23-01-2007 17:57

Madison

Re: pic: prototype of ramp in up postion

This is an interesting design for a lifting mechanism. Have you considered how you'll stow it inside the robot at the beginning of each match?

What sort of material were you considering for your platform?

I'd love to read more details about how you plan to implement this design.

23-01-2007 17:57

Kyle

Re: pic: prototype of ramp in up postion

How long is the ramp, what angle is it at?

23-01-2007 18:05

Madison

Re: pic: prototype of ramp in up postion

Based on the other photo uploaded to CD-Media (http://www.chiefdelphi.com/media/photos/26396?), it appears as if there's no ramp at all. Rather, it's a platform supported by a parallel four-bar linkage. By pulling up upon the top of the linkage with a pneumatic piston, the linkage swings upward and the retracted force of the piston will hold a robot and the platform 12"+ in the air.

This design and ones like it, if they can be made to work properly, are superior to ramps in almost every way, as far as I'm concerned.

23-01-2007 18:05

TheNotoriousKid

Re: pic: prototype of ramp in up postion

how do you expect this to work???

23-01-2007 18:10

fluffy

Re: pic: prototype of ramp in up postion

its actually a lift so it would be always parrallel to the ground

it would be folded up so it would be perpedicular to the ground. At the end of the game, a pin would be pulled, it would fall down, a robot would drive on it, and then we'd lift it off the ground to the position in the picture above
the platform would be made out of a honeycomb aluminum
unfortunately, we decided since it would weigh about 20lbs a side that it was a little heavy so we're going with something else

23-01-2007 18:11

Andrew Blair

Re: pic: prototype of ramp in up postion

Well, I can tell you this much- there is just enough air in four tanks to eek a little more than 150 lbs fourteen inches. How you link it properly in order to let the air do it's work- a bit of an issue.

23-01-2007 18:11

fluffy

Re: pic: prototype of ramp in up postion

exactly we designed it to go 13 inches to be sure it would clear the foot mark

23-01-2007 18:23

Madison

Re: pic: prototype of ramp in up postion

We've been looking into honeycomb aluminum for some of the surfaces on our machine as well, but we've not had much luck finding local suppliers. We'd like to take a small sheet and put it through its paces first before committing to its use. We have some concern about how rigid it'll remain over long spans.

20 lbs. per side seems about right, given everything that's involved. It's a fantastic system for teams that really want to focus on scoring bonus points at the end of the match because of the many benefits it has over most ramp designs -- primarily, ease of use by partner robots. I'm interested to see more of what you've decided to use in place of this design.

23-01-2007 18:40

fluffy

Re: pic: prototype of ramp in up postion

two years ago, we used honeycomb aluminum for the base and type of honeycomb plastic for the sides, last year, we used honeycomb for to mount electronics on, and both years, it stood up to time.

we also have a 1 inch thick piece about 4*4 inches and people have been jumping on it, throwing it trying to bend since we got it at the beginning of the season and nothing, except for being a little squished in the corners, has happened to it.

we're also thinking of using a new type of honeycomb this year for our frame, but we're arent exactly sure yet

24-01-2007 23:31

AustinSchuh

Re: pic: prototype of ramp in up postion

As I was looking at your model, I knoticed that at the position when the ramp is at its max, the piston is pulling dirrectly vertical. When it is in this position, the force from the piston is not able to prevent the ramp from going back down a little ways until the piston has a better pull angle. I think that you would have better luck if the piston was pulling at a slight angle when the ramp is fully up, or you figured out some other way to prevent this from happening.

24-01-2007 23:46

Tom Bottiglieri

Re: pic: prototype of ramp in up postion

Ha, we've got out 12" ramps down to 15 pounds for both sides.

Thank god for composites.