Arduino Smart Trash Bin

Hi, I have successfully connected Arduino, Ultrasonic sensor and Hitec HS-311 Servo Motor (Torque (Kg-cm/Oz-in): 3.7/49).

I bought this IKEA stainless steel bin (product name: strapats).

I'm trying to attach the servo on the cover and open it. I try to apply the force at the back, I tried also at the front. Still, the force required seems to be much higher.

My wife does not allow me to buy some servo for 65 USD or more. Because that is close to the price of the whole solution. We invested in this trash bin from stainless steel and complete smart bin cost around 100 USD.

Is there any trick how could I make it open? Some pulley, shaft, vertical movement from the inside of trash or some mechanical hack how to get a smaller requirement for the force to open the lid?

Picture: cannot attach webp, found only chinese Ikea, lol: https://www.ikea.cn/cn/en/catalog/products/60245410/

Look up levers, pulleys, screw threads and worm gears. (all the same principle)

A not large motor turning a bolt will move a nut held steady from turning with a good deal of force.

Rather than a servo motor you are going to need a "gearmotor".

Search them out on eBay. You will need limit switches to set the endpoints. Only the two end positions are important anyway.

But you will want to arrange so this only forcibly opens the bin so that it may still be operated manually.

Ok, so you think step motor is better? I have this one: http://shop.nanotrik.cz/domu/69-gear-stepper-motor-with-driver.html?search_query=Gear+Stepper+Motor+with+Driver&results=1 ...but it does not mention torque, so I could not compare the force against servo motor. I can try it today. Thank you. I need to study mechanics more now, hehe.

cyberluk:
...but it does not mention torque, so I could not compare the force against servo motor.

Put an arm on the stepper shaft, same length as the servo arm.

Try to hold both with your fingers.

Alternate is will one lift more weight than the other?

But unlike the servo, the motor can turn a winch which gives a big advantage in torque (over the end of the servo arm) but a big disadvantage in speed.

Strange, how can Xiaomi make it so cheap? Now they sell it at 50 USD complete with trash bin and electronics. And they make it fast. I chose a difficult task with stainless steel. I will try the gear stepper, but with plastic cover, I could put cheap servo inside like other youtube tutorials do. My wife says: This is fail and forget it. :smiley:

I did not mention a stepper motor but a "gearmotor".

Mind you, believe your wife! :grinning:

Can you counterweight the lid so the motor doesn't have to lift the whole weight?

Aah, I have around 4 of Pololu Zumo bots and I remember I bought various of their gear motors. They look exactly the same.

Good point with adding some weight to at least decrease by 25% or 50% the load.

I think if I construct some kind of winch, it might work with gear motors.

Got something working with servo motor and steel thread, but the maximum angle of a servo motor is not enough.

The whole point of the gearmotor is that it should be able to raise the lid simply by an arm bearing against the lid.

Probably something like this, but more lightweight and DIY?

cyberluk:
Good point with adding some weight to at least decrease by 25% or 50% the load.

Where is the axle that that the lid turns on? If it is not at the back end of the lid then can the back edge underneath be good spot to glue a weight?

I'd just stick with the trash can that has the little peddle that you push on to make the lid pop up. You might modify that to work electronically, but why? Too much time with nothing to do.