Register to reply

Rotation design

by dt1156
Tags: design, rotation
Share this thread:
dt1156
#1
Apr18-13, 11:45 PM
P: 3
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?
Attached Thumbnails
Untitled.jpg  
Phys.Org News Partner Engineering news on Phys.org
Identifying long-distance threats: New 3D technology could improve CCTV images
Intelligent system that predicts when alarms might be triggered could greatly improve the management of industrial plant
3D printed nose wins design award
NascentOxygen
#2
Apr19-13, 12:16 AM
HW Helper
Thanks
P: 5,328
Quote Quote by dt1156 View Post
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!

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
#3
Apr19-13, 02:48 AM
PF Gold
Danger's Avatar
P: 8,964
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
#4
Apr19-13, 02:33 PM
P: 3
Rotation design

Quote Quote by NascentOxygen View Post
Hi dt1156!

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 similiar 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.
Attached Thumbnails
269-ote-very-high-moment-2203.jpg  
NascentOxygen
#5
Apr19-13, 08:28 PM
HW Helper
Thanks
P: 5,328
.... One major omission in your specifications: the speed range over which you wish to spin it.
dt1156
#6
Apr21-13, 12:47 PM
P: 3
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.


Register to reply

Related Discussions
Computer design of retaining wall design Engineering, Comp Sci, & Technology Homework 0
Rotation of free solid object in vacuum, location of axis of rotation Classical Physics 16
Need to understand: derivating euler rotation from fixed axis rotation Engineering, Comp Sci, & Technology Homework 1
Find rotation to align two vectors by rotation about two arbitrary axes Linear & Abstract Algebra 7