Technic SG90 servo holder

[Ralphius]

After being thoroughly unimpressed with the PF servo motor, I've been trying to find a way to use cheap TowerPro SG90 nano servo's for part of my MOC that has a low torque requirement (steering rack). This would make it considerably easier to control the MOC from a raspberry pi which is also on my todo list.

So has anybody found a good way of mounting an SG90 servo in a Lego Technic MOC? The servo seems 3.3ish studs long by almost exactly 1.5 studs wide, but that makes centering the output shaft difficult. I've found that drilling one end of a 2 stud long axle joiner out to 4.8mm makes it a really nice stiff push fit over the servo splines but I'd prefer to keep any damage to technic parts to a minimum if possible.

 

I've attached pics of what I've got so far but I'm not completely satisfied with it so I would welcome any constructive criticism or alternatives.

Apparently I'm not meant to link to imgur so I've inserted them as deeplinks:

 

Edited July 23, 2018 by Ralphius

[Jurss]

Welcome!

 How can I upload pictures of my creations to the forums?

Eurobricks does not host pictures. Your pictures should first be uploaded to an image hosting service such as Brickshelf or Flickr.

How to upload images to Brickshelf

Operating Flickr tutorial

Then you can embed (deeplink) pictures in your posts on Eurobricks following the instructions in one of the tutorials below.

Posting deeplinked images from Brickshelf

Posting pictures from Flickr on Eurobricks

Please also make sure that the images you are posting are not oversized: at most 1024x768 pixels, ideally no larger than 800x600.

How to resize pictures using MS Paint

How to perform a batch image resize using IrfanView (a Pirate forum tutorial)

Creating clickable thumbnails (a Pirate forum tutorial)

For any other questions regarding picture uploading, use this thread:

Image uploading/posting

 

[oracid]

May be this can help you.

 

 

[Andy D]

Good stuff! Also on my to do list, but with Arduino instead  of Raspberry Pi.

i will keep a watch on this thread.

Andy D

Edited July 23, 2018 by Andy D

[dr_spock]

There are a number of 3D printable SG90 adapters for LEGO on Thingiverse.com.  There are some with Technic pin holes.  I haven't tried those yet.  I've only printed one with system studs at the local public library for tinkering with bluetooth & arduino train track switch remote control.

 

 

[Ralphius]

Gave up trying to mount them in pure technic (sorry purists) Found an excellent 3d printed design for an SG90 adaptor here: https://www.thingiverse.com/thing:4303585

Printed four of them and they work perfectly. Don't know who did the CAD but they've done a great job. Video below:

 

[Toni-23]

very interesting
I'm waiting for updates on this project

[oracid]

17 minutes ago, Toni-23 said:

very interesting
I'm waiting for updates on this project

 

What about this ?

These do not work, but I will soon present one that works in this thread, https://www.eurobricks.com/forum/index.php?/forums/topic/175266-fourbarquad-1-4bq-1-quadruped/

 

[Ralphius]

@oracid Wow! Every time I come on this forum I am amazed by the skill and ingenuity of its members! Following your other thread with interest!

I was playing with the idea of a 4x4 buggy with portal axles where each wheel is independently steered. Electronics not shown are an ESP8266 based Wemos D1 mini board with motor driver shield.

[oracid]

8 minutes ago, Ralphius said:

I was playing with the idea of a 4x4 buggy with portal axles where each wheel is independently steered.

This looks very interesting ! But as far as I can see the wheels motors are not yet on board. Do you intend to use SG90 servos with continuous rotation ?
If you are interested about mixed technos, Lego, Arduino, RC, 3D Printer, please have a look at my YouTube channel.

[Ralphius]

Yes it is at very early stages. The drive motors will be 2x technic PF large or medium, haven't decided yet. There will be one for the left side wheels and one for the right.

I actually had a quick look at your youtube channel last night, had a look through your Arduino code on github as well :-)

[oracid]

28 minutes ago, Ralphius said:

I actually had a quick look at your youtube channel last night, had a look through your Arduino code on github as well :-)

I hope this will inspire you.