Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: SmD13x on March 27, 2008, 07:40:53 PM

Title: Continuous Rotation Servo Suggestions???
Post by: SmD13x on March 27, 2008, 07:40:53 PM
At the moment, I am using the Futaba S148 servo motor. The problem is that it does not have a fast rpm, maybe about 50-60 rpm. I'm new to all of this, so any help would be appreciated. Anyways, I am looking for a servo that can output enough rotations so that it can travel at least, lets say 30 feet in about 40 seconds or so. The wheels I am using have a diameter of around 2.5". I am looking for any suggestions of a servo I could use to have a robot travel 30 feet in about 40 seconds. Again, any help would be appreciated. I'm new, so if you could provide a link if possible that would be great. Thanks.
Title: Re: Continuous Rotation Servo Suggestions???
Post by: airman00 on March 27, 2008, 08:17:05 PM
why does it have to be a servo?
Title: Re: Continuous Rotation Servo Suggestions???
Post by: SmD13x on March 27, 2008, 08:24:21 PM
It doesn't have to be a servo, but from what I read it is the easiest to control. Again, I'm new to all of this, so I'm open to suggestions. From what I read, DC Motors need an H-Bridge to control them, as for servos can be controlled directly from the microprocessor. At the moment, I kind of need to get this project done fast, so until summer comes around I can't really learn to work with the H-Bridge, even though I'm sure its not that much harder. Also, I am using the Basic Stamp 2 microprocessor with a Board of Education Carrier board. If you have any certain motor or work arounds, let me know please. Thanks.
Title: Re: Continuous Rotation Servo Suggestions???
Post by: airman00 on March 27, 2008, 08:31:31 PM
I would say go with a motor driver and a geared motor. They are really easy to use

How much torque to you need the motors to have?


A motor driver kit
http://www.robotobjects.com/scripts/prodView.asp?idproduct=67

A regular motor driver chip
http://www.me.umn.edu/courses/me2011/robot/technotes/L293/L293.html

But first find your motors and then buy the drivers based on the motor's requirements
Title: Re: Continuous Rotation Servo Suggestions???
Post by: SmD13x on March 27, 2008, 08:41:14 PM
Well, I really wouldn't need much torque since the tire is 2.5" and the robot is only moving on flat, smooth surfaces. Anyways, would I be able to get that motor driver to work with the Basic Stamp 2 and Board of Education board? I know that company has their own H-Bridges, but those are a tad bit pricey.
Title: Re: Continuous Rotation Servo Suggestions???
Post by: DC-Electronics on March 28, 2008, 11:32:37 PM
I have alot of motors that fit your needs I think. Take a look at my ebay store and see if there is anything there you like.
I can set you up with deal on a single motor of your choice, just let me know :)
Title: Re: Continuous Rotation Servo Suggestions???
Post by: SmD13x on March 29, 2008, 05:48:47 PM
Thanks DC- Electronics. For now since I'm pressed for time, I decided to just use bigger wheels. During the summer though, I plan on getting a new project together, so when I need some stuff I'll keep you in mind.
Title: Re: Continuous Rotation Servo Suggestions???
Post by: DC-Electronics on March 31, 2008, 12:44:02 PM
Hey not a problem :)

That post sort of reminded me of these little Nippo Denki motors I have. We custom ordered them without gearheads and all that... the go at about 30 000 RPM or something like that, Good times :)
Title: Re: Continuous Rotation Servo Suggestions???
Post by: Admin on April 06, 2008, 10:46:36 AM
http://www.societyofrobots.com/robot_faq.shtml#select_motor