I've been thinking of putting something together to either laser line or structured light scanning of objects. This project would be very useful towards that goal. What is the outer diameter of the main cylinder that holds the motor and gears?

what is the pot for?  and what value is it?

The potentiometer is there to adjust the brightness of the backlight of the lcd. I used a 10K one.

thanks i thought so but was unsure without the data sheet

Thanks for sharing this! Could you do some measurements on the accuracy of your stage.
The most familiar stage I am aware of are the heavy duty rotation stages of thorlabs see https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1064 . They costs like 2500 euro.
Could you share the accuracy and bidirectional repeatability. I understand you can't reach the specifications of thorlabs but it would still be interesting to know what you can achieve with this setup. Personally, i also think arduino is non sensical. The only thing what is important is the motor and stepper or servo driver you use. I would use a nema 17 motor and at at least something like TMC2130 or TMC2160.
Design looks real nice!

Hello, I did some quick calculating for you to get a rough idea on the accuracy. The stepper motor used takes 2048 steps to get one full rotation. The gear ratio between the small gear and larger inner gear is 1:7. So the larger inner gear needs 14336 steps to get one full rotation. One step would then rotate the larger inner gear by 0.025 degrees. 0.025 would equal about 436 µRad. This is a purely theoretical calculation, please keep in mind the bearing has a play of about 1 to 2 millimeters and there's also some play between small and larger inner gear. I really wouldn't know how to measure or calculate the bidirectional repeatability, I also don't think I have the right equipment for this. I wouldn't recommend to use this as servo or something similar as the 3D-printed bearing has to much axial and radial play. It's more then perfect for the turntable but not for a servo. If I where you, I would consider using some real bearings and create a custom design for your application. I think the right combination of 3D-printed parts and some real bearings could give you some good accuracy and repeatability. Of course not as good as a completely mechined one, but close enough 😜👍

Repeat-ability can be tested easily by putting a mirror upright on the table and shining a laser pointer onto it. Then approach the same position from both directions and measure the difference in angle. Divide the angle by two for the actual value as the mirror doubles it. But I doubt that kind of measurement makes a lot of sense for the intended use cases. This table is clearly not suitable for machining 

I wonder how many kg's this pretty thing can hold being printed with pla. The latest cylinder structure seems quite solid.

Hello Arye, it obviously isn’t intended for larger objects (they wouldn’t fit on the plate either) but more for smaller objects like action figures, small 3D-prints,... However, all the objects i put on the table so far didn’t seem to cause any problems. The servo i put on it is quite substantial and was about the max size of the plate and it worked great😁👍 I also forgot to mention in the details I added some fine machine oil to the bearing to get rid of the friction which seems to work very well 👌😁

I wouldn’t go over a kilo though 😬😁👍

The strength of the PLA isn’t going the cause any problems in this project, the strength of the stepper motor is 😅

Nice build! In the video, the servo had me confused at first - I thought it was somehow locking the turntable for each shot. Then I saw the Bluetooth remote - clever! I've got a build I need to do that requires button-pushing like that - thanks for the idea.

Thank you Dan! I would've preferred to use a less mechanical sollution to take the photos, but Apple product just don't like to connect with bluetooth modules like the HC-05 and HC-06. My first idea was to open the bluetooth remote up and extend the contacts of the pushbutton to the arduino, but the pushbutton turned out to be a capacitive or magnetic one like the ones you can find on calculators or keyboards. So the servo pushing the button turned out to be the easiest most straight forward sollution, I mean if it works, why not haha ;-)

Awesome to see the design evolve. Would have been interesting to have it use the same bearing as the manually cranked one so it would be an easier/faster upgrade, but the final product definitely looks better without having the circular mounts for the legs and crank on the sides.

Thanks Tom! Yes i also would've liked to keep the same bearing as the hand cranked one but I had to change to much to the design in order to place all the electronics and motor etc inside it. And like you say the circular leg holders were in the way and I had to delete them. The plan was to just add a motor to it, turned out to become a completely different design haha ;-)