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Sep 01, 2020, 04:56 PM
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cbalgra's Avatar
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Quote:
Originally Posted by JureZ
nice job !


no problem to define the CG here ( grin)
JureZ, I never weighed it or thought about the CG. Just a big pendulum.
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Sep 01, 2020, 05:00 PM
Sokol
JureZ's Avatar
I was joking !
Latest blog entry: Ahi, by Dream-Flight
Sep 01, 2020, 06:08 PM
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cbalgra's Avatar
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OK. Here we go Bob.

I saw you post this morning but was unable to respond, because I couldn't get logged on RCG on my phone , for some reason, and some of us still have to work. Haha.

A little side bar for a moment. I just re-watched the video posted by Bokkinen, and noticed that his rotorcraft had the same turning characteristics as mine did. Required a ton of left rudder to turn left, but virtually no right rudder to turn right. Now I don't feel so bad for not factoring in any torque compensation. Becuase the original flew the same way! With a normal tractor configuration aircraft, most require some right thrust to compensate for torque and P-factor, but this thing looks like it will require LEFT thrust, to compensate for unwanted right turn tendencies.

Back on point now.

1. The Lanier XL_4 VacuPlane has always been on my back burner, but I think all those directional changes in the wing, it would make for an interesting spar. Someday maybe..... With regards to translating that one website. Be sure to hover your mouse an area of text, then right click, then click on "translate to English" . It just worked for me. Hope it does for you.

2. Looks like you figured out that a front view is really unnecessary, since it's a flat sheet. i forgot to tell you that I doubled up the foam for the vertical structure and did remove the paper on all the DTF pieces. The vertical piece was quite flimsy after removing the paper, so a 1/4" square piece of balsa was glued to the front edge, in effort to stiffen it up. ( was still not that stiff after that)

3.The drawing looks real nice. One dimension I see a difference in is the width of the vanes/blades. Mine are actually 5 -1/2" wide. The drawing shows an them inch wider. Everything else looks good.
The vanes/blades are glued directly on center with the carbon rods. Not offset, my origianl drawing did appear to be offset.drawing (See photos below.)

4. Direction of the rotors. They should spin backwards. Or, the top blade coming toward you when standing behind it. To launch it, I gave them both a good spin, and immediately ran forward a few steps to keep the rotors spinning. Unfortunately in my video of the maiden, I forgot to start the camera before I launched it. But was able to start it with 15 yards of launching.

5. Bearings The bearings are CA glued into a hard piece of 1/8" balsa that is then glued to each side of the top, of the vertical piece. I assembled one side of the rotors, on the bench, before sliding it through the bearings ( a very tight fit) , then the opposite side of the rotor was assembled. (refer to pics)

My mind has been busy thinking of different ways to build this thing, and I think I think I may build a 15"X 15" balsa, under 250 gram version next.

I hope I have helped in answering some of your questions.

Brad
Sep 02, 2020, 09:30 AM
Retired CAD guy
birdofplay's Avatar
Thanks for the reply and info.

Sorry I miss read the width dimension on the rotors to be 6.6"
will change to 5.5" in drawings.

So um ...

At 1:45 in this video
Magnus aircraft 11,阿蘇観光牧場、強風、SE 3~5m/s (5 min 48 sec)


The rotors appear to be turning with the tops moving aft !

This was also found ...
Spinny Bird - One Weird R/C Aircraft (13 min 4 sec)

With rotor tops moving aft.
https://www.rcgroups.com/forums/show...us-Effect-Bird

Brad, I may reproduce your version but I really want to try doing one of those
EU planes with powered rotors and NO PROP !
Sep 02, 2020, 10:09 AM
flyin' fool
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Sep 07, 2020, 12:57 PM
Registered User
Very nice, I like how it flies.

This is my plane, I've been working on it for a while. At the moment the corn is still too high and I have not been able to fly version 3. Version 4 "Heavy" is almost finished.

CM2 - Magnus Effect RC Plane (1 min 11 sec)
Sep 08, 2020, 07:04 PM
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cbalgra's Avatar
Thread OP
Thanks Barnstormer. The main reason I built it was, I really liked the attitude at which it flew also. It is so unlike anything else I've seen before. It looked so unnatural. Seemed like a nice challenge to try to replicate it.
Sep 13, 2020, 01:28 PM
Registered User
cbalgra's Avatar
Thread OP
Took the Twin Rotor out for a "spin" this morning. (get it. "spin". I know... sorry)

RC Magnus Affect Twin Rotorcraft 9 13 20 (8 min 19 sec)
Sep 13, 2020, 01:33 PM
Sokol
JureZ's Avatar
looks great ! congrats !


so, it has a rudder channel and a throttle channel, and that's all ? ( besides a great pilot )
Latest blog entry: Ahi, by Dream-Flight
Sep 13, 2020, 01:58 PM
Retired CAD guy
birdofplay's Avatar
great demonstration !

GEEZ ?! is that a smoke cloud in the back ground ?
Last edited by birdofplay; Sep 26, 2020 at 09:12 AM.
Sep 13, 2020, 02:13 PM
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cbalgra's Avatar
Thread OP
That's it ! Rudder-Throttle only.

I recently changed the thrust angle to the left a bit, and it now flies straight, hands off. I think the vertical "fuselage" twists a little under heavy power. If the vertical was stiffer, I think that would have helped. It still is fun watching this thing just "walk" around the field! This morning the thought hit me to add a horizontal surface to it and use it as an elevator to change the angle of attack. I think that by doing so, I may be able to control the forward speed a little. "Power is altitude, pitch is airspeed"

Bob, It's a combination of marine layer and smoke. We are about 30 miles from the Bobcat fire and 70 miles from the El Dorado fire. Winds have been very minimal this past week and combined with the inversion layer, we a getting our share of smoke and light ash. You cannot smell smoke, but the air quality has been pretty poor for the last week.

https://www.airnow.gov/?city=Orange&...CA&country=USA
Sep 13, 2020, 02:44 PM
Retired CAD guy
birdofplay's Avatar
Thanx for info !

That miserable marine Layer was why I never got into Astronomy
while I was out in the NW.
Just about the time the Light got low the marine layer would show up ;>{

It's looking bad up where I used to live in the NW as well.

I was just thinking that a small EDF would allow for easy NO BITE catches !
Sep 13, 2020, 03:17 PM
Registered User
cbalgra's Avatar
Thread OP
Yep. Whole west coast is alight!

Hmmm.... The idea of an EDF sounds interesting, but most of the lift is developed by the prop, angled upward. I think the best combo would be a large diameter, low rpm prop on 2S, to keep the weight down. It feels like, the lower the weight is , the steeper the climb would be. Only problem with that may be having to extend the motor pod further in front of the "fuse", which may have some effects on the pitch of the craft. EDF would sound pretty sweet though!

I think I may try adding an elevator surface next and see if would effect forward speed.
Sep 26, 2020, 12:55 AM
Vacuum Tubes Forever BCT2/BCR3

Thanks


Thanks for the plan drawing.

my mods
strengthened the motor mount with 1/32 plywood
added shims to offset the motor, may have not had the motor square
increased the size of the rudder

need to reinforce the body, cover using glue paper method

fun to fly, had encore requests from the peanut gallery

Magnus 9 24 video (1 min 50 sec)


JohnB
Last edited by jiberk; Sep 26, 2020 at 01:01 AM.
Sep 26, 2020, 07:43 AM
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Thread OP
Jiberk,

Great job on the twin Magnus rotorcraft! It flies exactly like mine. I totally agree with you that the "body" could be reinforced. Mine seems pretty flexible as well. I'm sure paper/glue would stiffen it up considerably.

Good luck with future flights with yours!

I'm heading out the door now to go fly mine.


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