[SOLVED] Rotational motion to Linear motion

[goldriver]

We are in process of designing an automated fruit packaging system. Part of this system requires us to design a mechanism which converts rotatory motion into linear motion. Can someone with a mechanical background ,please guide me on how to design such a mechanism?. The mechanism will be controlled via a stepper motor which will move in steps ,few cms every time the stepper is given a command. We are looking for a cheap,reliable and quick solution which can be made with tinkering with junk or basic mechanical stuff.

 

[KlausST]

Hi,

Use a cogged belt pulley and a toothed belt.

But there are many other ways.

Hope this helps
Klaus

 

[BradtheRad]

Watch how a steam locomotive's wheels convert linear motion to rotary. You might use the same principle, in reverse.

There is a miniature model of a steam engine which does the same thing.

Also look into the nut and threaded shaft. Spin the shaft. The nut travels linearly.

 

[ahsan_i_h]

Google search with the words "stepper motor linear actuator" . See the pictures and you will get some ideas. Most of them are threaded shaft / nut system.

 

[Solar000]

Watch how a steam locomotive's wheels convert linear motion to rotary. You might use the same principle, in reverse.

There is a miniature model of a steam engine which does the same thing.

Also look into the nut and threaded shaft. Spin the shaft. The nut travels linearly.

Hi, i am trying to build something like that, but for linear to rotary motion.
Is it possible to make the angle bigger?
For example, pull 5mm and as a result to rotate 50-60 degrees, not 5-10.
How i can do that? with gears?

 

[ahsan_i_h]

For example, pull 5mm and as a result to rotate 50-60 degrees, not 5-10.
How i can do that? with gears?

Gear is a common solution. A good example using gear is bourdon tube pressure gauge. When pressure is applied, the bourdon tube expands a small amount. Then using gearing mechanism small amount of linear motion is converted to large angular displacement to indicate pressure readings. See the internal picture of bourdon tube pressure gauge below.

 

[Solar000]

Thanks,it looks helpful and i will try it.
Can i buy any pressure gauge to take the machanism or only bourdon tube ? because its difficult to find that kind of gears alone.

 

[BradtheRad]

That looks very much like a mechanical barometer. A sphere is closed off from room air. It expands and contracts a tiny bit, in response to air pressure. That tiny movement is applied to a mechanism like post #6.

 

[ahsan_i_h]

Can i buy any pressure gauge to take the machanism or only bourdon tube ? because its difficult to find that kind of gears alone.

The gears in pressure gauge or barometer are too small and weak for general work. Their purpose is only to deflect the pointer. Generally you can use two gears, one small and another big. Use the big one (after making a hole at suitable distance from center to join linear movement arm) as sector gear as shown in the picture of post #6.