So you want to build a robot……

Discussions regarding building a walking robot at home. Most of the robots participating at Robo-One competitions are custom fabricated.
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2 postsPage 1 of 1

So you want to build a robot……

Post by evaderdjo » Tue Sep 09, 2008 3:08 am

Post by evaderdjo
Tue Sep 09, 2008 3:08 am

I’ve decided to make a robot of my own. But starting from scratch is beyond my skill set, so I’ve decided to take the major components from a Robonova, and make my own modifications. This will include creating longer and bigger brackets, and that’s where I could use some help.

After reading the posts in this forum, it would appear to me that the key to creating a good robot bracket depends on three main things:

1) Material choice. So what is the best material for a home builder to create servo brackets from? The material needs to be strong enough to withstand the torque from the servos, but light enough to let the robot move smoothly. Cost is another big factor. Aluminum appears to be a good choice with 5052 or 6061 being the favored choices, but what thickness is appropriate? Please feel free to comment on your preferred choice of material, and why.

2) Cutting your bracket. What is the best way to cut your bracket from the material you have selected? I know there are some websites that will laser cut or water jet cut material for you, but are there cheaper ways to do this? Can you get decent results from using common cutting tools available at your local hardware store (like a Dremel or scroll saw).

3) Bending your bracket. What is the best way to bend your bracket into the shape you need? Again, there are websites that offer to do this. I believe the process is called “braking”. Can you get decent results with just a vice and a hammer? Is it worthwhile to build your own “brake”.

I’ll need to make at least 4 servo brackets for the arms and legs, plus the entire torso. Any thoughts or advice are most welcome.
I’ve decided to make a robot of my own. But starting from scratch is beyond my skill set, so I’ve decided to take the major components from a Robonova, and make my own modifications. This will include creating longer and bigger brackets, and that’s where I could use some help.

After reading the posts in this forum, it would appear to me that the key to creating a good robot bracket depends on three main things:

1) Material choice. So what is the best material for a home builder to create servo brackets from? The material needs to be strong enough to withstand the torque from the servos, but light enough to let the robot move smoothly. Cost is another big factor. Aluminum appears to be a good choice with 5052 or 6061 being the favored choices, but what thickness is appropriate? Please feel free to comment on your preferred choice of material, and why.

2) Cutting your bracket. What is the best way to cut your bracket from the material you have selected? I know there are some websites that will laser cut or water jet cut material for you, but are there cheaper ways to do this? Can you get decent results from using common cutting tools available at your local hardware store (like a Dremel or scroll saw).

3) Bending your bracket. What is the best way to bend your bracket into the shape you need? Again, there are websites that offer to do this. I believe the process is called “braking”. Can you get decent results with just a vice and a hammer? Is it worthwhile to build your own “brake”.

I’ll need to make at least 4 servo brackets for the arms and legs, plus the entire torso. Any thoughts or advice are most welcome.
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Post by Enderwiggins » Mon Sep 15, 2008 7:54 pm

Post by Enderwiggins
Mon Sep 15, 2008 7:54 pm

Go ahead and get some thin aluminum, get a few different thicknesses and experiment, for me i found 1/32" thick aluminum to be fine, it cuts like butter with a pair of shears and bends the same but once you get some nice corners in it its surprisingly strong, tho if your making something of a robonova size it most likely will not be strong enough so i would recommend some 1/16" thick, you'll get a nice workout on your fingers bending this with small pliers but its still possible to cut and bend with hand tools, it wont come out perfect but for the amount of money you'll be saving its worth it, and after you make about 10-12 of the same bracket you become good enough to emulate machine work, or possibly you'll just feel like you are, my robot will be very small like ayu's and I'm still building it (moving to a new town and in with my girlfriend + college and work seems to have slowed my progress) but for about 200 dollars i have all the components to build my robot (that including some cutting disks for my dremel which didn't work out as well as i hoped - stick with the shears) so it was a pretty modest investment into a hobby that can easily blow your college savings... a temptation i'm sure we all must avoid daily... careful making the brackets much bigger tho, low and short is the way to go, for every little bit you make it taller you put tons more torque on the servos and move the center of gravity even higher which makes your robot less likely to stand and walk when it comes time to play with it. I say just go at it, its bad bad bad advice but eh its more fun and you'll spend a lot of time learning to make things out of metal before you get anything useable for your robot so i say just go at it and rebuild it again when you get the feel of what your doing, you could plan then too heh.
Go ahead and get some thin aluminum, get a few different thicknesses and experiment, for me i found 1/32" thick aluminum to be fine, it cuts like butter with a pair of shears and bends the same but once you get some nice corners in it its surprisingly strong, tho if your making something of a robonova size it most likely will not be strong enough so i would recommend some 1/16" thick, you'll get a nice workout on your fingers bending this with small pliers but its still possible to cut and bend with hand tools, it wont come out perfect but for the amount of money you'll be saving its worth it, and after you make about 10-12 of the same bracket you become good enough to emulate machine work, or possibly you'll just feel like you are, my robot will be very small like ayu's and I'm still building it (moving to a new town and in with my girlfriend + college and work seems to have slowed my progress) but for about 200 dollars i have all the components to build my robot (that including some cutting disks for my dremel which didn't work out as well as i hoped - stick with the shears) so it was a pretty modest investment into a hobby that can easily blow your college savings... a temptation i'm sure we all must avoid daily... careful making the brackets much bigger tho, low and short is the way to go, for every little bit you make it taller you put tons more torque on the servos and move the center of gravity even higher which makes your robot less likely to stand and walk when it comes time to play with it. I say just go at it, its bad bad bad advice but eh its more fun and you'll spend a lot of time learning to make things out of metal before you get anything useable for your robot so i say just go at it and rebuild it again when you get the feel of what your doing, you could plan then too heh.
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