Making a DIY tv lift system

Hi All.

I am trying to make something like [1] with the odrive. I am a system engineer by day. so i lack in the mechanical/electrical skills department :slight_smile:

The TV i am trying to lift is speced with >=70lbs. I want to rate my system to be able to lift between 30kg to 40kg. I am still researching what type of pulley system i can use to reduce the load on the motor. Can i use an odrive motor for this or its an overkill ?

Would anyone of you please help me figure what i would be more suitable in terms of motor capable of lifting a load/pulley system load like this ? If i went with a cheap dc motor (there are plenty of videos on how to drive one with arduino) what would you recommend ?

[1]https://www.youtube.com/watch?v=gdvzEiHGiqU

just buy linear actuators off eBay. Cheap enough and come rated to the necessary force you want.

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This is super interesting for me to get into motors and arduinos. I am trying to make it a diy project and not buy something off the shelf

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Sorry, but linear actuators are the correct hardware for this. If you want to you could build one yourself with a motor, a threaded rod and a nut. I wouldn’t reccomend anything under M5.
They have backlash, but in this application that doesn’t matter. Be aware that they have a very fine pitch and you need to rotate them quite fast. For M10 e.g.:

Vlin(in mm/s)=RPM/60*1.5mm

Hi Leo.

I am super new to the jargon :slight_smile: Can you hydrate what you mean by M5/M10 for me please? Anything i can google will be fine.

I am glad you hinted towards a DIY linear actuator with a rod. i saw a youtube video [1] that (maybe) explains what you are saying. Unfortunately he does not cover the actual theoretical limits in terms of load this particular motor is capable of lifting. If you can point me to a (cheap) dc motor that can lift 30~40kg with that system i would really appreciate.

The only reason i was thinking about the odrives is because (for some reason)i thought these would have a higher load. And the fact that all was documented was super nice.

[1] https://www.youtube.com/watch?v=kaJVWoKj2a4

Regards

I’m talking about using threaded rods and nuts for this.
Mxx means “Maschienenschraube”(ger) or machinescrew and the number tells you the diameter in mm.
I would reccomend using a M10 rod with 1 or 2 nuts. It isn’t neccessary to use a ordrive for this, but is of course nicer than a standard motor. These are relatively cheap and very accessible.
Try using aluminium profiles or sth to guide the rods along with maybe some nylon wheels like you seen on cheap 3d printers. Maybe build everything inside of a hollow aluminium profle. I would reccomend using endstops, but if you want to have diffent fixed position, a odrive with a low resolution encoder would be nice.

Edit: took a look at your link, basicly what he’s doing, but I tend to overengeneer stuff

Just an example how cheap they can be.
Search for yourself to find a seller in your country

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Can i please pick your brain on the theoritical limits ? Whats the maximum load (in kg) on that motor ? They don’t mention any equations to figure the maximum weight it can carry.

Regards

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I don’t know either, but with a good design that supports the rods on both ends, it should be able to support quite some load. The torque for the motor should be sth like this:

F=50kg=~500N
pitch=1.5mm=0.15cm
We search the torque M

F=M/p
M=F*p
M=500N *0.15cm
M=75Ncm
M=0.75Nm

That equasion is (should be) correct if we don’t account for the friction of the bearings and more importantly at the nuts. You’ll have to add that, too.
But this is only correct for one motor. I would highly reccomend using 2 motors, or at least 2 rods driven by one motor and belts.
On the practical side:
Make sure to support the rods on both ends. Use two ZZ general purpose ball bearings, use a fixed mount for the bottom one and nuts on the rod to avoid putting pressure on the motor bearings.
That would at least be my approach

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