# Home Project: What motor do I need for my battery-powered, motorized, high-speed 'lazy susan'?

#### helencferry

Joined May 13, 2021
3
Hi, I wonder if anyone could help me!

In my project, I want to create a battery-powered motorized ‘lazy susan’, where the top part of wood will spin with an object on top. I am quite confident on how I will attach all the components to do this as there are many youtube tutorials on the internet that show a similar thing – here is a link to one that might give you a better idea of what I am talking about:
)

But what I am unsure of is what type of motor to get, so my question is:

What type of motor and battery voltage do I need to support the load of around 1.2kg of weight (the combined weight of the top piece of wood that will spin and the object on top of that) and still spin the load quite fast (up to 120rpm)?

I understand that the speed of the motor reduces with more load but I am unsure of how to work out what type of motor and battery I will need for my requirements.

I will also be attaching a reducer to my circuit so that I can control the speed of the motor.

The 'lazy susan' has to be battery powered as I intend to film it outside.

Any help would be really appreciated,

Helen

#### BobTPH

Joined Jun 5, 2013
3,308
Welcome to the forum.

The kind of motor he is using is called a geared DC motor or gear head motor.

The video shows it running at maybe 10 to 20 RPM. Scaling it up to 120 RPM would cause a whole new set of problems, like the wheel and object would have to be very well balanced or it would wobble noticeably.

And, I think the object would have to be fastened to the table to prevent it from flying off.

The weight is not the biggest factor in sizing the motor. Once it is going, only the friction needs to be overcome by the motor. The weight comes onto play
In starting up, where the motor needs enough torque to overcome the rotational inertia. Need some physics to compute this.

Bob

#### MrChips

Joined Oct 2, 2009
23,515
If I were to do this I would use a different approach.

I would have a circular piece laying on top of a bottom plate separated by marbles or ball bearings. The marbles would be kept in place in a circular track on the bottom plate and top piece. Or you can purchase lazy susan bearings:

The actual visible platform will be another larger circular board mounted on top of the motorized assembly.

The middle piece would be propelled by a belt drive driven from a small DC motor, something like this one:

#### KeithWalker

Joined Jul 10, 2017
1,778
https://www.aliexpress.com/item/10000008795281.html?spm=a2g0o.productlist.0.0.aed173b46bmIYh&algo_pvid=fb1e584f-445d-4560-acd9-014d98ebd46d&algo_expid=fb1e584f-445d-4560-acd9-014d98ebd46d-25&btsid=0bb0623116209137929388049ed442&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

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#### LowQCab

Joined Nov 6, 2012
510
This is all very entertaining ........
But until you actually describe what you are trying to accomplish, it's all "academic".
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#### Ian0

Joined Aug 7, 2020
2,189
You can get plenty of turntables that rotate at 33rpm or 45rpm. Some of them even do 78 rpm.

#### Yaakov

Joined Jan 27, 2019
3,152
Building something that will spin 1.2 kilos at 120RPM without shaking itself to death, flopping around, and/or making a lot of noise is not going to be simple. The more asymmetrical the weight distribution the harder.

Could you explain what this turntable will be used for?

#### helencferry

Joined May 13, 2021
3
If I were to do this I would use a different approach.

I would have a circular piece laying on top of a bottom plate separated by marbles or ball bearings. The marbles would be kept in place in a circular track on the bottom plate and top piece. Or you can purchase lazy susan bearings:

View attachment 238214

The actual visible platform will be another larger circular board mounted on top of the motorized assembly.

The middle piece would be propelled by a belt drive driven from a small DC motor, something like this one:

View attachment 238213
Thank you for your suggestion! I have seen other videos either modifying an actual lazy susan with these bearings or just purchasing these bearings to add on - I think I will do the same. Thank you.

#### helencferry

Joined May 13, 2021
3
Building something that will spin 1.2 kilos at 120RPM without shaking itself to death, flopping around, and/or making a lot of noise is not going to be simple. The more asymmetrical the weight distribution the harder.

Could you explain what this turntable will be used for?
Thank you for your reply. 1.2kg is the combined weight of the top piece of wood and the object (mostly the piece of wood) but on second thoughts, I think I will lower the speed and choose a lighter piece of wood as the top piece. It is for an art installation project with a friend. We're spinning these woven cylindrical objects that when when rotated, the pattern will appear to move - a bit like a barber's pole! It needs to spin fast enough to appear to move but could still be effective at 80rpm or maybe less. I just wanted the flexibility to increase or decrease the speed.

#### Yaakov

Joined Jan 27, 2019
3,152
Thank you for your reply. 1.2kg is the combined weight of the top piece of wood and the object (mostly the piece of wood) but on second thoughts, I think I will lower the speed and choose a lighter piece of wood as the top piece. It is for an art installation project with a friend. We're spinning these woven cylindrical objects that when when rotated, the pattern will appear to move - a bit like a barber's pole! It needs to spin fast enough to appear to move but could still be effective at 80rpm or maybe less. I just wanted the flexibility to increase or decrease the speed.
Well, keep in mind how much force is imparted by angular momentum. It will require a carefully balanced and rigid structure to make something stable rotating at that speed.

Noise is going to be a problem unless you don't care, but if you don't, I would investigate using a cordless drill. If you want something more quiet, idler or belt drive with a very fast but small motor might work.

#### Bernard

Joined Aug 7, 2008
5,788
What is diameter of the turntable ? What is maximum height ? I have a motor in mind that has good
specs. 140 RPM, 4.5 V, .21 A @ no load, 12 in. oz, reversible, continuous duty, shaft 6 mm X 15 mm, 1.5" X 2.25", US \$ 9.95 +/_, Item 5-1795 @ Surplus Center, NE, USA. From 2017 catalog but still in stock.
My thought- 12" dia. X 5/8" plywood turntable with lazy susan bearing on sub deck with large cutout for motor . Coupling like MW platter . Motor mounted on 3 rd disc which is attached to 2nd disc via 3/4" pillars. A skirt can hide workings.
If mounting turntable directly to motor would suggest 5/8 " to 1/2" shaft with dual ball bearings.

#### anniel747

Joined Oct 18, 2020
1,034
Hi, I wonder if anyone could help me!

In my project, I want to create a battery-powered motorized ‘lazy susan’, where the top part of wood will spin with an object on top. I am quite confident on how I will attach all the components to do this as there are many youtube tutorials on the internet that show a similar thing – here is a link to one that might give you a better idea of what I am talking about:
)

But what I am unsure of is what type of motor to get, so my question is:

What type of motor and battery voltage do I need to support the load of around 1.2kg of weight (the combined weight of the top piece of wood that will spin and the object on top of that) and still spin the load quite fast (up to 120rpm)?

I understand that the speed of the motor reduces with more load but I am unsure of how to work out what type of motor and battery I will need for my requirements.

I will also be attaching a reducer to my circuit so that I can control the speed of the motor.

The 'lazy susan' has to be battery powered as I intend to film it outside.

Any help would be really appreciated,

Helen
Drill immediately comes to mind.

#### MrChips

Joined Oct 2, 2009
23,515
Windshield wiper motors are readily available from automotive scrap yards for a reasonable price.
They operate on 12VDC and provide lots of torque. The electronics to control the speed is not overly complex.

#### MisterBill2

Joined Jan 23, 2018
8,736
I suggest NEVER trusting the junk shown on youtube.

#### shortbus

Joined Sep 30, 2009
8,568
Windshield wiper motors are readily available from automotive scrap yards for a reasonable price.
They operate on 12VDC and provide lots of torque. The electronics to control the speed is not overly complex.

View attachment 238937
Most only have a 45RPM top speed on the shaft.

#### Bernard

Joined Aug 7, 2008
5,788
Windshield motor average specs. 53 in. lb., no load 50 RPM- 1.5 A. Not easy on battery supply unless a car battery is used.
I found this comment on Richeleiu UC 6612, " its a little noisy & rough turning".

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#### MisterBill2

Joined Jan 23, 2018
8,736
If you useone of those "lazy Susan" ball bearings you will not spin it with one of those small toy-sized motors, unless you have an adequate gear reduction arrangement. And probably 20 RPM is a reasonable top speed, which will be quite fast in any video production. But the motor will run at least 2000 RPM, and so you need a 100:1 reduction, at least. To do that and not have a whole lot of drag will be quite an achievement.