Most of the lower cost “Hossfeld” style, or more precisely, rotary compression or rotary draw type tubing benders use a silk screen protractor and a piece of TIG wire to read the bend angle. This is then checked against a large bend protractors, mechanical or digital.
Larger, more expensive automated benders have digital read outs, accurate to about a 10th of a percent. The lower cost benders did have a third party option but late last year the company stopped producing them due partly to demand and they were a few hundred dollars. When you bend professionally, you are like to be using a larger commercial bender and not something like a hand operated rotary compression unit.
Looked like we were SOL in the digital bending gauge market. That is, until Troy at SWAG Off Road in Oregon City, OR came up with yet another great idea. A digital bender kit made by modifying an HF digital angle finder. It’s called the SWAG U-Turn Tube Bender Digital Readout.
Very cool and very affordable. I’ll put one together before I start back on the Miata cage. Also, check out some of the other handy little fab tools Troy offers.