Servo assembly for "heavier" load (moving couch around)

Hi,

I am a long time arduino fan and user but I have reached a small obstacle in my project planning. I am interested to automate furniture re-positioning in a test room. A few details - a floor is tiled and smooth, no obstacles.

What I am looking for now is a simple way to attach "wheels" to a couch/sofa. I am thinking about 4 wheels 2 of which will have power for manoeuvrability. So, to my main question - is there any ready-made solution I can just stick underneath the sofa and control? Some servo+wheel assembly that would be able to handle at least 150-200 kg?

Probably, but I would know where to look really - its probably something used in some industry
for moving trolleys or something.

I know there are electric motors for caravans that drive the tyre for positioning when parking up,
but they have a rough wheel to grip the tyre and are probably over-engineered for such a purpose.

Wheelchair motor sets might be closer to the application?

Below is probably the concept you are looking for, but developing servo based motor devices to actually move the heavy load you describe will take some effort and probably some $$$.

http://www.youtube.com/watch?v=0FGWKwIIKVM

Please, please ... don't continue with this application...

Mankind is already obese enough since TV remote controls were invented and they didn't have to get off the couch to change channels.

If they don't even have to get up to move the couch .... I shudder to think .....

:)

...R

I am actually building a "showroom" living room that will re-configure itself in order to provide space for exercise (like TRX or Kinect in front of the TV).. so in this case, it will actually help :)

zoomkat: Below is probably the concept you are looking for, but developing servo based motor devices to actually move the heavy load you describe will take some effort and probably some $$$.

http://www.youtube.com/watch?v=0FGWKwIIKVM

This looks amazing! I only need one direction though, with turning achieved by stopping one wheel and moving the other. No need for such complex coordination. I will keep looking, I am slightly time-strapped, hence the search for a ready-made solution I can just "plug" into my project

I'd look for something over at AndyMark (http://www.andymark.com/) - specifically, I'd go with four of these gearmotors:

http://www.andymark.com/product-p/am-2084.htm

...plus four of these controllers:

http://www.andymark.com/Talon-p/am-2505.htm

Angle them out at the corners, and mount some meccanum or omni wheels to them:

http://www.andymark.com/product-p/am-0137.htm

You'll need hubs to mate the wheels to the motors, and appropriate brackets to mount the motors to the sofa or chair. Some of the might be custom (maybe if you look carefully, you can find something to match things up at AndyMark or elsewhere).

You probably are noticing how expensive all of this is. You can probably find some way to do it cheaper, but not by much - the motors and the controllers get really expensive once you have to start moving heavy things. For the motor/gearboxes, you might be able to get by with some planetary gearbox/motor systems taken from cordless drills; but you'll still need to buy some omni wheels, and those don't tend to be inexpensive.

You definitely -will- want to have omni positioning capability for what you want to do; I honestly can't imagine moving a couch properly without it, unless you plan to only move the couch in a single direction or something.

The bearings in those motors cannot even remotely support heavy furniture, note - the wheel and its bearings need to be well engineered, which a good wheelchair motor set gives you.

Sorry, I know I should have resisted the temptation to take a cheap shot - but when you hold up such a huge target ....

Isn't there something a bit weird about spending time and money to save the energy needed to move furniture just to make space for exercises designed to ....... use up energy.

I promise to resist the temptation next time :)

...R

zard_cz: I am actually building a "showroom" living room that will re-configure itself in order to provide space for exercise (like TRX or Kinect in front of the TV).. so in this case, it will actually help :)

MarkT: The bearings in those motors cannot even remotely support heavy furniture, note - the wheel and its bearings need to be well engineered, which a good wheelchair motor set gives you.

Well - I probably made the wrong assumption that using the brackets and such meant to have an intervening shaft and bearings between the gear-motor and the wheel/hub assembly. AndyMark should be able to cover all that as well; if not, there are other suppliers.

While yes, a good wheelchair motor set would give you all of this - to do the proper positioning of the furniture would still require four of these motors, which aren't cheap to begin with, and even more insane sized motor controllers, plus 24 volt batteries, etc. The wheels are also going to be a lot larger, likely - to fit on the shafts of the wheelchair motors.

Ideally, you want the furniture to be able to translate in any direction, as well as pitch around the vertical axis - for maximum and efficient positioning; two motors and wheel combos in a differential drive fashion won't give you this on a couch (unless the room is very, very large and not very cluttered - in other words, completely unlike any real living room), while four motors and omni/meccanum wheels can (albeit at a higher cost and with more complex programming).

zard_cz:
Hi,

I am a long time arduino fan and user but I have reached a small obstacle in my project planning. I am interested to automate furniture re-positioning in a test room. A few details - a floor is tiled and smooth, no obstacles.

What I am looking for now is a simple way to attach “wheels” to a couch/sofa. I am thinking about 4 wheels 2 of which will have power for manoeuvrability. So, to my main question - is there any ready-made solution I can just stick underneath the sofa and control? Some servo+wheel assembly that would be able to handle at least 150-200 kg?

Great project concept !!

How does a couch weigh 150KG ? Whats it made of ?

I assume speed is not important (at least in the initial prototype ?)

As others have said - Wheelchairs are good - better are golf carts - not buggies - just the golf carts - go along to any golf store that repairs them and you will find them happy to give you old carts that have the 12v motors - many of these are geared right down and are very powerful - they also come with an axle assembly

You could place hall effect sensors to sense the number of rotations and hence map that to room positioning.

You will of course need a suitable driver board

Craig

Craig