Designing a Discus Rotator: Motor Solutions

[dt1156]

Hey guys looking to design something that will rotate a 2kg discus in place. I attached a simple schematic of what it will look like. I also don't know what kind of motor to use to rotate the shaft. I went to Fry's but their motors looked to weak to power it. Anyone know a site I can buy a motor that can get the job done for me?

 

[NascentOxygen]

Hey guys looking to design something that will rotate a 2kg discus in place. I attached a simple schematic of what it will look like. I also don't know what kind of motor to use to rotate the shaft. I went to Fry's but their motors looked to weak to power it. Anyone know a site I can buy a motor that can get the job done for me?

Hi dt1156! http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

One major omission in your specifications: the speed range over which you wish to spin it. Also, would be worth pointing out your discus's diameter.

Are you planning mains operation, or a low voltage? My first thought is a ceiling fan motor and speed controller, but take great care, because a smooth discus is going to offer far less resistance than a big fan, so the discus will have a much faster top speed. This could be dangerous.

To what purpose will you put this spinning disc?

 

[Danger]

A fan is a good idea. My first thought was to hit a surplus store or scrapyard and grab an old vinyl record turntable. You already have 2 or maybe 3 mechanically selectable speeds, with the option of adding an electronic controller. It has the advantage of needing only a restraint such as a couple of straps or some Velcro as opposed to an entire mounting system.

 

[dt1156]

Hi dt1156! http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

One major omission in your specifications: the speed range over which you wish to spin it. Also, would be worth pointing out your discus's diameter.

Are you planning mains operation, or a low voltage? My first thought is a ceiling fan motor and speed controller, but take great care, because a smooth discus is going to offer far less resistance than a big fan, so the discus will have a much faster top speed. This could be dangerous.

To what purpose will you put this spinning disc?

The discus's diameter is 9in, 5/16" screw size and weights 2kg and round shape. I've included a picture of a discus that looks very similar to mine. The point of this design is to create a test to gather data from the discus while it is in rotation without having anyone actually throw it. This is a group project where my group will be placing an acceleramator inside the discus and a programming a microcontroller to convert the acceleration readings into the distance the discus traveled. I'm just designing this rotational test part.

 

[NascentOxygen]

... One major omission in your specifications: the speed range over which you wish to spin it. http://physicsforums.bernhardtmediall.netdna-cdn.com/images/icons/icon6.gif

 

[dt1156]

Not much faster than the average rotational speed of a discus thrown by a olympic athelte. I couldn't find any measurements of a discus thrown by olympians so I asked my group and someone took a guess at around 10 revolutions per sec which is around 62 rad/s.