Dominator KFm3 wing, Beta release

BATTLEAXE

Legendary member
Can't wait to see how your build turns out and if you mod it any! Your builds are always so clean
I will be ironing the edges, maybe build an easy pod to remove the electronics, and maybe if there is room, installing a box spar between the wing halves to strengthen the center inside the fuse. Where do the doublers for the fuse pod go?
 

whackflyer

Master member
The pics I quoted are just to help visualize. The theory is that having at flat spot on the wingtip creates equal drag on each side which in turn creates yaw stability. If I was you I would build it the standard way and just mark the lines so you can cut them later if you want. I have flown it that way and it flies fine, but I don't know if you would like it or not, so maybe wait till your about done with it and then try that theory. The doublers are so a mini power pod fits because the electronics pod is 10mm wider then a mini pod.
 

BATTLEAXE

Legendary member
The pics I quoted are just to help visualize. The theory is that having at flat spot on the wingtip creates equal drag on each side which in turn creates yaw stability. If I was you I would build it the standard way and just mark the lines so you can cut them later if you want. I have flown it that way and it flies fine, but I don't know if you would like it or not, so maybe wait till your about done with it and then try that theory. The doublers are so a mini power pod fits because the electronics pod is 10mm wider then a mini pod.
Ok cool thanks
 

whackflyer

Master member
I will be ironing the edges, maybe build an easy pod to remove the electronics, and maybe if there is room, installing a box spar between the wing halves to strengthen the center inside the fuse. Where do the doublers for the fuse pod go?
That's probably a good idea to put a stronger spar in if you're scaling to 130 with a big motor.
 

danskis

Master member
What size/rpm is this Flite Test Power Pack F you speak of?
Did you use hot glue on the layers?
For me, putting some dimensions on the plans would help. I would be easier than tile-ing them in acrobat reader and creating templates.
 

BATTLEAXE

Legendary member
What size/rpm is this Flite Test Power Pack F you speak of?
Did you use hot glue on the layers?
For me, putting some dimensions on the plans would help. I would be easier than tile-ing them in acrobat reader and creating templates.
Acrobat Reader timing is the way I do it. Scaling is easy and it turns out to be more accurate to cut and tape I find
 

BATTLEAXE

Legendary member
Look familiar...
20200123_015829.jpg

Scaled up at 130% it gave the prop pocket a width of 9.1" I originally wanted to use just an 8" prop which would have given me lots of room. But looking at it once the plans were taped together I thought the option of using a 9" might be possible, so I angled the insides out a bit to give a little more clearance.

The way I have this marked out from the plans the elevons will be cut out and bevelled from the top, is this how you do it or do you bevel from the bottom?
 

BATTLEAXE

Legendary member
I bevel so it's on the bottom side of the plate, facing down. Looks great!
Here is what I have so far...
20200123_154958.jpg

I am trying to decide how to do the front cover to make it an access hatch for the battery. If you look closely under the nose there is a paint stirrer glued to the bottom the full length of the fuse to double up as a bumper and to reinforce the Velcro battery strap. I was gonna try to do a full length pod but the more FB I put in there the less room there is for the electronics, especially since I was thinking of recessing the motor into the fuse some instead of hanging it directly off the back to help with the CG. Thoughts?

Oh and I just cut the elevon bevels on top, smooth's out the bottom for landings...
 

whackflyer

Master member
You could just do the front curve and then cut it off where it gets flat on top. Saves your the hassle of having to hinge a hatch. It also is beneficial if your battery is too tall and the layer of foam that would be the hatch would contact it. It would fly fine the way it is, but you may want some cushion between your battery and the ground in the event of a crash🤣. As far as the motor goes you may want it in the fuse for cg, but that may leave you cramped on space. Just lightly tape or fasten it to the plane in the general area you're thinking of putting it, then take your battery and see if it balances there. If not make necessary adjustments. Hope that all makes sense. Also make sure that your control surface travels (most importantly elevator) are equal before maiden.
 
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BATTLEAXE

Legendary member
You could just do the front curve and then cut it off where it gets flat on top. Saves your the hassle of having to hinge a hatch. It also is beneficial if your battery is too tall and the layer of foam that would be the hatch would contact it.
So you are saying to leave the top open?
As far as the motor goes you may want it in the fuse for cg, but that may leave you cramped on space. Just lightly tape or fasten it to the plane in the general area you're thinking of putting it, then take your battery and see if it balances there.
That's done already, all the electronics are in and I could program it now and it balances a little nose heavy but I still have winglets to do. Now with your trimmed wingtips it's just about drag for yaw stability right? Full scale wings like the B2 bomber uses split flaps on the wing tips to achieve this, adjustable of course. What if I did something similar like what looks like leaned back vortex generators from the LE on the tips to hold yaw straight, but fixed and stationary. I want to save all the weight I can behind the CG. Mind you trimming the corners of the tips adds no weight at all, takes it away actually :unsure: And you say it works just as good huh
 

whackflyer

Master member
If you're slightly nose heavy now, two small pieces of FB behind the cg shouldnt matter that much. I would do the regular wingtips and then once you've flown it like that and feel game to try the other options go ahead. Yes, the trimmed wingtips act purely on drag. As far as the top, I would leave it open, just form a piece of fb around the curved front part so the front of the battery isn't catching wind.
 

whackflyer

Master member
If it ends up being a little tail heavy with the wingtips I wouldn't hesitate to trim them down smaller. In fact I built one for my brother, he crashed it and broke one tip almost off, so we just ripped it off. It flew fine with just one tip. If or when you end up omitting the tips, be careful on launch. Since there's no vertical stabs, at slow speeds it will be somewhat unstable and want to torque roll.
 

Hai-Lee

Old and Bold RC PILOT
Just a heads up! you can fit a small central vertical fin and attach short streamers to the wing tips for drag induced yaw stability. Just make sure that you fit one on each wingtip or you could find yourself flying in circles.

Have fun!
 

BATTLEAXE

Legendary member
If it ends up being a little tail heavy with the wingtips I wouldn't hesitate to trim them down smaller. In fact I built one for my brother, he crashed it and broke one tip almost off, so we just ripped it off. It flew fine with just one tip. If or when you end up omitting the tips, be careful on launch. Since there's no vertical stabs, at slow speeds it will be somewhat unstable and want to torque roll.
One more Question... any reflex?