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Author Topic: new to robots  (Read 4820 times)

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Offline yatsu86Topic starter

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new to robots
« on: July 21, 2007, 11:57:38 AM »
hello i have been reading a lot on the web site and the forums but im still having troubles with this robot that im building. I did see the 50 robot tutorial and i decide to go of that but replace a few things.

1. the cardboard wheels with 3" airplane wheels
2.the 2 servo with 2 dc motors
3.the photoresistors with ir sensor

now with those replacements i have been having trouble. because the dc motors i took them out of a toy and they dont have a gear system so i would have to create one and im not sure how to do that and because i took them out of a toy i dont know the voltage, operating current, or the stall current . but my biggest problem is the electronics systems because with these replacements i dont know it i would have to add other things to it.

i hope you could understand all that.

Offline Eco19R

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Re: new to robots
« Reply #1 on: July 21, 2007, 05:17:50 PM »
DC motors need an H bridge to drive,

Offline Admin

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Re: new to robots
« Reply #2 on: July 22, 2007, 09:23:04 AM »
When I was designing the $50 robot I first decided to use DC motors because its cheaper that way. But the problem with them, as you are quickly learning, is that they require gearing and control electronics - each complicating it for a beginner. Using the servos will save you between 5 and 10 hours of work for a cost of about $3-$4. You need to buy/make a motor driver.

As for the IR sensors, that replacement should be decently easy. I perfer the photoresistors for beginners though because they are easier to test with - the human eye can see the same light the photoresistor can.

because i took them out of a toy i dont know the voltage, operating current, or the stall current
Hook it up to a power supply or multimeter and run some tests on your motor. Chances are you have an 'el-cheapo' motor, meaning it will work at about 6V optimal.

As for the gearing, this has been mentioned many times in the forum. The gist is that homemade gearing systems are not worth the effort. You need a motor that already has this built in, such as a servo :P


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