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Old Jan 02, 2003, 06:55 PM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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my$0.02...

EFan...the quals are a little lighter than the Hippobatts...about 3/4 oz. The Hippobatts don't have the "chip" and therefore do not "Shut down".....which as you found out can be alarming....and they are capable of more overall amp draw....they both however fly the Bullseye long enough to make wish you'd brought a chaise lounge and a thermos of hot coffee!!!
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Old Jan 03, 2003, 12:05 PM
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Redmond, WA
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Thanks gpw. BTW, I added some removeable landing gear to my BE for indoor ROG/landings. It's quite light (approx 1/4oz) since it is made from cf rod, minimal piano wire, foam wheels and floss. I then took off the foil and film to compensate for the weight - it's b/w 6 3/8 - 6 1/2 oz. Been quite windy here, so I hope to test fly at first chance.

I'll post some pics soon.
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Old Jan 03, 2003, 05:47 PM
gpw
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Efan

really like the idea of a landing gear ,can't wait to see the pics......
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Old Jan 05, 2003, 01:40 AM
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Redmond, WA
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landing gear

Here's a pic of the lg (made from 0.047 piano wire, cf rod, floss, popsicle stick). Piano wire used for the bent portions (y shaped at root and for wheel axles), popsicle stick piece glued to balsa fuse for a strong base. Wire and cf rods tied together with floss and then CA glue to seal it. Floss is looped around the balsa fuse. Align the wheels square with the fuse and then add a drop of CA on the floss+balsa intersection to hold it in place.

First I had the floss going aft only. The BE flew nose high most of the time and I didn't quite get a hang of a good landing approach as it would nose in quickly as I throttled back. This pushed the lg assembly back till the nose hit (the lg would spring back most of the time). IMO, the springly lg and prop saver saved the model from any damage from the not so nice landings. However, a more rigid lg will be needed once I get the hang of this thing. So I added the floss going fore this evening and it won't flex at all now.

Another option is to use cf rods in lieu of the floss - 2 pieces going aft, with floss for the center since the forces on it will predominantly be tensile.
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Old Jan 05, 2003, 02:05 AM
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Redmond, WA
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flight report

First flight report of my elevon BE.

Did some glide tests yesterday in some tall grass (fully loaded). Power off CG was about 0.5" behind front tip of the hole. Light breeze, so I put on the 10x8 prop. Powered flights showed that it liked to fly nose high with a tendency to turn left. It was pretty responsive for turns, didn't have the power to loop, rolls were lethargic and lost a lot of altitude. But it flew!!

Didn't get the time to make any adjustments last evening, and flew it again today at the Rams Indoor fly-in. Being indoors, I used a 10x4.7 prop. Still flew nose high with above CG. I think this is due to the torque, but others thought the CG was too far back. So I tried moving it forward by 1/8" increments until it was at front tip of hole. Hangar was too small for me to try loops/rolls with other CGs w/o any damage, but it still flew nose high and wanted to turn left.

I think I will need to remount the motor at an angle (down and right from the pilots view) to compensate for the torque.

BTW, BullsEye is the right name for it. 2 Gym-E's and 1 TigerMoth nailed me once each with numerous near misses. Glitching causes several unintended landings - mostly saved by springy lg absorbing most of the energy. At the end of it all, just one tear in the foam from a 'hit' and a few small dents to LE. No broken motor mount or prop due to servo arm prop saver.
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Old Jan 05, 2003, 07:23 AM
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indianapolis, indiana
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WHEELS

hello
nice rig electrafan - do i recognize those wheels ?
salvaged off firebird ? looks like you no longer need the prop saver.

jerbear
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Old Jan 05, 2003, 01:18 PM
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Redmond, WA
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No, not Firebird wheels. I used the Dubro 1" Ultra light foam wheels (one can use the lighter GWS wheels too but they don't look as good) held in place with GWS retainers left over from the SlowStick, but the Firebird wheels should do just fine. You may have to use some other gauge wire for axles for them.

Prop saver may not be needed, but it doesn't hurt to have them for those unanticipated 'aggressive' landings.

BTW, the cf rods were free for me. I stopped by a kite store to pick some up and did. But then they also had left over pieces at the counter and I picked up a couple of the right dia. and long enough to use. The rod length on my BE are 7", dia. is about 2mm. Just pick up something that seems rigid enough at that length.
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Old Jan 06, 2003, 08:11 AM
gpw
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E-fan

Here are a few tips to help your Bullseye fly better....I'm using an maxx prod epu-6..."A" motor...with an apc 9x6 park/prop...Hippobatts or Qualcoms....or 8/270nimh which gives you alot more power....I know ,some guys say it'll burn UP the motor faster but I consider that a cheap and acceptable expense for performance....I really think as cute as the landing gear is ...it might be a bit too draggy.... (a simple plastic skid ,cut out of a 2L coke bottle would protect the goodies on landing, with almost no drag)....maybe a single wheel ????
you might sand the wing and rudder edges slightly to round the edges so the air can slip over them more easily...this plane was never designed to be a rocket , just a really simple and easy to build parkflyer( the Bic lighter of parkflyers)
Just a float around plane that was easy to fly and you could fly it in close( my own personal "flying field is 60'x60').....if you want something more aerobatic , build the UP!!!put a GWS twin "A" motor on it and go wild .I do!!! Bullseye is just another JWA experiment in reducing drag at high angles of attack....and it always gets the darnd'est comments at the field....and mine will loop easily!!!!my AUW is 6.5 oz.w/ Hippobatts....Best of all... it didn't cost $60.00 and really doesn't break that easily...good flying ...let me know what you think!!!!

PS....DON"T HANG IT ON THE PROP!!!!!!!!!...all it will do is wallow around and sink!!!this plane needs to fly on the wing and needs sufficient forward speed to fly..get the nose down ,you wouldn't do that to a piper cub eh?........a little down trim should do the trick!!!Once you get sufficient speed ,then you can slow it down to hover etc........if during maneuvers the nose goes UP and it starts to sink ,just give it some down elevator and gain some forward speed so you can climb right out.......
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Old Jan 06, 2003, 10:14 AM
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Redmond, WA
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Re: E-fan

Thanks for the tips gpw.

Quote:
I'm using an maxx prod epu-6..."A" motor...with an apc 9x6 park/prop...Hippobatts or Qualcoms....or 8/270nimh which gives you alot more power....I know ,some guys say it'll burn UP the motor faster but I consider that a cheap and acceptable expense for performance....
Similar except I am using a GWS 10x4.7 prop with the DX-A motor from my Moth. Just picked up a spare EPU-6 that I need to break in. Even tried a 10x8 & 9x7 props - flew a little faster and could take it up higher.

Quote:
I really think as cute as the landing gear is ...it might be a bit too draggy.... (a simple plastic skid ,cut out of a 2L coke bottle would protect the goodies on landing, with almost no drag)....maybe a single wheel ????
I'm sure that the gear is draggy, but shouldn't affect a slowflyer that much. Also, performance was only slightly peppier w/o it. Did I forget to mention that the gear is removeable?

Quote:
you might sand the wing and rudder edges slightly to round the edges so the air can slip over them more easily
It did cross my mind and I might try that later.

Quote:
...this plane was never designed to be a rocket , just a really simple and easy to build parkflyer( the Bic lighter of parkflyers). Just a float around plane that was easy to fly and you could fly it in close( my own personal "flying field is 60'x60')Bullseye is just another JWA experiment in reducing drag at high angles of attack
Exactly. What I did was just an experiment (cheap one at that) to see if one can make a more aerobatic version. I still think mounting the motor at an angle will help. All one needs are a couple of right sized shims to get the angle.

Quote:
.....if you want something more aerobatic , build the UP!!!put a GWS twin "A" motor on it and go wild .I do!!!
I am going to build that next.

Quote:
....and it always gets the darnd'est comments at the field
Sure does. Makes quite a few people stop and comment, many even just land theirs to watch it fly.

Quote:
....and mine will loop easily!!!!my AUW is 6.5 oz.w/ Hippobatts....Best of all... it didn't cost $60.00 and really doesn't break that easily...good flying ...let me know what you think!!!!
Mine will loop better if I build up some airspeed. Still I get about 12-15' dia. loops. What sized loops do you get?

Quote:
PS....DON"T HANG IT ON THE PROP!!!!!!!!!...all it will do is wallow around and sink!!!this plane needs to fly on the wing and needs sufficient forward speed to fly..get the nose down
I found that out. But it's a great way to perform a 3-point landing.

Quote:
Once you get sufficient speed ,then you can slow it down to hover etc........if during maneuvers the nose goes UP and it starts to sink ,just give it some down elevator and gain some forward speed so you can climb right out.......
Thanks, I am doing that already.
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Old Jan 06, 2003, 10:17 AM
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I should add that I am going to make the BE an R/E plane instead of an elevon. I think that will also help it some more.
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Old Jan 07, 2003, 07:23 AM
gpw
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Efan...Thanks ,you're a trooper!!!

You've probably done more testing than I have!!!! mine can do small loops from low altitude , I don't know what size , but pretty tight......did you make your elevons large??? like the UP size??? You'll like the RE version ,real easy flyer...we're working on cutting out even more area in the middle (bigger donut hole) in an effort to reduce drag!!!You're right it's fun to experiment!!! Thanks E-fan!!!
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Old Jan 07, 2003, 12:38 PM
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Redmond, WA
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gpw - did try some down trim to reduce angle of attack - got some airspeed but not much lift. Even with an 8x300 nimh pack.

Elevons are not like the UP. Here's what I did: made the elevons larger than the design by making the outer circle oblong. Basically, I drew the 2 circles (donut), then moved the center point aft by 1" and drew another half circle. This made the outer circle oblong and most of the surface area added was in the elevon. The original hinge point made the elevons too big, so I moved it aft just under 1".

However, the reason I think this will not work well as elevons is because the larger width of the elevon is toward the center. In order to get good response one has to deflect quite a bit which increases drag. Rolling isn't fun. I did consider increasing the hole size but then it compromises lift and wing loading.

If one wanted to pursue this option, IMO one has to move away from the elevons positioned to be in line with the oblong - they should be mounted on opposite sides (like a fish tail). This will move the widest portion of the elevon towards the wing tips and increase response at smaller deflections. Note that the hinge will get more stress and the elevon tip may twist due to stresses beyond a certain speed (but this flies slow enough that it may not be an issue at all and can easily be addressed with a thin strip of balsa or thin cf rod). I think it that the lighter it gets, it's more susceptible to torque and will benefit from a motor mount at the right angle. I was considering abandoning the elevon version, but these thoughts last night has made me reconsider. I'll build another stock R/E version for flying and continue playing with this one some more.
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Old Jan 07, 2003, 02:40 PM
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Aurora Municipal, Illinois, United States
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I'm still waiting for a break in the weather to fly mine. What I have noticed is that I am having a heck of a time achieving a dependable balance point. I marked my locations with tape but it seems that the cg point has to be dead nuts on or it will tip. If I put a little bend in the battery wire and the connector moves a touch for or aft - boom there goes my cg.

Am I putting too much into this? Should I balance slightly nose heavy then let her rip? Is it just me or has anyone else noticed this?
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Old Jan 07, 2003, 06:21 PM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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E-fan

The Bullseye was designed to be a simple ,float around the park plane ...it really doesn't do much except fly stably (as designed)...just a simple fun experiment with 3F....you're right about the shape of the elevons,but that would complicate things beyond this particular design.....I really believe that each plane is designed to fly within certain parameters,and this design is just an easy plane for newbies to cut their teeth on building...and it's great to learn to fly on ,because it's expendable and flys slowly and stably enough for beginners......I really think you'll prefer the UP ...with the twin motor will do everything you want it to......
BULL000... seems like the weather is holding us all UP.....Don't sweat the CG...it's really not that critical..just get close and you'll be OK! ....don't worry, fly happy!!!
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Old Jan 07, 2003, 07:52 PM
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Redmond, WA
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gpw - I understand what you say. I will be building the UP for fun. I may even build a stock BE.

But it's also fun to experiment and I am having a great time doing it. If it doesn't work out, I'm okay with it. Just have to be careful not to break the gear, that's all. Anyway, I'll keep my experiments off this thread.
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