Motorized Carts
 

We built a motorized car last year, but several times the battery died at competitions so we had to push the cart so we had to pust abainst teh motors. Has anyone out there built a motorized cart that they can disengage the drive motors so if the battery dies, you don't have to push against the motors?

If so, how did u do it, and if u have any pics, that would be cool too!

Thanks

Re: Motorized Carts
 

Make some type of quick release so the wheels can spin...or you could just get a human powered cart and not worry about any battery dying ;)

Re: Motorized Carts
 

Power wheelchairs have an interesting mechanism for disengaging the drive system.

Re: Motorized Carts
 

A basic system I've used in the past has a base frame with the wheels attached to it, and a second, sliding frame on top of that which the motors are mounted to. When using the motors, the second frame is slid and locked into place, the motors run directly on the tires (we put serrated shafts on them), and when we didn't need the motors, we slid them out of place and locked them into that position.

Re: Motorized Carts
 

Well if you have any old say two stage gear boxes around use those, they work by shoveing a piece into one of two gears, but if you hold it in between the two you have a neutral that does not engage the drive motors. Look up how a shifting gear boxs works, and use that so you can shift into a gear or into no gear..... or just keep tabs on your battery life, and plug your cart in when its idle : P

Re: Motorized Carts
 

A simple answer is to use bicycle sprockets and/or wheels. Figure out a way to attach the sprocket assembly from the back wheel of almost any bike to the live axle which is driving your wheels, and you won't have to push against motors. Or just make your cart a tricycle with one powered wheel in the back and use the entire wheel.

Re: Motorized Carts
 

Speaking of bicycles, how cool would it be to have a bicycle-driven cart, like with a bike actually towing the cart. I'm not sure if that's even allowed?!

Re: Motorized Carts
 

spring-type cotter pins on the wheels? (I have a roto-tiller with this design)

Re: Motorized Carts
 

Think a bicycle driven cart is cool? Way back in the day (3 years) I remember 1089 having a Moped Driven Robot Cart, that was about as cool as it gets.

What if you modified your original cart design to haul 2 or 3 batteries instead of just one? It's more weight, but hopefully a lot more range.

Re: Motorized Carts
 

Or you could use some of your pre-2007 batteries.

We had a motorized cart last year, but we weren't using the motors to drive the cart. We used a scissor lift to lift our robot into a working position (the top of the cart was roughly waist level) when it was in the pits and then we'd lower it to a moving position (the top of the cart was roughly shin level) to move our robot to and from the field.

We also had a little area on the undercarriage we could use to charge our pneumatics before matches and keep our tools for any on field repairs we might have needed.

Re: Motorized Carts
 

That sounds pretty neat, could you post a pic or something?

Re: Motorized Carts
 

I've got 2 1-ups.

1. A quad/golf cart pulling a trailer cart

2. A Segway pulling a cart.

We built a pull cart with some armor we had to take off rookie year to make weight. We stuck a battery inside with a switch to turn on neons colored to whatever alliance we were on.

We also (one day) decided to screw a 2x4 to our rookie 'bot and then one of our seinors rode/drove it around school. Suffice to say we got some odd looks from the teachers that were there that day...

Re: Motorized Carts
 

their cold cathodes grahm but what ever.

One thing i would want to do after ship date is motorize our cart somehow. any suggestions?

Re: Motorized Carts
 

im hoping to help make a new cart this year. im going to try and use an old set of the kit trannies from last year. and gear it really low and do a "power assist" think w/ some programming



but of course the robot has to get finished first.......lol

/forest

Re: Motorized Carts
 

Actually, Cold Cathode Flourescent Lights and Neons are different. For all you know, they could have actually used Neon lights (such as Streetglow's with a 12v adapter), but those would be more expensive.

Re: Motorized Carts
 

Good call! :p

I found this picture while browsing segwaychat.com a while back. It looks like it could work as a robot cart, without any major additional modifications (although standoff pipes or something similar in nature to elevate the robot wheels, so as to prevent the bot from sliding off the cart, would probably need to be added).



Okay, I know it says in the Segway User Manual to never pull 'trailers' behind the Segway, but there's certainly been a large amount of people who have safely done just that. The only problem I can foresee being a major problem is that I'd be worried about going down a ramp - like in Atlanta - and having the robot cart coast into the back of the Segway.... But if you're on flat ground and you keep it to slow, controllable speeds (as in the Black Key range), you should be fine.

I've pulled 228's robot cart (robot and six batteries onboard) through the halls of our high school school while on my Segway, by using my left hand to turn the Segway and my right hand to pull the cart. So I can vouch for the fact that Segways are powerful enough to pull a loaded cart. ;)

Re: Motorized Carts
 

Yep Art, that Home Depot available cart makes a most excellent robot cart. How do I know? We used one last year.:D

What we did was put some 2x6's around the edge, which the frame of our robot rested upon, allowing our wheels to spin freely, should they decide to begin rotating during testing in the pit. We'll most likely use it again this year. Also, this cart dissasembles very easily to stuff into a crate, and takes spray paint very well. Now to only find a segway...:rolleyes:

Re: Motorized Carts
 

Man, how do you guys have the money to ship these things? =P

We just go with a simple dolley... It works really well imo, plus it's light =/

Re: Motorized Carts
 

They were cold cathodes... I just didn't remember and was trying to get the point across... It looked pretty cool.

We don't ship them- we just bring them with us (it probably wouldn't fit in the crate anyways).

Re: Motorized Carts
 

I've seen bicycle pulled carts, Motorized carts, wooden dollies with barely 2 inches of ground clearance, and teams using handcarts to move their robots. While all are really cool and I’d probably enjoy the electric golf cart puling trailer more than anyone else, PLEASE THINK AHEAD when planning your cart. And remember these five things....

1- "I'm a doctor, not an engineer" Imagine the doctors in a hospital pushing a patient in a gurney... when they get to a door the patient has to get up and walk through, then they can get back on the gurney... doesn't make much sense huh? Neither does a cart that cannot fit through a standard doorway WITH the Robot ON It! (My first year our original cart could fit though the doorways, but we had to turn the robot 90 degrees and carry it though... at EVERY Doorway... VERY ANNOYING when late for a match!)

2- "Able to leap buildings in a single bound!" Sorry Superman moment there) Pits, Fields, and everywhere in between have cords, ramps, and carpets or mats on the floor. Try to design your cart so it can easily roll over them. (Preferably without you needing to reach under the 100-120 lb. robot with your hand to pull the barely 1' square or less dolly it's precariously balanced on over the cord runners)

3- "All I had to do was turn left" Turning is good! and you may need to do it to get around the field and through the crowded pits. (I saw a really neat motorize robot cart / toolbox one year, but they could barely turn, and they took up twice the space of other teams. It often took them forever to maneuver through the queues & seemed like more of a hindrance than a help.)

4- "I just can't do it captain, I don't have the power" If you do decide to pimp our your cart and motorize it... make sure you can still use it when it is un-powered.

5- "I'm going to pimp your ride" while I’m sure all robots would love someone from MTV's Pimp Your Ride to say that to them, I don't think that’s going to happen, so you need to do it yourself. A can of spray paint, some lights, maybe even some diamond plate. Decorating your cart to match your team image is fun, fills up time between ship and competitions (And is useful for field personal to find out which drive team to yell at when carts are left in bad places. :p )