Mechanics required for a stepper motor

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I am making an elevator controlled by a raspberry pi zero and driven by a stepper motor. I have managed to get the engine working using a python script and an MPC28017 pin expander (i2c protocol).

This is the script: https://gist.github.com/aitormendez/7797a6bc52e6f20c27abcad241225c9a

The script working: https://youtu.be/tuPRvOaolGY

And this is the elevator:

So far everything has gone well, but I have been stuck in the planning and construction of the mechanical part coupled to the engine and I need help and advice on it.

There are two problems to solve. The first is what and how it is attached to the motor shaft. The motor shaft (5mm diameter) does not have a gear attached and I cannot find one on the market with a 5mm hole. What options are there? How is it usually done?

The second problem is that the motor, although it seems quite accurate, turns very slowly so I will need more gears with the same tooth size to build a throttle.

In short, what elements are necessary to be able to transmit the force of the motor to a pulley.

Thank you so much.pi-zerodc-motorshareedit  follow  close 4flag asked 2 days agoaitor14544 bronze badges

• 2Not Pi specific. The 28BYJ-48 stepper will max out at 17 RPM and has surprisingly little torque (the 12V version is better). I would get another stepper. Re fixing to shaft look up shaft couplers. This is the wrong site for the question. he project is interesting. Have you asked on raspberrypi.org/forums ? – joan 2 days ago
• Ah, ok. I will try there. Thanks. – aitor 2 days ago
• 1@aitor, Welcome and nice to meet you. Your programs, video, and GitHub stuff are impressive. I look forward to see you elevator ascending! 🙂 BTW, you might be interested to read the catalog of motor shaft copulers: aliexpress.com/w/wholesale-shaft-coupler.html. /to continue … – tlfong01 2 days ago   
• 1I recommend newbies to start with something like this: fr.aliexpress.com/item/…. / to continue, … – tlfong01 2 days ago   
• 1And you might also need to consider high torques stepping motors: aliexpress.com/popular/stepper-motor-high-torque.html. /to continue, … – tlfong01 2 days ago   
• Thanks @tlfong01 for the welcome and for the buying advice. I find them really useful. – aitor yesterday
• @aitor, By the way, when the frist time I saw your wooden lift, I immediately recalled my once in a life time happy experience of taking a funny wooden lift when I studied at Imperial College, London, ages ago. Happy memories of paternoster lifts – Guardian 2015aug17 theguardian.com/technology/2015/aug/17/…. I still remember vividly that in one afternboon I got nothing to do, and so wandered from college building to building, to find anything exciting or interesting. / to continue, … – tlfong01 5 mins ago   
• (Before that I already got my first tourist’s surprise seeing that the London bus has no door, and the passengers just hop up and down, even when the bus is moving. I thought it was dangerous, until I saw some 70 years old ladies hop up and down so casually. So I took courage to have my first bus hopping experience, and it was wonderful.) Coming back to the college wooden lift. When I saw the wooden lift, there was no people around, no instructions, no button to press, … / to continue, … – tlfong01 4 mins ago   Edit   
• I first thought it was a cargo lift, but it was higher than a man, so I thought it should be for passengers. At that time, I alreaded trained myself to hop up and down the London bus, so with little hesitation, I hopped up the wood cubcible and enjoyed the once in a life time ride. It was only many years later I read that it was a “circular” lift, like the London’s Circular Underground Train Line. / to continue, … – tlfong01 3 mins ago   Edit   
• Any way, second thought about your project is that it can be a sort of basket for transporting vegetables and cats (yes, I did see cats taking the lift) to high floors in a locking down building. It is only a couple of days ago I read that eShopping is getting so popular these days and the express delivery guys could not cope. So people invented different days of collecting parcels. Perhaps you can start up a similar smart IoT project for express delivery of parcels. Thanks again for bringing back my happy memories. Cheers. – tlfong01 just now   Edit   

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