Designing a simple DC massage device

Thread Starter

crowtor

Joined Aug 26, 2019
4
Hi there,

My last massage device that I use for my back pain has burned down and it's the 5th or 6th unit that did that so I'm trying to make something more reliable and long lasting.

The current specs I'm thinking about are:

DC Motor up to 12V (preferred 6V), max. 28mm in diameter
2-4 18650 cells

Current motor candidates :
1. https://www.pollin.de/productdownloads/D310493D.PDF
2. http://www.ebay.de/itm/173909902699

My previous devices run 2 problems, I don't know why either of these happened.

- Batterries overheating
- Motor overheating

I'm still missing a controller, I'd love to make it future proof for up to 4 motors.

If there's anyone willing to bare with me, I'd very much appreciate help with any of the issues:

- choosing proper motor
- choosing proper controller
- avoiding either the batteries or the motor overheating

Many Thanks!
 

Picbuster

Joined Dec 2, 2013
982
We need more information about the mechanical load.
This is to split into;
start energy in Nm ( make it to run)
running at full speed and load Nm. ( keep it running under full load)
Interval and duration when intermittent load is applied. (This could produce a strong fluctuation in current and could be the source of (over) heating motor and batteries).

Information above allows you to calculate energy needed and will identify motor spec's.

The motor spec's is the handle to the electronic control unit spec's.

it's impossible to give you a solid and correct advice without mentioned information.

Picbuster
 

oz93666

Joined Sep 7, 2010
669
the links you give are just for normal motors ...

I think you need something like this ...

It's a motor with an off center weight , this is designed to vibrate , and will work much better than an ordinary motor , and use a fraction of the power .. you will only need a small one ...

Many different types available for a few Euro's each , buy a few different designs and see which is best , then we can sort out the power supply ...

Put "vibrating motor" in eBay search
 

Thread Starter

crowtor

Joined Aug 26, 2019
4
@Picbuster
Thanks for the reply. In all honesty, I don't know how to answer any of the questions. I figured out if I used the best possible motor given the maximum dimensions, I'd be fine.

The current motor is a cheap 6V, 10'000RPM, its unbranded and has no writing of any sorts on the outside.

As for the load, I take the vibrating motor and lay on top of it with my back, then I run it.
The actual load I assume would probably be calculated taking into account the muscle density and its deformability , elasticity of the mattress and my weight of 70kg. I have no idea how to calculate that.

I'd love to be able to run it for a max of 1h. It can get warm as long as it doesn't burn itself up.

@oz93666
I was under the impression that I can turn any motor into a vibration motor if I add an off center weight to it. Current motor looks exactly like that in the picture, It's not strong enough. I already searched ebay for a vibration motor, only found either too big ones or too weak ones.
 
Last edited:

oz93666

Joined Sep 7, 2010
669
@oz93666
I was under the impression that I can turn any motor into a vibration motor if I add an off center weight to it. Current motor looks exactly like that in the picture, It's not strong enough. I already searched ebay for a vibration motor, only found either too big ones or too weak ones.
In theory you can make one yourself ... in practice it will never be as good as a mass produced item , and will probably shake itself apart in a week ....

There are so many choices on eBay there must be something ... some already have an outer casing , they even have pads , I would look again .
 
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