Motorized Carts

[Nate Laverdure]

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

[DCA Fan]

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.

[Jason W]

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

[Cody Carey]

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.

[technoL]

Originally Posted by Cody Carey

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.

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?!

[FourPenguins]

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

[Conor Ryan]

Originally Posted by technoL

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?!

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.

[Jon Jack]

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.

[DavidGitz]

Originally Posted by jjack

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.

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

[Graham Donaldson]

Originally Posted by Conor Ryan

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.

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...

[ewankoff]

their cold cathodes grahm but what ever.

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

[fimmel]

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

[Otaku]

Originally Posted by ewankoff

their cold cathodes grahm but what ever.

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.

[artdutra04]

Originally Posted by robotcanuck1676

2. A Segway pulling a cart.

Good call!

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.

[Ian Curtis]

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

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...