Question for metal fab guys

• Question for metal fab guys
  Posted by Buckeye513 on 14 Mar, 2013 09:10
• What thickness of aluminum would you use for a custom air box for an lt500? Would you use sheet aluminum or plate aluminum?
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• #1 Reply
  Posted by Buckeye513 on 14 Mar, 2013 13:10
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• #2 Reply
  Posted by RustBelt on 14 Mar, 2013 13:16
• I bought mine from a member. Love it. I'd say it's a bit under 1/16" thick. Very sturdy.
  
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• #3 Reply
  Posted by RustBelt on 14 Mar, 2013 13:17
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• #4 Reply
  Posted by Buckeye513 on 14 Mar, 2013 14:12
• Shawn isn't doing any 500 boxes so I'm making my own.
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• #5 Reply
  Posted by STARPUSS on 14 Mar, 2013 16:52
• use what you can find cheap , And  what your Comfortable welding
  5052 series aluminum is what i would run, I Find its REAL nice to work with . 16Gauge 1/16"  .0625mm 
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• #6 Reply
  Posted by Buckeye513 on 14 Mar, 2013 17:45
• Thanks starpuss I'm not a welder and don't plan on learning on a custom aluminum piece. I'll be designing and cutting the aluminum but paying someone to weld it together for me. I'm just clueless on what type and gauge/thickness is to much and what's gonna be to flimsy or weak.
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• #7 Reply
  Posted by Dezsled on 14 Mar, 2013 18:21
• Good for you. Make a template so you can repeat your parts, you might be making extras for members here!
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• #8 Reply
  Posted by WestTexasKing on 15 Mar, 2013 01:39
• I wouldn't bother with welding it, just use pop rivets (or solid rivets if you have the tools and skill).
  .032"-.040" 2024-T3 would be a good metal to use, it's alclad (alloy that's clad in pure aluminum for better corrosion resistance), and it's been proven sturdy enough for airboxes in thousands of aircraft flying today.
  You'd need three pieces for the box, one U-shaped piece that makes two sides and the bottom, two flat plates for the sides, and another flat plate for the lid.
  Factor in the intake flange, drain hole, screws and rivets, and you're looking at spending maybe $50.
  Sheetmetal:
  http://www.aircraftspruce.com/catalog/mepages/alumsheet_2024t3.php
  Pop rivets and gun can be bought anywhere (like Ace hardware), these would be your strongest (and most expensive) option though:
  http://www.aircraftspruce.com/catalog/hapages/cherrymax2.php?clickkey=10160
  Tinnerman nuts:
  http://www.aircraftspruce.com/catalog/hapages/tinnerman2.php?clickkey=5485
  Simple button head sheetmetal screws:
  http://www.aircraftspruce.com/catalog/cspages/screws.php?clickkey=11590
  
  Making the box itself is really simple.
  Just imagine making a carboard box and using staples to hold it together.
  You'll need to bend a small portion of the sheetmetal (about an inch) so the rivets will have a joint to hold.
  
  -Cut and bend the sheetmetal (aviation snips for cutting, bend with a large vise or buy a sheetmetal brake at harbor freight for $20)
  -Coat joints in silicon
  -Drill two holes 1/4" from the corner joints and rivet pieces together (think of it like tack welding)
  -Fill in the gaps with rivets spaced out an inch or so (more rivets per inch=stronger joint)
  -Use self tapping sheetmetal screws and tinnerman nuts to hold the airbox lid on
  
  You'll have to make a few right angle tabs to rivet the intake flange to the airbox (4 tabs or more), and seal with silicon.
  I suppose JB weld or epoxy would work just as well as silicon too, as long as you get a good seal out of it.
  
  If I had the materials handy and knew the measurements, I could probably make one of these boxes in less than an hour...bending and riveting is really simple.
  
  End result is an airbox that's extremely lightweight and durable enough to last on aircraft for 10,000+ hours, no need for custom welding (or the costs that go with it), easily patched if broken, looks great (alclad takes very well to polishing btw), and the satisfaction of having built it yourself.
  
  
  This should give you an idea of the joints I mentioned that you need to bend:
  
  
  
  
  
  It's a great example of how simple an airbox can be made, all you're looking at is 3 pieces of bent sheetmetal.
  There's some tabs bent over to match the other pieces so you can drill through and rivet.
  They've already drilled in the right spots to tack the box together, once you get those corners riveted you can continue to add rivets as needed along the sides.
  
  It helps to use vise grips where you drill and rivet so the pieces are straight and flush when the rivet expands.
  One thing to mention that a lot of guys overlook when building out of sheetmetal...radius the corners and smooth the edges!
  All it takes is a few seconds on the grinder/dremel or a few swipes with a file and those sharp corners won't cut anything.
  A quick pass with a file along the edges followed by 80 grit sandpaper is all it takes to smooth out sharp edges along a cut.
  
  
  If you decide to give it a try, I'll be around for advice...
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• #9 Reply
  Posted by Buckeye513 on 15 Mar, 2013 03:50
• Westtex what about the hole for the filter and intake tubes I was gonna get 2 inch long round aluminum tubes 4" or 4.5" diameter and have them welded on each side. I like the idea of not welding the whole box though. I'm thinking I could even weld some nuts to the piece the filter mounts to and put like sticky foam on the seams of the box and it would seal once the nuts were tightened down. That way that plate could stay in place to hold the filter and the rest of the box could be removed quickly.
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• #10 Reply
  Posted by WestTexasKing on 26 Mar, 2013 12:43
• Whoops, guess I missed your reply, sorry for being so late!
  
  For the tubing connections, there's an easy way to secure them without having to weld.
  Cut a circle out of aluminum, draw the diameter of the tubing you want to use over the circle (the circle needs to be 1/2" or bigger than the tubing).
  Make some cuts radially out from the center and ending at the line you drew to make mounting tabs.
  You want them to be anywhere from 1/4"-1/2" so they'll accept a rivet.
  Cutting a circle out of the center with a hole saw or similar will make it easier to use shears for the tabs, and will result in fewer sharp edges.
  Take these tabs and bend them out 90deg.
  If you cut and bent it all correctly, the tubing that you want to use should fit snugly inside of this mounting flange.
  Insert the tubing, drill a hole in each tab through the tubing, seal it up good with silicone, and rivet as the silicone is drying.
  Rivet/seal the whole assembly to the box, using the 1/2" extra on the mounting flange to mate up with the box.
  
  You can use variations on this idea to suit your purposes, like using nuts/bolts instead of rivets on the ring so you can remove it, using sticky foam to seal it, etc.
  The picture below shows one way of doing it, but if you want the airbox to look nice on the outside without visible tabs and rivets, mount it backwards so what you see in the picture is on the inside of the airbox.
  Push the intake flange out of the airbox until you get the right length, rivet, then cut the excess tubing from the other side, flush with the tabs.
  
  
  
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