V-22 Osprey VTOL from BlitzRCWorks

[JimCR120]

Wow Bryan, sounds like fun every part of the way! I've always had Marines around. I was a Tron in my Navy days, did A school with a handful of Marines in each class. Same thing in Aircrew and SERE. I was fortunate to serve as an instructor with many great guys. Oh and my oldest was an 0341. Thank you for your service.

I got to see the Ospreys flying a lot when I was stationed in Pax. A very distinctive sound compared to regular rotary. It looks like yours might be actually able to land with the props rotated forward. I'll really be eager to see that in action.

Again, thank you for your service. I recognize the threat these days is quite different than decades past.

And again, welcome to the forum.
—Jim

 

[Munk]

We had a pretty steady wind around 12knots which took the full forward ability of the A/C while in helicopter mode to just maintain position. I was happy with the stabilization as far as not tipping over and the speed at which it rotated without making a huge dip to one side or the other but quickly realized it's not a PnP drone. It provides no altitude hold or GPS hold.

I'm looking for help in what it would take to add these two feathers while in helicopter mode. It currently has a 6 channel Rx/Tx with a toggle switch to transition between helicopter/airplane modes. Ideally I would like that toggle switch to turn off Alt/GPS hold and the unused 6th channel to move the nacelle angles allowing me full control from full forward to full up.

I think I missed anyone else answering this so I'll go ahead and throw out a suggestion. Like others said, a programmable transmitter is definitely wanted for this sort of thing.

In addition you might want to look into swapping out the factory flight controller for a programmable flight controller, such as a naze32. I believe most firmware programmers provide a VTOL option for the various setups you can program for (people will mostly program these flight controllers for simple x drones, but they have a wide variety of airframe options). Pixhawk, naze32, and even the old kk2 flight controllers do this to some extent, but messing around with VTOL control is definitely a path less traveled by for many hobbyists, but the results are often really exciting and cool looking projects!

As for how to get altitude/GPS hold, I've had a large amount of luck with setting up a NEO -
6M based GPS system for my multirotors. It's not the world's most accurate system, but it definitely works and provides a cheap and relatively painless way to add basic GPS locking to most Naze32 controlled airframes.

I hope some of this made sense. If you want I can try to clarify on any points you might want to know more about.

Welcome to the forums from another recent forum recruit!
-Dan

 

[F106DeltaDart]

Lots of great info there Munk. Another option that is predominantly used by VTOL projects (even the NASA greased lightning VTOL) is the KK2 flashed with OpenAeroVTOL software: http://www.altitudehobbies.com/kk2.1.5-lcd-flight-controller-openaerovtol-pre-flashed?search=kk2.1.5 I am currently working on an XC-142 VTOL project, and am planning on using that board. I'm not up to date with some of the newer stuff out there, but the KK2 still holds its own with VTOL projects.

 

[Munk]

Definitely agree with what F106DeltaDart said. I believe Peter Sripol's original Guinea Pig VTOL (and a lot of his following VTOL projects) all used the KK2 boards. Those boards are pretty solid from what I hear.

 

[Tabasco2931]

Thanks monk and DeltaDart for the great info. I'll do some research on it as I've never worked with custom flight computers before. Hopefully the motors and props come in next week and I'm able to move onto the next phase. (currently getting spooled up on flitetest's tricopter builds).

For those smarter than I, What would you suggest I tackle next?
A) better servos to smooth our Nacelle operations
b) New flight computer and get it working with the current setup
c) new TX with rheostat controls for the nacelle/6th channel for future GPS/ALT control
$) New Flight Computer and add in the gyro stabs, alt/gps hold right from the start (probably a new controller too) $$

Whatcha all think about this Leopard motor as well

 

[Munk]

New TX is always a good way to go. Especially if you think you're gonna continue with this hobby. I started with Spektrum (great for beginners) and went on to FrSky (which I love for scratch building) and I can definitely speak for both when I say they have a lot of capability for someone looking to stretch out into new areas of flying.

New flight controllers can come later, and FT or RCexplorer tricopters are a fun way to explore them. That's actually how I got hooked on the hobby, and I have the original Windestål tricopter to thank for my inspiration to get into engineering as a profession. KK2s are lovely for in the field troubleshooting, but again, this is all for down the road. Getting a good TX and getting to know it well will definitely expand your horizons in the future.

 

[Tabasco2931]

First Blood, War has been declared
"Don't power up the aircraft inside" They say
"Don't hold onto a powered up aircraft" They say
"Don't carry the A/C under your arm, hang onto the Tx, and use the free hand to open doors" I say

 

[JimCR120]

Wow look at the swipes it took and landed. I suppose those floppy blades just keep going as they hit, flex, and pull through. Good to see you didn't smash it out of anger.

 

[F106DeltaDart]

Ouch! Those props certainly have a nasty bite. As for what order next, I'd go with Munk and recommend a better transmitter. On thing you can do on most modern transmitters is to set a throttle cutoff switch. That way, you can disable throttle completely when you are touching the aircraft. Definitely a good safety measure to prevent this from happening again! I like Spektrum, and love my DX9, but I have no real experience with any of the other brands.

Next, a better tilt servo might be in order, something stronger with better resolution. Maybe something like an HS-85mg. The only potential issue is the spline of the stock servo. It may be different than the hitec servo, so it might not be a plug-n-play fit in the mechanism.

 

[Tabasco2931]

Thanks for the recommendation guys, I went with the DX6 as an intro TX. The 9 was just way too much cash for me starting out. After the new props and better controller I'll see if the nacelles are still having a hard time then go that route. Started my research on servos and am thinking a small stepper motor might be more desirable due to the contestant moment always on the pivot point and higher torque ability.

Also watching a lot of tricopter videos because that's really what it is with the hidden tail motor. Gives me the warm fuzzy for new avionics knowing I'm not the first to do a Tri with dual rotating blades for control.

BTW, the new props are looking pretty sweet on it. def need new motors to drive them though. it took a good 5 seconds to get them up to speed on the stock ones

 

[JimCR120]

If you're looking for other things to consider as you work on the Osprey, the relatively new EFlite Convergence operates on the same principle I think.



You might be able to gain some insight or maybe parts there.

 

[Tabasco2931]

Well I've gotten in the DX6 (feels sexy in the hands), the huge 1610 MasterAirScrew props and am waiting on a pair of Multistar 3510 350KV motors and a new AR636 receiver to control it all. i'm hoping the AS3X stabilizes everything without messing with the Flight commuter it already has. Last thing I really want to do is replace that too.

While, i wait... decided to try my hand in making some replacement parts. Got the rear vertical stabs cut out, shaped and sanded down. I'll be using the foam as a plug and make a fiberglass mold from that. Then I'll either use expanding foam to make light weight easy produced parts or try some carbon fiber and the food saver to try and do a vacuum laminate of the 2 halfs and then glue them together. If needed, i can do one final layer to enclose the two halfs.

 

[JimCR120]

It will be interesting if the two stabilizations fight each other or complement each other. If there is a dampening control I'm thinking it should work well.

I was at the local hobby shop yesterday and one of the heli guys that works there now has his son working there now who is also interested in doing the V-22. I mentioned you and the forum and all but he didn't seem too interested though he was aware of the BH frame and was looking to follow that model.

 

[Tabasco2931]

he didn't seem too interested though he was aware of the BH frame and was looking to follow that model.

We all must blaze our own paths.
To be honest, IF i could just buy a perfectly working V-22 to a perfect scale it wouldn't be half as fun. Tinkering kills time, expends money, and develops technical ability. At the time of purchase it was a tossup between the V-22 and the DJI's Mavic. Part of me wishes I did just go for the complete setup of the Mavic. But it's not a Osprey.

 

[Tabasco2931]

It will be interesting if the two stabilizations fight each other or complement each other.

I'm hoping that they work with each other and have different "levels" of stabilization. If they fight, I'll just disable the RX's and go with the onboard. (Until I have to upgrade the FC too)

BTW, I'm looking at upgrading that darn servo that controls the nacelle. If I went with digital, what would I have to change to get the signals right? Is it controller by the Flight Controller or by the TX? Or does the Flight Controller automatically recognize it and change the signal to comply (fingers crossed)?

 

[Brick Pilot]

Hardish landing = Stripped Servo

We need to find a replacement for nacelle servos! My Blitzworks V-22 arrived last week. As you owners already know, when transitioning from vertical to forward flight, a servo in each wing rotates the nacelles 90 degrees (as a pair). At each end position, the pair should be either completely horizontal, or completely vertical. That is the best-case scenario, but the manufacturers took a guess as to where the endpoints of your radio will align those servos.

With my DX6i, the endpoints didn't align with completely horizontal and completely vertical and even after adding 120% endpoint adjustment, my nacelles pointed forward about 5 degrees. Of course, with me being driven by my ADD, I flew it anyway, which resulted in my maiden VTOL "going south" ...err "north" as my V-22 wanted to move forward with relaxed sticks. Not optimal - but still flyable.

So, I looked to see how to fix it, and I have to tell you, it is a REAL pain. The manufacturers use a janky coupler from the servo to the nacelle shafts. At one end of the coupler, is a splined opening with a servo-screw hole down the center to attach to the servo. They also use 4 phillips-head screw to bite into the soft brass splines of the servo. The other end of the coupler has a smooth bore, and four set screws to bind the smooth nacelle shaft. This means that you need to unscrew 4 set screws to loosed the shaft to adjust it to vertical. In my case, they overtightened one of the setscrews on each coupler, so they stripped when I tried to loosen them. Get the drill. Drill out the setscrew. I was able to adjust the other 3 no problem. Ugg.

Everything is good. Perfectly aligned. Ready to fly. I test the nacelle rotation (bound to my Gear switch) and it works, but has a tendency to hiccup during rotation. Seems odd. Maybe the servos aren't up to task? Maybe a horn-and-control-arm would be better to drive the nacelle rotation? No matter. Let's fly.

It VTOLs great! 10 feet up and around and nose in, nose out, rotating, feeling good. Let's try a bit higher, wind is picking up (did I meantion a slight wind?), it starts to buck forward and backward - the "Osprey Yoyo" - as the gyros try to keep it level. I don't like it so I ease it to the ground and shut off the motor. Everything seems fine, but the right nacelle won't rotate now. Grounded. Back to the shop!

At the shop, I decouple the nacelle shaft from the servo, and dig out the servo from the foam wing. After removing the coupler from the servo, I take apart the servo case and see that the teeth on the brass output gear are damaged.



I hit Bananahobby to find that they don't yet offer servo replacements in the spare parts! All I know is that they call it a "17G metal gear servo", but no specs are called out, and there are no marking on the servo.
http://www.bananahobby.com/17g-meta...2-osprey-rc-warbird-airplane-227487-prd1.html

Can I repair the servo myself? If the teeth are damaged on one side of the shaft and only 180 degrees is ever used, can I just spin it around and use the other side? Let's see. So, opened it up, removed the shaft gear, popped out the nylon retainer-with-stop-pins, rotated the retainer 180 degrees, and pressed it back in, rendering the servo usable. Too much McGyver, but I wanted to fly! It now rotates well under power, but cannot be rotated by hand which means either some other teeth on other gears are damaged, or I probably dorked something up during reassembly.

As I mentioned before, Bananahobby calls these "17G Metal Gear Servo", but shows no photos or specs on the spare parts page on the website. On the last page of the manual, it is listed as "15218 17g Servo for Rotating Axis", but a search of the BH site, and Google, yields no match for a "15218 servo". Perhaps ANY 17g servo would work? Bananahobby lists a 17g servo for a number of products, so maybe any of them would work. The one in the V-22 are unique, in that the top of the servo looks different when compared to other servos - as one edge of the top of the servo does not "stepdown".

A candidate:
http://www.bananahobby.com/17g-meta...mm-lead-lx-f18-04.html?pSearchQueryId=1960562
DM17G : 2.2kg or torque @ 4.8v, and 17g.
Looks like the FMS DM0170 servo, used in LOTS of Blitzworks planes.

A HITEC option:
HS-81mg: 2.6kg torque @ 4.8v, and 19g.
The Hitec servo's case is identical in length-width, but is narrower in depth (as pressed into the wing). The spline is identical in diameter (HS-81MG is on the left), but the output shaft does not align exactly with the nacelle shaft, when the servo is placed in the original wing slot. Not a "showstopper" by any means, but will require some foam carving if used.


Tower Hobbies 81mg is on the left - a cheap servo, with aluminum shaft, and small diameter splines. Not a candidate! Original (disassembled) servo is in the center, and Hitec HS-81MG is on the right.


I have an FMS servo coming in the mail tomorrow from an eBay seller, and I'll report back with the results.

 

[Tabasco2931]

You. Are. A. Badass.

I'm so happy to meet someone else workin on the 22. Did you get a spectrum receiver to work with the dx6i? I've found a few beefy servos that I've been looking at trying, both analog and digital. Hs645MG is my front runner so far. Im more focused on getting the motor replaced to spin some 16's and 22's in the future. Please, let me know how the service hunt goes as I'd love to get them replaced. Something steady and solid at 0* 45* and 90* would be ideal

 

[Brick Pilot]

Did you get a spectrum receiver to work with the dx6i?

Yes, all of the orange receivers from Hobby King work well - both the micro bareboard versions, and the regular boxed one. I've even used their satellite plug-in board with them. I have 8 planes, all using these. Cheap, and solid.

..Hs645MG is my front runner so far.

The HS645MG is a beast of a servo. Well-built, but maybe too large for the Blitzworks V-22 wing? The servo may even be thicker than the wing at the chord!


Perhaps something in between the 2.2 kg/km of the HS81MG and the 7.7 kg/cm of the HS645, but still in a micro package. Maybe a 21g servo like the HS845MG @ 3kg/cm?

Or, better yet, a servo designed for slim-wing installation, with great torque!
Turnigy™ TGY-A55H Slim Wing Alloy Case DS/MG Servo 7kg @ 4.8v @ 28g @ $39

https://hobbyking.com/en_us/turnigy...g-servo-8-6kg-0-12sec-28g.html?___store=en_us

As for props, larger props would be gorgeous! At that diameter, they'd probably need to be geared down. I have a couple of 3D printers, so we could print some custom ABS mounts if needed. Let me know if I can help in any way.

 

[Brick Pilot]

I just bought a pair of KS-Servo PDI-HV2107MG for $12.65 from Hobby King

They give around 5kg/cm, which is about double what our current in-wing servos provide. For the cheap price, hopefully they can hold 90 and 45 degrees.

https://www.amazon.com/KS-Servo-PDI-HV2107MG-Wing-Servo-HV/dp/B01LSKT7WM

 

[Mangee]

If you want gps and or autonomous VTOL check out PX4.IO. They use a PIXFALCON on the E-flite Convergence which means it will most likely work on the V-22 from BananaHobby.
I also believe the servos are Freewing servos seen at motionrc.com. The BananaHobby V22 is most likely a XANE V22.
On youtube if you look at enough Osprey videos you find many Japanese RC sales videos.