Changelog/News:
2025-01-05: I designed [print-in-place PETG fin ray grippers](https://www.thingiverse.com/thing:6900815) which can be used with this design's robotic gripper part
2021-02-03: Added new variant "08 Gear rack drive (main body) v5_strongerprint" for easier removal of support structures
2019-02-24: Updated "11 Gripper arm" to v5, implementing [these suggestions](https://forum.ftcommunity.de/viewtopic.php?f=15&t=4954&p=37755#p37684)
2019-02-10: Peter ([PHabermehl](https://www.thingiverse.com/PHabermehl/about)) designed two five alternative [arms for the gripper](https://www.thingiverse.com/thing:3419079).
2018-12-21: Added adapter #12 for fischertechnik pneumatic manual valve (Handventil)
2018-12-17: Peter ([PHabermehl](https://www.thingiverse.com/PHabermehl/about)) designed [a tool for calibrating the servos](https://www.thingiverse.com/thing:3287773).
This is an enclosure for the ubiquitous [SG90 mini servos](https://duckduckgo.com/?q=sg90+servo&iax=images&ia=images) (and others with the same dimensions like SG92R or HXT900) which makes it compatible with the [fischertechnik](https://www.fischertechnik.de/) construction toy system. It comes in two versions, a "naked" one, and one with pegs at the sides.
As this is called "mini servo system", I included several adapters for different kinds of fischertechnik parts and applications:
1. steering arms with 15, 22.5 and 25mm radius, similar to those provided with the original ft servos (Lenkhebel [LR15](http://ft-datenbank.de/details.php?ArticleVariantId=4238754c-9f82-49e2-9617-a125d06f737b), [LR22,5](http://ft-datenbank.de/details.php?ArticleVariantId=0ba7154a-ecd6-4246-a563-ba41351d4695), [LR25](http://ft-datenbank.de/details.php?ArticleVariantId=679f47a6-8479-4b59-b9a6-c0c9ddb366f0))
2. building block adapter ([Baustein 5](https://ft-datenbank.de/details.php?ArticleVariantId=683ba3f0-eeaf-496e-b289-d4bb154f4600) and [Baustein 7,5](http://ft-datenbank.de/details.php?ArticleVariantId=85849bf0-b84b-4ee1-a636-9df31706a34e))
3. 10 tooth gear ([Zahnrad Z10](http://ft-datenbank.de/details.php?ArticleVariantId=fdb2325c-f18a-42f0-bda1-c6b25e5633c0))
4. clip-on axle adapter ([Rastachsenkupplung 15](http://ft-datenbank.de/details.php?ArticleVariantId=767769a8-0dda-4038-9154-82e356e53c81))
5. dedicated strut adapter for middle or end point mounting ([Streben](http://ft-datenbank.de/details.php?ArticleVariantId=415d9ccb-7039-4495-aade-8bd666efa710)adapter für Mittel- oder Endbefestigung). I used lamer's [Parametric Fischertechnik Parts](https://www.thingiverse.com/thing:86301) for this adapter.
6. adapter for small m0.5 Z20 gear ([S-Riegelscheibe Z20 m0,5](http://ft-datenbank.de/details.php?ArticleVariantId=ca73aca0-81e5-4232-9d12-9731fd52fa7d)), can also be used as alternative (less robust) strut adapter
7. adapter for bigger gears and metal axles ([Flachnabenzange](https://ft-datenbank.de/details.php?ArticleVariantId=cacb4054-5b30-4624-9a1f-7eb01fab49b1))
8. gear rack drive (similar to [ft Hubgetriebe](https://ft-datenbank.de/details.php?ArticleVariantId=2d174f2f-1e51-4fe7-8556-90fb4830555d)). This needs an enclosure with pegs and can be installed in two positions with a small gear (travel ca. 8mm) or a large gear (travel ca. 40mm).
9. adapter for roboter arm, with print-in-place mounting on the opposite side. Unfortunately, the SG90s are too weak for a reliable 3-element arm, but 2 will work, 3 in some cases.
10. pneumatic valve for 4mm tubes. This is kind of experimental and needs improvement, as it does not close completely air-tight.
11. robotic gripper with rounded gripper hand, needs enclosure with pegs. Compatible fin ray grippers [here](https://www.thingiverse.com/thing:6900815)
12. (added 2018-12-21) adapter for fischertechnik pneumatic manual valve ([Handventil](https://ft-datenbank.de/ticket/3225))
Most adapters are designed to be fixed with the screws included with the SG90 horns. Adapter 7 needs a screw with a smaller head.
There is a [thread on this thing](https://forum.ftcommunity.de/viewtopic.php?f=15&t=4954) in the fischertechnik community forum.
Find my other fischertechnik designs [here](https://www.thingiverse.com/juh/designs).
https://www.youtube.com/watch?v=ZpICI-pzrmg
https://youtu.be/4S-dK5tG26w
Edit 2018-09-18: Wow, things went crazy. This design seems to have hit a spot, in only three days it's become the [most popular fischertechnik design on thingiverse](https://bit.ly/2xoAM5X)! Thank you for all the likes, comments and PMs. Since this receives a lot of attention from international users, I just wanted to make sure that everybody realizes that this design is meant to be used with the [fischertechnik construction toy system](https://en.wikipedia.org/wiki/Fischertechnik). Most parts of the marble run you can see in the video are not 3D printed but from [fischertechnik](https://www.fischertechnik.de/en) (which I am not affiliated with), a construction toy which has existed since the late 60s and, though having been overtaken by Lego in regard to popularity in later years, still has a strong fan base mostly in Germany and its neighboring countries. So if you want to replicate my marble run, go and grab one of their sets from the Dynamic line (Dynamic is the marble run variety of fischertechnik), I'm sure you (and maybe your kids - it's Christmas, soon!) will have lots of fun with it. And if you print my servo design, be sure to post your make and leave a comment how it worked for you! -- end of edit --
juh
