Review - Bevel Protractor

Universal Dial Bevel Protractor

[Jan. 14, 2013]

This is a review of a "Universal Dial Bevel Protractor" - this device is sold by numerous vendors at varying prices, usually in the $30 - $45 range (I paid $33 for mine).

Summary:

This tool provides angle measurements to an accuracy of 2', via reading of a vernier scale. Simple testing of the tool confirmed its accuracy. The tool is reasonably well made for a tool of this price, and is adequate to its purpose. The tool finish is a bit rough in spots, but this does not impact its function.

To use this tool you will need to know how to read a vernier (if you don't already know how, it's quite easy to learn). The use of a small magnifying glass in reading the vernier is suggested, for greatest accuracy.

UPDATE: Jan. 16, 2013

Here's a link to another review of this item, with some good additional information: http://bbs.homeshopmachinist.net/threads/27013-Protractor-Review

Apparently the tool of is a Chinese copy of a Russian original (Semionov Universal Vernier Protractor). Here's a chart that was posted at the above link, from the Russian manual (click on the image for a larger view):

Photos and commentary

Here is an overall view of the tool(again).I tested the tool by measuring known angles on commercially purchased solid angle plates, and found it to agree with the angle on the plate. I also tested it with a home made solid angle plate (made for another project using this method), and again found that it agreed with the plate angle.

Adjustment of each leg of the protractor is done with a clamping screw. You can also see from this closeup that the finish of the tool is no better than it has to be. To put this another way - the finish of the tool is adequate to its purpose, but no extra effort was made to achieve a fine finish. This was expected in a tool of this low cost.The leg adjustment near the scale (top of photo) is a little difficult to get at, but not un-workably so. At the bottom right of the photo you can see the screw-lock for the scale (to lock a reading in place).

Here you can see the vernier scale, accurate to 2'. There were some light scratches on the (brand new) scale, but these were cosmetic only and did not impact function. For greatest accuracy in reading the vernier, a magnifier will likely be required (not provided with the protractor).

Here we see the back of the scale - a rack and pinion adjustment mechanism is provided. The adjustment knob for the rack and pinion was a bit wobbly, but otherwise works fine.Here is a closeup of the rack, which appears to be of good quality. Notice the milling behind the rack however - functional, but no extra effort made to achieve a fine finish.

Here is another closeup of the back of the tool. Notice the small gap just below and to the right of the adjusting knob. Again, this does not impact function, but is indicative of overall finish of the tool.