NerdKits - electronics education for a digital generation

You are not logged in. [log in]

NEW: Learning electronics? Ask your questions on the new Electronics Questions & Answers site hosted by CircuitLab.

Project Help and Ideas » Motor with constant force

April 15, 2012
by mcgroover
mcgroover's Avatar

Hi,

I am looking to create a project that pushes an arm against another object with a constant force. I originally thought I could just use a DC motor and have the gear held steady against something and vary the force by varying the current to the motor. However, I think the motor might overheat if I do it this way. Is this correct and if so, does anyone have any ideas of how this can be accomplished?

Thanks for your help!

April 15, 2012
by mcgroover
mcgroover's Avatar

Just realized I probably should have put this in the robotics forum.

April 15, 2012
by Ralphxyz
Ralphxyz's Avatar

Well how much force?

You might use an air compressor and piston. The piston could be as simple as a syringe.

I just got the vacuum air pump from all electronics to play around with. I figure with some sort of receiver I should be able to get a lot of work done on both the pressure and vacuum side.

Ralph

April 15, 2012
by mcgroover
mcgroover's Avatar

Hi Ralph,

Thanks for replying!

The maximum force I need is about 70 Newtons on the pressures side and no pull force needed. Would that jive with the vacuum air pump? I couldn't tell from the product description on that website. What do you mean by 'receiver'? Is that the part that physically connects to the part you are trying to move?

I am not sure if my application is different since I don't really need the device to move, I more need it to apply a force against the object (there might be some movement to a small amount of elasticity of the materials). I am assuming the solution is the same for both applications though?

Cheers!

April 16, 2012
by Ralphxyz
Ralphxyz's Avatar

I believe the little commpressor I referencesd will put out 40psi!

Have to look up Newtons to psi :-)

A receiver is a tank to hold your air or vacuum. It helps maintain a steady pressure especially with a small volume pump like this.

If all you need is to just apply a "force against the object" could you use a weight?

You could mount the weight on a servo to move it on and off the object.

Darn I could'nt wait for Newton to psi conversions, so 70 Newtons is 15.736625971010001 lbs.

So this would be doable with a air pump you could apply the force by hand even.

Ralph

April 16, 2012
by mcgroover
mcgroover's Avatar

Thanks for this. I will look into getting a pump!

April 17, 2012
by mcgroover
mcgroover's Avatar

Hey Ralph,

What kind of power supply are you planning for that air pump?

April 18, 2012
by Ralphxyz
Ralphxyz's Avatar

That is a 12v dc pump, oh I see the price has gone up.

The label is in German so I can not see if there is any load rating.

I have 12v 15 amp power supply off ebay that I might start with.

Ralph

April 18, 2012
by mcgroover
mcgroover's Avatar

Would using two 9V batteries work as well?

April 19, 2012
by Ralphxyz
Ralphxyz's Avatar

You would have to use a regulator to get to 12 volts but yes you can use any source.

The biggest concern might be amperage, how fast the/a battery gets consumed.

What is the object that you want to apply pressure to?

Ralph

Post a Reply

Please log in to post a reply.

Did you know that multiple microcontrollers can communicate with each other? Learn more...