We have a piston mounted on the base of our robot to push the ramp down. But it isn’t strong enough to push our ramp passed the point where gravity will bring it down. Our bot’s frame is triangle shapped. We can’t mount the piston higher on the frame to increase leverage because the throw isn’t long enough. An extra piston wouldn’t have the power either. We need a way to multiply the force from the piston. Any ideas?
have u tried attaching a spring near the hinge on the ramp? that would decrease the amount of weight the piston has to push to get it over the point where gravity takes over. i don’t really know how to explain it but maybe that will get ur mind going. think something like a counterweight with a spring…
Just an idea… maybe you can have the piston push a lever. You could have something like a seesaw… so if you mounted the piston to go out the opposite way (away from the ramp) it would push the see saw that could push out the ramp at a point higher up.
We’re worrid about the spring knocking the ramp down if we get hit during a match. Im not sure what was meant by the seesaw idea. I think you mean the piston would push a rotating arm that would be longer and intern push the ramp with more leverage becasue it would be higher. Is that right?
Thats the basic idea I had… I’m not sure exactly how it would work out though. I’m still thinking about it though! 
Thanks for your help, we found a bigger piston in the back but we’re not sure we have the power or pressure to run it.
Hello,
I just registered to cheif delphi, so i am new at using this site.
I hope i am doing this right.
Anyway, does anybody know what kind of what kind of motors can we use for the robot?
Can we use a motor from power drill?
http://img20.imageshack.us/img20/3999/ilovepaitsk7.jpg
i suck at paint
i think this could be a possible solution
I agree, this is pretty similar to my idea, only with more of a wheel to guide the rotation. I think it could work pretty well.
our team tried this as a possible solution be we came across problems such as the angles that we would need to set the piston because it would need to be relatively low and create a big amount of force in order to get the wheel rolling
the seesaw idea worked better for us but we don’t know right now what we are goign to do
Only the ones in the kit. Drill motors have not been included since 2004.
I don’t think a lever is going to do what you want. A lever would trade off between strength (torque) and the distance you can push the ramp.
If you have the piston push the shorter end of the lever, and the longer end of the lever push the ramp over, then the end of the lever might go a farther distance, but you lose torque.
If you have the piston push the longer end, then you’ll end up with more torque but a smaller output distance.
EDIT: Similar thing with a wheel…in terms of transferring rotational motion, levers, gears, and wheels are similar.
If you had a spring could you maybe put it somesort of mechanical lock on the ramp so that i cannon deploy until you disengage it. Maybe power it with a servo or something small. This way if you are concerned that it will deply accidentally there is always a good mechanical lock preventing it then you can still keep you current piston mount.
this is what our ramp folks are building, usign a gas spring to lift and deploy the ramp (it also cushions the fall, due to careful spring placement), with a small pneumatic cylinder to securely lock the ramp in the stowed position.
Hopefully it will all be built by the end of the week and we can make it work
the ramp surfaces are done, and the supports and such are mostly designed and ready to build.
Just an idea - if you already have an arm on your robot that’s used to pick up the ringers / keepers, maybe you can incorporate that into getting your ramps out. Shouldn’t be a problem if you use something like a Fisher Price + the kit gearbox, we found the speed of it to be about perfect and it still have a lot of power.
Thirded. Use springs that are strong enough to knock your ramp over and change the function of your piston to disengage a latch. We’re doing something similar, though we’re using our ramp lifting motors to disengage the retaining system. The retaining system is still to be defined, but at worst we’ll be using highly calibrated fishing line to tie the ramps together and just break it with our ramp motors.
Please read ALL the 2007 rules very carefully. There are limitations and restrictions on many things including motors and wire used.
To answer your question NO you may not use any motor that was not either provided in the kit of parts or is on a approved additional motor (quanity) list. All of this is very clear in the 2007 manual. FIRST did a very good job this year with this document.
springs are stored energy otherwise illegal
newbs
You could always have the pin/lock idea (where the piston pulls away something blocking the ramp from falling) and just spin your bot in the home zone. As long as your bot can spin in a somewhat small circle, then you might be able to pull it off.