RC India

While I wait for some parts for completing the extra build, here is another build completed over the long weekend that passed by;

This is the Mugi flying wing, 1.5 times of the stock measurements

The specs are:

Wingarea: 4 sqft
Motor: BLDC 2212 1200 KV
Prop: 9047 Slowflyer, Pusher
ESC: Flying 30A
Servos: Towerpro 9g
Battery: 3s 2200mah

more pics

final pics coming soon...bicycle spokes used as control rods

Nice but why dont you use a higher kv motor? 1200 kv enough for this pusher?
I am planning for a wing Like this.. Adding the Dimensions will be really helpful...  :) :)

Arun. I'm using a lower kv motor because the prop size is larger (9047) than the stock. If it were a 5.5 or similar, I'd have preferred higher RPM. During the first tests, this pusher was capable of vertical hover at about 70% throttle, and at about the same throttle, the horizontal speed should reach about 65 kmph. I don't plan to use this for any aerobatics, its my first flying wing. This is the calculation I've followed:

70% throttle = 0.7 * 11.1 v = 7.77v
=> RPM = 7.77 * 1200 = 9324 rev/min
=> Speed on a 4.7 inch pitch = 9324 * 4.7 = 43823 inches/min = 3652 ft/min = ~1100 m/min = 1.1km/m = ~66 kmph

given the weight being about 900 g, I am hoping the motor will be sufficient to drive it, but the field tests will define the outcome...

The dimensions are the basic dimensions of the mugi scaled up by 1.5 so its actually 2.25 times the original size. Sorry for the incorrect title. The starting sheet is 1200mm by 600mm... http://www.mugi.co.uk used as reference and all scales upto 1.5 times. I had to mount the servos a little aft than the one in plans but that has been compensated by placing the battery a little forward to balance the cg.

There is one problem I'm currently facing and that is torque rotation when hovering vertically, I don't know how this will be avoided in flight

The thrust may be fine but saving the props while landing is difficult i think.. if we are using smaller props the props damage are less... I am planning for the same with a 2200kv motor with 5-6" folding props... searching for a good plan now..
Let me ask you something flying a wing is harder than flying a normal plane? or vice versa??    :( :( 

This will be my first flying wing, so I cannot do a comparison unless this is airborne. But I feel control and authority are two different things. I feel, while the wing will have lesser authority in certain situations, it probably will be easier to fly. A plane, on the other hand, the authority is greater due to larger and independent control surfaces but the control is harder due to added mixing in the brain rather than the Tx

I think you're correct, landing will surely be difficult with a larger, unfolding prop, I also had in mind to add a trike landing gear to this but chose against it to keep the weight low

I found the mugi was the simplest design, and can be made from a half a sheet of coroplast with a couple of bends here and there :). Another good design is the dazi (based on the zagi). Attached are some PDFs for you.

hi,

recently built a mugi as per plan. have to maiden it yet. will be putting a 2000kv motor on it with a 6x4 prop.

also built a 46size flying wing, undergoing tests. we have clocked speeds of 140kmph till now.

pics below

Both the crafts look very good sire.

I see that in the Mugi, the vert stabs are absolutely vertical whereas the Mugi plans advocate them to be slightly angled. How would that affect the flying characteristics. Please advise.

one final covering strip and its ready to face the world...

Maidened the Mugi today, just flew off while I was still thinking what to do, too fast for a celeron processor to handle.

Arun, you were correct, although vertical lift and horizontal speed were fine, the torque of the 1400KV motor was probably quite a bit and the mugi wanted to flip over. so need to put in a higher KV motor and do more RPMs on a smaller prop.

Rai sir helped launching this. Vertical climb was quick, little elevator and it just swooshed through.

Had two crashes were it came nose down. and it looks still ready to fly :D. I love Coroplast.
Goes back to the board for some corrections and its going to the field again.

Yup, the Mugi was good fun. :thumbsup: A few kinks to be ironed out, and BP raising action will occur  ;D

The Mugi flew today...and it flew kicka** well.

Couldn't have done it without help from Ravi Subramaniam and Sanjay sir, and motivation from everyone on the field. Too bad I didn't get a chance to get a video but here's the lowdown,

1. the aileron throws on the mugi very super high so it was like over sensitive.
2. after multiple crashes one of the ailerons was curved a little. will be fixed
3. frame had a tendency to bulge on full throttle. needs reinforcements. since i was launching it at full throttle, it was behaving voilent.
4.  no reflex in the ailerons at neutral. So stability was less

Corrected all the points and it took off beautifully...

A home I tried charging the battery and realise its taken hell load due to crashes, the battery was squashed...will need replacement...

GS

Bad luck about the battery. This model is very fast and needs great skill to fly. Great, Girish :thumbsup:

Thank you Sanjay sir, couldn't have done it without your support. Still need a lot of hand eye coordination, so to speak.

I examined the battery last evening and though it had taken heavy beating, it did not seemed punctured, just twisted. So I sandwiched it between two sheets of board, lightly hammered from all sides (wearing my bomb diffusing suit...lol) and left it overnight with two bricks on the top, overturning it once during the night. In the morning, the battery looked good, took a 4.20 v charge on all cells. I've now taped it up. Hopefully it should be back to business. :D

Great. I'm sending you some of my bad Lipos

Sent from my GT-S7562 using Tapatalk 2

Anytime chief, bring em on...

Wouldn't want to land up with a twisted battery again. What do you think will help the most, Wrapped up in thermocole or high density foam before I install this again into the mauled Mugi
GS

After the Mugi flew successfully, there have been speculations on what would happen if a little downthrust/upthrust (using a wedge mount) is applied to the motor setup amongst the lot of us on the field. But there was no agreement on whether to give a downthrust or an upthrust and mostly left to the "try and feedback" approach. But I wish to totally understand the concept of thrustlines. I've since been reading this (great stuff by Gusty sir, like always):

http://www.rcindia.org/rc-general-topics/basic-aerodynamics-for-rc-flying/msg58217/#msg58217

So now the question is, in a Mugi the motor seems to be mounted right on the the thrust line and since this is a more or less mid winger, the drag line concedes with the thrust line. The drag thrust coupling hence does not determine the pitch up/down tendency of the craft. So does this craft really need any up/down thrust?

GS

Yes, good question :D

Yes
because it has to balance the Lift Weight couple to some extent, else tail down force will add to something called Trim Drag

Explanation of Trim Drag is the in the thread

if you need more explanation, ask question in that thread quoting this thread so that relevance remains and subsequent gent should benefit

When i come to delhi, i am going to fly your Mugi, looks like a capable bird

Pleasure chief, look forward to see you. I really wish to do one out of 2mm ply sometime when I get better at building stuff... and finish off what I already have on plate. This thing has taken quite some bashing.

Whenever you plan the Bash just keep me in loop... it will be pleasure to see...(if not fly !!)
Gusty boss... I am still in hobby just hibernating ... ultimately i have simulator working and started practicing.
New Job too less time for hobby so simulator is best now a days.

When are you expected in delhi?

God Knows When, but the plans are chalked out, lot of people to meet and catch up

coming to you point of aeroplane being sensitive, you need DR in a high speed aeroplane, in fact if your radio permits 3 point DR & Expo. Will explain why in the Basic Aerodynamics thread. Watch out for Control Force,Effect & Harmony (if i have not already explained there)

Yups chief, my radio has Expo and two point D/Rs on switches, but I think I can also program it to use the POTs for changing the D/R midflight, not sure will check. Alternatively, can program the three point switch as well for D/R so doable.

Will read up the topics you specified...

PS: Saurabh, yours will have as well when you update the fw :D

After about 7-8 successful flights, I got lucky enough to remember, and reminded, that there is a camera in the phone so here comes a very short video of the mugi (thank you sandeeppande). The Mugi nose dived into the ground today because of incorrect pilot input.

http://www.youtube.com/watch?v=hQcHHHFKsJs

It met its fate today, but another ones coming up sometime soon. Love the agility of the craft.

You take an inordinate amount of pleasure in posting your disasters ???