Mario Cart Challenge!

[mrjdstewart]

inspired by the FT episode on the SKY CART. i decided to throw down a challenge at my club.

simple rules;

1- has to be made of foam, and have at least a 20x30 measurement (standard $1 store foam board).
2- has to have 4 wheels.
3- has to be modeled after a mario cart or cartoon character (thank Rasterize for that bit, he wanted to build Dirk Dastardly).

the rest is open. you can use what ever motor(s), props, set-up, what-ever you thought would win.

the race will not happen until this fall, it's AZ and it's hot. most memebrs take off for the summer so we wanted to include everyone, and give plenty of time for building and testing.

race will consist of 3 laps with both ground and air portions. racers will qualify and be lined up based upon a single, individual lap time.

what happens after that, promises to be fun!

i was feeling pretty confident being the "foam" builder of the club and the guy who thought of the whole deal. that was until another racer showed up this weekend with his beta model ready for testing.

he had dual, thrust vectoring motors tied to his rudder, and actually got it to lift off the ground.

that motivated me to finish my beta today.

may i present my beta model.

so far i have a elevon mix with 2 - 9g metal gear servos, 2 - 5g servos for canard flaps, 9g metal gear servo for rudder set-up as pull-pull. turning a 13x7.5x3 blade prop w/ a 3720-620kv motor, 54A Thunderbird ESC, with a 3S-2200 to start. 3D printed the wheel hubs and motor mount. tires are super-sized pool noodles cut down.

no idea if it will fly yet, but it's stupid, crazy fast on the ground....

what you got?

i will keep updating this as i go and hopefully post video of the finally

laters,

me

 

[mrjdstewart]

so.....

my cart went out to the field today with my students. all 4 of them were maidening their FT Simple Cub. All of them asked that i bring it out to show. i knew my main rival would be out there as well (because he is an awesome guy and volunteered to help), and i knew he was brining his cart to show off to the kids. i just could not have that, i had to have something.

so, with no front flaps wired in, and on a stupid windy day, i did 3 taxi runs, last one i gave up elevator and it sprang into the sky. i immediatly chopped the throttle and it fell back to earth. no damage, flipped it back over, and went for my 4th. this time, i had already told the crowd i WAS going to fly this thing no matter what the result.

so, i lined up for the 4th run and just gunned it. it jumped in to the air just like before and then i started working the controls and throttle. the wind did not help, nor the fact that the motor and prop is prob WAY too big, but....i was able to take off, hover, and bring it back around the field and land it.

promising start for just looking @ a couple pics and hacking it together. plus i still have lots of time to develop.

things looks promising.

laters,

me

 

[mrjdstewart]

so far confirmed...

Mr. G - twin motor, thrust vectoring (elev & rud), Wonder Woman theme
Mr. T - 5 motor quad, 5th motor being forward thrust for driving mode, theme unkown.
Me. - single motor tractor, elevon w/rudder, front flaps (?). Luigi theme
Mr. S - (Rasterize) Dirk Dasterdly theme
Mr. A - Unkown
Mr. P - Unkown
Mr. J - Unkown

after seeing Mr. G and my cart drive and fly, the list will hopefully expand. we still have have plenty of time.

laters,

me

 

[Grifflyer]

I like this idea.

Oh, and make sure you get a video of the race

 

[mrjdstewart]

oh, i think it's going to be epically funny! i promise there will be video.

 

[mrjdstewart]

mario didn't fair so well today.

it's ok, i have plenty of ideas for improvement already. designed new motor mount in CAD and have it ready to 3D print. will firm up the front and improve wheel mounting points. i think it's close, just a few little things to improve the control when in the air.

laters,

me

 

[Grifflyer]

HaHaHa That was funny... I can't wait to see V2!

 

[mrjdstewart]

had another member show up this morning with his prototype cart. it was a Homer Simpson theme. he had 3D printed flexible wheels, a forward based pusher prop, and prob 1/2 the weight of mine. setup as a elevon w/ rudder. i will get the exact motor/prop/battery combo.

he was pretty quick on the ground, not bad turning, and it took off and flew.

not for long...but it did fly. very similar ending as mine.

unfortunately, i did not get any video. he was in a bit of a rush and sometimes has a hard time hearing.

i hope to have pics soon though.

i also ordered myself a lemon 7-channel rx/stabilizer. never used one and kinda opposed to them, but what can i say. i want to WIN!

laters,

me

 

[mrjdstewart]

i forgot, he did send me one a few days ago before he was done....

doh!

 

[mrjdstewart]

Round 2...

 

[mrjdstewart]

just finished.

using a smaller motor, 4 blade prop, lemon flight stab, and a 4S-2200. regretably going to smaller motor really messed up CG, hence the 4S-2200.

will test fly it tomorrow and report back...

laters,

me

 

[mrjdstewart]

well,

ground handling was vastly improved.

have issues with stabilizer and ground handling though. ended up having to disable it. sure could have used it though...

will keep working. getting closer.

laters,

me

 

[Grifflyer]

At least it flew longer this time

I also have some suggestions from when I made a square plane that flew great. Try going with a wider body it made my plane MUCH more stable, and these planes seem to LOVE nose weight, on mine it was like 20 X 10 in. rectangle and I ended up gluing a pencil and a ruler on the front to get to balance so maybe try gluing a stick on and adding some weight to the front, it can also be used to stab other planes out of the air

 

[mrjdstewart]

well for CG i have been running on the basic assumption it should be set @ 25-30% of root cord. for a piece of foam board that is just around 8" from the nose. that's where i was set today @ roughly 28%. i also need to do some double checking on the settings for the flight stabilizer. the way it was having issues on the ground was weird. i can shut it off for the ground portion of the race but i'm gonna have to turn it on before take-off. that means i have to be able to build speed without swerving.

i will get it sorted. stay tuned...

laters,

me

 

[mrjdstewart]

so, i lost the race to be the first to demonstrate real, controlled, sustained flight.

Mr. G showed up @ the field on sunday with his cart prototype.

his has twin, thrust verctoring (vert and horiz axis), and a flight stabilizer.

his ground handling was good. had an issue with a servo but nothing bad.

once sorted, it was time for fight...

so, in response i have decided to follow the KISS principal, ie- keep it simple stupid. in my research i stumbled across an rcgroups thread on a very similar type craft. Flying Genie on a Carpet and have built one purely for CG testing. no wheels, no rudder, no stabilizer, just simple fly by the seat of your pants kinda plane. i followed the dimensions and CG from the thread so in theory it should fly...

stay tuned.

laters,

me

 

[mrjdstewart]

hacked some foam off of Luigi to help balance with a smaller 1300mah battery and took out to the field this morning for its maiden.

happy to report that it flies! first was good but needed more throw on the control surfaces. brought it in and landed, then turned the throws up to 11!

here is the 2nd flight. comes down at end due to loose prop adapter.

now that i have a proven platform i will build another keeping the same CG but adding a rudder and 4 wheels for the ground.

getting closer. maybe have beta4 build by wednesday for testing. we will see.

laters,

me

 

[mrjdstewart]

race was held this saturday.

the plan was for 6 competitors. regrettably 3 had to withdrawal before the race.

A- got called away on family business
P- aircraft was crashed in testing on friday
Rasterize- was attacked by his craft @ 2am saturday morning and had to be put down...

the final line up was;

Wonder Woman- flown by Gaige, had twin, counter rotating props w 4 axis thrust vectoring.

Mario Cart- flown by Jon, single tractor config with huge motor and 13" - 3 blade prop

Luigi- flown by me, contra-rotating tractor config w/ 8" props.

i think now that we have proven it isn't that hard, our next race will have a lot more competitors.

i will be posting an article with more detailed info about all the racers.

now the challenge get's thrown down, what you got?

laters,

me

 

[buzzbomb]

That looks like it was a ridiculous amount of fun. I look forward to the day I can accept your challenge. Thank you for inspiring.

 

[donalson]

love this... watched a bit older video on it shortly after FT did their vid...

makes me really want to build one as well