FT Bloody Wonder - Scratch Build

[Twitchity]

Twitchy, How did it fly?
That looks like a better 3d trainer, if a standard symmetrical Airfoil were used.

The winds in my area were 25mph today, but I did send it up for a short flight. The design flew great, but I found myself constantly fighting the wind which was expected. I thought about creating a symmetrical airfoil for this design, but wasn't sure of a good way to mount it to the fuse. I thought about doing a KF style airfoil on the bottom of the wing on each side, or just bending foam to the same shape as the top and hot gluing it in place. I want to get a nice flight in better weather before I make any changes.

The winds are supposed to be 14mph tomorrow so I should be able to get a better flight in to test the design.

 

[Eugene king]

What did you build your plane out of?

My bloody weighs 425g with a 1800mah 3cell lipo. the battery alone weighs 170g.

I'm using my fish scale but I doubt its off too much.

 

[Twitchity]

I built mine with the Adams foam board bought from the Dollar Tree. I'm not sure of the weight since I don't have a scale to weigh the plane on. I have also used the foam board from Walmart and it seems a considerable amount heavier than the Adams board.

 

[Eugene king]

I built mine with the Adams foam board bought from the Dollar Tree. I'm not sure of the weight since I don't have a scale to weigh the plane on. I have also used the foam board from Walmart and it seems a considerable amount heavier than the Adams board.

I was referring to "disq's" 561g bloody wonder. But being in cypres I haven't a clue what's available to him.

As for your morfed 3d bloodyWonder I'm interested in it. Expecially how you tapered the tail.

I never concidered tossing the bloody in the air with 25mph winds. If its 5 to 10 and not below freezing I will go to the fields across the highway and fly till my fingers get cold.

I ought to be more brave. I have no problem flying my Dynam Hawk Sky in those winds.

 

[Bolvon72]

My bloody weighs 425g with a 1800mah 3cell lipo. the battery alone weighs 170g.

I guess my Bloody needs a diet, 490g with a 1800 3s. And my battery was only 155g. I did add the skids to the front and I was glue happy when I first started building, this was my second build.

 

[Eugene king]

I guess my Bloody needs a diet, 490g with a 1800 3s. And my battery was only 155g. I did add the skids to the front and I was glue happy when I first started building, this was my second build.

That could easily be a bigger motor and heavier speed control. And like I said I'm using my Walmart fish scale.

I do like that little micro receiver though.....it hardly weighs a thing.

 

[disq]

What did you build your plane out of?
My bloody weighs 425g with a 1800mah 3cell lipo. the battery alone weighs 170g.

Using generic both-sides-paper-backed "5mm" foam I found in the local crafts store, no brand or anything. Sold in 70x100cm sheets. Its 4.9mm thick with the paper on, 4.3mm with the paper off. On both sides, the paper is glossy and thick, but easy to get off. (measured with an "analog" caliper so I might be off a little)

In fact I really wonder the difference between Adams Foamboard/Readiboard and the material I'm using. Can you measure a scrap piece, weigh it, calculate the volume using area multiplied by height, and use this tool to calculate the average density?

The weight difference is probably caused by the excess extreme packing tape, but that's just a guess. I also use 2 small screws per control horn, so that probably adds about 15 to 20 grams.

 

[disq]

According to this thread and some calculations, density for the dollar-tree foam is 0.000026 grams/cubic millimeters. Doesn't seem right, but it probably is, if 10cm x 10cm x 5mm $-tree really weighs 1.3 grams

 

[disq]

I remeasured with a 200x200x5mm gray-colored foam board I'm now using for the F22, weighed 19 grams, calculates to 0.000095 grams/cubic millimeters density.

So that means my scratch builds would be about 3.6 times heavier than Adams Foamboard counterparts. Time to score some Depron I guess.

 

[Twitchity]

Eugene,

I was able to take the plane out for a longer flight today, although the weather was still less than desirable. The plane flew nice and steady, with the controls being a lot more responsive than the original design. I only have a DX4I transmitter, but the new modified version with the transmitter on the low setting is as responsive as the original BW on high settings. I'm still new to flying so my skills aren't that impressive yet, but the plane was fun to fly.

Here is a mock-up of how I created the tail section of the fuse. This image is not drawn to scale, but gives you an idea how it was created.

 

[Eugene king]

Eugene,

I was able to take the plane out for a longer flight today, although the weather was still less than desirable. The plane flew nice and steady, with the controls being a lot more responsive than the original design. I only have a DX4I transmitter, but the new modified version with the transmitter on the low setting is as responsive as the original BW on high settings. I'm still new to flying so my skills aren't that impressive yet, but the plane was fun to fly.

Here is a mock-up of how I created the tail section of the fuse. This image is not drawn to scale, but gives you an idea how it was created.

Good to here it flys well.

 

[sidneylopsides]

I just maidened mine, I've built and flown the swappable Nutball and Delta, now this. Flew great! Little bit of wind, but handled nicely, easy on low rates, spins and flips around like crazy on high.
It would be nice to have a bit more speed though, I'm using the basic Turnigy 24g motor and 8x4 prop.
Would a different prop help, or should I upgrade the motor too? I've got a 25A ESC, but can't seem to spot a motor that's a step up from what I have, yet fine with that ESC.

 

[Bolvon72]

I just maidened mine, I've built and flown the swappable Nutball and Delta, now this. Flew great! Little bit of wind, but handled nicely, easy on low rates, spins and flips around like crazy on high.
It would be nice to have a bit more speed though, I'm using the basic Turnigy 24g motor and 8x4 prop.
Would a different prop help, or should I upgrade the motor too? I've got a 25A ESC, but can't seem to spot a motor that's a step up from what I have, yet fine with that ESC.

How many cells are you running? You can run a 9x5 on 2s no problem but beware 3s, I pulled 8.7 amps WOT with a 9x5 which is over the max for this motor. Maybe try a Suppo: http://www.altitudehobbies.com/brus...rushless-motor-370-28-26-1450kv-suppo-2208-14 which is pretty calm on 2s and plenty fun on 3s or http://www.altitudehobbies.com/brus...rushless-motor-400-28-30-1400kv-suppo-2212-10 Which will give you plenty of speed without having to upgrade your esc.

 

[Eugene king]

Both those suppo motors world be good. The 2208 is very similar to my dynam A21 (2306) at 13a max current it is happy spinning a 9*5 prop on 3cells.

This is what I use for my small motor.

http://www.hobbypartz.com/60p-dy-1006.html

This is in my biggy motor power pod with dynam 40a esc

http://www.hobbypartz.com/86ma71-2215-1300kv.html

 

[sidneylopsides]

Thanks for the replies. I'll probably want to order from Hobbyking UK warehouse or maybe Giantshark, motors still don't make much sense to me. I'm 500 and 1000mAh 3S packs on this and the Delta.

I have a Turnigy Park300 Brushless Outrunner 1380kv unused, but I do't know if it would be any different to the one I already have fitted, but I have noticed there is a Park 450 one on HK that seems similar to the Suppo 2212.

 

[Eugene king]

I usually go by max amps and KV rating. because you can have two similar motors stator wise (width too) and one will be rated 7a max and one will be 13a max. their are a few PDF files if you Google around the subject of selecting a motor that have exelent info on motor selection.

also look at some sites you order motors from......they will recomend the prop size, as well as some will show thrust and max amp draw for a given motor. I've found the higher the KV the smaller the prop. the Lower the KV the bigger the prop. Also max amps come into play along with the KV rating to see how well it would respond to a larger prop without over heating the motor.

An axample is my A21 Dynam motor. its stator is 23*6 and hobbypartz recomends a 8*4 prop. but that motor comes standard in a few Dynam planes with a 9*5 prop...............other then that searching fourms (google is your friend) for the specific motor your looking at buying and seeing what others have done, measured, experianced with it.

Also pay attention to repair parts for whatever motor you chose. it sucks buying a motor and braking a shaft and not being able to find a replacement shaft for it........requireing you to buy another motor. I experienced this with my A21. but lucked out and found some info on some RC fourms and purchased a few spare prop shafts...........I really like this motor and now have 3 shafts for a prop saver, and 2 threaded shafts.

I use a 850mah with my A21 motor and can fly the Bloody at least 10min at half throttle. I also have a low voltage monitor pluggen into the battery and when it beeps I land it. With a 1800mah battery at half throttle the bloody will fly well over 20 min. And with it still being low 40's in my area the 850 battery is around the length of time until my fingers are cold and im ready to land anyway.

 

[RC-Flyer63]

Hello, I have been lurking here in the background for a few months now and I have been following all the build episodes and now have several planes built up and ready but only just recently got to get out and fly. Anyhow the Bloody Wonder was my first one out and I had a couple of minor problems so I came back and read all your post to see what others had experienced. In my oppinion this does need some down thrust on the motor I saw where several people kept moving their CG around to get it to fly more level even the young man in the video thought his plane was tail heavy because he needed to trim the tail down. My Wonder needed alot of down elevator for level flight even though it balanced just a bit nose down at the advertised CG and after inputing the needed trim when I cut power to land it dropped its nose instantly so that tells me that the down elevator was the cause, anyhow I am going to add some downthrust and see if I can do away with the trim. I will let you know of my findings, btw I am flying this with the 24gram Hextronik, 8*4 APC type prop, and an 850 3cell, I tried a 2 cell and found it to be a bit underpowered.

I have been out of the hobby for about 7 years and had been thinking of getting back into it when I found the Flite Test websight watched a couple of vids and I was again hooked. I never was one to scratch build but I now have 7 new planes and have enjoyed building every one of them. I never would have thought, 7 years ago, that foam and cardboard would have made a good plane but I now stand corrected and electrics have come along way in my absence and alot cheaper.

Well anyway glad to meet you all and I am sure I wil be posting other things in the future.

 

[Eugene king]

My brother and I flew as kids. 14 to 16 or so. Back in the early 80's using our lawn cutting money. At 16 cars were more important and we couldn't afford both.

My brother bought me a hobby zone champ for my birthday. I've been hooked ever since.

Edit: I have two strips of the clear plastic blister pack packaging as shims for down thrust on the A21 power pod. I've enjoyed flying that setup so much I haven't brought myself to putting the big 2215 1300kv exceed rocket power pod in. That motor is so heavy I doubt I'll be able to balance it with the battery inside. It's been in other bloody wonders I built. And I'll be putting down thrust on it as well.

 

[disq]

Anybody flying one of these with a DT700 motor? I wonder if it would behave weirdly with a 8x4 and DT700, or should I try it with the 11x4.7? (it would be huge though)

Keep in mind that my current setup with TGY Park300 and 460mah battery is 561 grams (bad foam, discussion/figures two pages back) so it's a lot heavier than your standard BW. (Would be heavier with this motor and a 1000mah zippy, of course)

The thing is I have this spare tricopter motor staring at me, the tricopter frame's not here yet, and I want to try something new...


A few forum threads later... I don't think this will perform better than the Park300 with a 8x4 prop. So, let's wait for the NTM 28-26 to get here, which will be next week hopefully.

 

[disq]

Well, turns out I was wrong. It's a beast with the DT700 and 11x4.7. Struggles to take off with the 28-26 (and 8x4E)

Still couldn't maiden, since it's been crazy windy out here past few days. Waiting for calmer weather