A simple flowchart to assist with classification of sunspots using the McIntosh system.

This is the original document by Patrick S. McIntosh (NOAA Space Environment Labs) originally published in Solar Physics 125: 251-267, 1990.

Originally published in the Journal of the British Astronomical Association, the paper describes how Sunspots are assessed and recorded for the BAA White Light database.

Authors: Frank J. Ventura and Tony Tanti

Original publication date: 1988 JBAA pages 282-286

READ.ME.FIRST

Revised - v2 - mod to Ring part 4 

This zip file contains the STL components for a set of rings for a Celestron C11 Telescope.

All parts can be printed on a 3D printer with 210mm square bed size.

There are 4 separate segments which are linked using 3 link pieces. The final two segments are clamped using a bolt.
The inside edge of the ring in covered in felt to protect the OTA paintwork from scratches etc.
The links are joined to the ring segments using M6, 6mmx25mm bolts with standard nuts
The clamp bolt is a M6, 70mmx6mm bolt with a standard nut.

You need to print two each of the ring parts plus 6 link spacers

The centre to centre spacing between the two rings is 140mm.

There is a choice of two platform mounts. Either a standard Vixen Bevel or a standard guidescope Bevel. These are interchangeable using a M5 hex Allen bolt.

Use brass threaded inserts (M5 for the platform mount and M4 for the instrument clamp on the platforms). 
To fit these, I use a hot air gun or small catering blowtorch to heat the insert. 
Thread the insert onto a long screw, heat the insert and gently push into the hole. Check the alignment is correct then spray with cold water.

Don't blame me if you burn yourself.

I use PLA for all the parts with 30% fill and 1.5mm or 2mm wall thickness. The rings and platform are very strong but will not support more than about 1 kg of guide telescope mass.
This is adequate for small guide-scopes (say max 60mm objective lens size) etc. Again, use your own judgement.

Note: there are a couple of minor anomalies in the STL files, very thin false walls. These can be ignored, they will not be printed. They were not in the original CAD files.

Version 2 has a change to TubeClamp4 to add a second platform

Martyn K
2024-01-27.

This is a set of Solar Stonyhurst disks centred on the 15th of each month.

Viewed as North at the top and West to the left or South at the top and East to the left.

They are used to record and track sunspots and are intended to be used with a refractor with diagonal.

It is assumed that an Equatorial mount is used.

2024-01-27 (Revised)

This is a set of Solar Stonyhurst disks centred on the 15th of each month.

Viewed as North at the top and West to the right or South at the top and East to the right.

They are used to record and track sunspots and are intended to be used with a refractor without diagonal.

It is assumed that an Equatorial mount is used.

2024-01-27 (Revised)