Polar Scope Align‘s Daytime Alignment tool is easy to mount on traditional equatorial mounts – just put the phone on the saddle (preferably with a dovetail extension) and you are set. Users have even made 3D printed dovetail holders:
However, the way the Vixen Polarie, SkyWatcher Star Adventurer and other star trackers are designed, there is no obvious way to mount the phone for Polar alignment so that you can guarantee it is parallel to the RA axis, although it could possibly be done with an attachment to the shoe mount, or even with an L-bracket. Here are some ideas on which you can build on for the two of the most popular trackers:
Polar Scope Align Pro user Noriyoshi Hashimoto (橋本 憲良) kindly send me the procedure he uses to get up to 60sec exposures on 200mm using an L-bracket:
Level the tripod head, but setting the phone on top of it and using PS Align pro’s Bubble Level tool:
Put the Polarie horizontally on the tripod head, verify it is still level with the Bubble level:
Attach a ball head (a Leophoto LH-25 shown here) and an L-bracket. Use the Bubble level on your phone to make sure the L-bracket is level with the Polarie:
If the ball head was perfectly rigid, with no play and no flexure, you would be pretty much done. However, that will most likely not be the case, especially if you live in low latitudes and will need to point low for polaris, so you should attach the polarie vertically (RA axis horizontal) and verify how horizontal the L-bracket is now with the added weight of the phone:
Repeat steps 3 & 4 until you are reasonably satisfied the L-bracket stays parallel to the RA axis when tilting. Note that this should be much easier on high latitudes where you point upwards for Polar Alignment.
Finally, with your phone on the L-bracket, parallel to the Polarie axis, follow the directions of the Daytime Alignment tool, adjusting the altitude/azimuth controls of your tripod:
That’s it, you can remove the L-bracket (and ball head if needed) and attach your astrophoto gear without moving the Polarie/tripod.
SkyWatcher Star Adventurer
The Star Adventurer is a bit more of an issue, since it has what appears to be a “saddle”/dovetail holder like equatorial mounts, except it’s not on the RA axis, but perpendicular to it and will not do for the daytime alignment tool. Instead, you need to attach the phone like you would a telescope tube, remember it is the top of the phone (not the front or back of the screen) that should be pointing to the pole star. That’s position A in the following image:
You could also secure the phone on the flat top of the Star Adventurer (position B above) – making sure the phone top is flush with the protrusion to make sure the phone is pointint exactly where the mount is. Depending on your phone, you might be affected by the metal/electronics of the mount at this position, so you might want to find a way to give your phone some distance. I saw an interesting way to do that using a Quad Lock case for the phone and a Quad Lock wall mount on the flat battery cover, on a blog post by astropills: