BendR

David, to be honest, I still haven't checked it. I am going to set it to the stock mugi CG and go from there. Original plans call for 210mm from nose which is right at 8 1/4" actually 8.26 blah blah. I might even try to get it a little further in the nose if I can without adding weight. Running a brush 480can and a NiMH batt it's heavy enough as it is.

I want to get cutting on the Mugi/Zagi/Charger but no can do tonight. Other plans. Maybe tomorrow.

semi_conscious

i think 5S got it right when he called it the "ZuMi".. good job!! thats its name from now on! it definately wouldn't have been created without the fff mugi.. thats for sure

steve - i think i read somewhere about the zagi flapping/fluttering at high speed without being stengthened with spars and tape.. it might not have been a zagi.. but a wing of that shape anyway... so thats why i was wondering what your crash looked like.. sounds like it may have been caused by too limber of wing at too high of speed.. i'm going to build a new one with carbon fiber spars... one crossways and two down the leading edges.. forming a triangle.. then wind up the 400df and let'r rip.. come what may

browndodge

Wow this place has grown quickly! Last time I looked we just started on page 10...
anyway,

Five- My latest plane is a blue foam version of a Superflea. 24'' span and 16'' length.

I mounted a single motor on top. It's a homebuilt cdr motor turning a 6 in prop.

The mount is a sheet of blue foam perpendicular to the wing that turns into a rudder at the back of the plane. The rudder is very effective and makes for some very exciting spins/tumbles. It also flies straight up as far as I can see! My camera is broken or I'd show some pictures.

Semi- I think some spars on a brushless Zagi-type plane are a good idea. I believe the new Zagis that come with brushless motors have spars included.

happy flying to all, hope your weather is warmer and dryer than mine!

five-string

Browndodge, So you have the motor on the front side of your foam mount and the rear of the mount is a working rudder, right? We are talking a mid-mount prop here, right? Gosh, I'd love to see it. Want me to send you a cheapie I-Spy dig camera? I got one of those $20 tiny pocket cameras from Wal-Mart that I don't use anymore. If you want it, pm me your address.

The rudder sounds exciting. The very little experience I have with rudder on a bipe I have is really alot of fun. I'm better at flying without it but when I want to do some fun maneuvers, it adds a whole new axis into the moves you can make the craft do. I can't even imagine what could be accomplished with a little practice.

BendR, whatever you are doing can wait. Start cutting.

How's the ol' back?

semi, seems like you are quickly becoming the R&D dept for the ZuMi. Carbon tiangle frame seems like a good idea.
You work out all the details, then we'll build 'em. Seriously, thanks for sharing your great ideas. I will have a ZuMi in a week or less. That 400DF is calling my name.

BendR

Semi, I made up a set of plans and templates using the same idea for the spars. I pretty much used the original figures you posted and went from there. The template I made is for a 38" wing but I might cut it down a few inches to keep it small and light. I had the same idea of putting one spar across the wing and two on the leading edges. I think it should make the wing nice and rigid. It looks like there are at least three of us that will be flying the ZuMi very soon. I have my calendar marked and counting down the days 'till my motor arrives and the other goodies I ordered. We should be having some interesting flight reports to post soon!

Brownlodge, Sounds like you have an interesting flyer there. I would love to see pics of it and even some vid. I have often thought about how a rudder would do on a wing. I bet it's NUTS!

5s, Had to spend some time with wifey. I have been spending a lot of my "free" time in the hobby room or on the 'puter and I don't want her getting cranky. When wifey aint happy, nobody happy! We spent the evening watching tv and talking. Maybe I can sneak into the hobby room for an hour or two tonight.[8D]
The back comes and goes. I have managed to stay away from doc's magic pills, so that's a good thing.

five-string

BendR, you're a better man than me. I had a disc blow up in my neck a few years ago. I ate Percoset like it was Pez. Ahh, good times. I was kayaking with a blown up disc and did not care. Didn't hurt a bit. Now I have metal plate and screws where the disc used to be. But I have no tolerance for pain when there are good drugs within reach. But then again, there was a time when drugs were a favorite pastime of mine...

I'm thinking of the motor mount I want for my ZuMi. I make my mounts from a 1" wide piece of aluminum angle. What i want to accomplish is being able to ROG from runners (like semi has on the Charger) if I have enough thrust. So, I don't want the prop hitting or near the ground.

1. Does mounting the motor up high on a mount cause a 'nose-down' thrust line?

2. Did Q #1 make any sense at all?

3. Where's my coffee?[sm=tired.gif]

David_McGinnis

Morning all. Spent some of last evening modifying my Mugi. I moved the motor forward about 1 1/2". That allowed me to remove all the lead I had added. I will let you know how much better it flew when the wind let's up here in GA.
Also, I folded up a new wing using Semi's design. Very flat and seemingly strong. I left the film on it so I will definately get a better finish this time. I also tried the strip of packing tape in the leading edge and WOW, what a nice round LE this time. Going to use a BP-21 brushless on this one so I will have plenty of ZOOM. I will try to post a few pics when I get home.
What design are you calling the ZuMi?

browndodge

Five- you are correct, the motor faces forward on the foam mount and the rear is the rudder.

It is pretty wild to fly too! Of course you can leave the rudder stick alone and fly as normal..

I did an inverted flat spin the other day by accident and was so shocked that I cut the throttle and watched the plane fall spinning to the ground.[sm=eek.gif] It dented the nose a little but I just picked it up and flew some more.

This plane is so tough! Of course weighing in under 7 ounces helps a lot too.
Kind of like how a lizard can jump off the roof of a house and run off like nothing happened.

The high mounted motor does cause some down thrust when you accelerate hard with low airspeed. As you gain speed it is much less noticeable. I've gotten used to it and it makes for some exciting outside loops!

the weather looks nice today so maybe I can try that flat spin again...

five-string

C'mon Brown. Quit teasing! Get some pictures. A camera phone (Razrs work great), film camera and scan the images, something!! Do you want this little camera? Free? I'll even pay shipping and include a usb cable to hook it up. I need photos. Can you tell I'm on my fourth cup of coffee?

I don't think I want a mid prop design so I have to rethink the rudder thing.

I think I could implement a single rudder on the back of the vertical stabilizer on the ZuMi. Why would you need to do both? As long as one gets into the airstream enough to deflect some air...

David, the ZuMi is a work in progress, mostly like the Charger semi built a few pages ago. The name is derrived from the cross of a Zagi and a Mugi.

David_McGinnis

Hi all. Well my Mugi build 1 is a goner. With the brushed/geared motor, it just flies like a hippo. Just wallors around even with the motor moved forward, all the lead removed and more elevator throw, it still would not loop. But the good thing is, I put what I have learned into my new Zumi. I will post pics of the finished bird after I do my airbrushing.

five-string

David, that is very nice looking build there. It just HAS to be fast. great job. I am jealous.

I'm anxiously awaitng the flight report. Did you use carbon fiber inside? Is that a bp-21 motor?

BendR

David, Very nice! I also can't wait to hear a flight report. Details, we love details!

Weather looks buggered for the weekend so MAYBE I can get my ZuMi cut and glued.

5S, did you get any cutting done?? I remember you saying something about junking a servo last weekend. Bummer, was it one of the UH ones? I am thinking to go with 81's on the big wing. I don't know if the smaller ones will handle it. I'm thinking not.?.?

David_McGinnis

5s, no carbon fiber. The wing feels stiffer than the Mugi so I think it will be fine. Yes I am going to use a BP-21 and an 8040 GWS prop.

Bender, won't be giving any details today. Rain, sleet, freezing rain, 33 degrees with a high of 37[:'(]. Maybe tomorrow.

I painted it black. I have got to get a better airbrush. Have to clean mine half way thru a bottle of paint. So annoying[:@]

BendR

David, Sleet and snow-DOH! and your in GA!? Sounds like the weather we're getting. They keep changing the forecast here and every hour it gets worse. This morning it was sunny and cold, by noon it was rainy and cold, now it snow and cold. Look outside and there is talk of it getting ugly before we go home today.

What's the WS on your new birdie? 32", 36"?? 8040 prop, that thing should have the thrust to go vertical right into orbit!

five-string

Bendr, The servo I toasted was a generic 9 gram servo. It was on my Stryker and it quit after some of the most aggressive flying I've ever done. Full throttle turns and hard dives into vertical limbs, etc. I have never bought any servo more heavy duty than an HS-55. I may learn what the limits are on these little 9g cheapies. I'm going to go with some UH 9g Hextronics servos for my first ZuMi. We shall see.

David, I run a bp-21 on my Stryker. After initial test flights of the ZuMi, try a prop in the 7x5.5 category on that bp motor with a 3S lipo. A tad less thrust but you should pick up a good amount of speed without going over amp limits.

We patiently await the flight results. Hurry up.

David_McGinnis

5S, took your advice and changed to a GWS 7X6, 7060, prop. My bird is finished so I will just wait for the weather to break. Still sleeting/raining.
As you look at the pics, notice the great detail I went to placing the simulated rivets. Dang, they took forever to get right...[sm=spinnyeyes.gif]

In future builds I will get more detailed in hiding the electronics.

It is almost the exact size of Semi's plans, 37" wingspan. The CG is at about 7 1/2", hope that is about right. The electronics are, BP21 brushless, BP18a ESC, GWS 6N receiver, HS55 servos and a Thunder Power 3s 1320Mah LiPo. My Scouting buddy has my scale right now or I would post a weight. Anyway, here are the pics for your viewing pleasure and be sure to check out the detail on the RIVETS...

browndodge

Hey guys, that ZuMi looks great. I may have to build a small version of it...

anyway I got a cheapie camera from wal mart so here are some cheapie pictures...

(thanks for the offer Five, but I didn't want to wait on the mail, besides the cost of shipping)

BendR

David, Looks great! Especially the rivits. Looking forward to flight report when things thaw out. I heard on the radidio about GA getting freezing rain and closing down all kinds of stuff. EEEWWWWW!! Best bet, stay home, inside, build planes.

Brownlodge, That looks like it is a trip to fly. I bet with all that rudder right behind the prop it will swap ends in a second.

David_McGinnis

Hey Brown, that is one wild looking creature. What motor is that? What is the wingspan?

browndodge

David, I agree the rivets look pretty cool. Did you airbrush those? I haven't tried painting any of that blue foam, seems like paint would eat it. That's why mine is still light blue.

The wingspan is 24''

The motor is a homemade brushless outrunner. I got the stator and winding info from GoBrushless.com. I have access to a shop where I built the rest. Its a 20mm 9 pole stator with 10 turns of 24g wire. It turns the 6x3 really fast and only draws around 5 amps on a 2 cell lipo.

With lots of throw on all surfaces it will just about turn itself inside out.

The weather here is not quite freezing, but lots of cold and rain. I agree its a good time to stay inside and build something.

five-string

David, That looks great. Yes, the rivets, very cool. What color did you paint the bottom?
If it's all black top and bottom, it may be fun to track orientation, but I'm sure you
already know that. Keep the sun at your back for the maiden.

Geez Louise! All this eye candy! Thanks a bunch for the picture effort guys.

Dodge, it sure is nice to finally see the Superflea. That, too is very neat. Very interesting mount. Me likey.
It has to be great fun to get that big ol' rudder into play.

Craft paints from WalMart do an excellent job on the fff. I especially like the Silver Metallic craft paint.
It looks very much like polished aluminum like you might see on a modern airliner. I have the bottom of the
Stryker (BendR-[sm=tongue_smile.gif]) painted silver and the top sprayed yellow and red. They now have most basic colors in
gloss and the Minwax water-based high gloss polyurethane is also available in the regular paint dept of Wally World.
That will make it shine even more and dries in minutes. Some of us think it also helps strengthen the body just a little.

David_McGinnis

[sm=lol.gif][sm=tongue_smile.gif][sm=lol.gif] You guys crack me up... The rivets are the dimples on the foam, when I airbrushed the black, it did not cover the dimples. They are on all of your FFF planes too...

5S, I tried to camo the top with grey, but the paint clogged up my airbrush so badly that I gave up. I then took a brush and just painted the bottom with the grey mess.
So after all that, yesterday I ordered a brand new Paasche VL airbrush and some REAL airbrush paint. I can't wait to be able to do some real painting and throw away that piece of junk I had been using.
Are you using brushes or an airbrush to paint your stuff?

semi_conscious

i gotta admit.. i looked at those pics more than once trying to find "rivets" but only seeing the perforation holes.. of course i say this after the fact so everyone will now just say "sure you did semi.. sure you did" lol

i think i have given up on painting fff all together .. im tired of spending all that time just to see it flake off and look bad.. the 'contact paper' is working really well with graphics printed on my ink jet printer.. i just have to remember to always seal the ink with some clear acrylic or else the ink will smudge with any moisture.

yesterday i ordered some 6 year sign vinyl off ebay.. i got three 10' rolls.. 15" wide for $22.49 after shipping. it's very glossy and adhesive backed.. i have read here on RCU that it can be heat shrunk and goes around compound curves nicely.. i plan to test it on the upcoming ZuMi build.. just waiting for the CF rod to get here to start building


daylight savings time comes early this year.. march 11th!!!!!! i cant wait.. then ill have time to fly after work.. anyone else tired of these cold short days? .. it's +3 degrees right now!

jmupilot

Ok, I have been reading the thread here and just had to build one of these little Deltas. I have it almost finished only a few hrs building time. I'm going to have the cheapie 9gram servos and a 18A brushless ESC, with little a brushless motor i bought off ebay powered by a 3s LiPo battery should GLH. Thinking of a all black Stealth look with a few Red strips for visuals. I'll post some pics as soon as I can.

Pete

.

browndodge

David, you had me fooled with the 'rivets'. I guess I didn't look closely enough, though since I've never painted this foam before I haven't seen what happens to the dimples.

As for the weather, I posted too soon yesterday, about 3:30 the rain turned to sleet and then snowed until after dark. I'm ready for the time change and warmer weather too!

what's up with contact paper and sign vinyl? why not just order some Monokote in whatever color you want? I've used the low temp kind, and the lightweight microlite on white styrofoam and they worked great. Makes styro really tough and they're both really lightweight.

BTW putting the motor up on top really helps with the orientation thing.