HL Miss Stik 2 for UAV (continued from Mini-telemaster thread)

[Disciple4123]

I have transferred the discussion of this project to this thread, as the subject no longer includes a mini Telemaster.

I have finally gotten together the UNAV RTL and ALT-3 units on the Miss Stik. The Mini TM had been too heavy/fast to takeoff and land comfortably. Additionally, it was underpowered with the 10x7, 2212/34 motor, and 3 cells A123. This build has a 4 cell A123 pack, same motor, and a 11x8 folding prop, and no landing gear (saves 2.3 oz.) and a custom larger, coroplast rudder.

The moto-calc tells me that I should get 65 minutes of hands off level flight, and 118 watts of power out of the power system. With other elec. loads in place, I'd be happy with 45 minutes. Final weight came out to 36.0 OZ

The camera /DL are still on the wing for now, good view from there. The downthrust from the factory was at 8 degrees :eek: so I put washers under the lower positions to bring it up and have not re-measured.

Because this airframe must be hand lauched, any pointers? I was a bit nervous hand launching the 78" Vista with cargo, but it went OK, with 52 watts per pound where do I stand with regard to hand launching?

http://www.aerialphotographyservices.com/misc/P1020992

http://www.aerialphotographyservices.com/misc/P1020994

http://www.aerialphotographyservices.com/misc/P1020995

[txflyboys2]

Sorry, I don't have a lot to say about hand launching but please do share your experiences with the UNAV unit, as I am considering getting one. Nice looking bird there! What happened to the Mini? Still flying it?

Larry

[Disciple4123]

Thanks, the mini is siting for now, I had doubts about it's lengthened wing and such, Just felt that I couldn't use packing taped up prototypes for delicate missions.

The unav units have worked on a number of airframes for me over the past year. I still have not gone far out (2-5 miles) for fear of losing a plane or injuring someone, this smaller planes are being built to allow me the comfort of long range flights with minimal risk. But that is the goal, navigate freely, and return to launch if lost...

[txflyboys2]

The return to launch is certainly a worthy enough feature, especially for safety reasons and in a larger or high $$ bird. I am also wondering how effective the UNAV might be for such applications as search & rescue........is it capable of programming waypoints to allow flying a grid course for AP'ing or live monitoring? Thanks!

Larry

[dmgoedde]

with 52 watts per pound where do I stand with regard to hand launching?52 Watts/Lb is plenty for a hand launch with that airframe. My Miss2 sustains on 15 Watts/Lb. At 50 Watts/Lb it climbs at about 300 feet/minute.

[Disciple4123]

I didn't know the author of the Attapilot was using a Miss Stik? Well good, glad to hear of your confidence on the power output, hopefully the 8 degrees, tamed to about 5 degrees of downthrust will be OK for a start, it seemed tipped down too far at the factory setting.

The return to launch is certainly a worthy enough feature, especially for safety reasons and in a larger or high $$ bird. I am also wondering how effective the UNAV might be for such applications as search & rescue........is it capable of programming waypoints to allow flying a grid course for AP'ing or live monitoring? Thanks!

The UNAV "NA" model can do RTL and program wapoints, uses the same boards as the RTL and ALT3 combined, and has software to do a bit further. the "NAT" adds throttle management for airspeed, my research here has shown that some oscillating occurs as the elevator manager and throttle manager would interact against each other, so I have reservations about the NAT unit for now (bear in mind I just own RTL-ALT3, don't have the others).

The intent of this airplane is specifically SAR work, sounds very easy on paper: get to 400 feet AGL, lock altitude, fly around on downlink for 40 minutes, when your lost, use RTL momentarily, or until full return; when signal is lost have failsafe's set for an alt locked RTL function. Easy on paper, been a year working on it yet to get 2 miles out :rolleyes: I need an area 51 type of place, we all do, nothing like the public observing/distracting during early development flights.

A lot of my challenges have been that I am an RC-heli AP guy, got into this with no airplane experience, most of you guys doing UAV development are already seasoned with airplanes, saving a lot of mistakes in the process.

[icebear]

Hi Disciple!

Nice to see you got yourself a Miss2!
I agree with Dean totally - dont be afraid to hand launch @ 50 W/lb - it will start flying directly after a simple toss. I hand launch both the Miss 2 (37 oz) and the Supermiss (42 oz) a lot of the time since ground handling on anything other than gravel or a fine grassfield is problematic (I have the "old" version without tailwheel!).

This is a video of a hand launch of the 42 oz Supermiss with the same wing as you have (and autonomous mission!);

http://www.vimeo.com/1164780

The return to launch is certainly a worthy enough feature, especially for safety reasons and in a larger or high $$ bird. I am also wondering how effective the UNAV might be for such applications as search & rescue........is it capable of programming waypoints to allow flying a grid course for AP'ing or live monitoring? Thanks!

Larry

Larry, like Disciple just said, the Picopilot NA is capable of programmed routes of up to 31 WP's incl altitude hold and I have set my failsafe to activate the autopilot. It always returns to the startup position (first GPS lock when turned on) so it works well as a RTL too.


/Björn

[Disciple4123]

Bjorn, I checked all of your videos, looks good.

OK, it flew. Hand launches with or without a headwind seem safe. The airplane came out trimmed correctly after setting the factory heavy downthrust, and one washer worth of right thrust. The Alt3 and RTL modules are working well together at 1/2 throttle. Winds are were 0-12 mph. I'd say the stability is adequate, some occasional rolling, but nothing that seems to end up upside down or nosedive. It flew 10+ minutes with just alt3 locked and looking at the base station, not hearing or seeing the aircraft directly, finally making progress.

I have an issue with landings in medium-high grass. If I shut off power, it loses control authority, so I tend to come in at 25% throttle, and cut throttle just before hitting the ground. It tends to come in fast and tip over on landing, only minor damage on the first landing, but I see surability issues with grass landings.

I was able to scope out a 2.1 mile long desolate road yesterday in farm country, after some more testing it would be a good location for a 2 mile out and back, flying along a road should allow me to find the aircraft quickly if it goes down next to the road, cutting across miles of un-roaded farmland concerns me if a recovery becomes neccessary.

Is it wise to place a small amount of carpet tape on the wing bed to keep the wing from sliding around? Running 6 bands instead of 4, but still concerned. Carpet tape is fibrous, light, and grippy, sticky, but easily detachable.

Thanks,
Eric

[dmgoedde]

Is it wise to place a small amount of carpet tape on the wing bed to keep the wing from sliding around?That is what I did (well, I used some tape-backed foam from the hobby store) and the wings don't slide around. So far, 4 rubber bands criss-crossed always works great for me. It got my Miss2 through a 30 minute 11 mile autonomous mission with an early AttoPilot.

[txflyboys2]

Eric and Bjorn, thanks for all of the good advice on the various UNAV models. As for shifting wing prevention, short of mounting with nylon bolts, small Earth magnets might be something to consider in the 4 corners of the saddle area in the fuse. Used in conjunction with rubber bands, the magnets would tend to hold the wing in its proper position, yet easily release in the event of a cartwheel landing or wingtip dragging the ground.

Larry

[Disciple4123]

Updates:

Been getting good autonomous flights. The L wing, 3" from the root, leading edge, cracked a little today. You could see the crack in the upper when flexing the wing, barely detectable with the covering on. I took off the covering, laminated fiber tape and epoxy over it, and taped over it with packing tape. I think I must be careful with the hard landings. The base of the plane is losing some covering on landings, I have just the packing tape to repair it, but thinking long term, I must replace airframe every 6 months, or learn how to land it gentler. Even if it means an airframe twice a year, it is still a rather affordable unit to fly.

Still haven't gotten to run the 2 mile course, schedule and timing mainly, shall do very soon.

I had been running about 52% throttle when level, today I tried around 25% throttle for a while, due to strong downthrust, it's ability to stay in level flight at 25-52% is about the same. At 52% it can stay aloft for 40+ minutes, I think loitering at lower throttles will open it up to an hour aloft or beyond. I'll be slightly upshimming the thrust angle, feeling that the -8 degrees factory setting is a bit excessive.

When I get a capture device, I may post some vimeo video of the UNAV in action on this machine, I use a base station that records to DVD, in DVD format, and currently am not equipped to put that on the internet easily, short of video'ing the TV set :eek:

[icebear]

Eric,

Thanks for the update - good to hear you have progress!

2 miles.. I guess you mean cross country - otherwise I did 8 miles last weekend :D...

I can recommend a L/G - mine has savead a lot of props, my camera AND the belly many times...

Looking forward to seeing that video when you can do it. Doesn't MS MovieMaker allow for MPEG2 (DVD) to be imprted and compressed?

/Björn

[Disciple4123]

Well, the landings have gotten better, I am gaining experience I suppose.

I've used a digital camera on movie mode, filming the LCD TV before, much easier than all the nonsense of converting files: Movie maker will not handle DVD MPEG-2 format. Conversion programs often have viruses to my understanding, and the two I have used TMPGEne as well as Handbrake, have not worked or not worked without errors. What a mess to do a simple task.

Last night I cut the coroplast rudder down by over an inch. It is one I made to have about 2x the tilt surface area as stock, by cutting it down it ends up with a little more area than stock, but not much more. The rudder was overcontrolling and the RTL was starting to miss, due to an odd form of adverse yaw (no ailerons on this plane). As the fuselage spring loads laterally with a rudder input, the old tall rudder prevented the appropriate amount of roll to fall in, the fuselage would spring back when the stick was released. Some wing rocking was taking place as well. The RTL was seeming to sometimes back off when the overcontrol started, and it would hesitatingly make it's moves. I turned the gain down and it helped, but I had to reduce the rudder size. Icebear, do you find the stock Miss rudder to be enough?

Perhaps tommorow I'll do the 2 mile run, if some more test flights prove reliable. The path is shown below 2.2 miles...http://www.aerialphotographyservices.com/misc/2 mile path

[icebear]

Thanks for posting the route - hope things go well!

I get the best results with the SuperMiss (with Miss2 wing) and I suspect it has to do with the rudder being larger.

The Miss2 works fine too, but there seems to be less authority in turns and if you turn gain up too much, then of course wing rocking starts.

I think there are different sizes of rudder between my SuperMiss/Miss2 (original Scorpio versions) and the newer Hobby-Lobby versions (made in China), so I can only compare the versions I have. See attached pics.

Bottom line is that I think the rudder on the Miss2 needs to be increased and by limiting mechanical throw, a gain setting of 30-40% should be possible.

/Bjorn

[Disciple4123]

It seems that the "Scorpio" line may have been higher quality. Both the mini-TM and this Miss 2 had warping wings. This one had a soft spot develop in the wind 2 weeks ago, it was epoxied and laminated with strapping tape. Today in 15 MPH winds, I noticed a change in throttle, I suspected failsafe had gone in, so I dived 300 feet, power off, toward me. At 100 feet up it snapped the wing 3" from the middle. The rest pummeled down, no expensive parts broken, but the airframe and minor parts are damaged.

Even though diving in turbulent air at 37 oz of weight may not be the smartest choice, I have some doubts about this unit's quality. Is the wood defective, do they miss gluing certain spots correctly, etc. It would be so much cheaper if they offered a $190 "UAV grade" version made to top quality, than $90 for a "China version" that does this. :rolleyes:

[Gary Mortimer]

I was looking at a plans book today for this very reason!!

Bad luck with your break up.

If I build it all myself, its only me to blame!!!

Now anyone have a plan for a twice size twinstar II, I'm currently beating an airframe to bits playing with cameras on board stock setup and 25 hours flight time, I'm loving it.

Would love a twice the size one!!!

[Disciple4123]

It's a bummer, put the gear back on the mini-telemaster today, thing flys 20deg. crooked, that mini-TM never flew right, numb yet twitchy, too fast to land, etc.etc.

I am going a far differrent route next, thinking of the Mountain Models Magpie AP. Hopefully my 2212/34 with the 11x8 folder, and 13 volts will be near what it needs. The foam magpie AP unit has a lot of dihedral, crash resistance, 481 sq foot short wings. It should offer the small "non-intimidating" size combined with some payload capacity and unknown flightime charicteristics.

Any thoughts on that?

[icebear]

Eric,
Sorry about the Miss2! My Scorpio (Czech made) versions are really well built and they were striaght as arrows. So far I have logged 100+ hours on them.
However, the Mini TM from China was crooked lika a banana and even though I spent time on ironing it out mine never flew well either!

I dont know how the Magpie flies but given all good AP reports I'd say it could be a good candidate. I just ordered a "New Timer" from Cermark. It'll replace the Miss2 if it flies well and if it is is light enough.

/Björn

[Disciple4123]

Your New Timer seems to have potential, seems likely to be a bit higher quality than some of what I've been getting, hopefully it turns out efficient for Icebear, any other long autonomous trips planned?

I've added 60 sq/in to the Telemaster's wing, this time with gentle permanent flaps and a washout end. All foamboard, adds 1.4 oz, we shall see. This is just temporary until going with a Magpie. Perhaps the miniTM tail will control a narrow broad aspect ratio wing better than the attempted wing extensions??

http://www.aerialphotographyservices.com/misc/telemaster8

http://www.aerialphotographyservices.com/misc/telemaster9

[Disciple4123]

Well the Magpie AP has seen many flights already, climb rate is slow, perhaps 250 feet/min. with the A123 4s 2212/34 with a 11x8 folder. It is better off than previous airframes, but just flying the FPV gear and autopilot, comes out to 35.2oz. Adding 6.5 oz for a camera, rest of the mount would probably be impractical, so in summary I may have been better served getting a Magpie non-AP, 7 oz lighter, same gear on it (since I will probably never run the camera mount system due to weight). That being said, it flies better than it looks, takes 10 degrees of downthrust, and zero degrees of rightthrust to fly right.
http://www.aerialphotographyservices.com/misc/mp2.jpg

I may build an "ORB" plane for pictures, and make this one a pusher on a custom, lighter, fuse, not sure yet. Another step in progress...