Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Daddysharky on January 20, 2012, 09:49:20 PM

Title: Really Newby! Needs advice on batteries and motors
Post by: Daddysharky on January 20, 2012, 09:49:20 PM
Hi, I am very new to robotics and honestly I call what I am attempting to build a "Robot" but it may be considered to be by some just a big RC toy. This is strictly an entertaining robot. Not equipped/expected to do any major task. I will tell you what I am attempting and you can decide. I am using rc transmitters and receivers to control servos attached to certain DPDT switches that are wired for forward/reverse abilities. I am using a Tactic 6 channel system and I have actually got a good part of the "robot" working. The head is on two channels of my receiver. This control is actually a 2 servo stack on a homemade gimbal to move the head in any 180 degree direction(up,down,left, right, diagonal) The base of the bot is actually the metal tubular frame of a Mongoose Dirt grinder. (Link to product at bottom for reference) Now I have had to do some adjustments to it such as remove the plastic body and I am using the speed controller that came on it with one dpdt switch inline in order to move forward and back at a certain constant speed (not to fast). This works remarkably well.
The steering is where I have run into a problem. I want to use a pwm controller attached to a 12 volt dc window actuator or windshield wiper motor in the same fashion as I am using the speed controller for the fwd/rev and honestly if I can get this to work I will replace the speed controller also with another pwm.  Why am I wanting to use a PWM? Well it is quite simple. The motor I want to use for steering moves much to fast. By the time I activate and then deactivate the dpdt switch the motor has traveled the complete distance the wheels will allow. which is fine if I only wanted to travel in circles and never straight fwd. So I need the pwm to slow it way down, almost to a crawl, so that I might be able to go fwd at some point.
So now you are caught up on my project and here are my questions.
1) Where can I find a PWM that I will not burn out with 12volt battery? (I have looked but not sure about the amps they can handle or how many I am dealing with. Amps confuse the heck out of me)
2) Can/should I use a motorcycle battery, or should I just use the Sealed Lead-acid (2)Batteries (12v12ah/20hr) that came with the dirt grinder to run all the 12 volt motors?
3) Can anyone suggest a better way (inexpensive) to turn the front wheels? (And I have tried giant scale servos and they are not strong enough)
4) Is there anything I am not thinking of that might be helpful in making less mistakes on this project?

I appreciate any help on this. Thanks for taking the time in reading my post,
Daddysharky

http://www.bicycles.justbetterhealth.com/mongoose-dirt-grinder-atv-electric-four-wheeled-off-road-vehicle/dp/B000JNI0SM (http://www.bicycles.justbetterhealth.com/mongoose-dirt-grinder-atv-electric-four-wheeled-off-road-vehicle/dp/B000JNI0SM)
Title: Re: Really Newby! Needs advice on batteries and motors
Post by: Soeren on January 20, 2012, 10:48:21 PM
Hi,

Hi, I am very new to robotics
And to writing?


4) Is there anything I am not thinking of that might be helpful in making less mistakes on this project?

I appreciate any help on this. Thanks for taking the time in reading my post,
Actually, I didn't, as it's one huge block of black :( (Did you try using "Preview" before posting?) Nevertheless this is supposed to be a help :)

So, to make less mistakes, make what you write easily digestible and make it generally easy for people to get your message, or they fall asleep or just find watching paint dry more entertaining.

More air, one or a few specific and to the point question(s) and not a lot else, that's the recipe for getting people to read your posts and that's the first step towards getting answers.
You may wanna just modify your post a bit and if so, use the "Modify" link (top  right in your post).
Title: Re: Really Newby! Needs advice on batteries and motors
Post by: Daddysharky on January 21, 2012, 10:04:41 AM
Wow. I didn't realize that the first comment would be from a complete jerk. I came here looking for advice on robotics. I gave an adequate description because too little info is not at all helpful. Because you can not or choose not to comprehend what I was describing does not give you the right to criticize my "writing" as you put it. And in YOUR reply you gave absolutely no help, which is worse. If you don't have the knowledge to comprehend or to give direct and helpful advice then my "ADVICE" to you would be to put your keyboard down and don't be a jerk.
Thank you for wasting my time and this forum can thank you for having one less person on it. There are plenty of robotic forums that would be glad to help and their advertisers will appreciate my business.
Have a nice day ;)
Title: Re: Really Newby! Needs advice on batteries and motors
Post by: Daddysharky on January 21, 2012, 10:15:14 AM
Heheh, I actually just found out why you commented at all. You comment on every post wether it is helpful or not. Keep that rating up! How the heck do you find time to work on robotics if you never get off this forum? Life's fun ... try living!