BJ- Simple Screamer

[BanditJacksRC]

oh man that is too cool.. that looks awesome man. what do you think of the build so far? its different that what I'm used to. Anyways I would love to try that mount on my next build!
Have you started the wings yet? I didn't take many pics of the spar or anything, but will PM you an explination on how it was done.

 

[KrisRoberts1121]

Thanks Bandit! Love the build so far. I'm not used to having a lot of bevels, but the fuselage was very self explanatory once you start folding it together. I have not started on the wings yet, I might transfer the plans and cut them out tonight, but i noticed there are no spar holes in the wing, so I am unsure where to place the spar. Would you be able to draw up how you placed the aluminum spar in with the foam spar? Also did you cut into the aluminum like NerdNic does? If so, what are the measurements for the cuts in the aluminum spar?

Also, where did you find was the best CG location?

I will print you a camera mount. It shouldn't be more than a few dollars to ship you one.

I'll be heading to work shortly....Man I just want to build!!

 

[BanditJacksRC]

Haha I feel ya! I'm at work right now. I did the aluminum spar just a lot like the spar nerdnic does on the nnMig3.
I know I took notes on a few measurments while I was building, but for the most part I just "winged it".

After making all my bevels and scores, to get an idea of where the spar will go - I folded over the wing so the top is parrellel to the bottom (without being to tall) and figured a 1/2" gap is perfect between the bottom and top foil parts (parrellel to one another).. Then marked where the center would be on the bottom plate (for spar).
I then taped together the 2 halves with extreme packing tape then glued (becuase there is no dihedral in the middle of wing both the top and bottom can be glued).
The spar is the 3' long X 1/2"tall X 1/8" thick purchaed at lowe's. I just marked the center (18") and placed it where you make the mark when I folded the wing over to get an idea of where it needs to go. with the spar centered put marks on each side where the dihedral will be. (i think it was 17 1/2" or something like that *not 100% sure on that!*).
Then you do the same thing as the nn designs. Cut with hack saw halfway down (1/4") and bend upward, for both sides!

I did not dig away any foam to place the spar and what I did instead was cut 1/2" strips of foam and glue on both sided of spar.




I was planning on another full build and will start with the wings tonight. I will be taking a bunch of pics (and documenting measurments) to create the build instructions. and will send you some right away to help you out.

 

[iwlf]

Looks good! Put a couple simple sponsons on the wings and you have an amphibian!

 

[BanditJacksRC]

Looks good! Put a couple simple sponsons on the wings and you have an amphibian!

or you could minwax the belly with a couple skies on the wings/tail for the snow days... although I don't get many here in AZ. lol. don't hate me everyone, I know the NE is cold as hell right now.. but Ill be suffering from heat strokes in the summer! haha

 

[KrisRoberts1121]

Yea, Central NY sucks right now. We have too much snow. I took my Bloody Wonder MKIII out about two weeks ago, and it wanted to play in the snow(Nose dive, completely engulfing the plane. No damage at all). I had to walk about 100 yards through 2.5 feet of snow to recover it... My LAST day flying in the snow...lol

 

[KrisRoberts1121]

Bandit, I was thinking... Since we might have to glue in the camera mount, It might be a good idea to make a cut through the fuselage just behind the mount and make it with a removable nose. Kind of like the FT Guinea Pig. Maybe with a long tray in the nose for the battery that slots into the fuselage? The nose cone could then be held in place by a few rubber bands and BBQ skewers.

What battery were you using? I plan on using a 3530 motor, 9x6 prop and a 4000mAh battery.

 

[BanditJacksRC]

Yeah not a bad idea at all.. I like it. I will have to play around with that idea on build2.
I am using the Suppo 425 equiv. and a 3s 2200mAh. - although the 4000mAh I'm sure would work a LOT better for getting the CG right. With my 2200 all the way up front ( i mean all they way) it was still tail heavy and I actually added weight to the nose (like 20g or something).

 

[KrisRoberts1121]

Cool. I'm going to figure out where would be the best place to make the cut. I might need to slice an inch or two off the powerpod, but that's no big deal. I'll take some measurements when I figure it out and report back.

I think in the final plans, it might be a good idea to make the fuselage bottom and top all one piece for a little more durability and alignment if we make a removable nose cone.

 

[BanditJacksRC]

That might be a bit tricky with all the beveling! lol but def. possible.
I'm thinking before I start the build for the second beta. I will see what I can design for a removeable nose and battery tray with the one I have now, then fly it through some real tough aerial tests to find any weak spots. I'm thinking something in the tail will show its weaknesses before anywhere on the fuse/nose does. - When I was punching the throttle on my flight last weekend I thought I could feel some slight tail flutter.
Although I wasn't pushing it too hard for too long. It might have been due to the prop wash with that prop closer than usual, and due to the pretty large tail feathers. Any thought on if a "T" type elev/rudd might help with that?

 

[KrisRoberts1121]

I'm not too sure if that would help or not. I've never flown any T type tails. My first sight of this plane, I did think the body connecting the fuse to the tail feathers looked a little on the thin side. Maybe the problem lies not in the strength of the tail feathers but in the lower body of the plane. Just a thought. I haven't built the fuselage completely so I'm just guessing it might be torsion.

Edit:

If torsion is the issue, maybe going to a twin boom(using the same awesome design!) would eliminate the fluttering. I used your file you sent me, moved some things around, duplicated the rudder, shortened the moment 4 inches and extended the booms some(not sure how much) The elevator would need adjustment though(I just downloaded sketchup...No skills yet lol). Slanted nose piece on the booms would finish it of nicely.

Here's what I came up with:

 

[BanditJacksRC]

haha! dude that looks awesome! did you upload it into the warehouse?

You would need A LOT more nose weight with that design tho.

 

[BanditJacksRC]

the nose can just be extended as well to help with CG.. When I get some extra time I will play around with that design, I like it!

 

[KrisRoberts1121]

Cool. I'll upload it to the warehouse in about 20 minutes when I get home.

 

[KrisRoberts1121]

Ok, I've uploaded it to the warehouse. Search for simple screamer and it should pop up.

I also just moved the boom in 2" on each side and it looks better that the one I uploaded.

EDIT:
Twin boom beta V2. Moved booms inward 2" and slanted the front of the booms 3", extended fuselage nose 4"(I really like how this design looks like a beak, and the fpv mount looks great in it.) and created an estimated fuselage cut for a removable "beak" for battery placement.

Update picture:

 

[BanditJacksRC]

UPDATE:
I have been out of foam and pretty busy the past couple days so I didn't get to do much more on this project. I went to the local DT and bought an entire box of foam board, so I *should* be good for a little while.
I have redesigned a few things and will begin the wing assembly tonight.
Here are some pics of the new design:







I felt the wingspan was just way too big for not having the ability to remove it - so now it will have the same polyhedral design, but will only be 44" long.

I have had bad luck in the past with small stabilizers, which is why I initially made these huge to begin with. I have now dialed down the size for both the vertical and horizontal stabilizers and hopefully they will work out okay!

I have also shortened the length of the plane by 4", but only with the "tail boom" type area. The main body of the fuse will remain the same size as before.

I think the double tail idea is a good one, but looks like it would add a tremendous ammt. of tail weight to a design that already needs additional weight ON TOP OF a battery all the way in the nose.

 

[KrisRoberts1121]

Looks good with the shorter wingspan. I abandoned the twin boom idea once I realized how much weight it would add. I haven't gotten any further with the build yet, but I did realize my camera mount tip is right in the view so I'll have to raise the platform up a little.

 

[flyingcow11]

i'm a noob

ware do you find the plans

 

[KrisRoberts1121]

ware do you find the plans

The first post has the V1 plans

 

[BanditJacksRC]

Looks good with the shorter wingspan. I abandoned the twin boom idea once I realized how much weight it would add. I haven't gotten any further with the build yet, but I did realize my camera mount tip is right in the view so I'll have to raise the platform up a little.

Thanks. As Im working on the newer version, I am on the edge about a removeable nose. I want to keep things simple, but the nose hatch I made on V1 isn't all that simple either. I'm pretty sure I am just going to put an access hatch on the side, near the front area.