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-   -   MonoProp EasyVTOL Prototype (https://www.wattflyer.com/forums/showthread.php?t=80493)

VAALLEON 11-30-2019 08:30 PM

MonoProp EasyVTOL Prototype
I have started this EasyVTOL project about one year ago to harness the lift from high attack angle wings, on an easy to control VTOL setup. The project started as EDF and I have put the link to that thread, showing the last successful videos of the EDF unit (https://www.wattflyer.com/forums/showthread.php?t=79779). Even though I was able to extend the flight time significantly via transitioning to horizontal flight, EDFs are by definition inefficient compared to props and the best flight time that I will get will be around 8 minutes. This is pretty good for EDFs but I wanted to create unit that lasts longer in the air so I can do longer FPV runs.

Loving how the EDF unit flies, I revised my plans to utilize a large prop in place of the EDF, using the same principles of the EDF unit. Still working progress, but after many failures I was able get a proper stabilized and controllable hover. This last hover test is about 1.1 minute and used approximately 330mah of my 2600mah capacity on board, which gives it a theoretical hover time of +8 minutes, which is pleasantly surprising (almost double the EDF hover time).

I believe I can get the unit a little lighter and improve the air flow to push it a little further, not to mention the newer and higher capacity (and same weight) battery that I will get for it. I believe I will be pushing 10 minutes hover time, which will be quite awesome. With 10 minutes hover time I can probably get +15 minutes horizontal flight.

Now the challenge is to get it to fly horizontally. The unit drops the head too fast, risking to stall. But Havenít really pushed it to see what it can do. That will be coming soon😊

VAALLEON 12-01-2019 03:00 AM

Another short test, getting closer to the full transition.

VAALLEON 12-02-2019 12:48 AM

The effort to achieve horizontal flight capability in progress. Videos of 4 test flights with crashes due to hardware issues. I think I will need to do some aerodynamic changes to go with the tuning. The balance is still not there. After the second flight I took of everything that I believed not to be needed to reduce weight and get a better understanding of the issues.

VAALLEON 12-05-2019 01:22 AM

A better flight. It got into trouble 2 times but other than that it was pretty good. I started with a higher attack angle but after a minute or so switched over to a lower attack angle and got a better result. It is favoring left a little but so I need to re-tune the wings to fix that.

The problems and the solutions that I tried:

- The unit is too slow in transition and thrust vectoring and lift from the wings not in balance. Solutions tried: reduced from surface area, retuned the wings to balance a little better.

- Unit drifting when transitioning, resulting from counter torque from the prop. Solution tried: favored the left wing over the left one to balance.

- Attack angle not stable: I have not resolved this yet but I think I am in the right direction. I added a stabilizer wing to the top and will extend it a little more.

My initial flight time calculation was not correct. This flight used about 1367 MAH and is about 4 minutes. So, with the new battery I will probably break 10 minute level but not sure if it will do 15 minutes. May be if I hand launch, fly really slow and not hover at all…

VAALLEON 12-06-2019 02:40 AM

A muuuuch better flight. Extended the rear stabilizer and a slight tune-up and we are there. This is 3 minutes flight that I used close to 1000mah. Which should give me about 9 minutes max on a full charge. The unit drifts a little bit in different attack angles but I can live with that. Everything works fine. I am almost full roll + a little but of yaw from time to time to keep it on the park. When I apply a little more yaw it makes super tight turns. The neutral hover has a little forward built into it for added hover stability and easier turns. Will get the new battery ready and test the flight time. Interestingly, the unit doesn’t seem to have a significantly longer flight time over the same size EDF unit…. Am I doing something wrong here? Props supposed to be way more efficient. Anyways, happy with the result. Very fun to fly. Time to install the cam.

VAALLEON 12-07-2019 02:20 AM

Re-balanced the wings. A better flight. Ready for the cam.

VAALLEON 12-08-2019 12:53 AM

Below is a new +5 Minutes flight (onboard + ground cam) that used 1950MAH of the 3000MAH on board. I messed up the transition back to horizontal and crash landed the unit. Minor damage. The thrust is significantly lower at the end of the flight which also contributed to unsuccessful landing. I want to test a 3 blade prop to see if I can get some more kick...

Onboard cam:

Ground cam:

VAALLEON 12-11-2019 03:16 AM

I extended the wings and did get a better flight time. This flight is about 4 minutes and used up 1341mah, which points to an estimated flight time of 9 minutes. I did get into trouble once, so need to re-tune some other parameters to accommodate the new wing angle. However, overall good flight and I had enough juice to land. I will see if I can somehow push 10 minutes with some other adjustments. Meanwhile waiting for the 3 blade prop to see if it can give me a little more kick so I have enough juice to land after a 7-8 minute flight.

Don Sims 12-11-2019 11:41 AM

Great flight. The land and roll looks like one of my typical plane landings. :)

VAALLEON 12-13-2019 04:49 AM

Originally Posted by Don Sims (Post 1021928)
Great flight. The land and roll looks like one of my typical plane landings. :)

Thank you sir! Yes, it does fly like a real airplane:) However, it is a completely different concept. I had no idea it would fly like this when I was building it:)

The latest flight after further tuning. The unit is pretty stable. Did a couple of stop and go's to practice the transition. The unit is consistently pointing to a 9 min max flight time. However, that would mean slowly laying it down on the belly at the end of the flight as it wouldn't have enough juice for vertical landing. This this make MonoProp a VTO? lol

I got the 3 blade air screw props. Haven't air tested yet but they sound completely different. I am very curious how the unit will perform with the new prop.

VAALLEON 12-14-2019 04:03 AM

Installed the 3 blade props. Much better sound and less noise, better thrust and the unit felt a little more controllable, except a wobble started when hovering. It is very weird that the prop chance impacted the hover characteristics... I'll need to do PID again to see if I can fix it.

The flight time shows between 8-9 minutes, a little less than 2 blade prop but 3 blade test was promising enough for me to pursue this setup further...

VAALLEON 12-15-2019 02:27 AM

Making the final adjustments. This was a good flight. I think I am transitioning back too fast and the unit is kind of losing it. But I was able to save it with the extra kick from the 3 blade props. One more flight to confirm the setup and test transitioning and I will call this one done.

Don Sims 12-15-2019 12:51 PM

That flight did go well. Nice landing and beautiful sky too.

VAALLEON 12-15-2019 08:31 PM

1 Attachment(s)

Originally Posted by Don Sims (Post 1021954)
That flight did go well. Nice landing and beautiful sky too.

Thank you sir! It was another one of those unreal Arizona sunsets. See the pic from later into the evening.

VAALLEON 12-15-2019 09:48 PM

A pretty strong head wind. It gave me the opportunity to do some descent testing, hover, transition and horizontal flight. The unit handled the wind beautifully. It looks so much like a bird with the active wing control that contributes to the stabilization. To be able to beat the wind I went -2 degrees from last night’s attack angle. I have some close ups and some interesting transitional flight against the wind.

The trick to transition back successfully is to take it slow, and let the unit slow down before going fully vertical.

This will be may last test unless something goes wrong. I will install the FPV cam and see if I can have some fun. The hardware’s useful life is almost fully consumed with all crashes and tests.

I will probably be building a new one with a different wing mechanism.

Thank you!

VAALLEON 01-04-2020 07:11 PM

The final flight of the MonoProp prototype. It’s final because I had technical issues during the last 2 flight where I was practicing FPV. I lost the footage of the first flight (my DVR battery died). So the unit will be retired…

This is the second and the last flight from this morning. I took of with visual to make sure the unit operates properly after yesterday’s crash. I did a quick spin and transitioned to hover to put my goggles on. Then I have a couple of minutes of FPV flight at a higher altitude (as I don’t want to hit trees again). Then I transitioned back successfully (first time with the goggles on) and brought the unit down in hover. At this point I wanted to take a couple of more spins with visual but the unit lost power and crash landed. Unfortunately lost the lipo as it detached and hit the prop (DAMN!!! Brand new lipo…)

With this better battery (Zee is better than Ovionics) I am pretty confident I can FPV for 9 minutes. The unit is very controllable in airplane mode and you don’t really need to think about the controls as you can control it with 3 channels (throttle, pitch and roll). It auto balances, etc… It wobbles a little but this unit was always a little wonky, so I can live with that. The only tricky part, transitioning back to hover, can be achieved successfully with being easy on the stick and taking slow, and adding some throttle to compensate for the additional thrust needed for hover.

Now my buddy @Pysbog got in my mind a sub 250g unit. He thinks that I can make the million with that… lol, just joking:) So, the next MonoProp will be a smaller unit that incorporates all lessons learned with this and the latest watcher unit that I built.

Thank you

VAALLEON 01-18-2020 03:21 AM

Decided to convert the MonoProp to test the autonomous unit with ardupilot. As can be seen in the pic we have lots of cables. The reason for this is that I have an Arduino board at the exit of APM to do the necessary mixings and convert the signals to a format that can fly the MonoProp.

- Re-flashed an old OP GPS unit to work with APM board.

- Arduino board is doing the necessary mixings for the thrust vectoring and the wings. One change is that on this version the wings are opened with the tilt angle instead of pitch input. I am able to reverse the yaw compensation feeding into the wing servos, so I am hoping that this unit will be more capable of handling the tail wind. There is a little bit of jitter caused by the Arduino but not too bad.

- If successful the unit will be fully autonomous, using the awesome autonomous capabilities of Ardupilot.

This is the first test. It didn’t take too long for the unit to tumble but still promising. I thing the thrust vectoring servo ranges are insufficient so I will adjust them via Arduino code and some additional tuning will need to be dome.

VAALLEON 02-02-2020 04:37 AM

Crash compilation for the new sub 250g watcher. Currently the unit is around 300g but It will go below 250g with the new battery. The unit is about to completely give up due to too many crashes during tuning. Last 2 minute of this video is the latest and the best so far. Lots of tuning and fixes. I am hoping that I can complete the tuning on this unit and the next one can be crash free…

VAALLEON 02-03-2020 01:44 AM

Slowly getting it dialed. Much better control on this flight. I will need to build a new one soon as this one is kinda losing it over damage from crashes. It flies really well horizontal. Vertical flight and the transitions are still problematic at this point. Will wait for the new battery before further testing. It is lighter and I believe It will help with the balance.

VAALLEON 02-08-2020 03:03 AM

Many crashes after slowly getting somewhere. I have no idea how the unit is still surviving…

VAALLEON 02-08-2020 10:39 PM

Got it mostly dialed at last. I cannot believe this unit actually survived this many crashes and still flies. Of course the crashes took their toll on the unit and you can see it flutter and shutter… Made some improvements in the configuration and learned a lot. I will do some further testing for fine tuning. This design and configuration will be the base for the autonomous unit.

It was a tough one…Flight time shows to be around 8-9 minutes which is not a bad time for a tiny VTOL unit like this one.

VAALLEON 02-10-2020 02:27 AM

Quite a windy day, great opportunity to test the skills of the little watcher and get some closeup footage of the flight, thrust vectoring and active wing compensation. Amazing little thing started the build journey very rough, not even hovering properly and crashed tens of times. But now it turned out to be the most skilled watcher I have built, which I have learned configuration tricks from which I will use on the bigger units. If you like aeronautics and flight in general you will definitely enjoy this video, especially the close-ups. I changed the attack angle setting multiple times during the flight so some passes have the higher and some have the lower attack angle.

VAALLEON 02-17-2020 10:43 PM

Indoors hover maiden of the bigger Ardupilot unit. Looks pretty well balanced and controllable. Ourtoors is a completely different game and may immediately crash, but this is a good start.

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