![]() |
pic: FRC973 offseason teaser #7
|
Re: pic: FRC973 offseason teaser #7
Cant wait for this weekend!
anyone notice the small reflection off the sheet metal on the right? |
Re: pic: FRC973 offseason teaser #7
New elevator on your drivetrain? Beast.
|
Re: pic: FRC973 offseason teaser #7
Make sure you get some video :)
|
Re: pic: FRC973 offseason teaser #7
I'm sick of teasers! Don't you think 7 is a little obsessive! ;)
Second a request for video! |
Re: pic: FRC973 offseason teaser #7
I will make sure to get atleast SOME video of it at the Fall classic
|
Re: pic: FRC973 offseason teaser #7
Awesome elevator and all, but where's robot #3? I bet there's some Pink clone hiding under that picture.
I love how that lift keeps the visual appearance of the arm robot's mast such that it takes a second to see if it's different. :) |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
i cant wait for tommorrow, its going to be amazing playing with/against you guys. And the elevator looks great.
|
Re: pic: FRC973 offseason teaser #7
I believe I see some constant-force springs on the lift. What force rating do they have and where did you guys get yours?
Looks good! Can we see a whole picture now? -Brando |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
We'll post a full picture tomorrow, we've been so busy preparing that we just haven't really had time for this stuff. It was really hard to get the robot programmed as all the programming mentors just got back to school Monday.
Quote:
Tom, these guys aren't too bad at 7 lbs, easy enough to handle by hand without cutting yourself (although I have a few times already). The 40 pounder we have but didn't use scares the heck out of me however. |
Re: pic: FRC973 offseason teaser #7
Sean lied to me! He said you were all too busy with that last robot to build an elevator.......
|
Re: pic: FRC973 offseason teaser #7
Looking forward to seeing your stuff this afternoon!
|
Re: pic: FRC973 offseason teaser #7
Adam the color scheme on those bots looks really familiar =). I applaud the amount of off-season work you guys do. The robots look great, best of luck in the off season. Tom those elevators in general are not my friends. They work great when they are working but keeping them working is certainly a challenge. As 125 well knows I am sure.
|
Re: pic: FRC973 offseason teaser #7
Quote:
I guarantee you that Adam and company will have no problems with this elevator. The engineering that has gone into it is more than I have ever heard of on a FIRST team. |
Re: pic: FRC973 offseason teaser #7
Sean,
We were missing the pesky constant force spring Tom is so in love with haha. So needless to say the elevator cable on our robot if it was full forced powered down would continually jump off our spool. I know 973 probably didn't have any problems with that elevator. We used a similar elevator style setup as well which is why I was commenting. |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Aren,
I haven't seen there exact setup as I am stuck on the east coast but I actually pm'd Adam to see if would mind sending some pics of their setup or giving some advice on implementing the constant force springs into the design. I am interested to see how they accomplished a similar design better then the one my team used in an effort to try to better my teams knowledge of this mechanism. I thank you guys for your comments. |
Re: pic: FRC973 offseason teaser #7
The key to not having cable/rope/whatever jump off a spool is to not use a spool plain and simple. We used 25 chain to drive the first stage and then cascaded the second stage. Adam has an even cooler setup but again no spool. As you found managing rope is a pain and is why many teams this year especially avoided it in lift designs.
Quote:
|
Re: pic: FRC973 offseason teaser #7
Sean after this season I completely agree with your above statement. Trying to find out about all the alternatives and from our teams own opinions on the best way for us to accomplish this better if we do a similar design again.
|
Re: pic: FRC973 offseason teaser #7
I'm a big fan of the chain route and also the way that 973 is doing it, although chain is easier with less machining resources, there's is cleaner though. You can alsu use timing belt like 971 did although it has to be gt2 or else it will slip. Stick to cascading if possible as it is much easier to counterbalance the elevator.
Quote:
|
Re: pic: FRC973 offseason teaser #7
Quote:
We used an aluminum tube (2" diameter, about .030 thick) for our spool, with a sprocket on each end (driven by a banebot transmission/550 each). We used Spectra cable (high strength kite string), which is very VERY strong, light, and very thin (roughtly 1/8" diameter). The spool/drum runs between two sheet metal plates that support the elevator, so the drum is as wide as the elevator (about 20"). We used two 20lb constant force springs for 20lb of total force all the way up, which is actually more than the weight of the carrier assembly. So, if you tip our robot on its side, the elevator begins to go up by itself. We decided it was more important to go up fast than down fast, so we like this. We got our springs from Mcmaster. They are "fun" to work with. |
Re: pic: FRC973 offseason teaser #7
Why didn't you copy 254 to begin with?
|
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Quote:
254 has created one hell of a bot for 2011 and it is arguably one of the best things to emulate in the offseason if you have the materials and time to create it all. |
Re: pic: FRC973 offseason teaser #7
I had a dream last night that it had an 8 wheel crab drive. :rolleyes:
|
Re: pic: FRC973 offseason teaser #7
Quote:
/now if you were being sarcastic I take my comment back :p |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Calm down, I think he meant "Why didn't you go with the elevator and wrist concept for the real robot" rather than meaning anything about the nitty gritty technical details.
I imagine they did that to build a more simple, easier robot in the build season. I really admire teams that go all out once they are done with the season and build the most technically complex robot they can for kicks. From what I've heard, this is some kind of magical thing of beauty. |
Re: pic: FRC973 offseason teaser #7
From what I know of this robot, I freaking love it. Adam, can I have one?
-Nick |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Oh wow, there are a lot of responses! I'll try to get them all, but might miss some.
We chose not to do an elevator for season because of the few "gotchas" the 254-style has. They are minimal to nonexistant to 254 clearly, as they have many iterations under their belt. But, a linear driven spooled cable elevator can be a royal pain in the arse if not done correctly. We knew arms, and knew we could make an arm much faster so we chose too. It was a though choice however, as we knew the very, very best robots would likely be elevators. As for pics, sorry guys! No hotel at the internet I'll get them up ASAP (need to get them from the photographer). The robot itself did poorly at this event, the code worked very well (VERY VERY well considering it's a 4wd independent power and steer swerve that's only had about 5 hours of debug time), but we were plagued by electrical failures. We used the electronics off of many old and practice robots which have been thoroughly worn. For the brief time before we loaded it in the trailer when the code worked, it drove AWESOME. We immediately learned that crabs are not 6wds and require a totally different mindset to drive. The elevator is real slick, and we spent a lot of time on it. We chose to cascade rig it to reduce parts, and the initial gearing of driving the 2nd stage are two very light 16DP rack gears. This brings the elevator to a total weight of 23 lbs with our claw from this season (which is a very, very heavy claw). We haven't coded it yet, but it works really well when hooked to a battery and I feel we'll be very happy with it. It's near-neutrally balanced with standard constant force springs. We didn't expect to even get this robot running for this event, with our real goal being the Madtown Throwdown in November. We'll certainly use the next 7 weeks to debug and practice and get this beast truly driving smooth. I'll post more detailed specs of the robot when we get pictures up, and ideally start a new thread, but in summary it's a sub-40 lb independent swerve (including bolts, belly pan, battery box, etc...) which is module based (each corner has a completely self contained drive module not linked to the rest). Designed separately and then implemented at the last minute is our take on a 2-stage elevator, which was heavily influenced by 254, 971, 1114, 2415, 118 and 16 in one way or another (thanks for all the advice given at IRI), but also has some cool new concepts. Thanks for all the support guys, a few key students and myself spent a long time designing this, and then nearly the entire team busted their butts the last few weeks to get it done. We're really happy with it so far, and plan to show up ready in November. |
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
I need to see a complete picture of this robot. This might be one of my favorite robots of the season... and it was designed for off-season.
|
Re: pic: FRC973 offseason teaser #7
Congrats to Team 973 and 973 and 1538 as they are the winners of the 2011 Fall Classic in Burbank Ca. Hope to see everyone in the Spring and again in the Fall for another great Fall Classic.
|
Re: pic: FRC973 offseason teaser #7
Quote:
|
Re: pic: FRC973 offseason teaser #7
Quote:
The devil is always in the details, and for any system, it takes time to develop a really finished design. Often, this is several build seasons as we can see with teams who continuously improve their drive designs each year. Same goes for lifts like this. What few people realize, is that our 2010 robot actually had a linear lift just like our 2011 robot. We learned a lot from that lift, and in turn have learned alot from our 2011 lift as well. We're getting to a point now where we can really tune the details of our design and have a go-to design in our in pocket. A lot of our issues this year came from the 775 motors which we simply could never get without a case short. We will be sure to not make the same mistake next year, and with some more added improvements, our lift design will continue to improve. Adam- get some pictures up! I want to see this thing. -Brando |
Re: pic: FRC973 offseason teaser #7
I've never had no hotel at the internet! That must be quite difficult for you. :rolleyes:
|
| All times are GMT -5. The time now is 01:01. |
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi