Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: sotu on April 08, 2007, 02:33:34 PM

Title: Will This Work?
Post by: sotu on April 08, 2007, 02:33:34 PM
If i buy one of theese: http://www.pololu.com/products/tamiya/0061/ (http://www.pololu.com/products/tamiya/0061/)
Can i buy a motor or a servo connected (not with wires) but screwed together or glued so they stick together. The motor or servo will be connected at the top with the rotating pin pointing down at the product i gave u the link to. The motor or servo will only be able to spin 90 degrees at each side (180 degrees together) So if the robot is going to turn the motor or as said servo will turn to the side its going to turn to and because its connected to the product it will also turn the product (With wheels) to one of the sides and then make the robot turn. Will this work and make the robot turn?? ???

If u dont understand what i've been trying to explain here post what u dont understand and i will answar as soon as possible.
By the way, with saying "Product" i mean the thing on the picture on this page: http://www.pololu.com/products/tamiya/0061/ (http://www.pololu.com/products/tamiya/0061/)
Title: Re: Will This Work?
Post by: Joe on April 08, 2007, 04:09:37 PM
So you're saying turn the thing in the picture (which will have the bot's 2 wheels on it) to steer the robot, right?
Title: Re: Will This Work?
Post by: Hal9000 on April 08, 2007, 04:10:54 PM
Is it going to be like a car? Use rack and pinion if yes.

Draw a diagram and post plz.
Title: Re: Will This Work?
Post by: sotu on April 08, 2007, 04:54:45 PM
Ok i will draw in 3D and prtscn it! My plan was using the "Thing" on the picture for both driving and swinging by turning it when turning and make it stand right ahead for driving right ahead! But i will post a planning picture so it will be easyer to understand.
And again sorry for writing the same post in different categories!
Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 03:04:02 AM
Parts:
* A chassie, i'll figure that out
*A motor: http://www.clasohlson.no/Product/LargeImageViewer.aspx?Path=/Archive/images/products/N/Hi/323263_3264_3265_3266_B_2006-07-04_112050_950.jpg
* This driving mechanisme: http://www.pololu.com/products/tamiya/0061/
Title: Re: Will This Work?
Post by: Hal9000 on April 09, 2007, 05:40:03 AM
Thing is, the other one is just two motors 'stuck' together with loads of gears on. Everyone knows what motors look like.

I think the chassis (main idea, whatever) is why people are struggling to help you
Title: Re: Will This Work?
Post by: Hal9000 on April 09, 2007, 05:47:21 AM


This is how i envisage what you are saying

Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 06:44:42 AM
Im not using a servo im using a motor. The link i gave u was 2 motors rotating a stick. I will attach 2 wheels to the pin!
Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 08:46:16 AM
Picture: http://s173.photobucket.com/albums/w60/sotu_maskot/?action=view&current=Forumplan-1.jpg (http://s173.photobucket.com/albums/w60/sotu_maskot/?action=view&current=Forumplan-1.jpg)
The line pointing at the pin at the motor is the place at the motor beeing attached to the other place the red line is pointing at. So if u add power to the motor it will turn the Gearbox around and make the robot turn. So the motor will stand upsidedown! U understand now?
Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 09:13:32 AM
Hal9000: I just understood ure drawing and thats exactly how i want it, but instead of a servo i will use an EL motor. Will this work or will the drifting gearbox be to heavy to move for an upsidedown motor? AND: There will be 2 pins or something making sure the gearbox won't be able to turn all the way around..!
Title: Re: Will This Work?
Post by: Hal9000 on April 09, 2007, 11:54:52 AM
Well there are a few major issues with your idea.

Motors are quite heavy to move. The initial amount of torque needed is significant (i.e from resting to moving), and therefore is out of the question A servo version of this (as I detailed) is far more sensible. Correct me if i'm wrong.

Another issue is, why the hell would you need two motors at the bottom of this?

Many robots only ever need two motors.........and that's it. One motor moves forward. One backward. The robot now turns. None of this 'pin' stuff.

If you were to do your design, maybe a servo at the top and one motor driving both wheels at the bottom. But then, as I said, you might aswell be sensible and do two wheels by themselves. word.

Seriusly, though, build ONE robot. That's all i'm really asking of you. It can be as rubbish as you want..........uncomplicated........whatever.

Actually FEEL the torque on a servo. FEEL the torque on a motor. APPLY different voltages to a motor. Does it move? Does it move faster given different voltages?

I urge you actually do this. Before you do anything else, ask any more questions etc etc.
Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 12:51:34 PM
Am i right knowing that motor with wheels driving at the same time as turning, turns way better then if the robbot is standing still and the wheels aren't moving? If this is correct theres a higher chance of success at my project if i drive it at the same time at the motor on top of it is rotating it. Am i right?
Title: Re: Will This Work?
Post by: sotu on April 09, 2007, 01:07:53 PM
I may have understood u wrong when i read ure post. On this photo: http://www.pololu.com/products/tamiya/0061/ (http://www.pololu.com/products/tamiya/0061/)
is there 2 inputs on each motor or 1 on each?
And can i drive forward on one motor and backward on one motor so it will turn? Couse as i understood it both motors where attached to the same metal pin so i dident think it was possible of turning with it!

Am i wrong? Can u turn with it (Drive forward with 1 motor and backward with 1) Couse if i can that would be just great..!:D
Title: Re: Will This Work?
Post by: dunk on April 09, 2007, 01:42:15 PM
sotu,
pleeease read the specs of the components before posting here.
the 2nd sentence of the link you posted to:
Quote
It contains two small DC motors that drive separate 3mm hexagonal output shafts.
so please have a go at answering your own question.

dunk.
Title: Re: Will This Work?
Post by: sotu on April 10, 2007, 01:15:50 AM
I may have got it different now. First i dident think the gearbox could turn. But after talking to some people watching other robots like the 50 euro robot(Here on the forum) i understand that the gearbox can actually turn to. As i understood it both of the motors in the gearbox where attached to the same metal stick so if wheels were attached to the stick it could only drive forward and backward.
Title: Re: Will This Work?
Post by: Hal9000 on April 10, 2007, 06:20:31 AM
Yeah each motor is separate. It would be a good idea to make the $50 robot to help avoid this sort of confusion in future :) good luck!
Title: Re: Will This Work?
Post by: sotu on April 10, 2007, 07:33:16 AM
Ok, thnx!