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Jul 24, 2013, 06:36 PM
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awrightbrother's Avatar
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Here is a video in daylight. 4 cell, 2.2AH, 3 blade props, no foam removed. The hatch cover had to be taped down because the 4 cell battery hits the hatch cover.

Tell me what is going on and what I am doing right or wrong?

Here is my take:
It has no problem lifting off at about half throttle. More throttle makes it rise even more. As you can see it was at 4 to 5 feet which means it is not air cushioning like a hovercraft. It is flying like a real UFO.

I think a major part of the problem is a newbie pilot. I did not let it go higher because the area I am flying in is very narrow. House on one side and water on the other. Also every time it started to tilt, I would panic and cut throttle instead of trying to fly it.

Conclusion: Fire the pilot and hire an experienced one and she will fly just fine

UFO 2e (0 min 45 sec)
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Jul 24, 2013, 07:55 PM
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transient's Avatar
Quote:
Originally Posted by awrightbrother
The props were carried over from the B24. They are 6x4x3. I have 6x4x2 APC but I don't have their counter-rotating ones. I have ordered some today.

The 25Krpm is still OK. The 2 bladers are more efficient and should provide more thrust.

I spend several hours today fine tuning the gyros, the throws, etc. On 4 cells with 3 blade props, it does rise several feet on full throttle and could go even more but I kept it low. The problem now is that when it starts to pitch or roll it does not have enough reserve thrust to correct because the throttle is full.

So I think, more thrust and less weight is what we need now.

Fahim
Ok I was under the impression the props were more like 8" or more- so I think you answered your own question, not enough reserve to compensate for the mass. It may be a gyro instability issue, but for now we'll assume all of that is correct.

You have plenty of efflux speed, but not enough volume for that amount of mass, it looks like.

Hate to say but I don't think 4S will help in this situation, and could make things worse potentially.

Without increasing your fan size, weight loss is really the only option. I wonder if you could core out the foam (and a LOT of it I think) wherever you can, probably from the underside. That would seem to be the easiest to cover back up, wouldn't want to see all your work on the topside have to be messed with!
Jul 24, 2013, 09:06 PM
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awrightbrother's Avatar
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Quote:
Originally Posted by transient
Ok I was under the impression the props were more like 8" or more- so I think you answered your own question, not enough reserve to compensate for the mass. It may be a gyro instability issue, but for now we'll assume all of that is correct.

You have plenty of efflux speed, but not enough volume for that amount of mass, it looks like.

Hate to say but I don't think 4S will help in this situation, and could make things worse potentially.

Without increasing your fan size, weight loss is really the only option. I wonder if you could core out the foam (and a LOT of it I think) wherever you can, probably from the underside. That would seem to be the easiest to cover back up, wouldn't want to see all your work on the topside have to be messed with!
3S just did not have enough thrust to climb past the air cushion. So we are stuck at 4S. Higher efficiency props, lower weight, different controller, is the order in which to proceed, I think.
Fahim
Jul 24, 2013, 09:22 PM
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transient's Avatar
Quote:
Originally Posted by awrightbrother
3S just did not have enough thrust to climb past the air cushion. So we are stuck at 4S. Higher efficiency props, lower weight, different controller, is the order in which to proceed, I think.
Fahim
I forgot to say, congrats on the liftoff

Cheers to 4S, keep an eye on motor & esc temps, if they get hot, back down on the pitch, just like you would a plane.

Will be watching!
Jul 29, 2013, 10:25 AM
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awrightbrother's Avatar
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Here is the revised lighter version UFO 2.0

I was able to save about 1 lb of weight just by removing the dead foam
More can be saved in the construction and finish. e.g. instead of using 1/8" ply for the hatch floor, I can use 1/16" ply with a spruce cross brace.

I am confident it can be built between 2.5 to 3 lbs. That's a 25% to 37% saving!!!

Should fly even better than the prototype.

Fahim
Jul 29, 2013, 06:18 PM
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awrightbrother's Avatar
Thread OP
Thank you guys. It has been an exciting project. More time needed to cut the kit because it is a series of complex curves, but easy to build because it is basically a few parts.

I have added a webpage to my website where you can order your very own UFO !!!

http://www.wowplanes.com/product_inf...roducts_id=217

Also, there is a link on that page for the construction manual.

If you order as soon as possible, it will help me estimate how much foam and how many boxes I need to buy.

Happy landings
Fahim
Aug 11, 2013, 05:33 PM
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transient's Avatar
Any updates on flight testing?
Aug 11, 2013, 06:55 PM
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awrightbrother's Avatar
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Quote:
Originally Posted by transient
Any updates on flight testing?
Things have been a liitle hectic at the UFO factory here.
I have the new controller, and I am waiting for the props and motors, then I plan on building the 2.0 version and will post pictures and videos then.
Aug 12, 2013, 07:11 PM
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transient's Avatar
Nice, hope that all goes well

Just saw this, remember I mentioned retracts?

lol it's been done

Slow Retracting Landing Gear for Multirotors (3 min 37 sec)
Aug 18, 2013, 07:37 AM
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awrightbrother's Avatar
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OK guys, my UFO adventure continues with UFO 2.0

I spent a couple of days building 2.0 version and here are some pictures showing the changes compared to 1.0.

Then I took it to the field for the maiden and made a video to follow in the next post.

Fahim
Aug 18, 2013, 08:33 AM
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awrightbrother's Avatar
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OK here is the UFO 2.0 Maiden, but I should explain a little about what you are going to see.

The Naza controller has 3 modes of flight.

1. The Manual Mode:
I have to fly it like a dumb helicopter with only gyro stabilization to help me. I have never flown a helicopter so this was not the mode for me.

2. The Attitude Mode:
In this mode the UFO will maintain the last attitude before the controls are let go, except for the throttle. So if I take off in a level attitude, and only use throttle to rise and descend, it maintains that attitude. But if there is wind, it will drift with the wind and I have to steer it back to me.

3. The GPS Mode:
Here it maintains attitude as above, but also maintains its position in 3D space. So if I take off in level attitude, it will stay level, but rise or descend with throttle. In addition, if I take it up and let go of the throttle, it will use the GPS to maintain its position in 3D space. In other words, it will not drift with wind, or rise, or descend.

I was not going to try the Manual Mode, and I have not figured our how to calibrate the GPS. My problem is the English manual written in Chinese grammer. But I am sure I will figure it out eventually with your help.

So what you are going to see is flight in Attitude Mode only. I started with a 3s, 2.2Ah, 20C battery. The UFO was kinda wimpy and did not have much duration of flight. So I switched to a 3.7AH, 4S, 30C battery and boy what a difference a cell makes. It rises like a rocket and flies more stable.

But there was a 5 mph wind and it would drift away and I had to keep landing it to avoid having to walk a mile to retrieve it. The landings are controlled and very easy. All I had to do was gradually decrease throttle and it would sit down softly.

I could not steer it back to me, because I had set the gyro gains at the recomemnded levels for a quad. Since the UFO shape is somewhat different than a typical quad, I think I need to crank up the gains. But I did not take my laptop to the field, which was a mistake, so I was stuck with the gain settings. There is a way to change gain setting on the fly with a Tx knob, but it also has to be enabled before hand via a PC. I had disabled that too.

The manufacturer's instructions say that gain should be increased 10% at a time until the machine starts to oscillates, then back off the last 10%. So I have my work cut out for the next maiden. Tweak the gains and figure out how to hook up and calibrate the GPS.

But all in all, It was giant leap forward from the 1.0 version and the less sophisticated controller I had used.

I hope you enjoy, and please post your observations and any help you can provide.

Fahim

UFO 2 1st flight NTSC (2 min 52 sec)
Aug 18, 2013, 09:16 AM
Registered User
2 suggestions.

1. If you can keep orientation, add some thrust vectoring blades so you can have forward flight without pitching like a -real- UFO.

2. If you can't keep orientation, then don't. Get a fc that has polar orientation, some people call it cheat mode. Basically regardless of orientation, if you press stick forward, it will pitch away from you. Then you could let it rotate like a -real- UFO and still have control. also drops the requirement of needing counter rotating props
Aug 18, 2013, 09:45 AM
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awrightbrother's Avatar
Thread OP
Quote:
Originally Posted by resago
2 suggestions.

1. If you can keep orientation, add some thrust vectoring blades so you can have forward flight without pitching like a -real- UFO.

2. If you can't keep orientation, then don't. Get a fc that has polar orientation, some people call it cheat mode. Basically regardless of orientation, if you press stick forward, it will pitch away from you. Then you could let it rotate like a -real- UFO and still have control. also drops the requirement of needing counter rotating props
Thank you for your suggestions.
Thrust vectoring will add weight. Pictching like a real UFO is good, because it is more scale, isn't it?

The Naza controller does have a feature called Intelligent Orientation Control (IOC) that works exactly as you have described it.. However, it uses GPS to work and I have not been able to get the GPS right yet. When I do this would be a baby to fly.
Aug 20, 2013, 08:43 AM
Registered User
Followed this build from the beginning, and really happy you get it fly.
Just some suggestion on the Naza GPS, i think it is not that hard to install, DJI has the instruction video on their site and the manual also easy to understand.

Basically just hook up the GPS puck, then set through the assistant (distance between the GPS to the main controller on all three axis x,y,z), then on the field do the calibration (try to find the video on youtube).

Hope you can sort this out.
Aug 20, 2013, 09:06 AM
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awrightbrother's Avatar
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Quote:
Originally Posted by Rc16
Followed this build from the beginning, and really happy you get it fly.
Just some suggestion on the Naza GPS, i think it is not that hard to install, DJI has the instruction video on their site and the manual also easy to understand.

Basically just hook up the GPS puck, then set through the assistant (distance between the GPS to the main controller on all three axis x,y,z), then on the field do the calibration (try to find the video on youtube).

Hope you can sort this out.
Thanks. Yes the installation and calibration is pretty simple. I do think my GPS is defective which is why I am having this much trouble. I am waiting for the vendor to open shop, they are on the West Coast 3 hours behind me.

I think this is the last step, then I should be able to send the UFO in space and abduct a female ET and return her safely back to home.

Meanwhile I can finish the paint job and clean up a few minor esthetics.


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