Tips for bending aluminum sheets?

Posted: 4/1/2013 6:05:47 AM
Chainsaw Willie!

From: Just a short walk away from Nike Missile Site S-13/14

Joined: 1/28/2011

You guys are working with some pretty thick stuff.  I have done a fair amount electronics chassis fabrication at work, and bent a few guitar amp chassis as a hobbyist, and have always used .062 because anything thicker gets difficult to bend.

There are some interesting DIY sheetmetal brake videos on YouTube.  Guys are using kludgey contraptions made with 2X4 lumber and door hinges!  Harbor Freight sells hobbyist quality brakes for under $100 but are typically limited to 18 gauge.  Which I think is around .050".

Scoring the inside of the bend is common, but mostly just to make a visible line in the tooling ink, or to make a line that you can "feel" as you drag it along the upper die of a break and allign the material.

Be aware that the bend changes the length of the metal.  That is, if you took a 3 inch long piece of .060  and wanted to bend into a 3 sided C shape, you might divide it into thirds by scribing lines at 1" and 2" and then bend it on those lines expecting to get a channel that is 1" X 1" X 1".    Then you put calipers on your finished item you will find the two outside pieces to be slightly longer than one inch, and the center section even longer (as measured from the outside).  So you can look up bending charts knowing the thickness of the material and the radius of the bend and use the correction factor they give you when laying out your work, or you can take a scrap of aluminum and bend up the 3 sided item described above and calculate the difference between the dimensions you scribed and what you actually measured at the end, or you can design around the in accuracy.  That is bend your chassis first, then build your cabinet to fit whatever size the chassis actually is. 

This is no use to Jason now, but for future folks looking for a method for cooking up a homebrew chassis, probably the best option for a hobbyist without acces to a sheet metal shop is to just buy a Hammond 1444 or BUD AC series aluminum enclosure from Mouser or Digikey.

Posted: 4/27/2016 4:45:52 AM
MikeMunter

Joined: 4/27/2016

Hello Everyone!! :) 

Must say @Jason!! Aluminium bending can be a little tedious at times. Some aluminium bending techniques that shall come in handy are:

1) Buy aluminium sheets to match the colour of the use you need it for. Take sheets that are slightly bigger than the place to be used as some of the area may be reduced on account of bending.

2) Check with local hardware shops to find brakes that can be rented out. With the help of a brake, you can bend aluminium uniformly and quickly. This will save you a good amount of time in the case of large projects. If a brake is not available, then get a combination square so as to get a solid edge that can be used for manually bending aluminium.

3) At a small distance from the short edge, use your combination square or brake as a straight edge and cut into the sheet using a utility knife or blade. The cut should just be deep enough to allow for bending but not for snapping.

4) Bend your aluminium sheet to ninety degrees along your cut. This surface shall serve as an underside for securing the sheet to any places needed.

5) Cut out small marks on the sheet using the knife to mark the places where the sheet has to be bent. Along these marks, make forty five degree incisions on your bottom fold.

Cheers!!

 

You must be logged in to post a reply. Please log in or register for a new account.