That's my kind of hobby project! Looks like a vey nice design. most people just build a wood wedge for a fixed location, so they usually aren't adjustable. It looks plenty sturdy, and should last for a long long time.
My only question is why do you want a wedge for a computerized Evolution Alt/Az mount? Is if for a special purpose like AP?
To polar align the scope on the wedge. The scope should be pointed straight up on the Evo mount. Then raise the wedge up so the scope and wedge is pointed North and straight at Polaris as seen thru the eyepiece. Also, make sure the base of the wedge is as level as possible at the start.
Setup this way the the Az base of the Evo mount will rotate on an axis perpendicular to the the Northern pole, and thus can easily track objects in the sky as the Earth rotates (with no Alt motor tracking needed). Just be sure the EVO is setup of this (EQ Mode I believe).
I hope you find this helpful. And I do like how you built the edge!
Thanks, JohnBear. It's not finished yet. I haven't rounded the tripod mount, the wedge base or the mount base yet, and I haven't sanded anything and obviously haven't varnished it yet. I wanted to make sure it worked before going through that effort.
Why did I build it? I want to learn astrophotography and I decided not to fork out $350 for the Celestron wedge. Everyone here says to buy an HEQ5 or EQ6-Pro at least, so I decided to do this part on the cheap. Besides, I really enjoy woodworking and this provided another opportunity to learn more about precision craftsmanship.
I will play with this while I save my pennies and decide whether this really is the hobby for me. If I decide yes then I'll take that $350 and put it towards the right equipment for the task.
I use SkyPortal on my iPhone to connect to the scope WiFi. Its instructions for alignment are different from yours.
First, I pointed the bubble level on the tripod to north. Note that I built the wedge so this level remains visible; that way I don't have to put a level on the wedge.
Second, SkyPortal told me to align the mount's markings, position the scope level with the mount (not with the tripod), and make sure it was pointed straight south. This jibes with their instructions and illustrations I've read online. The mount points towards Polaris; the scope points south towards the celestial equator. Then I was to tap an Enter button.
Then the alignment. SkyPortal asked me to locate an object in the eastern sky and choose GoTo to let the scope go find it. It sort-of did, and then SkyPortal told me to use the on-screen arrows to center the object in the eyepiece and hit Align. I did. SkyPortal asked me to find a second object in the eastern sky and repeat that exercise. Then it asked for an object in the western sky and I did. Unlike the Alt/Az 3-star alignment procedure, SkyPortal kept allowing me to add more and more objects to the alignment until I tapped Done. Then I could get pretty easily to objects. I still needed to center them after a GoTo but I could then tap Align and that increased accuracy.
As I had read before, using the wedge caused the scope to end up in some weird orientations. When it pointed to Polaris the star diagonal was right on top of the center of the mount base. I kept having to rotate the diagonal so I could see things. But I sort-of expected this.
Then I decided to test the alignment by doing a few images. I went to my car to grab my camera and discovered I had left my Nikon F to Z adapter at home. ~!#$!^& So scratch that idea for tonight.
Regardless, I think this was a successful night. The wedge worked, and the alignment process was almost as easy as SkyPortal's three-star Alt-Az alignment.
Edited by PLShutterbug, 21 September 2020 - 01:16 AM.