FT Bloody Wonder - Scratch Build

[BrownEyedFool]

The Wonder is slowly coming together, first ever true scratch build.

Thoughts and observations as I begin to glue in servos.
1- The video direction for the rear piece of the fuselage is very sparse. The sides are supposed to be folded differently than the power pod, but I didn't know that, so mine is two foam thicknesses too narrow. I'm not going to combat the plane so it shouldn't be a major issue, but it wasn't clear at all. The notch out of the foam so it locks in is also completely undefined and almost appears like magic in the video. I did a TLAR on the length of the notch and laid a piece of scrap foam next to it and ran a razor blade along the top of the scrap to get mine kind of right.

2- Will have to transfer the CG location from the plans to a more traditional " x mm from the leading edge" once I'm done, then locate the battery location to hold CG and transfer that inside. Not hanging a battery out in the air on a belly lander.

3- Made a pushrod from thin CF with a z bend glued and shrunk on, it bowed a lot when pushing down elevator. Went to music wire thicker gauge. It still bends some. Will probably both install a guide (might use a spare servo arm hacked up and drilled out) and limit elevator throw in my radio. You shouldn't need 45 deg down elevator on this plane. Actually will try it with throws turned down then install a guide if needed.

4- Thought I had located everything right, but my aileron servo cutout does nick the edge of the spar. So my spar has a notch about 1/8" into the side of it all the way through. Couple minor hiccups on the plane throughout, should still fly.

5- My kingdom for an economical source for Dubro mini ez connectors. best option I see right now is a 12 pack from HeadsUp.

6- I have some control horns floating around, but does anyone have a good source for bulk horns for DollarTree or ModelPlaneFoam type builds? Whether a bag of a dozen plastic ones with glue on backings or a sheet of a dozen in ply to remove from the scorched laser cut.

7- The power pod description has you use strapping tape across the firewall, but the build they actually make doesn't have it. I notice a lot of little variations like that across the videos, which is why my power pod for my Wonder has holes where skewers for landing gear would go.

Fun build, and I'm starting to feel like a real scratch builder, it may fly before New Years. Also need to order about a dozen HXT900 servos or similar, these builds should go faster as I gain clue.


Wish me luck.

 

[MrClean]

1. yea, they are. though the plans and videos are getting better OR we're just getting better at doin it.
2. Made a hatch on the bottom of mine, it was already taped so I just did a control surface cut on the inside and cut the hole way through for the rest of the hatch. Then I hot glued a scrap piece of foamboard and rounded out a finger hole on the hatch. I bought some neodym magnets at Walmart and was going to use a washer instead of the foamboard, the hatch stays closed so far so no need.
3. If you haven't seen the zip tie trick yet, you close an electrical wiring, nylon zip tie around the wire, snip off enough tail to cover the distance from pushrod to fuse plus thickness of the fuse and punch it through the fuse then pull it out and put a drop of hot glue in the hole, reinsert. The Zip tie becomes your pushrod guide. They're cheap and effective and don't look bad at all.
4. probably still more then enough strength. Mine doesn't way anything at all. My biggest mistake was cutting the firewall dowels flush. Now I worry I'll sneeze, pull a 2 foot loop and the fuse will detach. Leave a little extra on them dowels.
5. No joke. My hobby shop is starting to put them behind the counter when I come in.
6. Popsickle sticks man. The average 4 dollar, 300 stick box has more control horns in it then you can use in a life time. Last one I got was on the clearance table for a dollar and it lasted me 10 years of epoxy stirring.
7. I thought the wonder was the first plane I made and it did have the strapping tape mod. Not bother easy to add and does streghten everything. I dont' know about swappable though. I haven't made any two of these pods the same. My printer doesn't seem to print exact and I certainly don't cut that way either. But with practice things get better. Good side is, they still fly pretty good regardless of not being 100% plumb.

I have paint on my Baby Blender downstairs though I have to paint the tops of the wings tomorrow. I've had better luck with my tape this time. Make sure your shirt is clean and then using low tach blue tape, pull off a length and put it on your shirt once or twice till it detachs a bit, then put it on. I painted and waited an hour and the tape came off without pulling paper. Better then my Bloody Wonder, it looks like a high school kid with zits. Still flys good. The wrapping paper on Bubbles the Old Fogey looks good, give that option a thought with all this xmas paper not quite yet stored.

 

[Eugene king]

I too folded the rear portion of the fuselage incorrectly. I also noticed that the paper started to pucker just after it ended. Like the elevator was flexing. So I cut another small piece and extended it all the way back.

 

[Bolvon72]

Decided to liven up my Sunday afternoon by taking the Wonder out for a little fun. Okay, it was a lot of fun. Running the Suppo 1450kv with a 1800MaH 2S battery on an 8X4. Will be upgrading it in both areas once my next order comes in. I don't think there's much that will make this girl fall out of the sky. Lovin' it.

 

[Eugene king]

Bravo. Bravo. Bravo. You need to upload that to YouTube so I can send the link to some friends.

These two pictures are the small dynam A21 motor power pod finding where to place everything to put the 850 battery pack inside the power pod.

 

[Bolvon72]

Looks good, I should put the battery inside as well. I cut the part out of the video where, from excessive banking, the battery came off the velcro and knocked a wheel off. You might notice the wheels magically disappear in the video. I use Josh's idea of using hot glue as a wheel collar but I've had 3 wheels come off as a result. I'm sure it works well for good pilots like him, but for rough landing amateurs like me I should just bend the wire up.

PS: Its already on YouTube, it was linked in above. Thanks for the compliment. You made this rookie feel good.

 

[Eugene king]

For some reason I couldn't share it. I thought it was through YouTube but the share feature wasn't poping up when I tapped the screen.

Liked the sound of the music too. Couldn't understand it, but liked it.

My big 2215 motor power pod I must have the battery's outside.

 

[MrClean]

Youtube upgraded to make things 'easier'. Now to share you right click on the video and pick the option you wish to use. I know this but still spend a couple moments looking for the easy Share button.

 

[BrownEyedFool]

Where are you guys putting the CG? Transferring the marks from the plans to the wings I'm getting about 70mm back from the leading edge, which I have to move the lipo back pretty far, almost to where that top piece of fuselage (that I made too narrow) fits in to get the CG that far back. Was made interesting fitting everything inside because my motor-esc leads are rigid for over an inch in length across the 2mm bullets, guess I tinned a bit much. Fitting the long antenna of the ar600 inside also necessitated running it next to the battery, not sure I like that.

My plane is now done and together except for installing velcro and configuring throws and any reversals in my DX7s. Looks like I have some differential built in to the ailerons, they go up much more sharply than they do down, wonder if that's the 45 degree bevel causing that. Control horns about 1/4" from the inner edge of the aileron, pushrod holes over the hinge line, and the horn lined up linear with the pushrod when the servo is centered.

Any recommends on how far down to dial throws for low and high rates? probably run 20-30% expo throughout.

I've found a number of spots where things aren't as square or clean as I'd like, but it should fly. Don't know when the snow on ground will let me maiden, will have to see.

 

[Eugene king]

With the little motor this is my layout.

 

[Bolvon72]

Where are you guys putting the CG?

70mm is where mine sits.

As for throws, with my push rods linked medium on both the horns and servo arms I run high 100 low 75 with 30% expo all around. I'm pretty comfortable with that setup.

 

[dugmar]

Love this plane, it rips with this set up. I replaced all control surfaces with pin hinges and it reacts much better now, crisp and fast. Strongly recommend this $2.00 mod.

 

[eagle4]

I'm looking at getting started on building this (my hardware is in the mail) I've noticed that there are no dimensions on the plans, also that the rear section of the fuselage doesnt have the notch cut out of it like in the video. Is this something that we can just wing? or can the plans get updated by someone who knows what they are doing (its my first scratchbuild, so i really dont know what i'm doing lol)

 

[MrClean]

I have on the bottom of the wing ailerons as 2" full span.
wing chords are
tip 4"
root 9" from le to section that tapes to tail.
spar 1.5 from le half inch spar
span 28 "
with those dimensions you should be able to figure the others equives from the plans. my wing is of course folded up so I can't give you an accurate measurement.

Make the inner tail piece longer then the plans. Make it to fit snug on the inside of your swappable fuse both in width and height. Then make the plane portion of the fuse to fit snug on the outside. Then slide it into position so that your rear bamboo skewer goes through all three sections give it a good half inch to inch overlay. Mark where the step should be and cut it in.

I think the assumption is that if you print the plans with adobe you'll just copy the plans to the board and Voila your done. Problem is my printer does not always give me a square plan and measurements would save on a bunch of paper for square designs such as this. The Baby Blender has dimensions so that's cool. Now, if you take the file up to a kinkos they can print it for you solid and to scale, which means you can blow it up too if you choose. That's more money in plans then in plane though.

Make the control horns large, you don't need a lot of throw.

 

[Eugene king]

I thought in the assembly video he mentioned where to put the lines on the board??????

I will put my little keychain camera on it for next flight with the A21 motor. The 2215 rocket motor from hobbypartz is a beast......I have the motor shimmed down and to the right and its still out of control above 1/2 throttle........The motor torque wants to make it twist with the 9*6 prop its a little better with the 8*6......

With the A21 motorswinging a 8*4.3 prop and the Turnigy Nano 850 battery I can go full throttle holding the wing and let go and it goes strait up for about 5 feet then starts leveling off.

 

[BrownEyedFool]

He does mention the measurements going down the side of the foam board to make the wing, so you can mark both sides of the board and connect the dots. Take note that Josh basically freehands in the aileron cuts after folding the wing rather than following the exact plans. My first wing I followed the exact plans but messed it up later, the second one I freehanded similar to Josh, and when it came time to connect the horizontal tail section to the main wing the widths didn't match up, I had to trim the tail very slightly to match. Personally I laid the plans on my board and used a pin to pokes holes and locate lines

The inner tail piece is not heavily documented, the biggest advice I can give is when you fold it into the channel shape. Instead of bringing the side pieces up on top of the bottom piece, push them down so they sit next to the bottom piece and are glued to the side of the bottom piece where you removed foam. This makes the inner piece wider and you should end up with a gap between the fuselage and the inner piece on both sides just wide enough to friction fit the swappable power pod in. It doesn't look to be critical if you do it the other way, mine is that way (but hasn't maidened yet), the skewer that locks the rear together provides plenty of strength.

The notch in the inner fuse piece I eyeballed the length. For cutting the notch out of each side I put it on the table and laid a piece of scrap foam next to it, laid my razor blade on the scrap foam and made my cut. Easy way to get that fit that Josh talks about being so important in the video.

 

[Eugene king]

http://www.youtube.com/watch?v=CSnukBeIsLI

may it rest in piece.................not repairable this time.

Now I get to make another and not make the same mistakes I made on the first one. While set up I may as well make two.........its only another 2 dollars..........

Dugmar, what motor and prop combo are you using?

 

[Bolvon72]

Dugmar, what motor and prop combo are you using?

It is in his youtube description.

 

[Eugene king]

Ok I'll look at it.

 

[Eugene king]

He's got the motor recommended / used in the hobbypartz video. I have the 1300kv version of the same motor besides the A21 dynam motor.