Author Topic: help! making dc motor robotic base (Read 4037 times)

jellis359 · « **on:** March 08, 2009, 10:02:43 AM »

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.

want to use an off road 4.75" diameter rc car wheel
it uses a 6mm shaft
http://www.trossenrobotics.com/store...5-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...385-Motor.aspx with this http://www.trossenrobotics.com/store...l-Bearing.aspx this http://www.trossenrobotics.com/store...-0-8-Wide.aspx this http://www.trossenrobotics.com/store...-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...45A-peak-.asp

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

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

jamort · « **Reply #1 on:** March 08, 2009, 11:41:55 AM »

Whats the point of the sprocket and chain system... also why dont you simply make it four wheel drive if you want to use chains and sprocket... or even tracked

jellis359 · « **Reply #2 on:** March 08, 2009, 05:12:58 PM »

i'm trying to incorporate the most simple drivetrain into the robot to learn from it
by drivetrain i mean system
but still keep it relatively "cheap"

jamort · « **Reply #3 on:** March 08, 2009, 05:23:34 PM »

o so you basically mean a couple of ruber bands with little wheels?... I think that is your going to develop a drivetrain you would benefit from 4 wheels... or tracks( I have found that sometimes caster dont work to well on surfaces such as carpet

jellis359 · « **Reply #4 on:** March 08, 2009, 08:37:18 PM »

i do mean chain and sprocket
like the bot in this vid


Motor Controllers

by "cheap" i meant only a couple hundred dollars

if you see faults because i'm sure there are (this is my first experiment with DC motors) please point them out and try to explain a solution to me because i'm very new to this

jamort · « **Reply #5 on:** March 08, 2009, 09:07:09 PM »

Ok well for a few hundred dollars you can do a lot... you can tmake anything like what the army pops out, but you can make a nice robot...
one thing to remember a good desigend robot and poorly programed is better than a welly programmed robot and a poor design...
for dc motors your going to first off need an H-bridge... for motors I would reccomend anything from trossen robotics on the dc motors list i t mainly depends on the size of the robot on what to get... you sound like you experienced in electronics but I throw this out there anyway www.maximumrobotics.com has value packs of everything from ics to resistors to beginerrers I reccomend this because it gives you the ability to experiment with a breadboard and have a couple of circuits burn out.. I admit some of t isnt the best quality but it does the job ad its all individualy labeled... I understand you want the caster but personally I think I would use tracks....

I couldnt get the video to work mainly because I'm on dial up and downloading a file... um I think that your going to need a fairly big battery not huge... depends on motors with dc I" try to give them the rating they recommend...

jellis359 · « **Reply #6 on:** March 09, 2009, 02:35:29 PM »

i'm going for a 12 volt battery

and i'm not that experienced, i just know what i want it to do
I'm having trouble picking a motor though. i don't know if i should go for banebots or lynxmotion

jamort · « **Reply #7 on:** March 09, 2009, 03:04:23 PM »

ok so what type of battery are you going to use a tweleve volt (try to find a lithium they run over $100 I thinik) as far as motors i think either of these would do...
http://www.trossenrobotics.com/store/p/4927-16-1-36mm-Planetary-Gearmotor-RS-540-Motor.aspx this or maybe even the motor below it is what you need
for your drivetrain I would suggest buy from robotshop.ca

jellis359 · « **Reply #8 on:** March 10, 2009, 05:20:36 AM »

does anyone know where i can get the tread/track components

for the 12v battery i was going to connect two 6V rechargeable batteries with a Ycable servo extender
would this work. if not how are you supposed to do it

SmAsH · « **Reply #9 on:** March 10, 2009, 02:39:50 PM »

yoyu could look up tamiya track kits. and the y-harness will work

Razor Concepts · « **Reply #10 on:** March 10, 2009, 02:58:14 PM »

You cannot use a Y-Harness. The Y-harness will connect the batteries in parallel, not series.

SmAsH · « **Reply #11 on:** March 10, 2009, 03:06:23 PM »

couldnt you connect one of the batterys backwards tho?

Razor Concepts · « **Reply #12 on:** March 10, 2009, 03:09:52 PM »

Nope, then you will short out both batteries at the same time. Not good for the batteries

jellis359 · « **Reply #13 on:** March 10, 2009, 03:47:47 PM »

if i use a 12V battery how does one determine what mah is needed

Trumpkin · « **Reply #14 on:** March 10, 2009, 05:48:52 PM »

You find out how much current your circuit and or motors will draw. For example, if your motors draw 18A and you have an 18AH battery, your battery will last for 1 hour.

jellis359 · « **Reply #15 on:** March 11, 2009, 04:18:20 PM »

i still can't find some decent tracks
maybe these http://www.robotshop.us/lynxmotion-track-trk-02.html
http://www.robotshop.us/lynxmotion-sprocket-9-tooth.html

so do i need 2 of these http://www.trossenrobotics.com/store/p/4267-BaneBots-Motor-Controller-45A-peak-.aspx for 2 of these http://www.trossenrobotics.com/store/p/4927-16-1-36mm-Planetary-Gearmotor-RS-540-Motor.aspx

does this mean i'll need 2, 12V batteries then

so because this motor is geared (has bearing blocks on it already) i will just be able to attach the tracks straight to the motor shaft?

SmAsH · « **Reply #16 on:** March 11, 2009, 04:47:06 PM »

Quote from: jellis359 on March 11, 2009, 04:18:20 PM

does this mean i'll need 2, 12V batteries then

so because this motor is geared (has bearing blocks on it already) i will just be able to attach the tracks straight to the motor shaft?

you dont need a battery for each motor unless you really want one. and you can put the tracks straight on to the shaft if thats what you mean? you will need to put the right sprocket on first. but you will have to find some way of getting the shaft hole to "grip" the shaft.

jellis359 · « **Reply #17 on:** March 11, 2009, 08:56:07 PM »

i was planning on using clamps to attach the wheel to the shaft

from the warnings on the motor description it sounds like i can put the wheels right on the shaft if i add an extra bearing block to support the shaft

what would i use to cnnect 2 of these http://www.trossenrobotics.com/store/p/4267-BaneBots-Motor-Controller-45A-peak-.aspx
to one of these http://www.trossenrobotics.com/store/p/3448-Gel-Cell-12V-7-2AH-Zeus.aspx

or do i even need 2 of thos controllers for 2 motors

I think this is about right (is it?)
Item Qty Each Price
16:1, 36mm Planetary Gearmotor, RS-540 Motor M-200-30-MP-36016-540

Update $41.10 $82.20
3/4" Hex Mount Hub, 3/8" Shaft, 1.6" Wide M-400-30-T80H-SS32

Update $9.50 $19.00
6/12V Lead-Acid Battery Charger P-BC-SEM1562A

Update $43.00 $86.00
BaneBots Motor Controller (45A peak) C-100-DC-BB-1245

Update $57.00 $114.00
Bearing Block, 1.5 x 1.5 inch, 0.375 inch, with Ball Bearing M-800-PB-S3751-BB

Update $10.00 $20.00
Gel Cell (12V 7.2AH) Zeus P-B-ACC137

Update $27.00 $27.00
Rubber Wheel, 4-7/8" x 0.8", 3/4" Hex Bore T80P-494BO-HS6-BLUE
Type: Blue Hard 50 Shore

Update $6.80 $13.60
Tamiya Connectors (Male and Female) P-B-CN-TMMLFM

Update $3.85 $7.70
Subtotal $369.50
Shipping - UPS Ground
(13.66 lbs.) $11.22
Total $380.72

Coupon Code:

Shipping Method: UPS Ground - $11.22 UPS 3-Day Select - $24.74 UPS 2nd Day Air - $38.58 UPS Next Day Air Saver - $81.58 UPS Next Day Air - $89.89 UPS Next Day Air Early AM - $124.21

PLEASE CHECK MY LIST WITH TROSSEN IF YOU COULD, THIS IS MY FIRST TIME TAKING ON A PROJECT THIS EXPENSIVE AND I DON'T HAVE MUCH $$$ TO BURN!!!
IF ANYTHING LOOKS OFF PLEASE NOTIFY ME, I NEED TO GET THIS RIGHT B/C I'M PLANNING ON CONTROLLING IT WITH EITHER ROBODUINO OR THE AXON
(WHICH WOULD YOU RECOMMEND FOR A PROJECT SUCH AS THIS)
ALL COMMENTS WILL BE GREATLY APPRECIATED AND TAKEN VERY SERIOUSLY, THANK-YOU

jellis359 · « **Reply #18 on:** March 11, 2009, 09:35:19 PM »

my main reason for taking on this project is that i want a robot that can travel outside, so... ya
i'm cocidering just modifying an r/c car because it will be much cheaper

SmAsH · « **Reply #19 on:** March 11, 2009, 10:29:52 PM »

if you get either roboduino or axon they both have power buses so you will need to plug the battery in so it provides power to the bus. the plug the two motor controllers in as if you were using servos. and you do need two motor controllers. i would recommend the roboduino unless you want more than six actuators running.
compare the two and see which best fits your needs:
http://www.societyofrobots.com/axon $130-$150
http://www.curiousinventor.com/kits/roboduino $40.00-$55.00

jellis359 · « **Reply #20 on:** March 12, 2009, 01:47:07 PM »

but how do i connect the one 12V to the 2 motor controllers

SmAsH · « **Reply #21 on:** March 12, 2009, 02:33:54 PM »

do you have a seperate battery for your mcu and motors or just one

jellis359 · « **Reply #22 on:** March 12, 2009, 08:07:14 PM »

they are seperate
i already have a 6v rechargeable

SmAsH · « **Reply #23 on:** March 13, 2009, 12:57:18 AM »

then you could probibly just plug it into a spare slot on your motor bus! or if the motor controller needs a battery fed into it just plug it straight in.

Admin · « **Reply #24 on:** March 26, 2009, 01:27:18 AM »

If you need to know the bare basics on mechanical construction, start here:
http://www.societyofrobots.com/mechanicsbasics.shtml

jellis359 · « **Reply #25 on:** April 01, 2009, 03:31:20 PM »

i'm good on construction. Even tough i'm sixteen, i've done a lot of work with my cousins rebuilding old tracters and ride-on lawnmowers. (this includes MIG welding)

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Author Topic: help! making dc motor robotic base (Read 4037 times)

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