Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: icoms8 on October 12, 2009, 09:02:14 PM

Title: robot arm chassis
Post by: icoms8 on October 12, 2009, 09:02:14 PM

What would be the best material to use on a robot arm? I'm using 4-5 hs-311 and 1-2 are on the gripper and 1 is the bottom that moves the whole arm if i have to change the bottom servo so it can move more i can but what kind should i get? The arm wont lift much mabye a few grams.

Title: Re: robot arm chassis
Post by: galannthegreat on October 13, 2009, 12:23:52 AM

If you're going to use it for very light things Sintra (expanded PVC) would work great. It is very easy to work with, and at 6mm thick it has some decent strength too.

http://www.solarbotics.com/products/sin6mm/ (http://www.solarbotics.com/products/sin6mm/)

Just a suggestion of a personal preference of mine. :)

Title: Re: robot arm chassis
Post by: dellagd on October 13, 2009, 05:15:58 AM

I've attempted a robot arm, and bear in mind, theres gonna be a lot of leverage on thoese small servos.

Title: Re: robot arm chassis
Post by: SmAsH on October 13, 2009, 06:03:09 PM

Quote from: dellagd on October 13, 2009, 05:15:58 AM

theres gonna be a lot of leverage on thoese small servos.

That made no sense to me?
Are you sure the 311's can take all that load? 2+ servos+the materials+the load?

Title: Re: robot arm chassis
Post by: dellagd on October 13, 2009, 06:16:04 PM

look at this

Title: Re: robot arm chassis
Post by: SmAsH on October 13, 2009, 06:37:10 PM

Yeah, i get that... but leverage doesnt seem like the right word? thats what confused me...
if you want to try and explain it to me, do it over pm's, we dont want to flood this topic :)

Title: Re: robot arm chassis
Post by: Admin on October 14, 2009, 08:37:00 PM

Quote

What would be the best material to use on a robot arm

The strongest and lightest! :P
(you need to choose the one best for your application - if we don't know any details, we can't help!)

read this:
http://www.societyofrobots.com/mechanics_statics.shtml (http://www.societyofrobots.com/mechanics_statics.shtml)
http://www.societyofrobots.com/robot_faq.shtml#robot_arm (http://www.societyofrobots.com/robot_faq.shtml#robot_arm)

Quote from: dellagd on October 13, 2009, 06:16:04 PM

look at this

dellagd, I think you meant 'torque', not force :P

Title: Re: robot arm chassis
Post by: dellagd on October 15, 2009, 05:06:59 AM

(facepalm) yes!

Title: Re: robot arm chassis
Post by: SmAsH on October 15, 2009, 05:32:48 AM

So does the leverage thing still go? And isn't torque a measurement of force?

Title: Re: robot arm chassis
Post by: galannthegreat on October 15, 2009, 08:04:10 AM

Torque is moment of a force, it's a measure of a force related to an axis (in this case the main output gear is the axis). While leverage is the action of a lever, or the mechanical advantage of a lever.