prototype DIY 3-bearing AOB Sliderule released

[Pisces]

I have created a circular version of the tool I mention in this post some time ago. It isn't completely to my taste yet. The AOB should be given with reference to the last bearing taken for ease of use. And hopefully I can add functionality to allow unequal time intervals. However I have decided to upload this prototype now since I have to live up to the promise somehow someday. It was triggered by a topic in the Sh4 forum. And maybe I can get a bit of feedback before I develop it further.



Filefront description:
Sliderule to compute Angle On Bow (when stationary, if moving Direction of Relative Movement wrt the first bearing) based on 3 bearings only, in 2 equal time intervals. Intended for use with Silenthunter 3 or 4. Inspired by a straight design ("Another Course Computer") on this site: https://www.gizmology.net/silenthunter/ [EDIT]Unfortunately his link to the 'ACC' is dead, possibly even infected by a trojan. See the first link in this post for a (bad) webcam image of the one I build.

DIY- circular sliderule PDF:

https://ricojansen.nl/downloads/3BearingAOBfinder.pdf

1. Print out
2. Cut out
3. Don't forget the window on front disk
4. Laminate both disks
5. Make a hinge in the center.
6. Instructions for use are on the front disk.

7. Be patient! It takes time for a good meaningfull AOB value. Forget the 3m(15s)-rule for this thing. Allowing longer time periods for more bearing drift leads to more accurate values of AOB.

A complete walkthrough is something I keep promising , but I do not have time to make right now. But I wil do it before I go on my next patrol. (got to force myself with something, don't I. ) Anyway, I think the front disk speaks for itself. If not, ask!