http://www.wolvcatrobotics.com/resources/arm%20extension.MPG
take a look at this, i found this video, and was a bit confused on how this actually works.
its almost mind boggling to me.
anyone have any ideas?
- Bochek
Its a cascade style lift, just with the chains/belts ran internally. Its actually much like what our team is doing this year for a lift - it makes the sections extend simultaneously. This helps make it smooth with an equal motor load throughout extension, and also helps stability - as you have greater overlap across multiple extensions until you near your limit.
Check out slide 17 on this powerpoint from the workshops at championships last year - it shows the cascade and continuous systems drawn out side-by-side. http://www.usfirst.org/uploadedFiles/Community/FRC/Team_Resources/Team_Resources_Assets/Manipulators_Needel.ppt
so it is a cascading style arm then, but how do they run the cables on the inside?
lots skill and pulleys/idlers/sprokets.
yea actually theres 2 hamsters inside and when connect to power we shock them and that pushes it up…other than its complicated we dont expect u guys to understand lol
We ahev worked our buts off in this tower! Its the first year we implement it. It has no idles gears. It has sprocket and chain but its a rather innovative design.I’ve seen other towers and our works a little different. We’ll post more pictures later. Ohhh wanna know how we got rid of idler gears?? search for our tensioner pictures those are cool!
that is wicked cool, im still confused on how it goes back in so well.
going back in is a process aided mainly by gravity. The weight (not mass) of the arm pulls it back down in, so that when you loosen the chains/pulleys, the arm slides itself back down. After having used a similar design in 2004 (having a 15 foot tall arm) I’d say this is a strong option. It’s a fairly easy design to make, and easy to maintain (ours never broke, only bent in one place that was weakened for other functionality purposes.
Our 2005 arm was aided back down by gravity and because of that it proved painfully slow. It was 9ft. high and took about 4-5 seconds either way. This one is 8.5 feet high and it goes up or down in less than two second regardless of its aid by gravity. We didn’t want gravity to be the driving force for lowering the tower and we came up with the mechanism you see to power the tower both up and down efficiently and quickly.
looks really nice, hopefully it weighs very little, and the rest of your robot works just as well! Can’t wait to see video of you guys competing!
it weighs 15lbs including the claw that is not in the video clip
It took 4 ever to make
We are using somthing like this as our end effector/arm
80/20 lift
I have to give you major props for this design. The ThunderChickens (217) tried a similar design back in 2004 and we had a heckuva time with cables binding inside our extendo-arm. It was really hard to troubleshoot too since all of the components were enclosed in the arm.
Our 2004 robot can be seen here.