Intro: Add a Bending Computer to an Analog 3-in-1 Sheet Metal Machine
This instructable is about using a digital level (or digital level app) to make repeatable bends with a finger brake. I was working with the Baileigh 3-in-1 shear/brake/roll machine at Instructables’ Pier 9 Workshop, but I think this should work with any similar machine.
For a great general intro to using the Baileigh 3-in-1 sheet metal machine, check out this instructable:
If you have access to the workshop at pier 9, it is worth learning to use this machine for the view alone...
The Finger-Brake on the Baileigh has a stop-gauge that you can set, stopping the bar at a certain point, allowing for repeat bends. If you will be doing a series of bends at different angles, one after the other, the stop-gauge will need to be adjusted each time, and if someone else needs to use the machine, you’ll lose your setting. In my case, I was bending 16 sets of metal visors, each with 5 different bending angles. I needed a way to make 5 different, repeatable bends with some form of regularity.
Enter the next generation of 3-in-1 sheet metal machines: The ultra high-tech Bending Computer
Step 1: The Bend Computer
Here's what you need to do:
- Buy, have or borrow a small, robust computer that has a built in tilt-sensor (bonus if it can send text messages and tweet). Then download a digital level app such as iHandy Level Free for iOS or Bubble Level for android.
- Alternately, buy, have or borrow a digital level.
- Zero your level against a flat, horizontal surface, then mount your level on the crank arm. Use tape, glue (no, not glue), a custom 3d printed snap-on mounting device, or just be prepared to hold it there like I did.
- Make some test bends, taking note of the angle on your level. It doesn’t directly reflect the angle you are bending to, ie, if it says 20 degrees, you have not made a 20 degree bend. There is a correspondence between the angle of the crank arm and the angle of the bent piece: If your level says 20 degrees, and your piece of metal is bent to 45 degrees, you can make more 45 degree bends by lowering the crank arm to 20 degrees, as long as it’s the same type of metal with the same thickness and width. To know exactly what angle you've bent, you'll need to take out your bent piece and measure the angle.
- For best results, place your sheet metal in the same spot each time: the different fingers of the finger brake are removable, and seperately calibrated, so they may be at slightly different heights, and produce different results.
This bend computer was already damaged, but if you’re concerned about damaging your own, borrow one from a friend!
Here are the numbers I ended up with, so I can make more of these visors in the future.
And here are the results of all that bending:
That’s it! Hope you enjoyed this glimpse at the cutting edge of bending technology.