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Single Fan Thrust Vectoring VTOL Project - MonoPhan

VAALLEON

Active member
#22
I tested the EasyVTOL concept with a unit re-designed for propeller to see how much I can improve the flight time. I was at least hoping to get +10 minutes. It turned out to be a beauty after lots of testing and variations (see thread: https://forum.flitetest.com/index.php?threads/monoprop-easyvtol-prototype.61095/page-3#post-523755), but it didn’t break 10 min limit. The highest estimated flight time that I got was in 8-9 minutes range. This caused a light bulb moment and made me realize that if I need to get a good flight time in horizontal flight 1- I need to reduce the drag caused by the design significantly, 2- Come up with a folding wing design which will avoid continuous heavy load on the servos while the wings are extended or folded (to reduce the energy consumption).



To achieve this, I started building a new EDF unit using what I have learned from the first ever unit that started this thread and the later units. I am using paint stirring sticks from home depot to build the frame:) It smells like pine and I like working with wood again. I had to use some carbon fiber reinforcements to make sure she can survive the test crashes.



Below is the maiden test flight to test the stability and hovering. I have not installed (or designed) the wings yet. But I added some surface areas at the top to balance the unit as it has a very high center of gravity. The unit is stable from the get go but with two major issues: 1- one of the brand new wing servos turned out to be defective, not performing as well as the other, 2- the unit is grossly underpowered with 3S. I need to resolve these issues before moving forward.



I am hoping that I will be able to reduce the drag significantly with this unit and get a better flight time than even the prop unit. One of the other advantages of the unit is that I can test different wing designs as the wood/carbon fifer frame below will support anything.



 

VAALLEON

Active member
#23
The first short hover test is with an old 1300mah and the second test is with an older 2200mah battery. This is not bad. A little more powerful battery of the same weight should do it. The unit tends to drift due to high CG. This should stabilize when the rest or the aerodynamics go in place.



 

VAALLEON

Active member
#24
Maiden with wings installed. Problems: 1- Immediate loss of yaw with the wind hitting from the side. So, my assumption that the new design would help with vertical flight didn't work. I need to work on the settings. 2- The wing compensation is actually destabilizing the unit when there is a strong side wing. 3- This 2 min flight used approximately 1000mah, which points to a not so good flight time.



I will try to: 1- reconfigure the wing compensation to fit the new design. 2- Trim the wings to get the unit speed up a little more to increase the lift.



 

VAALLEON

Active member
#25
Keeping on making further refinements to the design and parameters. This is the best flight so far. But unless something changes significantly the flight time will not be better than the prior units. Not sure what I am missing here. I am open to thoughts and suggestions. Thanks



 

VAALLEON

Active member
#26
Much better handling and very easy to control. One more thing to test is to apply a higher yaw compensation at lower attack angles and/or raise the CG just a little bit to see how it handles. There is a tiny bit of occasional wobble while flying horizontal. But overall great flight and looks like an eagle:)



 

VAALLEON

Active member
#28
I’m really looking forward to seeing the details and theory on this once all the bugs are worked out. And it looks like most of them are at this point,
There is still lots of tests to be done. If I don't get a decent flight time in my eyes this is failed. In the last flight, the wings were extended further than the previous one, which gave me a significantly better estimated flight time. To get a better flight time, I will extend the wings further to the limit which will impact the flight characteristics. I have been thinking about it, how the current control surfaces can handle that, and I think I may have to revise the frame geometry. We will see with the coming tests.

Thanks and happy holidays!
 

mach1 rc

Master member
#29
Much better handling and very easy to control. One more thing to test is to apply a higher yaw compensation at lower attack angles and/or raise the CG just a little bit to see how it handles. There is a tiny bit of occasional wobble while flying horizontal. But overall great flight and looks like an eagle:)



Really cool 👏👏as always 👍
 

VAALLEON

Active member
#32
Ok. Wow, just wow. That's cool. I'd love to see some schematics because it looks complicated, but there's so much you could do with the wing design.
Thanks bud! Still working on fine tuning the design.

Revised the frame geometry and re-tuned for better horizontal stability and got a very good result. Most of this flight was to test the vertical capabilities that I have not really tested before. Not bad. The unit is controllable. Now I need a longer horizontal flight to test the flight time. The major issue is that the unit is under powered. If I improve the fan the weight will go up as well. So, I don’t want to go that route but improve the design to reduce weight.

 

VAALLEON

Active member
#33
AT LAST +10 minute EDF VTOL unit!!! Decided to take it out for a longer flight to test the flight time and good thing I did. It used 1693mah for 5:20 minutes, which puts the estimated flight time approximately to 9.5 minutes. When you account for the marginal efficiency improvement over the take off and landing taking less portion of the overall flight, a longer flight will definitely exceed 10 minutes. This proves the design successful... Now need to build a better and lighter unit of the same concept:)



 

VAALLEON

Active member
#34
This is the new unit that I built to reduce the weight and get a better hover performance. I used balsa, foam board and reduced the carbon fiber usage significantly but still used it for some reinforcements. The unit came out 70g lighter than the previous one. Not bad!



In this flight, the horizontal didn't go very well. The unit kind of dived and didn't fly in a balanced manner. So, I decided to use the remaining battery for a hover test. The unit can sustain a full vertical flight but still feels under powered. The transitions are spectacularly smooth, and the wings create great lift. I need to make some changes and re-tune to get the horizontal flight going. I am hoping to get well over 10 minutes flight time with this new unit.



 

PsyBorg

Wake up! Time to fly!
#35
That LOOKS awesome mate. The clear covered wings where you see the structure as well as the yellow n black colors (STEELERS NATION!!!) It flys super smooth even when going slow.

70g makes a MASSIVE difference on things this small well done.
 

VAALLEON

Active member
#36
That LOOKS awesome mate. The clear covered wings where you see the structure as well as the yellow n black colors (STEELERS NATION!!!) It flys super smooth even when going slow.

70g makes a MASSIVE difference on things this small well done.
Thank you sir! The wing design saved me 10 grams:) I'll re-tune for the horizontal flight and see what it can do. I could do a little more power but this is not really built for more power but a longer flight. Later I may replace the fan with one with a little more kick.

go STEELERS:)
 

VAALLEON

Active member
#39
I'm loving this project. Thanx for the continued sharing. The only thing missing from the outside looking in at this point is a simulated cockpit. Perhaps incase the battery in it?
Thank you sir! That is a good point. I am thinking of something similar. Probably after I get it all tuned up.

I re-built some parts of the unit due to some build errors. Re-tuned the unit and took it out. A much better flight. There is a little wing flutter when hovering and a little bit of wobble in turns. I'll look into these issues. Other than these the unit performed pretty good. I took off from the ground and transitioned back and forth twice and I wasn't very mindful of the energy savings. Still I only used 1760 mah for this 6 min flight. Which puts the estimated flight time to over 10 min for this particular flight. It's time for a 10min flight test and see how much juice gets left in the battery:)



 

VAALLEON

Active member
#40
This is the 10 min flight. Still have some minor issues, with flutter and balance. But overall it was a good flight. Used 90% of the battery, which puts the estimated maximum flight time to 11 minutes. Will make a couple of minor changes and try to strengthen the frame a little bit to avoid resonance.