72mm/45mm Solar Filter Holder/Nexus 6P Eyepiece Bracket

SAFETY WARNING: DO NOT LOOK AT THE SUN DIRECTLY, ESPECIALLY NOT THROUGH A TELESCOPE. PERMANENT EYE DAMAGE WILL RESULT.

I am not responsible for any loss or damage caused by the use of these designs, they are provided for information only. All use is at your own risk.

This set is designed to make solar observations through a mobile phone (Nexus 6P, but you can remix the design for your own phone) using a small spotter scope. My scope's eyepiece has a 45mm external diameter and a 72mm externai diameter at the objective end. Of course, if your measurements differ, you can alter the design. If you're not using Blender like me, you may have to scale the STL files anyway - Blender seems to not get scaling quite right on STL files.

In use, it is best to align the telescope first using a white sheet of card to obtain an image of the sun, then attach the filter holder and phone holder. You can drill a hole into the side of the eyepiece tube and attach a screw if necessary to hold the phone firmly in place. It works best if the phone is upside-down, as it moves the centre of gravity over the telescope.

The filter holder is designed to take solar filter sheets, cut to size. You'll need to glue (or friction weld) the two parts together. Use only a good quality solar filter sheet (such as Thousand Oaks or Baader).

Note The "Lens Check" file does not need to be printed; I've included it in case you are remixing the phone holder. It can be inserted into the eyepiece tube so that you can check the phone camera lens is centred in the eyepiece tube easily.

The picture of the sun included above was the first I took using this setup, so not great quality, as I need a little more practice. I hope you'll agree it's a decent start though.