loading. It is not really that good a material to withstand heavy loads. It is strong for its weight but it's mechanical properties are distinctly inferior to steel. You do not see aluminum reinforced buildings both due to cost and due to steels superior properties. Old airplanes are risky because you cannot depend on aluminum forever.
For an application like you describe, everything I just said is immaterial.
JimComment
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