Telescope Phone Mount

Hi, I built this for my Galaxy S5.

I like to play with astronomy and since I'm too lazy to learn star charts and wheels as such. I tend to use programs called Skyeye and Google Sky for ID and guidance. Since you're always looking thru the scope and wondering what is that stars name is behind the one you're looking at. Plus it just looks cool when its in use.

So I decided to put my phone to a little more use.

I'm not going to try to tell you how use a saw, and files and tape measures. I'm going to try and help with design and function.

Since this was going on a GOTO scope and it had to be able to simply assembled and had to have the ability to rezero in the dark without much movement there were things to consider.

Weight. CG. Expansion of materials. Types of materials. Assembly.

Weight, I wanted it to be strong enough to hold the phone and if it got knocked off in the dark to be able to cradle the phone somewhat to reduce the chance of dmg to a 600$ phone.

CG (Center of Gravity) - This is going to effect balance, motor slew etc. You need it to be able to shift. Off the 0 point for the Y axis. I'll talk more about that in a bit.

Expansion of materials. - You might not think this is an issue, but when you're relying on non-adhesive / non screw-bolt attachments this is a factor. The best observation nights come when its cold. We all know that. Cold contracts metal. I can hear my scope creaking / adjusting when i first take it out of a warm house onto the cold driveway. I needed something that wasn't going to contract and pop a set pin off or something.

Assembly - I'm lazy, but I wanted this to look somewhat good. So I progressed in my techniques as the build when along. When going metal to metal i mostly used 1/8" rivets. However in hind sight if i do another one, i might go a different route.

After you've figured out your design for the 'cradle' (where the phone sits). You're going to be sanding / grinding / and whatnot.

I folded the 1" aluminum angle to make the cradle.

I did not get my 45's for the fold points properly cut. I used a scroll saw with a wood blade. Not the best combo but it was what i had. Probably wasn't the best choice.

One corner turned out rounded. After I did the first, i used a 1" wood chisel and 'tapped' a groove in the other side to fold it. You can get away with this, but dont' open and close that fold too many times, you'll snap it off.

For the inside of the cradle, i attempted to use JB Weld Plasti weld. While it works, and its somewhat easy to mold. You need to be aware. This stuff turns very sticky, and when you sand and shape it, it produces a stink when it goes active and huge amount of dust when you sand. Leave it out of the equation. Too much trouble for very little reward. If i was to do it again, i'd leave this step out and find a very small metal angle and use that to trap the phone. After a couple months, the plasti-weld cured very nicely, but still looks uneven under close exam. Leave it out, go another way.

At this point, i've folded and (probably) attached the backing plate. At first i saw this look and it was decorative, then i realized that the folds in the angle would be knocked off and break. (Yes i've adjusted those angles so many times at this point the metal is getting weak) I needed something to lock the sides to bottom and freeze the angle. I had this copper piece from another project that i was building at the time (maybe i'll do my decorative laser pointer holder :) It was approximately the right width, so why not. I free handed the drill points and popped in some rivets. I sanded off the backs of the rivets. Lots of heat doing that. Careful.

This part took me a little while to figure out.

Why? Multiple factors. I wanted it to not only work but look nice. I had to have the weight balance and center of gravity shift while scope was in motion. I saw that when the phone was first trial fitted and i raised the scope i could feel extra weight appear when i raised it . That meant the CG was off. At first i didnt see what was happening. When the phone was in the cradle, and scope was level to ground. It was balanced, but when i raised scope the weight would shift due to height of phone. I needed a solution.

This mount was to have more than one piece to attach to it. I also had a decorative laser mount that i was building at the same time as the phone mount.

Materials.

Scrap 4" PVC pipe (wanted 5-6" but couldn't find any in the trash piles)

Glue, (used 2 component PVC glue, but was too old and wouldn't adhere.} Switched to slow hold super glue.

Nail plate.

I took the PVC pipe slit it in half, then half again and then stacked the halves glued then started cutting to fit.

Thats the simple line. If you've looked at the pictures you notice that the nail plate on the top is sitting pretty much flat. This was the hairy part. I had to figure a way to level the top without loosing fingers or going thru 10 sanding belts. I do not advocate this, but i used my RAS to multipass over the top arch of the pvc till i had a pretty much level surface then sanded to fit.

I attached the nail plate to the PVC once cleaned up and sanded a bit smooth with more superglue. It worked. Think i might screw it if i do again. I'd like a bit more adjustment next time.

Now how to attach various devices to the mount. Without a viable !easy! attachment they would be useless. This was built to assemble in the dark without a flashlight. Magnets. I have a planetary mass size ball of buckyball magnets. Decided to sacrifice some for the cause. I set a forward and rear set pin in place, and then drilled the plexiglass of the mount and pressed in some buckyballs to set an attachment point for the devices. I drilled some receiving holes for the magnets to sit in. Next time note, use square or small bar supermagnets instead of round. Better contact. but it works. if the mount is tipped, the energy is absorbed and the magnets pull the cradle back to the mount.

I used the belt sander mounted inverted to sand the mount to scope surface gotta watch those fingers. Used a bar clamp as a handle, worked pretty good to sand with.

In this, you really need to worry about the CG and how to balance the scope.

This mount with its attachments will shift the CG while it in motion. So doing your leg work is going to save some trouble.

I used hot glue to hold the mount down for sizing, balance and whatnot. I also used hot glue as the 'permanent' attachment process.

First i needed to level the scope.

Then i needed to make the plumb and center lines of the scope.

I used a chalk line and an extra pair of hands for doing this.

Then i 'tacked' the mount and started doing plumb / CG experiments to see how weight was shifting.

Once i had it all together, i marked off attachment / balance points with post it notes and chalk lines. Then final assembly could start.

After i had zeroed the mounts and then zeroed phone to mount. I hot glued the final attachments and started tuning.

The mount works very well. It rezeros on attachement, holds the phone and the software adapts to the landscape view. I used it to find Uranus after the eclipse a few weeks ago. In the cradle i made it wear i could access all buttons, and even put a port in where i could charge my phone if i'm out all night. The charging port took me about another hour to cut / file. The S5 has a water resistant case so when you go to charge it you have to open a door. Thats why the port is so large.

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I know most of this is build notes. Since this was a custom 'one-off' build i chose not to try to teach you how to use power tools or design. I tried to share some of the concepts and lessons learned while building. Feel free to ask questions if you want.