Thursday, December 26, 2013

What's the wind look like?

Check out this amazing animated wind map.  You can drag the globe to look at different places.  You can see the air mass flow off of continents at low places... check out the Sea of Cortez by Baja California, for example.

Tuesday, December 24, 2013

Taranis Battery Notes

Bruce has a great video on using different types of batteries in a Taranis. Here's a few notes that I've put together.

  • The illustration is from the Taranis manual, which also notes that the operating voltage range is from 6 to 15 volts.  You should read the manual.
  • Don't charge anything but the stock batteries with the internal charger.  Specifically, don't charge LiPo or LiFe with the internal charger.
  • The Taranis originally came with 800 mAh battery pack.  Currently ships with 2000 mAh battery pack.  This battery pack is also available at FrSky dealers.
  • On older models, charge light was solid.  On newer models (the ones that came with 2000 mAh battery), charge light blinks.
  • Internal charger shuts off automatically when battery is full.
  • If you change battery types, update the voltage range and warning values on menu 1 of the radio setup screen.

battery        high  low  warn  notes
NiMH 800 mAh    8.0  6.5   6.5  stock battery on older models
NiMH 2000 mAh   8.0  6.5   6.5  stock battery on newer models
2S lipo         8.4  6.6   6.9  can plug into balance plug
3S LiPo        12.6  9.9  10.2  need to make plug/adapter
3S LiFe        10.8  8.4   9.9  need to make plug/adapter

Superfly Tuning

Tram has some great advice on tuning a Superfly.  Since RCG posts tend to get buried and lost, I'm copying it here.

tl;dr:  1/8 inch up trim for level flight.

I would definitely go with a CG that suits you. Any time a kit has a recommended CG, that's all it is - a recommendation. Some folks will fly a little more nose heavy, some folks will fly a little tail heavy.

If the plane is laying flat on a table, and the elevons don't have a little up at neutral stick, it's not going to fly as it should, as the nose is being pushed over due to aerodynamic forces.

All flying wings need a little reflex. Essentially "up trim" at level flight. Superfly's need about 1/8th inch.

I'm no Bernoulli, but as a wing develops lift, it naturally wants to pitch forward. What most aircraft use to counteract this force is the tail. Flying wings are missing this. So, a little up elevon (reflex) at the rear of the plane helps to counteract the force and thus, push the nose back up to attain level flight. 

You said previously that your having to use half stick up to keep it level. Try adding some reflex and then adjust from there.. Lay the plane flat on the table and give it 1/8" to start. You may have to add more. Once this is accomplished, the aircraft can be subjected to the "dive test" to find true CG state and adjust accordingly.

Dive test:
From level flight at typical cruise trim, enter into ~30* dive.
Let the airspeed build a bit and let go of the sticks.

If the plane pulls up sharply you're nose heavy.
If the plane pulls up nice and slow, the CG is pretty much spot on.
If it stays where it was or increases the dive angle you're tail heavy.

Sunday, December 15, 2013

My Favorite RC Pilot

Her Dad is a pretty decent pilot, but this young lady is going to be a champ.
She's flying the Bixler 2 (zoom the pic and you can see it), using APM's Fly-by-Wire mode.  She did a great job staying in the square and keeping the plane out of the sun.

HobbyKing PUMQ Notes

Got the PUMQ (Pocket Ultra Micro Quad) put together and flashed.  Here's some notes.

  • Using the Cesco PUMQ V4 build.  Build as Leonardo, ran and connected to MultiWiiConf with no problems.
  • Micro prop balancer here.
  • Easy way to remove micro props using side cutters.
  • Attach micro props with white glue or clear contact cement after roughing up the shaft.  Don't use super glue.
  • Interested to try BradWii and see how the autotuning works.
  • The battery connector is placed pretty inconveniently, with the battery cable hard to hold.  It would be nice if the connector were on the edge.

Results of first indoor flights.
  • PIDs seem OK, but it's super sensitive on pitch and roll.  Added about 60% expo which smoothed it out a little, but I'm hoping to get something close to Ladybird stability.
  • Climb was super hard to control, couldn't keep it level very easily.  That could be because I was flying it indoors and didn't have a lot of space to get used to it.
  • Bound the Rx using an OrangeRx 6 channel Rx, using the OrangeRx module.
  • Popped a prop.  Will attach as per above.
  • Calibration reminder: ACC right stick down, left stick upper left, GYRO left stick lower left.

Nice Looking Paint Finish on Foamies

 Here's a couple of really nice foamy paint jobs over on RCG.

747pilot covered his EPP Skywalker with Krylon Shortcut.  He mentions "Dries fast. Full set up in a few hours. Just don't use any type of tape on it afterwards. Tape control surfaces or whatever prior.  You can find it mostly at Michaels crafts store."

 snoshoe62 covered this Bixler 2 with Minwax Polycrylic Gloss to get this finish.  I couldn't figure out what was underneath.

Neither posting has any mention of the weight of the paint.

Saturday, December 14, 2013

RCG User Granted shows a foam carving tool with interchangeable tips and suggests a good power supply. The tips are made from .023" mig wire and xt60 plugs.

Royal Aeronautical Society Library Catalogue

"The National Aerospace Library houses one of the world's most extensive collections devoted to the development of aeronautics, aviation and aerospace technology.

This catalogue lists over 100,000 items held in the library, including books, journals, technical reports, regulatory material, images, letters and manuscripts. Please click the button above to start browsing, and do not hesitate to contact our expert librarians if you require assistance. Contact details and library opening times can easily be found within the catalogue."

Sunday, December 8, 2013

Jason's Homebrew APM Transmitter

I was visiting with APM Developer Jason Short, and he showed me a project he had been working on... His own radio, integrated for use with DroidPlanner running on a Nexus 7.

I hope Jason will say some more about it later (note to Jason: no more prestigious venue than EastBay RC!); I was really impressed.  Custom electronics and code, a nice 3D printed case which felt nice in my hands, a really nice job.

He didn't know it, but it's the same glorious yellow color as the old Kraft radios!

CME Minutes, Nov 12, 2013

 Concord Model Engineers
Nov 12, 2013

CALL TO ORDER: 7:30 pm