Building another JR SATAN

I like the pattern from the coffee topper, looks cool.

Last night, I decided to try the JR Satan. I went over to my neighbour Jacques' garden. The one with the most hair,that's me!







The plane got airborne, but for a short time. It was in fact quiet unsuccessful.

Lieven

Uh-oh! We don't like hearing that! Grass underfoot. Was it needed? Soft landing?

Hi Doug,

I'll post a thread in Flying Discussions. I have plenty of questions. Apparently I'm good in doing nr 9's. Damage was limited to a broken landing skid.



Lieven

Still looks ok, figure 9's happen....

Ouch.
Those flying wings can be tricky to launch. Did it seem to have a balance problem, or was it just pilot over-control?

Hi Lieven,

As Rusty, is your balance point isn't too far ? The flying wing needs to be really well balanced in the opposite situation, a flying wing is really impossible to control.

Hope this Satan will be back in the air soon.

Rémy

Guys, I don't know what it was. In the last picture I posted, when it is in the air, it seems that the elevator is fully up. So that's probably me doing something wrong. On the other end, from where I'm standing, I cannot see 15 meters further away, what the exact position of the elevator is. It is possible that the lines were not tight. The plane seemed not to gain speed and moved forward under a great angle. The CG is as on the drawing, although Ken once said that the model was kind a twitchy. Also, when hand launching, the lines might not have been straight. Maybe I'll try to make a "Rusty stooge"; as you pull the model out of the math, lines are under tension while starting. I'll try to make it more nose heavy. One loop and a figure 9 was the most I got out of it and it didn't go further than a 1/4 turn.

Before playing with the Satan, I tried the Blue Pants. It was also hand launched. It didn't gain speed, lines were slack and it almost hovered at 45° before making a loop - read 9- and hitting the ground. Only the prop broke.

Lieven

The Enya is a heavy engine for the Satan. This doesn't mean that it won't work. I mentioned early on, wings until they come up to speed can be very twitchy. The launcher should have his hands over the leading edge just wrapping his fingers over it. The nose should be pointed outside the circle and in a graceful forward motion he should just open his hands. Tossing the model is going to result in a roller coaster ride. I would have to ask what size is your flying lines. Having them at 52' center of plane to center of handle is where I would start. You could always shorten a addtional foot if needed. Is your line size .015" ? What prop are you using? You may just need a smaller prop to get the rpm's up a bit which would assist in launch. I wind them up and I use smaller than suggested props. If your suggesting the plane wouldn't loop, it sounds as if it's stalling or it's just too noseheavy. Having a stooge isn't going to assist you in line tension and it could really be catastrophic until you figure out what is going on. The Jr uses a 2" bellcrank which is going to make the controls very fast which could overcontrol the elevator and cause the plane to stall. A taller control horn or a smaller handle spacing may be the solution if the controls are moving too quick.

You do have a little tip weight installed? Just to get things in the air and to increase some line tension during takeoff, tape a nickle to the wing just to try. Too much weight isn'g good either and will causes flopping and hinging on certain maneuvers. But until you sort some of the issues out, I would do the above. When the lines are installed hang the plane like a plumb bob and observe the angle of the plane to the ground. Is the nose pointed towards the ground? Is the nose level to the ground? Just another thing to think about due to the lead out guide exits which may need to be swept back slightly. I never ever go by the prints anymore. Ken

Usually line tension is at a minimum right at release. A little engine offset will help greatly if you have none.

Ron

It's not impossible, just tricky. Instruct your hand launcher to hold it high, make sure he feels tension on the lines, and points the plane slightly UP and Out, and just lets go with no push or toss. Don't use full up or you might loop around and hit him in the butt. It's hard to control until it hist flying speed.

EDIT: Oh I didn't see there was another page of advice before I posted this. So do what Ken said.

Hand/stooge launches are tricky. I have some planes that fly out of the stooge beautifully and others that try and immediately loop. With the loopers I back up to maintain line tension and give full down to keep it pointed up. It's a bit of a dance until it climbs about five feet and builds enough speed to be controllable. Watch the first 30 seconds of this video to see what I'm talking about,
https://www.youtube.com/watch?v=vLP36vMP8z8&feature=youtube_gdata_player

Edit: both of my lil' satans have been VERY bad about looping out of the stooge. It would stand to reason that the Jr. Satan would behave similarly.


Jim

Here's another hilarious example of a loop right out of the stooge. Matt was new yo C/L that day. Check out the wingover when he finally gets it in the air:

https://www.youtube.com/watch?v=0FzPcccyC78

That was on traveling prop day 2012. No we didn't do that flight with the TP, but that was a Mudhen built RR1.

RknRusty wrote:Here's another hilarious example of a loop right out of the stooge. Matt was new yo C/L that day. Check out the wingover when he finally gets it in the air:

https://www.youtube.com/watch?v=0FzPcccyC78

That was on traveling prop day 2012. No we didn't do that flight with the TP, but that was a Mudhen built RR1.

Yep, that's the loop! The Lil' Satan is a whole lotta airplane for a first timer. Surprised that the wingover didn't end straight into the ground!

Jim

Thanks to all for the replies and tips. I read through it a few times to assimilate the info.

The line length is about 51 ft till the centre of the plane. I use .015 wire. At the moment, I use a 9x4 prop. It's a Master Airscrew and when I look at it now, the blades seems to be bend backwards. I have a spare Graupner prop, same size, but it's 10 grams heavier. I'll get an 8x4 and 8x6 prop to get the revs up.

The line spacing at the handle was about 3.5" -8.5cm. I can reduce that to 2.5" - 6cm. I have 15g or 1/2oz of weight in the outer wingtip. I hung the plane on the cables and the nose pointed slightly to the ground. Is it that what it should do? The CG is at 5 cm - 2" from the leading edge. I've got some engine offset. I used a plastic credit-card-thick shim.

Looking at the little videos I still have to post, I think I gave too much up both on the Satan and on the Blue pants. As both planes ended up the same way, It might be a steering fault.

Jim, Rusty, looking at your videos, I see what you mean. I had something similar, just didn't know how to handle it, I guess. It's a great job of Matt getting that Li'l Satan on the right track.

Lieven

Don't feel bad, I don't think anyone But a 14 year old(or younger) could pull that off.

Lieven, a 9x4 is quite a large prop for the Enya.19 even though the instructions probably have that prop as a suggestion. The large prop is going to make needling more difficult and the plane will also turn better using the smaller prop.   I use 8x4's on my .25's on wings. I personally would even consider a wide bladed 7x6. Like a Top Flite woodie. The .19 size engines are somewhat caught between a .15 and a .25. Prop manufacturers don't really do a whole lot for these engines as their popularity was down due to larger size engines.  A APC 8x4 trimmed down to 7.5 would probably serve you far better. This would put you in 2nd gear right off of launch vs 4th gear. Ken

You should be able to hand launch that thing no problem. we have even hand launched .35 size planes that wouldn't take off the grass. The best method I've used is, hold onto the outboard wing with one hand and the fuse with the other hand. Turn the plane up a little an out a little, take a step or two, then just let go. Don't push or toss it. it'll get up there.