Baby Bugatti

[varg]

I got my hands on an MT1806 and some 6x4 props cheap so it turns out I am going to build one of these in mini form. My smallest ESC is a generic 20A and my smallest battery is a 3S 1000mAh though, so I'm crossing my fingers hoping it all fits. I have a smaller 4channel receiver on the way which I'm sure will help since my only receiver is an 8 channel and it's definitely on the large side for a plane this small.

 

[MrFowl]

I got my hands on an MT1806 and some 6x4 props cheap so it turns out I am going to build one of these in mini form. My smallest ESC is a generic 20A and my smallest battery is a 3S 1000mAh though, so I'm crossing my fingers hoping it all fits. I have a smaller 4channel receiver on the way which I'm sure will help since my only receiver is an 8 channel and it's definitely on the large side for a plane this small.

I finished mine about a week ago, but life has gotten in the way... My AUW is about 290g (pretty heavy). With a 2308 (1800kv), 18a esc, 3s 850mah, 8x5 folding prop, and a lot of carbon reinforcement. I'll let you know how the pig flies as soon as I maiden it.

 

[varg]

I just finished mine and I have no idea what mine weighs but it's probably pretty heavy. Since I only have one receiver at this time I put it below the wing where it would be easy to get to, and the battery slides above. The aileron servo is placed in a cutout in the wing itself, and the servos are both 5g for the sake of weight. The battery being above the wing puts the CG above it and there's no dihedral, so hopefully this thing doesn't have too much roll instability, the CG is right where it needs to be longitudinally though. Here it is with the tail of my sportster.

 

[Mid7night]

Looking forward to seeing these new maidens! FYI: I just recently flew my 24" span version, with a larger (2212 bell-housing) motor and a 7x6 APC prop, on a 1000mAh 3s. I don't know what it weighed but it was quite a bit more than the original Baby. Also, the CG was forward, basically right on the wing LE. Result?: It flew great! It's nice to know that pushing the CG forward only helps to settle things down, and there's still plenty of elevator authority. I even had someone else at my field take the controls, and he said it was the best-behaved model he's ever flown!

With a bigger prop and motor, there is more torque-roll to trim out with ailerons, but once you get that trimmed, it flies straight and true. I can't wait to share the new plans with y'all! Soon!

 

[varg]

Well that didn't go well. I gave it a good toss and it immediately banked left and spun into the ground, I couldn't counter it fast enough so all I could do was cut the throttle to save the prop. I then threw it with the motor off to see if it would glide straight and it did but when it hit the ground the nose ripped off completely, so I'm adding a few more grams of weight gluing it back together. No sense in building a new one just to crash that too, may as well learn on a torn up model. I'm going to try dialing in several clicks of right aileron trim and adding a bit of right thrust because I'm pretty sure it was just an unexpectedly strong torque reaction.

 

[SlingShot]

Looking forward to seeing these new maidens! FYI: I just recently flew my 24" span version, with a larger (2212 bell-housing) motor and a 7x6 APC prop, on a 1000mAh 3s. I don't know what it weighed but it was quite a bit more than the original Baby. Also, the CG was forward, basically right on the wing LE. Result?: It flew great! It's nice to know that pushing the CG forward only helps to settle things down, and there's still plenty of elevator authority. I even had someone else at my field take the controls, and he said it was the best-behaved model he's ever flown!

With a bigger prop and motor, there is more torque-roll to trim out with ailerons, but once you get that trimmed, it flies straight and true. I can't wait to share the new plans with y'all! Soon!

That sounds pretty good. Have you tried any V-Tail mixing on it?

 

[Mid7night]

That sounds pretty good. Have you tried any V-Tail mixing on it?

No, still just using one elevator servo.

FYI: I just weighed my 24" span version ... it tips the scales at 307g, and on 3s with a 7x6 it still had unlimited vertical.

 

[Tsavah]

Rounded Fuselage - Bugatti P100 RC Park Flyer

Did a quick tape mock-up with the rounded fuselage and weighed it.

View attachment 91978

End Quote

I am thinking round fuselage also , but I started with a glider by recycling a $1 foam toy glider kit I purchased at the Dollar Tree store a few years back to test the CG location that works best. Posted a few Youtube videos to show the conversion steps and then did another kit to make one a bit longer. Currently working on a slightly larger fuselage I plan to use as a build-over jig and will be going with a low wing rather than a mid wing version. Wondering if it would be OK to post the Youtube links since this is going to take more than a few videos I posted already? https://www.youtube.com/watch?v=W56ynMM5Pn4

For the build-over jig, or plug I am recycling foam drink cups as skins. Something I've done a few times before with a larger Titan foam glider kit by Air Hogs. I also have a few Youtube videos about how to cold roll thin foam board like the Adams poster board foam core (paper removed), Blu-core (Dow fan fold) and even cold rolled some of the Pink fan fold (Corning), but it is brittle, so you have to take a bit more care. Have other videos planned, but I am an old guy and move a tad slower than most here.

 

[MrFowl]

Just realized I never uploaded my finish baby bugatti! Here she is in all her glory! Will paint her after I maiden ..I hate crashing newly painted planes hence the white foam board. I must say, this was a little more involved build than I was expecting, but then again ...I added quite a lot of stuff that the plans didn't call for.

I have a battery cut-out in the wing (shown). The servos (4g elevator, 9g aileron) are mounted in wing cut-outs too (elevator behind the battery, Aileron in front). If you do it this way be sure to cut out the holes before you mount the wing, but DON'T glue in the servos until you install the wing!!! I used straws so the pushrods don't rub on the battery. It has an AX 2308N 1800kv motor (https://hobbyking.com/en_us/ax-2308n-1800kv-brushless-micro-motor.html), an 18A ThunderBird ESC (discontinued), an 8x5 folding prop from the Spirit 815mm (https://hobbyking.com/en_us/spirit-815mm-replacement-prop-and-spinner-set.html), and I'm using a 3S 850mAh 45-90C battery (https://hobbyking.com/en_us/turnigy-nano-tech-850mah-3s-45-90c-lipo-pack.html). AUW is 290g including the 73g battery.

The fuselage and wing are reinforced with carbon rod, the hatch is balsa (secured with a pin/tape method), I added a brass tube under the tail to reinforce the lower vertical tail for landings, and the forward fuselage was rounded out to match the folding prop. I added one fuselage frame to help hold the fuselage shape and to hold the power pod. The spinner came with a nose mount that I used to strengthen the fuselage even more. Should hold up okay, but I'm sure it's not as strong or as light as the square fuselage.

 

[varg]

That's fancy looking.

I tried to fly mine again today and it wound up in pieces and now in the trash. The longest flight was its last, gave it a strong discus launch, It flew almost perfectly straight and level for 50ft or so with minor corrections before pitching up and tumbling into the ground again when I throttled up and gave it some up elevator to climb out. A smooth arc followed by some manner of spin or backflip each time. CG was where it belonged, controls were free and correct. Not sure what I did wrong. Not sure if I'll build another one, It's not enjoyable to do a build that is 100% failure and not know what the problem was.

 

[Mid7night]

That's fancy looking.

I tried to fly mine again today and it wound up in pieces and now in the trash. The longest flight was its last, gave it a strong discus launch, It flew almost perfectly straight and level for 50ft or so with minor corrections before pitching up and tumbling into the ground again when I throttled up and gave it some up elevator to climb out. A smooth arc followed by some manner of spin or backflip each time. CG was where it belonged, controls were free and correct. Not sure what I did wrong. Not sure if I'll build another one, It's not enjoyable to do a build that is 100% failure and not know what the problem was.

I'm so sorry you had a frustrating end to your flight. I 100% agree that it's disheartening to have a failure that you don't know the reason for.

I would encourage you to come back and try it again when the scaled-up version is posted - the increased span and body volume really makes it more manageable to build and fly. I will absolutely make it well-known and clear when those plans are posted. Stay tuned, and keep flyin'!

- Ben

 

[varg]

I don't see how any of the changes I made to the design would have such a negative effect. Putting the battery on top of the wing shouldn't cause it to stall and spin like that, the CG was where it should be and I moved it forward a bit before the last flight, and the only other changes were 5g servos placed where they'd fit instead of 9g. Throws too high? I launched on low rates, which were very small, the ailerons and elevators didn't even clear the foam next to them on full deflection. The only thing I can think of is that the wing was a little off shape, it was different than the slots in the fuselage; because of the way I taped the leading edge it did not fold over as sharply. Because of that and the weight (82g battery, 12.4g receiver, 20A ESC) it might have just not ever reached a controllable airspeed.

(edit)
I put together another one and flew it on Sunday. I only changed 3 things vs the first one; I taped only the corners of the wing fold before I folded it (the leading edge is a bit more sharp), I reduced control throws further, and I put a smaller receiver in it (5.8g vs 12.4g). I think the other one just never reached a controllable speed. This one flew fine when I gave it a fastball style launch with someone else at the controls, but when he threw it for me it stalled and spun in both times, he just couldn't get the speed on it like I could. Since even with the reduced control throws it still spun in it has to come down to speed. Now I need to practice throwing left handed so I can get the kind of speed out of my left handed transmitter-in-hand launch that I do out of a right handed launch. Or hope that it's trimmed well enough for me to launch it right handed. I'm also going to try launching at full throttle since the recommended half throttle launch doesn't seem to be enough for my portly Baby Bugatti without a seriously hard throw. Now I just need to see if I can find a smaller 20A ESC (can't go with 12A, this one gets pretty warm with the 1806/6x4 combo) and try a smaller 3S battery.

 

[mrjdstewart]

take two...



much better this time but still some issues. might i suggest, since you have changed the plans since your first post/pics, that you update the pics. since there really isn't a "build" process laid out other than pics, it sure would be nice.

as for programming? what are you using? i got elevator on tail, but what about the ailerons?

crossing my fingers still, hopefully i won't be on take 3 before this one flies...

thanks,

jason

 

[nautilusroom]

Baby Bugatti 200%

Hey Ben and Baby Bugatti builders. I decided to build a 40" version of Ben's Baby Bugatti

 

[rockyboy]

Welcome to the forums!

And we need video of the maiden on that sweet 40" Bugatti. I would expect her to behave better than the tiny one. What size motor/prop are you planning for this one?

 

[Mid7night]

That's great!! Even just scaling it up to 24" I found that it settled down nicely. I bet it'll have a great presence and be a ton of fun at 40" span.

VIDEO!!

 

[Michael9865]

Wow! That looks cool.

 

[willsonman]

At 40", you are pretty close to my 1/6 scale version... need a 1600W contra motor setup?

 

[nautilusroom]

Welcome to the forums!

And we need video of the maiden on that sweet 40" Bugatti. I would expect her to behave better than the tiny one. What size motor/prop are you planning for this one?

I will mount the Propdrive v2 3536 1800kv with a APC 8x6 - 8x4 or 9x6, not sure about that. Lets se how it all work out. I will bring my headcam with me

 

[nautilusroom]

That's great!! Even just scaling it up to 24" I found that it settled down nicely. I bet it'll have a great presence and be a ton of fun at 40" span.

VIDEO!!

Thanks Ben. I have a 32" cutout laying on my desk but decided to go for the 40". I will record the maiden, hopefully;