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jellis359
03-06-2009, 04:40 PM
hey,

I'm starting with my first project with DC motors. I want to have the bot be able to travel outside on sidewalk and streets. I'm planning on using 2 wheels and one caster.
I want to use a chain and sprocket system with the 28.00 banebots motorcontroller.
I'll be using reinforced plexiglass for a body material.
I plan on the bot being about 8lbs max. when i'm completely finished.
Now the only problem i'm having is that i don't know what dc motor to use, but i do know that i want a banebots motor.
I don't really know how to pick it.
I expect the robot to travel at walking speed or faster.

so can anyone give me some advice. I'm using this project as a learning experience so i'd like to learn whatever you have to offer.:happy:

Thank You

(I'll put a google sketch model up soon.)

Adrenalynn
03-06-2009, 04:52 PM
>> 28.00 banebots motorcontroller

You mean two of those controllers - one per motor. And two motors.

Before you can figure out the motor, you need to figure out the wheels - those directly impact speed and power.

jellis359
03-06-2009, 05:40 PM
i want to use an off road 4.75" diameter rc car wheel
it uses a 6mm shaft
http://www.trossenrobotics.com/store/p/5549-Off-Road-Robot-Tire-4-75-D-x-2-375-W-pair-.aspx

I really have no idea where to start=
what i'd like:
-power to push through dirt
-walking speed
-chain & sprocket system with shafts and bearing blocks
-motor controller
-motor w/ 18Amp max. peak (to work with banebots motor controller)
-i'd like the bot to be about 1' X 1'

i was going to use this http://www.trossenrobotics.com/store/p/4230-16-1-36mm-Planetary-Gearmotor-RS-385-Motor.aspx with this http://www.trossenrobotics.com/store/p/5088-Bearing-Block-1-5-x-1-5-inch-0-375-inch-with-Ball-Bearing.aspx this http://www.trossenrobotics.com/store/p/5840-1-2-Hex-Mount-Hub-6mm-Shaft-0-8-Wide.aspx this http://www.trossenrobotics.com/store/p/5798-Rubber-Wheel-4-7-8-x-0-8-1-2-Hex-Bore.aspx with steel sprockets and chain for a drive system.

i want to use a 1/2" thick plexiglass thats 1' by 1' for the body

i want to use the BS2 and this motorcontroller- http://www.trossenrobotics.com/store/p/4267-BaneBots-Motor-Controller-45A-peak-.aspx

how does it look (what do you suggest/what can you teach)

Alex
03-09-2009, 04:33 PM
[moved to rovers forum]

robologist
03-10-2009, 01:38 AM
The motor above has a 3/8" output shaft, so different hubs and wheels need to be chosen.
A very fast walk could be 5 mph, but figure 3 or so for normal people. The motor has a free run of 1000 rpm or so. Estimating running half that speed loaded, 500 rpm on a 4.875 wheel would be about 10 feet per second. The 3 mph walk is about 4.4 feet per second, 5 mph (joggish) around 7.3 feet per second. Some folks go with a rule of not having a robot faster than you are, for safety/liability issues. It might be ok, if you feel confident about control, or it might allow things to get out of hand. If doing RC, it could be controllable. If building autonomous, need to get the long range sensors out, so the robot can detect something before it runs it over.

jellis359
03-10-2009, 07:10 AM
how did you calculate this? (for future ref.)
wait nevermind i remember