When it comes to photographing products or small items, sometimes it’s useful to get vision from all angles. Shooting a video of an item on a turntable is an ideal way to do this. [ROBO HUB] built a super-cheap turntable for just this purpose.
The build relies upon a regular micro servo to handle rotating the turntable. However, it has been modified from stock to rotate 360 degrees instead of its usual 180 degree range of motion. This is a common hack that allows servos to be used for driving wheels or other rotating mechanisms. In this case, though, any positional feedback is ignored. Instead, the servo is just used as a conveniently-geared motor, with its speed controlled via a potentiometer. A CD covered in paper is used as a turntable, with the electronics and motor assembled in a cardboard base. Motor Dc 5v
It’s a simple hack, and one you can probably put together with the contents of your junk drawer. Combined with a lightbox, it could up your photo and video game significantly. Those skills are super useful when it comes to documenting your projects, after all!
This is not the “common hack” of making a 180 servo go 360. He literally snips off the IC and uses the servo as a DC motor. Makes a 3D printed adapter for a CD without adding something for centring it, adds a potentiometer to limit the current from an 18650 and hot-snots it into some cardboard.
Butcher a servo to into being just a DC motor, glue it to a CD and hook up a battery.
A cheap TT gear motor would be better than butchering a servo if all you want is a geared DC motor.
The problem of these tutorials is that they’re aimed at the general public who don’t usually have surplus servos just laying about. They’re instructions on how to make stuff, which implies telling people to go out and buy a servo just to destroy one.
A tiny blue SG90 servo costs $1 including shipping from Aliexpress.
Only because they’re abusing the postal system, and the servo is fake.
The cheapest TT motor I saw was 78 cents.
Plus, when you buy a regular gear motor, you don’t need to modify it in any way.
Even though a cheap knock-off servo might be cheap from China, it still makes more sense to pay five bucks to the local supplier for a proper motor and save yourself the effort and wait.
Great potential for 3d scanning via photogrammetry, though releasing a signal to the shutter at every n degrees would be ideal – if drive speed is steady and shutter fired at regular interval, software can fill in the gap.
That’s neat but I suspect it’ll only work for lighter items. The entire thing looks to be resting on the servo’s spindle, and from my experience it’s unlikely that it’ll hold the table flat and wobble-free if there’s much weight on it.
Not an issue for lighter items – which is likely what a compact table like this is used for – but something to consider if you’re shooting larger/heavier stuff.
I did the same with a rotating cheese tray coupled to a scavenged geared motor and a rubber pulley.
Retired phonographs are widely available, some with built-in fine-tuning for speed (though of course off-the-shelf you’re limited to something close to standard record speeds). Combine with a photogrammetry app that can stitch out-of-order images, and you’re all set for lightweight non-moving objects.
Haven’t yet figured out how to get a cat to hold still for low-budget scanning except catching her when she’s asleep.
if you dont mind working with mains AC, salvaging a turntable motor from a dead microwave is a nice cheap option. they run at about 6rpm and have fairly good torque
the only downside is that sometimes they rotate in the opposite direction, and im not sure what triggers that.
I’ve used several for animated Halloween props now.
> im not sure what triggers that.
It’s a geared down synchronous motor that has no preferred running direction – just which way it happens to start.
https://www.youtube.com/watch?v=WT-rWaPFcQE
It’s a single phase AC permanent magnet synchronous motor. There might be some shaded pole action going on with that smaller metal tab to set the preferred starting direction, but if it gets up to speed the “wrong way” it will happily run like that.
It is not difficult or expensive to build a precise and capable turntable for photography. I did it years ago : https://hackaday.io/project/6752-yet-another-turntable-for-photography . While it took some iterations and the setup is different now from what it was in the HAD.IO article, basically it remains the same. The BOM of the current setup probably is about 30 euro’s.
This is Q&D and I approve.
This is a bit HaD unworthy. Unless.. is this is done by a young kid of one of the editors? I mean if it’s for encouragement then sure.
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