Made My Own Protractor.

[Steve Garrison]

I had an idea a few weeks ago about making an accurate protractor that could measure an angle to 1/10 of a degree for setting up angles on tablesaw, jointer, bandsaw or whatever. It uses a level vial and a vernier scale I drew with autocad. It works pretty good! I have free instructions on how to make one on my site if anyone wants to see. http://www.stevengarrison.com/id28.html

[Barry Vabeach]

Steve, looks pretty cool. I tried to download the file, but it appeared I would need autocad to open it? I am a fan of vernier scales and would love to make one for my outfeed jointer table ( for adjusting the height of the outfeed to compensate for knife wear) and one for table saw - once you use your device to find out where true 90 is, you could tape the vernier in place to allow you to return to it easily.

[Steve Garrison]

I just made two pdf files of the template and put them on the page. You can adjust the vernier to read to either true horizontal or relative to any other angle.

[Barry Vabeach]

Steve, thanks for the help. Barry

[Brian Backner]

Steve,

Interesting idea, and website.

If you wanted to make a REALLY accurate protractor, you might want to consider using a bubble vial from a master machinist level (like a Starrett model 99). Used for setting up machine tools and work materials, these levels are accurate to something like 0.0002" per foot - you sneeze, and the bubble moves - you shift your feet and the bubble moves - literally.

I imagine you could buy a replacement vial from Starrett, but I'm sure it wouldn't be cheap (their best 12" level is something like $600).

Brian

[Steve Garrison]

Thanks. A level with the kind of sensitivity like you are talking about would be overkill but possible. My goal is to make it where someone could make their own for next to nothing in materials and get accuracy around 0.1° - like the Wixey or Beall tilt box. I've got a nine minute acrylic bubble vial on its way to me which should be ideal. Most carpenters levels use a 38 minute vial.

[Ed Sallee]

That's a very cool project. Question, what if your floor was out of level... would that have an effect? I know my shop floor looks flat, but I don't know how level it is across a plane.

[Steve Garrison]

That's a very cool project. Question, what if your floor was out of level... would that have an effect? I know my shop floor looks flat, but I don't know how level it is across a plane.

You can turn the disc that the vial is on to compensate for a floor being out of level. Just keep the protractor facing the same direction as when you zero it when you measure or set an angle. The level vial disc can be turned independent of the angle vernier and then tightened down to move with it.

[Ed Sallee]

Excellent!