11-02-2005 21:43

Yan Wang

Re: pic: 1474 Lift Teaser!

Ah, that looks awesome! It's simple, fluid, and looks very functional... and TALL!

It brings back some great memories:
http://www.chiefdelphi.com/forums/pi...&quiet=Verbose
http://www.chiefdelphi.com/forums/pi...&quiet=Verbose

It's so similar. I predict great things.

11-02-2005 21:53

Pi Is Exactly 3

Re: pic: 1474 Lift Teaser!

Wow that's cool. I told the team about putting a banner like urs running up the lift so when it raises it'll pull it out. I'm glad to see I'm not just crazy, but its actually a possibility.

11-02-2005 21:54

tiffany34990

Re: pic: 1474 Lift Teaser!

very cool!! nice scissor arms. great job. how high is that? (can't see)

11-02-2005 22:03

Yan Wang

Re: pic: 1474 Lift Teaser!

NO.

Yeah, that was my idea too and it was great while it lasted. We stuck out like a sore thumb and were easily the most recognizable presence on the field.

However, we made that banner system such that it folded into a pocket at the beginning of the game and opened up as we lifted up. However, in the first match on Saturday morning, our controller accidently left the lift switch on so once autonomous ended, the lift shot up, the banner unrolled, and it became tangled as soon as the lift was put back down. We won that game 20-15 on balls and it was NOT pretty seeing the robot I was driving being pushed around the field at 5ft/s because the banner was so slippery.

I suggest not doing it or fully testing any entanglement possibilities.

11-02-2005 22:23

Lil' Lavery

Re: pic: 1474 Lift Teaser!

Well anything with a scissor lift as tall as that is gonna stick out anyway, but as for the other problems with a banner...
Cool job. How tall is though, I want to know as well. And how many tetras can it lift at once?

11-02-2005 22:27

Pi Is Exactly 3

Re: pic: 1474 Lift Teaser!

We measured 10' 6" and that's only when the scissors make 90degree angles. So it can go higher, but probably not gonna happen.

Then we're adding a manipulator on top of that, it'll be a little less than 4 feet long. So if we wanted to, we could touch something that's 14' high. Hopefully that won't be needed in the competition... or someone's gonna get squished by a falling stack of tetras.

11-02-2005 23:22

sanddrag

Re: pic: 1474 Lift Teaser!

I am impressed by the height. I think it is officially the tallest FIRST scissor lift I have ever seen. In the picture, I do not see any flex at all. How is stability, does it wobble when it gets up that high?

12-02-2005 04:44

Leav

Re: pic: 1474 Lift Teaser!

yeah, we were thinking about a scissor lift, but we wernt sure because we figured there would be so much wobbling that it would become unusable and might even flip the bot.....

you proved us wrong i guess... it looks really stable!

12-02-2005 09:05

Yan Wang

Re: pic: 1474 Lift Teaser!

I don't think that you can tell its stability by looking at the picture. We found last year that our scissor lift was extremely wobbly left and right when we turned fast (but that was OK since we just had to get on top of the platform, align, and shoot up in 1.5sec). I think it will be much harder for this year's scissor lift teams to maintain balance if they want to move quickly. Once you start trying to move fast and turn rapidly to avoid other bots, the scissor lift actually becomes quite wobbly due to the even distribution of weight through it, bottom to top. Once you add a manipulator (or in our case last year, a carabiner "tulip") to the top of it, it becomes even more top heavy. I would really like to see some video of scissor lift robots this year and how well they can move around the field and maintain balance. It's a large field and there are lots of places to get to.

12-02-2005 16:07

Lil' Lavery

Re: pic: 1474 Lift Teaser!

Yeah, you definately should see how your lift reacts when your robot is moving, particularly turning or starting and stopping quickly. Also try moving with a tetra on it and see how it reacts.

12-02-2005 18:40

Pi Is Exactly 3

Re: pic: 1474 Lift Teaser!

Yeah, we've thought of it all. Can't prevent it all, though. Right now we've tested it with the arm up going forward, back, and turning sharply. Forward and backward momentum doesn't affect a thing, its just fine... but it's very dangerous to turn sharp. We also got the manipulator on top of it mounted this afternoon. I got a pic of it, so I may post that later on.

12-02-2005 18:51

Rick TYler

Re: pic: 1474 Lift Teaser!

I think that's going to be true for most of us, regardless of design. I really expect (as I've written here before) that some robots are simply going to drive out from under their arms. A 'bot with an extended arm with a tetra on it is going to have a high polar moment of inertia in the vertical axis. I might have to buy a new video camera for the tournarment.

12-02-2005 18:55

Pi Is Exactly 3

Re: pic: 1474 Lift Teaser!

lol good point. This is going to be a very interesting competition to watch. Videos of this year's competition will prove to be very helpful for next year's build season.