pic: Stuypulse team 694's Bot

[CD47-Bot]

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[Ianworld]

Here it is. Basically finished and in full competition condition(the picture is from about 3 hours before it was completely finished). The robot works like a charm. We've got pvc wings on pneumatics on the outside, at the great 6 inch height. We have the kit wheels on right now which allow us to drive up the side and manuever around the raised areas easily. We have a second set with our own special rubber to be put on. The drivetrain has two speeds controlled by a servo on the bosch gearbox, light simple and it works as long as you're not moving. We've got an arm, the bottom joint has two positions controlled by a pneumatic and the top joint has full rotational ability. The ball grabber has large 20 inch hoops which completely encompas the ball and lock it in. We can place the ball on the tall and short goals. We've got a goal grabber on the back of the robot. Its a drive on mechanism. We can just drive back onto a goal to grab it. To release it we have a pneumatic. The tube along the arm is our extender. The one in the picture isn't completely up to date, but it extends to well over 10 feet and is guided by the arm so we can grab from many locations and do it easily. So that about covers it, we do everything except grab the 10 point ball or store little balls. I'll get some pictures of it in action up today. Plus you can see more at http://stuypulse.com

~Ian

[dez250]

nice looking robot, i just have a question, have you had any problems with that long chain snagging or dismounting the sprocket while you are manipulating your arm?

[MASherry]

nice bot! just wondering what type of stering you guys were using, b/c our team is using tank turning and we ran into a problem with the pneumatic wheels gripping too much. How did u solve that problem? Can u guys hang?

[Josh Siegel]

Originally Posted by MASherry

nice bot! just wondering what type of stering you guys were using, b/c our team is using tank turning and we ran into a problem with the pneumatic wheels gripping too much. How did u solve that problem? Can u guys hang?

Increasing the pressure in the tires reduces the contact patch, so you can reduce traction that way. That should help turning somewhat, without a whole redesign. Hmm, Hummer-style tire inflation, anyone? :-)

[Ianworld]

Originally Posted by MASherry

nice bot! just wondering what type of stering you guys were using, b/c our team is using tank turning and we ran into a problem with the pneumatic wheels gripping too much. How did u solve that problem? Can u guys hang?

We do have a turning problem. An hour more of work and we will have replaced the kit wheels with our own custom wheels. We covered the wheels in velcro and then have sets of treads which velcro on. The one we'll probably use has a very low side to side coefficient of friction and a very high forward back coefficient of friction plus his ridges to help climb steps and lips easier. So we are sorta of doing a whole redesign.

The poor traction of the kit wheels were something we took into account when we decided what to make. They're designed for wheechairs which usually have two casters. The result is that they have a very high side to side friction(just look at the tread). Its going to be a big problem for first teams this years. You can cover one set(forward or back) in a slippery substance and it should allow you to turn, but you'll lose the traction those wheels provide which could cause a problem going up the lip.

As for hanging, we can hang the robot pulled itself off the ground to weigh itself today. We do have a bad habit of breaking a piece of our extender turned out the veclro that the hook sticks to the tip of the extender with was stronger than the extender's wood. So we're hardening that up so we don't have to replace it every match.

~Ian

[mtaman02]

Cool Design!

Do You guys plan on going for the 10pt. balls to release the 5pt'ers or are you guys just gonna hang and mess with the 2x balls.

[pras870]

Very nice bot. I see a pneumatic system at the base of the tower. Is this to be able to have the tower go parallel to your bot and be able to herd balls?

[Ianworld]

The arm has positional control so we can set it to a position and it will stay there. This allows us to hit the ball on the stand. We've also got light sensors on the bottom so we can do it accuratly.

The pneumatic system at the base of the tower is to allow it to have 2 positions. We have one angled up and back a bit and another down at about 60 degrees. This allows us flexibility without the complexities of having to have the arm powered by a motor(which we did last year). The arm doesn't need to drop down since we have the wings which pop out the side and we need to protect our ball grabber.

~Ian

[ngreen]

Ian,

Add a single solenoid to your exhaust of the solenoid for your tower tilt and you can have several positions instead of two.

Check out this thread to see how:

http://www.chiefdelphi.com/forums/sh...ad.php?t=23934

I think it would be helpful and it would only cost you a 1/4 lb of weight and some extra programming for control of the angle of your tower. This would be helpful both when climbing stairs and when manipulating the 2X ball. If you have any questions about multi-positioning just ask. We did this last year and it worked great.

[Ianworld]

I saw that and was thinking of adding it but the main idea of using the pneumatic instead of a motor was not for the weight but instead because we wanted to keep it simple. We don't need any more positions and so having them will only get in the way.

Presently we're programming the arm so that it will automatically go to positions such as to place the ball in a goal or pick one up off the ground. It does 90 degrees in about .3 seconds so having it under computer control should allow us to go much faster than human controlled teams.

We might work on the multipositional thing after competition but for now we really don't need it.

~Ian

[ngreen]

The cool thing about it is that you don't have to use it. You can have a switch which will turn it off or allow you to use it or disabling it completely involve removing a piece of tubing. It's just an idea if you ever need that mid position with the 2x ball. So I decided to throw it out there. If you want any help with it just ask. And you can make some very simple controls for it. Our system was you held one button to make it go out, and one to go in. If you let go of the button somewhere in the middle it would stop. But good luck whatever route you choose. It looks good.

[Ianworld]

I've posted a minute long video showing off some preliminarytesting of our robot you can find it here:

http://stuypulse.no-ip.com/ftproot/L...%201%20low.wmv

those of you who are apt might be able to find a medium quality video too

~Ian