Moving parts for cake

Hi all,
I’m trying to make a teenage mutant ninja turtle that has the turtles pushing up the drain lid. I thought of using a linear actuator but they use 12v batteries which is not doable.
Any advice on how I could do this? I need the lift to be about 5-15cm.
Would greatly appreciate any assistance!!!


Hi Taryn,

Welcome to the forum!!

I’d have a look at using a servo to get other parts connected you can use paper clips in the servo horns. How heavy is the toy?
To control everything you could use an Arduino or Maestro connected to a PC.


Hey Taryn,

Thanks for posting!

What kind of weight are we talking about for your drain lid? If it’s not too much a small hobby servo may do the trick and would be extremely easy to use as Liam has suggested. Otherwise, there are some higher torque models too you may just need to look into using a dual-H bridge or mosfets to isolate the high current from your signal lines.


Servo was my first thought, same as Liam & Bryce. Does depend on how much of the cake you still want to be cake. If servo is moved through 180 degrees and you want 5cm lift then the arm on the servo would need to be 2.5cm; taking some space inside the cake. 15cm it would be 7.5cm.

Alternative would be a motor with a worm gear thread, basically what a liner actuator is. But have not seen any that run on 5V and fit your size, would have to be a custom deign.



@Taryn179715 James is exactly right, you’ll want to make sure to take that into account when deciding which servo to go with.

As Liam also suggested earlier, you can attach a paperclip to essentially act as an impromptu servo horn extension, which if attached in the right position on your lid (I’m assuming it’d be cardboard) you can get a higher velocity ratio in what is essentially a third class lever (small motion on the servo leads to a large movement at a greater distance from the fulcrum or pivot)


You can either mount the servo underneath and push close to the fulcrum from underneath, or mount it off to the side somewhere to pull it up (I’d usually suggest braided fishing line in smaller projects, but you really don’t want to have that anywhere near food as they tend to break up over time and be very difficult to find depending on the quality :sweat_smile: a paperclip or small piece of wood cut into the right shape is a much better choice, or if you’ve got access to it you can get something 3D printed)


Thanks for all the advice! I’m unfamiliar with servo’s, but googled it :grin: are you thinking something like this?

I can’t find one with a long enough stroke length.

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The screw is suitable for precise control with plenty of torque over short distances. For the small amount of power needed for your project a rotating arm would be used to push on a lever to give the required length of travel.

Something like this: