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Variable height desk: replace hand-crank with some kind of electrical motor Answered

Hi,

First time poster here, sorry if I'm misplacing this. I have near zero knowledge of engines, though I understand physics, at least from my civil engineering college years.

I bought a variable height desk from IKEA (Skarsta model), which has a 12cm radius hand crank (see photos) that ends in a hexagon shape, h=6mm (so diameter around 6,93mm).

This hand crank works fairly easily, needing little effort to crank the table up, with ~45kg of weight on it (it's supposed to go up to 50kg).

So basically I was thinking if there was a easy, cheap and safe way of automating this with some sort of electric motor (I even looked up those Lego Technic motors!).


Any suggestions?
Thanks
 


Discussions

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Techack

2 years ago

I have cut the 6mm allen key supplied with the kit and use it with a cheap drill from Home Depot. I work just fine.

I don't care about the look since it is a home office.

Good luck.

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acnTechack

Reply 2 years ago

I missed your post [quite] a while back but this is a pretty good idea. Thanks for sharing

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acnacn

Reply 2 years ago

One thing though, how much load do you have on the table?

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KevinW193

2 years ago

Techack - I'm thinking of doing the exact same, but maybe with a wired drill I don't use any more. How did you attach the drill to the Skarsta?

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Downunder35mKevinW193

Reply 2 years ago

If you do want to go a bit smaller in size than a drill:
A lot of cars use motors to move the seat back and forth.
Some of them work the same way as your drill, a geared motor spinning a threaded rod quite slow - they are easy to mod for this.
Another great option if you want to stick to mains power is a motor for a spit roast, you know these tiny boxes that spin your deer over the bbq (ok, take the smaller version please!!).
All they need is a square axle that connects to your drive mechanism and if you buy a cheap kit you could cut the spit rod as without the motor it has no use on your bbq anyway ;)
And if you want to go totally overboard you can also use a Nema17 motor with a nice reduction gearbox and an Arduino to set the table height accurately by the mm, even with presets if you want.

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ishamsulDownunder35m

Reply 6 months ago

Thanks for this. I'm thinking about the Arduino solution. Will I need a motor control board with the Nema 17? Does the reduction box help increase the torque output to lift a heavier load, and would plastic gears do (thinking about 3D printing it). Cheers!

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KevinW193Downunder35m

Reply 2 years ago

I'm now using a little Black & Decker cordless driver. At first I thought it wasn't going to be powerful enough, but it does the job fine. Even faster if I push the table up while it's raising it. Going down is no problem at all.
Because of the tight space, the drill is wedged there, so there's no need to attach it. Beautiful.

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Downunder35m

3 years ago

Get a motor that drives the seat in a car.
They are still 12, but with a high power gear box and lots of torque.
Best is their size, which makes them ideal for such things like moving a table top.

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Toga_Dan

3 years ago

automobile window motor assembly. Junkyard part is likely good enough.

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alpdToga_Dan

Reply 3 years ago

Would a auto window motor have enough torque to handle ~30kg? I'm unable to find how much does a side window weight, but I fear it's much less.

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ilpugToga_Dan

Reply 3 years ago

Wheelchair motor maybe? If the resistance of turning the handle isnt that much you could use a power drill motor and gearbox.