I am a 25+ year veteran research scientist, and have been an avid developer of UxV's for a long time. My R&D focus has been on experimental sensors and automated system health monitoring and now I am adapting that to UxV's.
Please tell us a bit about your UAV interest
I work for the DoD and am developing new sensor payloads. a DIY drone is ideal for prototyping and field testing.
I finally got my many talents out for the maiden flight this afternoon. Went pretty well, crashed a couple of times, it sure does fly fast! No real harm done, but I am curious, do you have any tips on how to II finally got my many talents out for the meeting but flight this afternoon. Went Went pretty well, crashed couple times, it sure does fly fast! No real harm done, but I am curious, do you have any tips on how to better fly these planes? Seemed to like higher speeds to avoid stalling. Also very responsive to aileron and elevator input, much more than I expected. It felt a bit like flying a racehorse, if you know what I mean! I'd like to find out how to make it fly a bit more docile in manual mode.
Thanks for the tape tip, by the way. I think that saved my fuselage today.
I appreciate your feedback and insight on these little flying machines, and it's very good to hear that some modifications can be made to make the min talon more suitable for aerial mapping through enhanced lift, slower flight, etc. For comparison, my current configuration is a Sunnysky 1250 kv motor, 30 amp ESC, 8.5" prop, and 4S 4200-4500 mah battery. Sounds to me like our setups are similar, just with the prop size adjusted for # battery cells. I too found that there's plenty of power with this kv range.
First off in response to your tips - I have added flaps (25 deg) using aluminum plate. I'm only using the fiber tape currently but wondered if any additional reinforcement might be prudent? I've used Gorilla white glue to assemble the airframe so could add that to better secure the flaps. But it doesn't sound like you have needed anything but the fiber tape to EPO?
I've also cut the extensions to address elevator/rudder authority out of the same aluminum plate. Just need to secure those, I'm thinking just aft of the servo horn plate. Also looking to use just the fiber tape - hopefully it's strong enough. One thing I noticed in sizing the extensions, with the goal of actually doubling the surface area of the elevators/rudders to 2x, was that to avoid contacting the prop, I had to keep the size increase closer to 1.5x of the OEM size. I suppose moving the prop (or motor itself) further back with a spacer or something similar might be an option to gain more clearance for the extensions, but I didn't want to start modifying too much just yet. Do you find just the fiber tape supportive enough to withstand the moment induced on the extensions, or would a screw-through plate - perhaps similar to the servo horn plat but flat - be needed to anchor the extensions?
Interesting to hear that you're using APM 2.4.1. I assume that interacts with Mission Planner or other ground control software the same as the newer APM versions? I had intended to install a Pixhawk fc, as I've been please with it's performance on my multi-rotors. But I do see that the APM 2.5 hardware is a bit cheaper. I haven't yet found a source for pre-installed 2.4.1 but I suppose that firmware can be downloaded.
I hope to get the modified talon up in the air again soon. Will keep you posted on new lift/stall/handling characteristics.
Also came across your narobotics blog site - the prairie sled concept is intriguing!
I am definitely checking out the APM 2.5-2.6 FCs. Seem to be some pretty good deals out there for these.
For the UV protection, I will be sure to add a good coat of paint to my accumulating layers of fiber tape! Sounds like that's the way to go to keep the adhesion good.
along with adding the flaps and rudder/elevator extensions, I've been researching flaps this week to try to prepare as best I can for any modifications I need to make to my piloting technique. Many folks claim that applying and/or mixing in some up elevator is needed to avoid noise-diving the aircraft. Curious if you and Mark have found this to be the case?
I've also added a sled of sorts on the front portion of the fuselage, using some foam and a strip of 1/16" ABS, along with the increasingly ubiquitous fiber tape. We'll see how that works this weekend.
And still brain-storming about your water landing interest, I pulled the trigger and ordered a set of $11 small wing pontoons from a catalina style model. No big deal if they don't work but will be interesting to look at. 2 large pontoons (~75-80% of length) on a frame under the mini talon seem like the other viable option. That route may be better given the aerial mapping application, as otherwise I haven't thought of a good way to keep the camera lens/lens portal from getting splashed. The ideal setup would allow for either land (skid) or water (buoyant) landing, keeping the camera high and dry for either case. Perhaps 2 pontoons with wheels?
Mike and mark, I squeezed in an early morning flight today, & I can report that the enlarged control surfaces and flaps have definitely helped the slow speed handling and stall characteristics. I also reinforced the control surface hinges, per your suggestion, after managing to tear off the to rudder flaps on Friday. At least the tear was clean, so the fix was relatively easy. I also went ahead and reinforced aileron hinges, just to be safe. I think I will wait to install my camera gear or any sort of auto pilot, probably apm 2.x, until I improve my landing technique just a bit more. Need to get just a little further up on the fixed wing piloting learning curve. I also need to learn to use my rudders more, I think, as at the moment I'm essentially flying without them. Do you guys use them mainly for scrubbing off speed before landing? In any case, this morning mark some good progress as I managed three clean landings and no damage to the airframe. Unlike Friday, when i tried to land by coming down through a tree canopy. Thanks again for all your great tips!
Mike and Mark,
I appreciate the consolation - it's nice to know that everyone has climbed the fixed wing learning curve at some point! Your testimony (Mike) on apm 2.x has convinced me, so I've got an apm 2.5.2 setup with telemetry ordered and on the way. Also will add a mobius camera as a step-up from the keychain cam I've used starting out. My only remaining decision is mapping camera mounting in the mini talon. I've used a canon a2200 on my quads with good luck so plan to stick with that. No fisheye like gopro, plus the chdk option for intervalometer make it a decent unit. Placement will likely be in front the equipment tray to maintain cog. I hope I can enable a fast enough shutter interval to keep up with mini talon's speed - slower speed stabilization should be helped by the apm I'm sure.
One question for Mike) - do you use the analog airspeed sensor with pitot for apm 2.x? This is what I ordered as using only gps estimated speed didn't sound as reliable. But maybe that's not the case. Just curious.
I hope all is well in the Midwest. I finally got the mini talon with APM 2.5 up in the air this past weekend. I took off in manual and then switched to stabilize mode for the majority of the two brief flights. I did try FBWA mode, however I immediately got some weird heading lock behaviour so switched back to stabilize. So it looks like I need to dial in that flight mode a bit more, in addition to FBWB. Which mode do you tend to use the most? Other tweaking that I need to do includes shifting the battery back a bit further, or perhaps angling the nose up a bit more during calibration. You suggested this in one of your past comments and I did try to angle the nose up by about a half an inch during accelerometer calibration, but this may not have been enough.
In any case, the Stabilize mode certainly helped. It gets rid of a lot of the shakiness and sensitivity to wind gusts. I do look forward to refining FBWB mode soon, however, as the altitude hold will be very helpful for mapping. I did take an in-flight video with the Canon a 2200, which turned out quite well.
Also on my to do list is to take better still images with the Canon. I have it mounted in the center cargo section looking groundward through a portal that I cut and reinfoced. Then the autopilot is mounted directly in front of that compartment on a platform. I have some Dubro foam underneath both the apm and the camera, however my custom ABS camera bracket does still transmit vibration to the camera on several of the corners. I think this may have contributed to the blurriness and vibration indications that I saw in a test flight with the camera last weekend.
In any case, progress is being made! I'll try to post some photos of my set up once I get it tuned and working properly.
Mike and Mark,
The Cruise mode behavior you describe sounds similar to the FBWA response I saw. I didn't stay long in the mode since the plane appeared to be heading off to Oz of its own accord...I'm used to this sensation in Auto mode but not for the less automatic control modes. I'll add that to my list and mode switch to test on the next flight to see if I'm able to duplicate what you describe.
On the camera topic, here is a shared download/upload folder for some photos of my setup: https://files.apaienv.com/owncloud/public.php?service=files&t=84ad7685287cf5d22a6b3612b77119ed
Hopefully the pics are clear enough - basically a simple 5-sided abs box with slots/cutouts where needed for the camera. Foam on all sides and not just left and bottom would of course be ideal, but I ran into the space constraint in inserting the box for mounting. A bit more room on the right/tail side is available, perhaps for revision 2. Camera is secured in from top by a large piece of pool noodle foam cut and taped to underside of talon hatch, and centered over the canon rear face.
The NIR capability is intriguing, particularly for the wetland veg monitoring application. I've looked at this a bit but was putting it off until my next refurb Canon, as the mods I've read about sounded fairly permanent.
Sounds like you've been pleased with the SJ cameras? They appear to offer similar capability as the go pros but at a more expendable price point.
Just let me know if the link doesn't work and I'll share the photos another way.
Wanted to ask which version of Arduplane you are using on your apm 2.4 mini talons? I've noticed a few posts describing some unusual fbw mode behavior when using the latest arduplane (currently 3.2.3) on apm 2.5. Given your recent comments and my own as-yet unresolved fbw mode experience, I'm considering dropping back to AP 3.1.1 on my APM 2.5 for testing over the next few days. Thoughts on this? Thanks, Mateo
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