Some of my SeeStar Projects

Project 1 - The Dew Shield (25% fill - 4:45)

STL file for the Dew Shield

Any exposed glass will want to dew over, at least here in Florida. The S50 has a built-in dew heater and it works well. Dew heaters suck power and I wanted the battery to last as long as possible. Dew shields greatly delay the lens dewing up and draw no power. So it was time to make a dew shield. Attaching it to the s50 uses a standard compression fitting inside the micro built-in mini lens shield. As a bonus this also blocks some stray light.

Project 2 - Modify the Megrez oak tripod to use with the S50

Back in the Y2K year of 2000 I made the weightless oak mount to handle the Megrez 80. The tripod that comes in the SeeStar box is a beautiful thing, especially for traveling light. I wanted a more substantial and taller tripod at home and when it was practical to use it. My first thought was a bigger photo tripod and then I remembered the weightless oak mount project from 25 years ago. Since the weightless arms came off of the base tripod all that I needed to do was drill a 3/8" hole in the top plate and urethane the new exposed wood hole to waterproof it.

I had a 3/8" threaded hand clamp bolt. I added a bubble level to the top of the tripod to ballpark it in on the initial setup. A three point leveling base was also add between the tripod and the SeeStar to fine tune the level during the SeeStar setup. A few inch length of glow-in-the-dark tape is on each tripod leg to help prevent anyone from bumping into the tripod in the dark. It's rarely dark enough during public observing to need the glow tape.

During public events the tripod tray holds a tablet in guest mode and extra power supply to show what the SeeStar is imaging. The tablet is strapped to the tripod to help prevent it from being borrowed.

Project 3 - The Dew Shield with a 2" Filter Holder (40% fill - See Below)

The LPR filter built in the S50 helps quite a bit and I've been impress with it's results. I was thinking that If I could use a standard 2" filter I would like to try one of my favorite filters, the Optolong L-Pro, on it. A quick web search turned up a filter holder made by lewisite on Thingiverse (Thank you!). I liked the idea but with the filter glass even more exposed that the original lens this really need a dew shield. The part that attaches to the SeeStar wobbled a tiny bit. I changed the SeeStar coupler with the one from the earlier dew shield and added the dew shield to the other end. The twist lock was angled slightly differently to allow more surface contact. It locks with only a slight twist between the two halves. The filter may rattle a tiny bit if shaked because the size of the frame around the filter varies quite a bit. In practice the scope is angled up and it doesn't move while in use.

STL files for the Dew Shield with a 2" Filter Holder (both parts)
Part A - Filter Tray section (40% fill - 1:23)
Part B - Dew Shield section (40% fill - 4:47)

Project 4 - The Dew Shield with Drawer for the ZWO (Gen 2) Filter Tray (40% fill - 7:31)

STL file for the Dew Shield with Filter Drawer

⚠️ This project really should not have the magnets installed. They are pretty strong and may alter the internal compass of the SeeStar. Further research is needed on this. If the filter slot is on the top of the tube when the adapter is installed the filter should not fall out.

Most of my astrophotography filters are in ZWO Gen 2 filter trays. I really like this system. It allows for quick filter swaps and less chance of touching the filter greasy finger prints on them at 2am. The previous 2" filter holder was made using three sections: SeeStar coupler, 2" filter holder and dew shield. If I replaced the 2" filter holder section with a drawer that fit the ZWO filter tray it would allow easy changing filters on the SeeStar and between telescopes.

I put quite a bit of time into getting this just right. The gaps were tweaked at the 1/100th of a millimeter (decimeter) level. I wanted a smooth fit but no wobble. The magnet placement was critical. Quite a few trimmed models were printed. I removed the coupler and dew shield to speed up the test and use less filament.

This must be printed using supports everywhere.

There will be quite a bit of supports to remove but the results will be worth it. A downside of the supports is that when removed they leave some small roughness on the surface. Where the tray slides in you will need to carefully file off this roughness for the tray to slide in. The bumps need to be smoothed all the way in the back where the thin part of the tray slides in. Make sure that you don't grab the sides of the battery hole with the needle-nose pliers and tear them out when removing the supports.

The magnets (see the note in the box above) for these parts are sold as 5mm wide x 2mm thick. In reality they are 1.78mm thick and the STL files are made for this thickness. I have been using JB Weld 5 minute epoxy to hold the magnets in the holes and have been successful so-far. I use a toothpick to place the epoxy in the hole. Press the magnet in the hole all the way and make sure that it's flat. The magnet will stick out slightly above the hole and this is intended. Wipe off any visible epoxy. I haven't tried these in freezing weather yet.

The filter holder (below) has the same dimensions but since it is printed with the opening vertically there are no supports and the filing is not needed.

Project 5 - Filter Tray Holder for the ZWO (Gen 2) Filter Tray (see below)

This project is independent of any telescope and anyone that uses ZWO Gen 2 filter trays may benefit from it.

Having the commonly used filters in filter trays begs for a safe way to store and transport them. While not SeeStar specific I added the holder here since the other parts are here.

Now that I had a properly fitting filter drawer I should be able to remove the coupling and dew shield, rotate it 90 degrees so that the opening is facing up, add a base to it and have a filter holder. Butting these together would make multiple filter holders in theory as wide as the 3D printer can handle. It would use more magnets but I have a box of more than 200 so that's not an issue. Sweet!

The filter holders use the same magnets as the dew shield with filter tray.

STL files for the Filter Tray Holders (1-5 trays)
One Tray Filter Holder (40% fill - 3:53)
Two Tray Filter Holder (40% fill - 6:27)
Three Tray Filter Holder (40% fill - 9:25)
Four Tray Filter Holder (40% fill - 12:10)
Five Tray Filter Holder (40% fill - 15:01)

Recommended - External Battery Holder (25% fill - see below)
This isn't my design but it's worthy of using

An external battery holder allows the S50 to add hours to its usable time. I have been using this one for a while: Mike Steffek's S50 Power bank holder. The small holder handles power banks up to 20mm thick and the larger one up to 32mm. This fits on the S50 nicely and works well. I use a couple of 10,000mAh battery packs (one at a time) with the smaller holder. The battery pack drains before the internal battery starts to drop so they may be swapped out. This allows you to monitor the S50's battery power in the SeeStar app and you'll know when the external pack is empty when the S50's battery starts to go down.

In the second photo an external battery is being used and the dew shield with a 2" filter is installed.

Small Battery Holder (25% fill - 11:36)
Large Battery Holder (25% fill - 12:23)