03-23-2020, 02:50 PM
I have used the $75 USD Gritomatic (basic) goniometer for about three weeks. Gritomatic sold out their first batch. It's now back in stock. They also just introduced a Pro model for $101 USD more:
https://www.gritomatic.com/collections/e...ometer-pro
TL
R: I'm happy with what it does for the price. It's one of the cheapest ones available (I just missed the cut-off for Ken Leonard's $40 USD laser edge knife reader on Kickstarter). Besides, I didn't want to wait.I run a sharpening business. I use it to give me a (rough) idea of the existing angles to set up the sharpener (I still use a Sharpie to see if it needs fine-tuning).
It works best for straight bevels. Had a ceramic knife with straight bevels and the image was crisp and clean. On the other hand, convex edges scatter the laser beam. I measured the Japanese sword in the picture, circa 1630 (as confirmed by the NBTHK Hozon paperwork). The convex edge measured about 20 degrees per side. As a side note; the BESS = 270. (I'm sure it has been sharpened since 1630!)
The goniometer is made out of plastic and looks a bit fragile, but seems well made. The fit and finish does not reflect (get it?) its $75 price. Nevertheless, I'm going to put it in a foam-cube container along with the angle block, the PT-50B, the caliper, the loupe, and the lens for the cell phone camera.
In short, highly recommended. I'm not sure if the Pro model is worth the extra $101 as I haven't used it.