Building for a cool kid

[MortisSanguine]

I posted this to a Reddit group and got one response, so if you lurk there, that is why this looks familiar.

New to the group, I've never done this before, so please be gentle.

Just to spike your interest: I want to build an RC Red Shell from Mario Kart for a kid who is paralyzed from the neck down.

Details below:

I am a builder for a charity organization called Magic Wheelchair ( magicwheelchair.org ). We get matched with a kiddo. Then we build costumes around their wheelchair at no cost to them or the family. It is whatever theme they want, and we always strive for EPIC results. They don't get to see the final result until the reveal. Kind of an Extreme Home Makeover "Move That Bus" experience.

The child we are building for is paralyzed from the neck down but uses a sip/puff device for playing video games and has a powered wheelchair. There are instructions on line with a specialized device that would allow the kiddo to control an RC vehicle using the sip/puff controller.

My kiddo's request is a Mario Kart Standard with Red Yoshi. We are currently building it. However, we like to add all sorts of features. Sound. Music. Effects. I like to go as big as I can, given my time and budget.

I want a red shell. I want an RC Red Shell. If I can get enough time, I want the kiddo to be able to chase people with a red shell. If I don't have enough time to get all the setup for him to do it, I want his friends or sibling to be able to chase people with a red shell while my Kiddo drives his Mario Kart.

Things I have to consider:

-Probably not an extremely fast RC (that could be...dangerous)

-Easy to add an upper shell to, probably on top of a regular body

-Durable, I imagine it will hit plenty of curbs

-Some decent ground clearance for going up ramps, over bumps

I have never done this before, and I ask for the benevolent wisdom of this group.

I don't want to spend a huge amount of time building the actual RC portion, as I will be sculpting and adding the red shell (probably a thin shell with flexible foam and rubberized for durability).

Any suggestions? And a HUGE thank you in advance.

Edit: What I REALLY need helpnwith is finding a tough enough RC car with controller for under 300 bucks if possible that could handle a kid playing with it. Something good but not Walmart box RC

 

[9x19]

Awesome endeavor, but I am at a loss to help.

 

[Guest D]

Sounds like a cool build.

 

[Doom!]

Sounds like a cool project but it's one of those things I would probably fake as I go along. I'm not going to be much help. I would probably start with a block of styrofoam and carve to shape then it could be coated for protection.

 

[MortisSanguine]

Awesome endeavor, but I am at a loss to help.

Any suggestions on a durable RC body that is affordable and not too fast?

 

[MortisSanguine]

Sounds like a cool project but it's one of those things I would probably fake as I go along. I'm not going to be much help. I would probably start with a block of styrofoam and carve to shape then it could be coated for protection.

I am totally able to do the red shell part. I know how to sculpt and mold that. What I really need help on is finding an appropriate RC car that can handle a kid playing with it and be durable enough that I could smack into a couple of curbs. I would like to spend less than $300 on it also for the RC portion and the controller

 

[WickedFog]

So by red shell, you are trying to build something like the turtle shells that Mario shoots out of his cart? The chasing people part is kinda scary, because hitting someone with an RC car is something we try very hard not to do, as these things can be quite heavy, and at speed could break bones.

So if that is indeed what you want him to be able to do, you'd want something small scale, and not very fast. Like 1/18 or so. I have a 1/18 Dromida buggy that is very fast, and if it hit me I wouldn't be too concerned. But if it hit a little kid, it's gonna sting.

So if I were building a little RC with a red turtle shell made of foam, I would probably go with something like the Arrma Grom. It's peppy. Small scale, and should do nicely. And there are plenty of parts available for it to repair or upgrade it.
https://www.amainhobbies.com/arrma-...-electric-desert-truck-rtr-ara2104t2/p1566679

Make sure you use Amain's discount code if you buy from them.

 

[Doom!]

I can personally vouch for both of these being fun and durable. The Granite Grom is a little smaller being 1/18 scale making it better for smaller areas. It also might make it easier to make a body for.
Arrma Granite Grom

The Gorgon is 1/10 scale which is probably the most common size. Great rig.
Arrma Gorgon

Both of these fit in your budget and are guaranteed to put a smile on anyone's face.

 

[CertifiedMike]

I will add that the Gorgon has worked flawlessly for me in box stock form. The nicad battery would help keep it on the slower side, simplify use too.
The radio also has a throttle trim switch that can cut throttle power by 50%.


I list these trucks as my top suggestion for a 1st time RC'r on a budget. This truck could be perfect for purposes here too.

It is a monster truck so its durable as heck. Never broke a single part on it. If its the right size, this is a great chassis!

Rc cars need air flow to help keep the electronics cool as they run.
Be sure to allow fot that in your shell design.

Try to keep it light weight so its not top heavy, not tipping over all the time.

Maybe some soft edges on the body so impacts are fun, not painful to the other kids playing too. As mentioned, these cars are still somewhat large and heavy to be running into a potentially unsuspecting kid (or adult) and could hurt someone.

I can't think of other pointers right now... ask away though. This is a really cool project. I'm happy to help!

I checked out your link. This looks like an amazing program. Thanks for being amazing too!

 

[majin]

I am totally able to do the red shell part. I know how to sculpt and mold that. What I really need help on is finding an appropriate RC car that can handle a kid playing with it and be durable enough that I could smack into a couple of curbs. I would like to spend less than $300 on it also for the RC portion and the controller

i love this idea!
i think your causing some confusuion for yourself by thinking the body has ANYTHING to do with anything.
the bodies are interchangeable based off of wheelbase.
it sounds like your looking for the turtle shell you shoot out in a race? awesomeness!
your best bet with your budget constraints seems imo to be look around fb marketplace. your just wanting a rig (thats easy to repair and tough) arrma is known for speed and durability in the basher world, you could look for an arrma big rock for instance? they are pretty durable and quick,
that being said you could then fabricate your own shell to fit the common wheelbase that looks like the shell?
i think if it were me thats what i would consider.
I've curbed a few and they are all gonna break with the right contact, but the easier it is to wrench on the faster your back on the road with it!!

 

[MortisSanguine]

First off, let me say you folks are absolutely amazing for this knowledge.

I definitely don't want to cause injuries. No matter how much my cartoon-damaged brain giggles at the idea of a line of children being flipped up in the air from a red shell mowing them down. I mean... no. Yeah, let's stay away from flipping children like Meet Joe Black car collisions.

A solid smaller-scale truck-type thing looks like it would be my best bet. Something solid and not too hard to play with.

For the shell, the airflow thing is an excellent suggestion and one I will definitely take into account.

As for creating a shell that is not extremely dangerous:

Right now, I have a few ideas for that.

1st idea: Vacuum form the shell shape and coat with an EVA foam (either craft foam or a floor mat foam pad) but I am concerned about the overall weight, and the top-heavy nature this could cause as has been mentioned.

2nd idea: Really lightweight shell with a two-part epoxy putty from smooth-on (Free Form Air) https://www.smooth-on.com/products/free-form-air/. This stuff is super strong and so lightweight. When you mix in in your (gloved) hands it feels like playing with marshmallow fluff.

3rd idea: Using hotwire knives I can sculpt a vented foam shell that is glued to the truck body that is also vented, and the shell sits over top of it with small latch attachments for ease of removal.

There are also some cool foam compounds from HotWire Foam Factory to add a rubbery coating that is pretty durable.

And, if I may add. I think I am screwed. I never delved into RC stuff before. This looks addictive. Would that be accurate?

Again, THANK YOU SO MUCH!

 

[WickedFog]

First off, let me say you folks are absolutely amazing for this knowledge.

I definitely don't want to cause injuries. No matter how much my cartoon-damaged brain giggles at the idea of a line of children being flipped up in the air from a red shell mowing them down. I mean... no. Yeah, let's stay away from flipping children like Meet Joe Black car collisions.

A solid smaller-scale truck-type thing looks like it would be my best bet. Something solid and not too hard to play with.

For the shell, the airflow thing is an excellent suggestion and one I will definitely take into account.

As for creating a shell that is not extremely dangerous:

Right now, I have a few ideas for that.

1st idea: Vacuum form the shell shape and coat with an EVA foam (either craft foam or a floor mat foam pad) but I am concerned about the overall weight, and the top-heavy nature this could cause as has been mentioned.

2nd idea: Really lightweight shell with a two-part epoxy putty from smooth-on (Free Form Air) https://www.smooth-on.com/products/free-form-air/. This stuff is super strong and so lightweight. When you mix in in your (gloved) hands it feels like playing with marshmallow fluff.

3rd idea: Using hotwire knives I can sculpt a vented foam shell that is glued to the truck body that is also vented, and the shell sits over top of it with small latch attachments for ease of removal.

There are also some cool foam compounds from HotWire Foam Factory to add a rubbery coating that is pretty durable.

And, if I may add. I think I am screwed. I never delved into RC stuff before. This looks addictive. Would that be accurate?

Again, THANK YOU SO MUCH!

Yes, RC cars are fairly addictive, especially if you like to tinker. And it sounds like you do.

As far as the heat goes, if you gear the car down by putting a smaller pinion/bigger spur on it, heat shouldn't be an issue. You just have to find the right combo for the weight of your RC. So for that you would want to go with a bit of overkill on the electronics side.

To do that, you would want an ESC that can easily handle the weight of the vehicle (higher amperage than sctually needed), and a low kv motor. That and the gearing should be enough to keep things cool, even in an enclosed environment. To handle the heavier shell, you will probably want to stiffen the shock springs.

I think this sounds like a really cool project, and I hope once you figure everything out you share the build here so we can follow along.

 

[xjtorc]

This is very cool. I came to second the Arrma Grom. Definitely a solid choice for this project. I have to assume little buddy spends a fair amount of time indoors and the smaller size would be perfect for him to tear around the house, red shelling his pets or siblings when he's bored.

 

[MortisSanguine]

I can personally vouch for both of these being fun and durable. The Granite Grom is a little smaller being 1/18 scale making it better for smaller areas. It also might make it easier to make a body for.
Arrma Granite Grom

The Gorgon is 1/10 scale which is probably the most common size. Great rig.
Arrma Gorgon

Both of these fit in your budget and are guaranteed to put a smile on anyone's face.

Okay, so, we pulled off the reveal. One Yoshi Standard Mario Kart with Red Rollers completed. As an added bonus a red shell RC car his family can chase with or send off after other people. Thankbyou so much for your suggestions and support.

Not sure how to post some video in the feed. So I will add a link to a news story.

https://www.ktvu.com/news/boy-10-paralyzed-oakland-shooting-gets-custom-halloween-costume

Again, thank you all for the input.

 

[xjtorc]

That's so awesome!

 

[Doom!]

Awesome! Glad everything worked out. Thanks for sharing the update.

 

[Ritz413]

That's great!! Thanks fir sharing, and welcome!!

 

[luke66]

Wow that's so cool!