Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: vipul1994 on March 25, 2014, 12:59:33 AM

Title: Combact robot of 35 kg which components(motors specifically)
Post by: vipul1994 on March 25, 2014, 12:59:33 AM

Hello
I want to build a combact robot and researching on it currently completely wireless i need to choose the motors for the same please help me in this project

Only thing i am focusing on my robot is the drag power and control the weapon is not at a priority right now

For complete Details ::   CHECK HERE (http://onlyonezero.com/my-researches/hardware-and-robotics/god-1/)

Title: Re: Combact robot of 35 kg which components(motors specifically)
Post by: jwatte on March 25, 2014, 10:50:32 AM

There are robots that are a cubic inch in size that are "compact."
There are robots that are a cubic meter that are "compact."

There are motors that are very high performance that are very expensive.
There are motors that are very cheap and have some performance.

Without having ACTUAL NUMBERS, it's impossible for anyone to answer your question.
- How big?
- How much load?
- What budget?

Title: Re: Combact robot of 35 kg which components(motors specifically)
Post by: knossos on March 26, 2014, 12:15:58 AM

Looking at your detailed specs it looks like you need to move 95 kgs (approx 210 lbs).  It sounds as if wheelchair motors might be suitable for your needs, but as Jwatte mentioned we would need additional information to make an informed recommendation.  Read through the robot dynamics (http://www.societyofrobots.com/mechanics_dynamics.shtml) tutorial on this site to get an idea of some of the considerations in selecting a motor.

I noticed you need recommendations for a motor controller.  While you need to pin down your motor specs first, I would recommend the Sabertooth motor controllers from Dimension Engineering (http://www.dimensionengineering.com/) as I have personally used them.

Reading the description on your site, it appears that you likely would not need a microcontroller since it would be remote controlled.

Good luck.

Title: Re: Combact robot of 35 kg which components(motors specifically)
Post by: vipul1994 on March 26, 2014, 11:59:38 AM

Thanks @knossos and @jwatte for your replies they were really helpful

@jwatte I do understand there are a lot of motors and devices available i have put in the numbers in the link  http://onlyonezero.com/my-researches/hardware-and-robotics/god-1/ (http://onlyonezero.com/my-researches/hardware-and-robotics/god-1/)

although i am making a combact robo currently concentrating on drag and control of robot please help me in the same
@knossos
Thanks for your really helpful description your links helped me a lot in understanding the motors, tyres etc
I will do all my calculations and get back to you asap

thanks

Title: Re: Combact robot of 35 kg which components(motors specifically)
Post by: jwatte on March 26, 2014, 02:57:30 PM

Your numbers are not sufficient. They only talk about mass, not acceleration or assumed friction.

A tiny, AAA-battery powered motor can move a metric ton of mass if it's suspended on good bearings and you don't need it to accelerate quickly.

So, how much acceleration do you need? 0.1g? 1g? 10g?
What friction coefficient will that mass have towards the ground? 0.0 (lifted in air)? 0.1 (greasy bronze on steel)? 1.0 (iron on iron)?
How much money are you willing to spend? What's the trade-off between efficiency, weight, and cost?

Title: Re: Combact robot of 35 kg which components(motors specifically)
Post by: vipul1994 on March 29, 2014, 02:29:20 AM

Hello @jwatte

I am a rookie right now in hardware and robotics world and am a student of Computer Science.

Ok i figured out that you would be needing the numbers first
so here is the table of the same below

Robot Dimensions	700mm x 700mm x 750mm (l x b x h)
Weight Max.	35 kg
Coefficient of friction	0.8(Guessed and searched on google need help on this)
Tyres Diameter	will be max 4.5-5.5" (Not decided)
acceleration	Need Help (I am making for war so speed is not that imp but i need acceleration Please suggest )
Weapon	Till now only very high dragging and wedged shaped robot design
Max Budget	$670(INR 40,000/-)
Tradeoff	Efficiency is very imp after that its cost then weight is secondary so its 3:2:1

BTW thanks for replying i am trying my best to answer you if i am mistaken or you need More info please feel free to ping me at http://www.onlyonezero.com (http://www.onlyonezero.com) or firebladevips[at]gmail<dot>com

Thanks