Powered Robot Carts

[Racer26]

How many teams have built, or plan on building a self-powered cart?

I have seen these at regionals before, and 1075 has built one in our infinite amounts of spare time (:rolleyes: ).

It is absolutely our favorite new toy. It travels at about walking pace running wide open throttle, and carries our robot and its driver no sweat.

Its also useful for things OTHER than moving the robot.

For testing we had to move a bunch of tables and books, so we loaded them up and drove through the halls of the school.

Before anyone says it, yes, safety with such a device is paramount, and we fully plan to have several students assigned to accompanying it through the pits as "safety crew", to prevent accidental robocart->human contact, by alerting people in the vicinity.

It also has a number of safety interlocks to prevent inadvertent driving, and inadvertent moving of the forks, such that in the event it is left on with nobody on it, it does not move should the joystick be accidentally nudged. It is also equipped with the ever popular revolving light from pre-2004 seasons to provide a visual warning that it is turned on, and should be treated with caution. Furthermore, it has pneumatic locks to prevent the robot from unexpectedly falling off of it, and potentially crushing toes.

I was just curious if the few of these we've seen before are growing in popularity.

[octothorpe]

That sounds very cool. Do you have a picture of it? I like the idea of a warning light and a clamp-on robot securing system.

Our cart still relies on the sweat and tears of the drive team to haul it from place to place :rolleyes:

[CraigHickman]

To quote the ever present internet phrase: pics or it didn't happen.

But anywhoo, my old team looked at doing that... and decided it's already stressful enough to keep the robot battery live, adding another battery to that would make competitions even more tough.

[Blue_Mist]

That sounds very cool. Do you have a picture of it? I like the idea of a warning light and a clamp-on robot securing system.

Our cart still relies on the sweat and tears of the drive team to haul it from place to place :rolleyes:

You forgot the blood! I can't count the number of times that I or a team member have scraped or cut ourselves on robot or cart, especially since the 2007 robot had an off-board compressor. Someone built a simple shelf to hold the box so it could charge the robot while the robot was being hauled from Pit to Arena. Fine, except that the shelf dual functions as a razorblade when the compressor box isn't on it.

Now that you mention it, our cart should have warning lights to warn people away.

[Racer26]

We'll get some pics up eventually, once it doesn't look like a big heap of steel welded to an electric wheelchair with some IFI electronics stuck on.

To avoid the battery issue its got twin big 12V batteries in parallel (sorry, I don't know the specs on them, but each one is about 4x the size of the KOP batteries), hooked up to an onboard charger which will (hopefully) have a spring loaded spool of wire attached, allowing us a retractable charging cable, much like your electric vaccuum cleaner at home. We drove it probably a total of about 22,000 ft this past weekend without charging it, and the batteries only lost about 0.2V under load. I was thoroughly impressed.

EDIT: Also, I think we will likely bring our trusty man-powered cart with us, since we CAN run with it to make those last minute matches, and our motorized cart can't go faster than a brisk walk.

[octothorpe]

But anywhoo, my old team looked at doing that... and decided it's already stressful enough to keep the robot battery live, adding another battery to that would make competitions even more tough.

Nuclear powered robot cart, anyone?

You forgot the blood! I can't count the number of times that I or a team member have scraped or cut ourselves on robot or cart, especially since the 2007 robot had an off-board compressor. Someone built a simple shelf to hold the box so it could charge the robot while the robot was being hauled from Pit to Arena. Fine, except that the shelf dual functions as a razorblade when the compressor box isn't on it.

I think the blood was mostly from the robot, either lifting it on or off the cart. Simply pushing the cart was not, as I observed, a lethal activity. Was anyone really de-ankled by the compressor box shelf? :ahh:

[TubaMorg]

Some of our kids built a cool motorized cart. They put it on the chassis of an old robot. It even has a pneumatic ramp to dump the robot on the ground. We use older batteries so no worries about draining our competition batteries.

[Racer26]

There may well be 3 or 4 more safety features added to our cart before it sees a competition, in light of some past discussion of powered carts.

[Jeff Waegelin]

Looks like you guys have done a good job of focusing on the safety considerations of having a powered cart in a crowded event. That's a really good thing to see!

[IndySam]

Please be kind to your queuing staff. If you have a powered cart it must be able to be quickly and easily moved by someone other than your team.

I have seen carts that team members have put a lot of work into have to be put back into the truck because they were just too much of a pain for the field staff to move around.

[Racer26]

Please be kind to your queuing staff. If you have a powered cart it must be able to be quickly and easily moved by someone other than your team.

I have seen carts that team members have put a lot of work into have to be put back into the truck because they were just too much of a pain for the field staff to move around.

I don't foresee this being a problem as it is built on a wheelchair base. The wheelchairs motors have a simple lever that disengages the wheel, and it can easily be pushed. I will remind the team tonite that we should leave access to these levers open. In its former usage, this was so it could still be used like a traditional wheelchair, should the batteries die.

[R.C.]

pictures?

[synth3tk]

Our cart is powered by two trained pigeons and a glazed Krispy Kreme donut.

The ROBOT cart is a fusion of last year's fail'd cart plus last year's fail'd robot to make an awesome looking cart. Functionality is optional. I just finished putting in eight 12" cathodes around the chassis. Next on the list is to create access to the electronics, build the driver's mount, program the cart, and (after reading this thread) make sure it is non-powered capable.

It doesn't have all the safety features that you include, but we will have the rotating light and install a small siren (adjustable, of course) to warn people. Also, the cathodes are connected to a single Vic, which can be programmed to flash different patterns on command. That was random...

[Racer26]

All of our safety features have stemmed from having been at FIRST competitions for 5 years running, and knowing just how downright anal they can be about safety (there are many things they argue are unsafe that when done properly are totally safe).

Also, we've seen a few of these robo-cart's before, and figured there was loads of ways we could build in safety features, just to please FIRST, and ensure they let us USE the cart.

Personally, I'm all for being Darwinian. If you're stupid enough to get yourself killed, or otherwise removed from the gene pool by not paying attention, or just general stupidity, the world has been made a better place. Natural Selection trumps warning labels in my books.

[1502]

How many teams have built, or plan on building a self-powered cart?

I have seen these at regionals before, and 1075 has built one in our infinite amounts of spare time (:rolleyes: ).

It is absolutely our favorite new toy. It travels at about walking pace running wide open throttle, and carries our robot and its driver no sweat.

Its also useful for things OTHER than moving the robot.

For testing we had to move a bunch of tables and books, so we loaded them up and drove through the halls of the school.

Before anyone says it, yes, safety with such a device is paramount, and we fully plan to have several students assigned to accompanying it through the pits as "safety crew", to prevent accidental robocart->human contact, by alerting people in the vicinity.

It also has a number of safety interlocks to prevent inadvertent driving, and inadvertent moving of the forks, such that in the event it is left on with nobody on it, it does not move should the joystick be accidentally nudged. It is also equipped with the ever popular revolving light from pre-2004 seasons to provide a visual warning that it is turned on, and should be treated with caution. Furthermore, it has pneumatic locks to prevent the robot from unexpectedly falling off of it, and potentially crushing toes.

I was just curious if the few of these we've seen before are growing in popularity.

We're working on our second motorized one currently. The first was a wheelchair cut in halve, with all its origional electronics/portable programmer. Plus some cold cathodes, leds, a Xenon headlight and a dual scissor lift. Oh, almost forgot the spinners ;)

Our cart team decided to make a second to A) test out mecanum drive and B) increase manuverability. Yes this means it will use mecanums. Yes we tested for wire looms. And yes, it works. So I wonder, what else could we add to the second considering were keeping the first?

[Al Skierkiewicz]

While we see a few motorized carts come in every year, be advised that some venues do not allow them for insurance reasons. Some venues just want to minimize the amount of damage to the venue and some will make a blanket statement about all carts when one really bad design shows up. Be advised that the people you have to satisfy will be venue staff, event coordinator, regional committee, UL Safety Advisors, FTA, Head Ref, and possibly LRI. I rarely have seen a motorized cart come in a second season, never a third.

[1502]

While we see a few motorized carts come in every year, be advised that some venues do not allow them for insurance reasons. Some venues just want to minimize the amount of damage to the venue and some will make a blanket statement about all carts when one really bad design shows up. Be advised that the people you have to satisfy will be venue staff, event coordinator, regional committee, UL Safety Advisors, FTA, Head Ref, and possibly LRI. I rarely have seen a motorized cart come in a second season, never a third.

Really? We've never had any complaints, and last year was the fifth seaon for ours.

[Al Skierkiewicz]

Consider yourself lucky.

[EricH]

How long did Truck Town's powered cart(s) last, Al? I remember them using those carts in '03 at Houston (where I also remember hearing that they couldn't handle the ramps).

[Al Skierkiewicz]

I haven't seen one in a while. The truck belonged to GM as I remember so it was a sponsor ad more than anything. It is the team built items that seem to have grabbed the most attention lately. I can tell you horror stories of some that I have seen.

[Koko Ed]

Really? We've never had any complaints, and last year was the fifth seaon for ours.

The last team to bring a motorized cart to FLR was ordered to remove it when they pulled into another team's pit to back into their pit.
As a lead que I have and always will hate motorized carts. I think they are unnecessary and stupid. The time spent on building one could be spent on designing a better robot but teams that build them are like Tim Tebow fans no matter what people say about them they'll build and use them anyways.

[Jim Wilks]

Powered robot carts are an accident waiting to happen.

[Billfred]

How long did Truck Town's powered cart(s) last, Al? I remember them using those carts in '03 at Houston (where I also remember hearing that they couldn't handle the ramps).

When Truck Town came to Palmetto in 2006, they had it with them. It stayed parked on the periphery of the pit for virtually all of the regional; it was much too large to get through the pits and to the field safely. So it lasted at least that long.

[Jon Stratis]

But anywhoo, my old team looked at doing that... and decided it's already stressful enough to keep the robot battery live, adding another battery to that would make competitions even more tough.

The key would be to incorporate a charging circuit directly into the cart - plug in the cart when you get to your pit and your done! For a bonus, have the cart charge several robot batteries as well, so you always* have a fresh one handy.

*well, until you forget to plug in the cart, that is...

[LeelandS]

Creating a Powered Robot Cart would be a great project. However, it should be just that, a project. Having a flashy robot cart (in my mind) would be great for demonstrations and presentation, if it looks nice enough to be driven in front of people. Perhaps even give your audience a chance to drive it. It seems like something that could be a huge hit.

However, its use at competition would be extremely limited. Keeping it powered could be a real pain, especially while making sure your robot is adequately well-off, battery wise. Secondly, most carts are big enough as is. If you have an even bigger cart driving through the pits, it would be hard to make the necessary turns, and probably too easy to bump someone standing by their pits. Getting bumped by a regular cart is a shock enough, imagine this big ol' motorized cart running by you. I wouldn't feel comfortable. Then, as Ed and other said, your cart has to be easily movable by the field crew, as well as needs to be quick to get on and off the field. I just don't see how a motorized cart can fulfill both of those things.

In my opinion, building a powered cart could be a great experience for a team, and great learning experience, and a great project overall. But there place at competitions... Well, I don't see why they need to have a place at competitions. If your robot is too heavy to be moves on a manual cart... you have bigger problems to deal with.

-Hope this helps,
Leeland

[Andrew Schreiber]

When Truck Town came to Palmetto in 2006, they had it with them. It stayed parked on the periphery of the pit for virtually all of the regional; it was much too large to get through the pits and to the field safely. So it lasted at least that long.

Last I saw it was tucked in one of their closets but that was last year.

[Racer26]

@Koko Ed: I believe that was probably the very same one that this thread was started about, 4 years later in 2011.

Its been with us to WAT and GTR consistently for the last 4 competition seasons. There have been minor concerns voiced by the UL/BrucePower Safety team, and by queueing staff, all of which have been addressed successfully (except FLR2011)

[VKP]

http://www.saintsrobotics.com/wp-content/gallery/2011-frc-championships/img_1396.jpg

Our team (1899) started using a powered robot cart last year and we have found it very useful, and have not experienced any of the problems others are describing.

We used an old powered wheelchair base, but removed the chair, and instead added a platform for the robot to sit on with room to place tools and other equipment.

It is controlled by the original Wheelchair controller and is mounted near the back of the cart. The controller allows us to change the speed of the cart, and since it is a wheelchair base, it can turn on a dime and is extremely maneuverable.

If there is a team out there looking into making a robot cart, I would suggest giving serious consideration to modifying a motorized wheelchair.

Here is a picture of the robot cart from the front:
http://www.saintsrobotics.com/wp-content/gallery/2011-frc-championships/img_1509.jpg

[1502]

http://www.saintsrobotics.com/wp-content/gallery/2011-frc-championships/img_1396.jpg

Our team (1899) started using a powered robot cart last year and we have found it very useful, and have not experienced any of the problems others are describing.

We used an old powered wheelchair base, but removed the chair, and instead added a platform for the robot to sit on with room to place tools and other equipment.

It is controlled by the original Wheelchair controller and is mounted near the back of the cart. The controller allows us to change the speed of the cart, and since it is a wheelchair base, it can turn on a dime and is extremely maneuverable.

If there is a team out there looking into making a robot cart, I would suggest giving serious consideration to modifying a motorized wheelchair.

Here is a picture of the robot cart from the front:
http://www.saintsrobotics.com/wp-content/gallery/2011-frc-championships/img_1509.jpg

Agreed. Ours is a wheelchair base only we have a welded steel frame.

[kws4000]

I would think it would make a wee bit more sense if you could disconnect the geardrive from the motor so you could push it on your own and still be complient with use on the field, while flipping a switch to engage the motors for a boost up ramps or lage bumps.