Battlebots

A new forum for battlebots enthusiasts, competitors, and fans.
 
HomeCalendarFAQUsergroupsRegisterLog inBuilders DB

Share | 
 

 Help with DC Motor Decision

View previous topic View next topic Go down 
AuthorMessage
MatK



People Skills : 2080
Registration date : 2012-01-16

PostSubject: Help with DC Motor Decision   Mon Jan 16, 2012 1:49 am

I need a small DC motor that can spin a plastic sword weighing 2 ounces fast enough to make a juice box fall down with an effective hit.

The motor must be able to do this with a 180 degree rotation.

I am looking to find out how much torque, rpm and voltage the motor would have to be.

Please be as detailed as possible as I am not an expert with robots, thank you everyone for your answers.
Back to top Go down
rdubard
mega contributor
mega contributor


People Skills : 3552
Registration date : 2009-06-10
Age : 52
Location : Ransom Everglades, Miami, FL

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 5:30 am

180 deg? I think I would take a look at a high torque servo for a not-really-spinning application. Go browse around RobotMarketPlace.

Is the juicebox full, or empty?

How much money do you want to spend?

What sort of controller are you using, and what kind of space, weight, and power restrictions do you have?
Back to top Go down
MatK



People Skills : 2080
Registration date : 2012-01-16

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 1:11 pm

The full juicebox is only an example of how much the object will weigh.

I am looking to spend between 10-30 dollars on a motor and it cant be longer than 2 inches excluding the motor shaft.

Right now I have no controller.

Would I be able to achieve the same results with a double pull double throw switch on a DC motor compared to a servo motor with a controller in terms of reversing the direction of the motor?
Back to top Go down
Camden W
mega contributor
mega contributor
avatar

People Skills : 2806
Registration date : 2011-04-10
Age : 23
Location : Blaine Minnesota

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 5:18 pm

Probably not, considering servos are usually heavily geared down, and are able to change direction very quickly. that and the amperage requirements for a servo are much smaller for a motor that would be constantly changing direction just as quickly. compare 1A to 20A.
Back to top Go down
rdubard
mega contributor
mega contributor


People Skills : 3552
Registration date : 2009-06-10
Age : 52
Location : Ransom Everglades, Miami, FL

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 8:27 pm

There is a device called a servo tester that can drive a servo. You have to turn the little knob to a given position, and as a result the servo turns to a specific position. It requires a battery input, but a 4-AA battery holder, with 4 AA batteries in it obviously, can do the trick for most servos. This would be a better option for overall control than a simple switch, and it can be really useful for other projects where you don't want to use a transmitter/receiver setup, but would like to use R/C car, plane, or boat electronics (such as ESCs).


This servo looks pretty strong and fairly fast--with metal gears it's also unlikely you will damage it internally.

You're looking at around $50 for all this, so maybe you can shop around for a similar servo that's a bit cheaper, but this stuff can all be useful for other projects too.

Hope this helps.
Back to top Go down
MatK



People Skills : 2080
Registration date : 2012-01-16

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 8:52 pm

Thank you very much!

What is the fastest speed that the servo tester will drive ther servo? I am looking for one that can rotate the servo quickly.

Also are there any simple videos that demonstrate how to connect the servo tester to the servo, I dont know how.
Back to top Go down
Camden W
mega contributor
mega contributor
avatar

People Skills : 2806
Registration date : 2011-04-10
Age : 23
Location : Blaine Minnesota

PostSubject: Re: Help with DC Motor Decision   Wed Jan 18, 2012 10:06 pm

the pins on teh front right corner of the servo tester are where it would plug into - it looks like you can connect two at once. as for speed, I would say as fast as you can crank the knob, depending on the servo. to find the speed of them, most servos are rated in degrees of rotation per second. the higher that number, the faster. you can do the math to change it to RPM, I'm too lazy to.
Back to top Go down
Sponsored content




PostSubject: Re: Help with DC Motor Decision   

Back to top Go down
 
Help with DC Motor Decision
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» Old Motor Week Jon Moss T56 Impala SS road test video
» Window motor replacement
» power antenna motor problem
» Hobby King ESC and Motor
» Motorcraft 200k at Texas Motor Speedway

Permissions in this forum:You cannot reply to topics in this forum
Battlebots :: Bots :: Technical help-
Jump to: