OG Star Tracker V2 Mods (Single piece/beefier gearbox, logo doors)
Description
PDFUpdates:
- 2025-05-10
- updated v1.1 of Gearbox-part-1-2-Combined (with and without letters)
- enlarged hole for the intervalometer port to 5.6mm. The original hole interfered with the 2.5mm jack seating fully.
- updated v1.1 of Gearbox-part-1-2-Combined (with and without letters)
- 2025-05-08
- Finally received the PCB and everything fit and is working great. The additional mounting point for the tension works great, and I'm really liking how everything came together. Now to take some pictures!
Intro:
These are a few mods to the excellent design of the OG Star Tracker V2. After building it initially, I wanted to make a few changes to the gearbox to make it a little beefier and make a few small aesthetic changes.
- Changes impacting strength
- Combines gearbox part 1 and part 2 into one piece for a cleaner look and improved rigidity.
- Thickens the back face of the combined part 1 and 2 for extra rigidity.
- Adds additional bracing to the 625 bearing mount that the tightener pulls against.
- Thickens the mount for the NEMA 17 stepper.
- Adds additional mounting point for the belt cover to keep it from lifting when pushing against the 400mm belt.
- Other Changes
- The files are now multi-material files with separate bodies for colors so you no longer have to do multi-material painting.
- Added the logo to the [doors]
- added optional idler carriers
- added camera holder that uses a 3/8"-16 x ½" bolt versus the ¼"-20 x ½"
- Downsides
- It is a little more tricky to assemble because access to a couple the bolts is slightly worse. However, I think it is worth it.
| Mods |
 Gearbox Part 1-2 combined The back wall and NEMA 17 mounting surface are thicker. The lower 625 bearing mount was braced to the side wall The upper 625 bearing mount side walls were also made thicker. a small lip was added to the bottom (left side of the pic) to help the mating with gearbox-part-3. |
 Gearbox-part-3 Thickened the NEMA 17 mounting surface Added side lips that brace the side walls of gearbox-part-1-2 Don't forget to remove the blue support! |
 Tightener This is a slight mod of the beefier tensioner by @eoyilmaz_384382 located here. I trimmed a little bit of the surfaces to give better clearance for the bolts of the NEMA 17 stepper. I recommend checking out his mods and recommend printing out his Arc-right which has the numbers that are not backwards. |
 I noticed the back of the belt cover was bowing up when tensioning the 400mm belt. This adds an additional mounting point for the belt cover. |
 F695 bearing smooth idler carrier (goes under the belt cover) You'll need 1x m5 x 16mm Socket Head Cap Screw, 2x f695 (flanged) bearings This replaces the 20t gt2 idler (with no teeth). The 20t idler I ordered was too big to fit the original part. I had plenty of f695 bearings around. This part also beefs up the walls of the original part a little bit. Don't over tighten the M5 bolt! Just screw it in until the bolt head is flush with the bottom. Note: since the F695 bearings measure diameter 13mm versus 12mm of the gt2 idler, your tension line will be ~0.5 mm less than what is marked on the belt cover. |
 625 bearing smooth idler carrier (goes under the belt cover) You'll need 1x m5 x 16mm Socket Head Cap Screw, 2x 625 bearings This replaces the 20t gt2 idler (with no teeth). The 20t idler I ordered was too big to fit the original part. I had extra 625 bearings from the build. This part also beefs up the walls of the original part a little bit. Don't over tighten the M5 bolt! Just screw it in until the bolt head is flush with the bottom. Note: since the 625 bearings measure diameter 16mm versus 12mm of the gt2 idler, your tension line will be ~2 mm less than what is marked on the belt cover. |
 Doors file was modified to mate with the modded gearbox-part-1-2-combined. Multimaterial logo added. Counter bores added so the bolt holes print cleanly. I've also included a multi material version of the original doors. |
 Logos are now all separate bodies. You can use it to print multicolor or just disable them to have them embossed. In prusaslicer right click the object and choose “split to parts” I print the main logo and tension lines as multi color and just leave the label lettering for Camera, Intervalometer, etc as embossing. |
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| How to split multi-material parts. Right click the object, then choose split>>to parts | |
Model origin
The author remixed this model.
Differences of the remix compared to the original
These are a few mods to the excellent design of the OG Star Tracker V2. After building it initially, I wanted to make a few changes to the gearbox to make it a little beefier and make a few small aesthetic changes.