Laser Knife Edge Reader

[RickKrung]

Has anyone tried this laser gionometer? 

The wider angle scale looks attractive, better resolution than the CATRA one I have.  I wonder about it, however, as the reading being shown (in the Amazon ad) is fairly diffuse. I suspect that is a result of the knife edge not being very well defined/sharp.  But it would be nice to hear from anyone who has used one. 

Rick

[BobD]

Rick,

I bought one a while ago. I was curious about it's construction, dimensions and if things could be improved upon for possibly making my own.  Unfortunately, I do not have experience with either of the Catra models or the new Goniometer from Gritomatic so I dont have much frame of reference. Regarding the one listed on Amazon, honestly its a very simple yet clever configuration (two pieces of coated plastic with a sub-$10 3rd party laser bore sight (chambered in .223/5.56 that ships in it's original package). I assume because the market is so small they have to price in a way to make it worthwhile. The laser has an annoying flaw; you must unscrew the battery compartment and remove 2 of the 3 batteries to turn it off because it will remain on if more than one battery is inserted even with the cap removed. Likewise, you have to replace the batteries and screw back on the cap to turn it on each time. Regarding the laser appearance, it displays as a thin rectangular line when viewed close up and is fairly bright as is needed for it's original purpose. In the pictures below you can see the line oriented both vertically and horizontally. It's very difficult to accurately represent what it looks like in person through camera. The cleverness of incorporating the .223/5.56 design is that there is an abundance of already manufactured materials specific for those measurements, many that are high precision. This would also allow you to replace the boresight with one from another brand. Unfortunately, by design many of them will have the same power on/off shortcomings.

You are correct that the geometry and precision of the bevel alter how the readings are displayed

[RichColvin]

Bob,

So, the primary angle is 8° per side, and the secondary/micro bevel angle is 13°?  Is that how one reads this?

Kind regards,
Rich

[BobD]

Just to clarify as to not cause any disappointments; I'm not personally recommending this. Although it's suited what I was looking for it's not for everyone. It might have been a nice economy option if it was at a lower price point. If anyone's interested I'm happy to provide some of the devices' measurements or pictures showing the readings from different blades. I inserted a used Stanley utility blade in the photos where you can see the angle measurements. At least one of the photos was taken outside in daylight to help reduce glare from laser reflection. You can still see the readings in person (not in direct sunlight) even though it's not all captured in the photo