Question about carts

[Adamz_]

Originally Posted by Jon Stratis

- Sturdy work surface - you can really pound on something here, unlike on the tables usually included in the pits at events.

if you don't mind my asking, what did did you use for the top of the cart, and also the internal support?

[Adamz_]

Originally Posted by M. Lillis

The one thing that I would caution is having motorized wheels on the cart. If the motors or batteries die mid-competition then you will have to manually push the cart.

One thing i should clear up, is that this cart will mostly stay in the pit, so pushing it around is not too much of a concern.

Originally Posted by stinglikeabee

You will want to design it for a 30" door opening. While 36" is the standard for exterior doors, many interior doors are 30" or 32". That one time you need to go through a narrow door, you'll be thankful.

it has been designed to fit through through a 30" doorway, if i remember correctly the design is 28" wide.

Originally Posted by stinglikeabee

I agree with the points about not having an unnecessarily complex charging system on the cart. Just get some battery chargers and extension cords. You should never be without wall power. Safety inspectors may tell you to disconnect a charging system for a deep cycle battery in the pits.

after some thinking about what everyone has been saying about the battery not really being needed, I have decided to remove it from the design.

Originally Posted by stinglikeabee

I also agree with others' statements regarding separate carts. Don't try to have a single cart for everything.

i should clear up that this would basically be my teams tool chest as we currently do not have one. Also there would be a different cart for the robot transportation. (basically some plywood with support on wheels.

[chmconkling]

Deep cycle batteries are not allowed in the event. Some regionals don't care but the one I was a safety advisor at, one team wanted to use one and we had to end up taking it from them.

[Adamz_]

Originally Posted by chmconkling

Deep cycle batteries are not allowed in the event. Some regionals don't care but the one I was a safety advisor at, one team wanted to use one and we had to end up taking it from them.

I have decided to remove the battery from the design for the reason of having plugs around 90% of the time.

Let me thank you for clearing this up, because i have heard about some teams having them on carts, but it is good to receive clarification from someone that has been an inspector!

[fb39ca4]

Our cart is on a motorized wheelchair base, and that has a pretty big battery, and we have never gotten any trouble for it, so I would say the battery isn't really an issue.

[protoserge]

Originally Posted by fb39ca4

Our cart is on a motorized wheelchair base, and that has a pretty big battery, and we have never gotten any trouble for it, so I would say the battery isn't really an issue.

Are you using a non-sealed lead-acid battery or a sealed type like that on the robot? The initial suggested battery (by the way, the OP is no longer considering this option) was a deep cycle spillable lead-acid battery. Lead-acid batteries product hydrogen while charging and are a potential safety hazard given certain conditions.

I don't see a problem with using a motorized cart, so long as appropriate design considerations are made: speed is no faster than a moderate walking pace, a dead man switch or emergency stop is in place, a beeper/flasher or other acoustic or visual device to inform those around that it is powered, and the batteries of the sealed, non-spillable type. In my opinion, however, it adds needless complexity and weight to what I believe is a very simple device.

[MrBasse]

Originally Posted by stinglikeabee

Are you using a non-sealed lead-acid battery or a sealed type like that on the robot? The initial suggested battery (by the way, the OP is no longer considering this option) was a deep cycle spillable lead-acid battery. Lead-acid batteries product hydrogen while charging and are a potential safety hazard given certain conditions.
.

Given the culture of safety that is built into FIRST competitions, I'd like to hope we have the respect for other teams to think that they would take into consideration items like this. The general idea between using a large deep cycle battery is to gain the benefit of a large reserve capacity so charging at an event should be a non-issue. With that said, even if you are charging a battery at an event, charging in an open area like a gymnasium or similar area should be another non-issue as long as there is some ventilation.

There are some things that I can agree the rules should address. I don't think that this is one of them. There are enough people at a competition to observe and make recommendations about safety aspects. I don't want to see the rule book increasing in size again after it was shrunk down. It's hard enough to get kids to read the whole thing the amount of times that I ask them to.

If we ask for rules on every last item that could ever prevent the slightest possibility of an unsafe condition, we run the risk of crushing opportunities for innovation. Im not saying I'm not in support of a perfectly safe environment, just that if the people who make the final call are in New Hampshire, it would be hard to judge a system they have never seen or witnessed operating. We have had a number of things that have been quoted to us as safety law that I would never let a student do for fear of personal injury. I don't even want to start thinking about the event electrical wiring set-ups at some of the events I've been to in the past three years...

[chmconkling]

It is NOT a FIRST rule, it is a event and safety advisor rule. Some events are held on a floor that have a sensitive floor to acid type chemicals(ex. Basketball arenas). FIRST knows this and has ways of covering the damages from a robot, but not a battery to charge your cart.

[Alan Anderson]

Originally Posted by chmconkling

It is NOT a FIRST rule, it is a event and safety advisor rule.

There is no such thing as a "safety advisor rule". The green-shirted volunteers are there to give advice and promote best practices. They do not have the authority to make rules.

I'll go along with venue restrictions beyond what's in the FRC manual, as long as they actually come from representatives of the venue.

[techhelpbb]

If FIRST is okay with venue restrictions that vary they ought to clarify that sort of thing.

It makes it hard to build unique things when you wonder if you'll make it half way through the season before finding yourself having to take it all apart.

At least if we know that some venues allow nonFIRST style batteries on the carts and others do not; people will know to ask the question about the venue at that level.

Let us not forget there are plenty of rookies. It is not really fair to them that they have to guess about things like that either. They may not know the venues or even who to ask.

There are really 3 answers to this: yes, no, maybe

As far as the size of the manual. I worry more about the quality than the quantity.

[Alan Anderson]

Originally Posted by techhelpbb

If FIRST is okay with venue restrictions that vary they ought to clarify that sort of thing.

They do. I've seen it in the past few years of the Administrative Manual, at the end of section 4. Here's an excerpt:

"Please read the following common site restrictions and adhere to them in order to promote an orderly, safe, pleasant and exciting competition. Please refer to Section 4.2 of this manual section for additional site restrictions at your event."

[techhelpbb]

Originally Posted by Alan Anderson

They do. I've seen it in the past few years of the Administrative Manual, at the end of section 4. Here's an excerpt:

"Please read the following common site restrictions and adhere to them in order to promote an orderly, safe, pleasant and exciting competition. Please refer to Section 4.2 of this manual section for additional site restrictions at your event."

This is true and section 4.2.2 defines a bunch of loose parameters for the carts at the events. With only this mention of electrical safety:

"Do not add music or other sound devices to the cart; and"

That is definitely a rule that has been ignored in the past.
Though no mention of other electrical apparatus on carts.

[EricH]

Originally Posted by chmconkling

Deep cycle batteries are not allowed in the event. Some regionals don't care but the one I was a safety advisor at, one team wanted to use one and we had to end up taking it from them.

Got a source? Neither the FRC Administrative Manual nor the FIRST Safety Manual says anything about deep-cycle batteries that I can find. On the robot, sure--everyone has to use the same batteries, and that's in the rules. Not on the robot, I see nothing at all to prevent someone from bringing one in, barring safety concerns (and if the battery is handled properly, not a concern).

[MrBasse]

Originally Posted by chmconkling

Deep cycle batteries are not allowed in the event. Some regionals don't care but the one I was a safety advisor at, one team wanted to use one and we had to end up taking it from them.

I'd also like a source on this. We have a lawn tractor battery and a UPS in our cart that charges in the pits with a standard computer power cable. We use the battery to provide power for our UPS and the UPS to charge our driver station as well as an electric linear actuator that lifts our robot from 18" off the ground to 36" or anywhere in between. This makes our robot cart a huge resource for us in the pits for working on the robot at a comfortable height, but has also proved to be an amazing resource during eliminations for keeping our DS charged and ready. We have even loaned our cart to other teams to work on their robots during eliminations.

[techhelpbb]

Best way to be absolutely sure about the legality of something with FIRST FRC is to ask in the official FIRST forum. I would ask early as this is a pretty straight forward question.

Generally, from what I have seen, people manage to get batteries that are not FRC legal into carts and pits as long as someone does not catch it. That is not exactly the most reliable tactic in the end and I prefer not to encourage people to find ways to stash things that really could be dangerous if done improperly or with people unaware.