Welcome to the forum, Hugh.
Let me take two guesses, hopefully favoring the scientific portion of SWAG (Scientific Wild Ass Guesses).
First: When you use the Anglemaster, is the angle pointer positioned so that the bottom touches the grinding wheel?
Second: Since the 5° error seems consistent, especially since these are school machines, is it possible that your pointers may be worn. We have had a few posts where these are the problem. I suspect that this wear occurs from measuring while the machine is still running, but that's just a guess.
Third, I would suggest that you email support (support@tormek.com) The two pointers are both available as replacement parts. I do not speak for Tormek; however, I would not be at all surprised if Tormek gifted you the spare parts. Support is very experienced and dedicated.
Please keep us posted.
Ken
Let me take two guesses, hopefully favoring the scientific portion of SWAG (Scientific Wild Ass Guesses).
First: When you use the Anglemaster, is the angle pointer positioned so that the bottom touches the grinding wheel?
Second: Since the 5° error seems consistent, especially since these are school machines, is it possible that your pointers may be worn. We have had a few posts where these are the problem. I suspect that this wear occurs from measuring while the machine is still running, but that's just a guess.
Third, I would suggest that you email support (support@tormek.com) The two pointers are both available as replacement parts. I do not speak for Tormek; however, I would not be at all surprised if Tormek gifted you the spare parts. Support is very experienced and dedicated.
Please keep us posted.
Ken