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Posted by JD-Slow-Thumbs | Oct 07, 2015 @ 12:10 AM | 1,802 Views
I am doing some catching up on my writing tonight. A few months back (April 2015) I built another plane, the JD-11, and it has some good potential, but it also needs some refinement / reinforcement. It is a slow flying Delta, has a 48” wingspan, 20” length of blue foam, 26” from prop-spinner to rudder. It has a 100 Watt power system, Blue-Wonder/HexTronik-24grams 3s/1500kv motor, one of my bamboo motor mounts, 12Amp ESC, 1,000mAh/3s/20c battery, 6x4 MasterAirScrew GF propeller, and last but not least a Lemon receiver with DSMX and stabilization and delta mixing all built in (works good with my newly upgraded 9X transmitter).

I got one of my buddies to maiden it, and he said that I needed to adjust my Center-Of-Gravity. Before building it I had studied COG for deltas, and found settings for beginner / intermediate / advance. Now I thought that COG meant the balance point between the front and back, you know 50/50 and make minor adjustments from there. Well I was quickly reminded that Deltas “need reflex” where the nose is up a little, most of the wing is down a little, and the Elevons (elevator-ailerons) point up a little. Apparently for slow flying a Delta, beginners should have a little more of the nose-up higher angle of attack.

Something else we quickly noticed was that the wings were bending upwards, not hinging at the root, but curving upwards trying to look like the bottom of a circle, not good for consistent control with those elevons. An easy fix for some carbon-fiber tube.

Here is the best picture.
Thanks for reading
Posted by JD-Slow-Thumbs | Apr 05, 2015 @ 03:58 AM | 2,208 Views
Last Thursday 3-26-2015, I got six flights on my latest plane, the JD-10. It was a chuck glider conversion, starting with an Air-Hogs-Titan and adding electronics. The star of the show was a Lemon Receiver featuring DSM-X + Stabilization + Delta-Mixing all in one small unit + a small satellite/diversity receiver. Once I got it airborne it worked good.

Other features were as follows:
1 – The Air-Hogs-Titan has wings that are both swept back and have dihedral, probably resulting in a strong self-righting dihedral effect.
2 – The As-Found center-of-gravity for the chuck glider before adding electronics was approximately 5-1/2 inches back from the leading edge of the wing root (~3/4 of wing root), and when adding the electronics I balanced the components to maintain the same center-of-gravity.
3 – After determining the As-Found center-of-gravity, I placed a piece of heat-shrink across the top of the fuselage so that I could repeat the balance point (see picture below). I have used this several times now and it works great for repeatably balancing a plane.
4 – I added left and right elevator so that I could use them as elevons (Delta). I also added rudder mostly for later use. Because I wanted to keep all of my wiring and servos on the fuselage and integrated empennage (tail), and because I wanted to keep the known-good wings clean, I did NOT add ailerons. Of course, these control surfaces used three servos, and I used 9gram servos because sometime in the...Continue Reading
Posted by JD-Slow-Thumbs | Mar 19, 2015 @ 04:16 AM | 2,405 Views
Previously I wanted to use my Turnigy 9X transmitter to talk to a “Lemon Receiver with Stabilization”, and quickly learned that there was a channel assignment mis-match, which could be remedied with a firmware upgrade to ER9X, which required additional hardware to perform the firmware update, so I put in an order for the necessary hardware …

This afternoon I received the “USBasp Delux” from “9XRprogrammer dot com”. This is a kit containing an EEProm programmer on little circuit board that has a usb connector on one end and connects to a ribbon cable on the other end. This evening I soldered the ribbon cable to the prescribed pads according to YouTube. Then I downloaded a hex file, and downloaded an EEProm loader/programmer. And by carefully following directions on YouTube I managed to successfully update/flash the transmitters firmware to the desired ER9X which is supposed to be flexible enough to do anything that I want.

While I had the transmitters back cover off, I also installed a back-light kit resulting in a very big improvement to the readability of the LCD display .

Hey, I just noticed that I am on my fourth upgrade to this radio that I had been wanting for over a year.
But the good news is that my soldering is good and all of these upgrades have worked on the first try.

Now I am reading the ER9X firmware manual, light reading at only 46 pages, learning how to setup the first four models that I need.

Thanks for reading.

I am starting to like YouTube, the instructional videos are actually useful.
Where to solder in the transmitter and how to flash new firmware.
er9x Turnigy Flash Radio Control Upgrade from beginning to end! Firmware soldering eePe etc (20 min 18 sec)

How to install the backlight kit.
DIY MOD: Adding LCD Backlight to Turnigy TGY-9x Transmitter (9 min 17 sec)

Posted by JD-Slow-Thumbs | Mar 13, 2015 @ 02:10 AM | 2,832 Views
After receiving my Lemon DSMX Stabilizer Receivers I tried them out and promptly discovered a channel assignment mismatch.
Turnigy 9X - - - Lemon Stabilizer
Ch1 = Ail - - - Ch1 = Thr
Ch2 = Ele - - - Ch2 = Ail (Right Aileron)
Ch3 = Thr - - - Ch3 = Ele
Ch4 = Rud - - - Ch4 = Rud
Ch5 = Gyr - - - Ch5 = Reserved - Stabilizer On/Off
Ch6 = Flp - - - Ch6 = Aux1 (Left Aileron, Gear, Flaps, etc...)
Ch7 = Aux - - - Ch7 = Aux2
Ch8 = Aux - - - Ch8 = Reserved - Master Gain
With stabilization dis-abled I could move the servo leads around as needed, but when I wanted Stabilization and Delta output, all I got was junk.

I asked about this in the Radios forum and learned that the Turnigy 9X radio uses the Futaba channel sequence while the Lemon (and orange) receivers use the Spektrum channel sequence. And to fix this state of affairs I would have to upgrade the firmware in my Turnigy 9X radio to a non-default open-source firmware. And I would need to modify the transmitter with a usb programmer to do this. I now have the parts on order.

Looks like a minor delay before my stuff is fully capable of doing what I want.
In the mean time it is back to the older FlySky FS-CT6B system.

Thanks for reading

The discussion in the Radio forum is here
Posted by JD-Slow-Thumbs | Mar 09, 2015 @ 01:23 AM | 2,280 Views
Somebody started a thread asking how many batteries people have. I replied with a number ( 26 total with 9 ready to be sold/traded/donated and 4 ready to be trashed). And I also added that your variety of batteries will be matched to the variety of the sizes / missions of your airplanes from Micros to Trainers to Warbirds to EDF's to etc …

The discussion is over here

Thanks for reading
Posted by JD-Slow-Thumbs | Mar 04, 2015 @ 01:11 PM | 2,250 Views
Three weeks ago I ordered three of the Lemon Receivers with Stabilization and Satellite, and they finally arrived last night (2-11-20015 to 3-03-2015). I have been looking forward to getting these, I have several applications in mind.

Let the experiments begin.

Thanks for reading
Posted by JD-Slow-Thumbs | Feb 24, 2015 @ 03:03 PM | 2,895 Views
After getting several informative responses to my poll regarding Scroll-Saw vs Band-Saw in the Balsa-Builders forum, I decided to start a poll regarding the use of power-tools in the construction of scratchbuilt foamies. I am very curious to know how many people use power tools to make their foamies, to shape the actual foam itself, to make component parts like motor-mounts, and how many people do not use power tools at all.

I am predicting that most people will vote for “No power-tools at all” since scratch building foamies is generally a low-expense/low-capital/low-overhead endeavor.

Thanks for reading

The Poll with discussion is over here in Scratchbuilt Foamies
Posted by JD-Slow-Thumbs | Feb 19, 2015 @ 01:29 AM | 3,968 Views
JD-Slow-Thumbs, Poll For Most Popular Style Of Bench-Top Saw

I got frustrated with the scroll-saw that I recently purchased. I was having difficulty with simply making straight long cuts in hobby plywood, so I started a poll in “Aircraft-General>Balsa-Builders“ to get some opinions about better bench-top saws.

The Poll with Discussion is over here:

Thanks for reading
Posted by JD-Slow-Thumbs | Feb 03, 2015 @ 12:51 AM | 3,356 Views
I have been looking for Saitek brand of flight simulator accessories especially their Yoke, Throttle, and Rudder-Pedals hoping to buy them cheaply. Aside from occasional visits to thrift stores, I have also been checking CraigsList (not so much eBay because of the cost and complication of shipping a good sized box). I have been looking and waiting for a l-o-n-g time. Finally today I got lucky and found somebody selling the Saitek-Rudder-Pedals for only fifty dollars which is a third or less of the retail price (and good luck finding them in a store). Made contact with the seller, drove out to get it, completed the transaction which was the easy part, thanks to city traffic it became a four hour round trip.

Plugged it into a vacant USB port, Windows-8.1 did not know what to do with it, loaded the software on the included CD, and it is now recognized by the system, and all of the visual sliders in the test/calibration pop-up show 100% travel in all appropriate directions. Tried it out in MS-FSX and it works on the default Cessna C172 for steering while taxiing. Yeah it works!!! Now to get some practice with it.

Thanks for reading
Posted by JD-Slow-Thumbs | Jan 26, 2015 @ 09:54 PM | 2,372 Views
Today I made two modifications to my Turnigy-9X radio. The first was a mod that allows for the clean removal of the Wireless-Module, instead of the stock situation where it still hangs on by a a coax wire/cable that feeds the antenna on the main transmitter box. The second mod was to enable the use of the trainer port for buddy-box-ing or simulator-input-ing while the Wireless-Module is still installed.

I learned about them on RC-Groups dotcom, and found the how-tos on YouTube.

Turnigy 9X Antenna Hack (Allows complete removal of the 2.4GHz Wireless Module)
www - youtube - com/watch?v= W74Acmam_0c
This involved re-routing the coax cable going to the antenna and re-mounting the antenna to the wireless-module. Dang that coax is really really tiny !

Hobby King Turnigy 9X Trainer Function and Simulator Modification Fix Resolution DIY
www - youtube - com/watch?v= C-6upAsvt7w
This involved cutting a trace and soldering in a 1KOhm resistor (a lot easier to see than that coax).

Thanks for reading
Posted by JD-Slow-Thumbs | Jan 19, 2015 @ 09:44 PM | 2,795 Views
Somehow I ended up with three fuselages for EasyStar derivatives (very cheaply, one of them only cost me five dollars worth of raffle tickets) and I wanted to upgrade to more modern brushless motor technology. Even with a little creativity these planes have a propeller diameter of "not-to-exceed" six inches. Previously I found a very nice motor but experimentation showed that it worked great with 7x4 and 8x3 props so now I had to find an even higher Kv motor to drive the target six inch diameter prop.

For the this iteration of experimentation I selected the HobbyKing AXN-2208-2150.
(replacement motor for AXN-Floater-Jet (EasyStar Derivative))
( 2150-kv / 11.1-V / 20-A / 180-Watts / 44-grams)
Tested with battery 3s(11.1v)-2200mAh-20c starting at 11.6v
Propeller ------- Watts - Thrust - Rank-By-Thrust
6x3---MA-GF ------ 147 -- 433 ---- 1
6x3.5-MA-GF ------ 151 -- 429 ---- 2
6x4---MA-GF ------ 147 -- 418 ---- 3
6x4x3-MA3blade --- 185 -- 407 ---- 4
6x4---APC-E ------ 166 -- 357 ---- 5
6x3---MA-E ------- 180 -- 289 ---- 6

Immediately afterward I tested a “Blue-Wonder” 24gram 1500kv Brushless Outrunner which apparently is very popular for use on small scratch-built foamies.
(1500-kv / 11.1-V / 7-A / 78-Watts / 24-grams )
Tested with battery 3s(11.1v)-1800mAh-20c starting at 12.1v
Propeller ------- Watts - Thrust - Rank-By-Thrust
6x3---MA-GF ----- 63 ---- 201 ---- 3
6x3.5-MA-GF ----- 66 ---- 209 ---- 1
6x4---MA-GF ----- 64 ----
...Continue Reading
Posted by JD-Slow-Thumbs | Jan 15, 2015 @ 01:43 PM | 2,714 Views
Background - I am experimenting with combining some of the “Armin-Wing” technique with some KF-Airfoil technique. Because I want to use half inch R-Tech foam for the KF-Airfoil step, I need to know how well it can be bent / formed in the Armin-Wing technique.

Today's experiment - Part-2 - I tried using wooden boards to accent the pressure from the fifty pound bag of sand onto the leading and trailing edges of the wing.

It was kind-of-sort-of successful, I did get good contact at both the leading and trailing edges, but the two layers of "interior-build-up" slid out of place and became only one layer of interior-build-up (not very challenging) and the glue under the wooden boards was deformed into an ugly ridge next to where the boards had been placed on the wing. Not quite what I had in mind, this will ... Require Further Research !!!

( I am curious to see if I can get good contact using "vacuum-bagging" (seel-a-meal), if I see one in a thrift store I will pick it up and try it out).

Thanks for reading.

Here is information for the R-Tech foam that I am experimenting with,
Posted by JD-Slow-Thumbs | Jan 12, 2015 @ 05:46 PM | 1,760 Views
I am combining more than one technique for building wings of my own invention. I am combining some of the “Armin-Wing” technique with some KF-Airfoil technique. Because I want to use half inch R-Tech foam for the KF-Airfoil step, I need to know how well it can be formed in the Armin-Wing technique, and this is the goal of today’s experiment.

Today's experiment showed that the R-Tech foam is harder than expected to bend / form into a good leading edge. I am using a fifty pound bag of sand to press everything together. Only about half of the twenty inch span of my experimental wing had good contact from the R-Tech foam at the leading edge. Where there was good contact at the leading edge it looked like it would make a very good hybrid wing.

I will try again tomorrow.

Thanks for reading.

edit - Here is information for the R-Tech foam that I am experimenting with,
Posted by JD-Slow-Thumbs | Dec 30, 2014 @ 02:14 PM | 2,530 Views
SCORE! Small Monitors For Instrument Panels $10

Last weekend I stopped into a Salvation Army thrift store looking for joysticks,
instead I found half-a-dozen smaller LCD Monitors, two of which caught my eye,
a 15 inch monitor marked as $25 and a 19 inch widescreen marked as $20,
then I noticed a sign saying "All Monitors $10",
so I bought two monitors for $20. SCORE!

I figure the smaller 15 incher can hold the beginners six-pack of instruments in front of my 32 inch scenery display, and later the 19 incher can hold all of my instruments including the radio stack.

Of course, your mileage may vary, stock at a thrift store depends on donations of discontinued equipment. Hooray! Two monitors for $20, SCORE!

BTW I am noticing a trend in the retail stores and even the thrift stores, almost nobody seems to carry/stock joysticks or PC accessories, and the retail stores seem to carry very few PC Game Titles. My local (Los Angeles) Salvation Army and Goodwill thrift stores no longer carry joysticks! These are lagging indicators (not future-tense leading indicators but past-tense lagging indicators) that games have already moved from PC's to Consoles-with-gamepads and beyond to smartphone-tablets. Ouch, makes me feel like a dinosaur

Thanks for reading

Originally posted at FlightSim dotcom on 08-22-2014

Attached is a picture of my home flight simulator with 32 inch widescreen for the view out the front windshield, smaller widescreen for instruments, throttle, small keyboard with overlays, and joystick.
Posted by JD-Slow-Thumbs | Dec 26, 2014 @ 01:31 PM | 2,174 Views
Yeah !!! - I finally got them to play nicely together !!!

I had purchased RealFlight7 in early fall, it is an rc flight simulator, and I got the "interface" version so that I could use my own transmitter. Tried to get it to work with my FS-CT6B transmitter which does not really have a "trainer-port" function and would need modifications to work. Tried to get it to work with a generic wireless adapter, with no luck. Sometime in late fall I purchased a Turnigy-9X transmitter so that I could more easily tune aircraft parameters, and also tried this transmitter without success. Over the Christmas holidays I finally had the opportunity to do more research into this subject and finally got it to work, Yeah !!!

Found instructions that worked successfully here in post #7 of this thread,

Getting these two items working together is like getting a new toy for Christmas.

Thanks for reading
Posted by JD-Slow-Thumbs | Dec 18, 2014 @ 07:02 AM | 2,040 Views
Early in my RC flying hobby, I was having planes that would take-off and a few seconds later lose power and say “Beep Beep Beep” as it was falling into the ground. After some reading here on RC-Groups I figured out that the motor (with propeller) was pulling more power than my battery could keep up with, leading to a voltage sag and the electronics resetting, not good for flying.

I bought a watt-meter and built a test stand for testing out my powertrains from the propeller, to the motor, to the ESC (electronic speed control), to the battery. I have include a drawing and a picture of my test stand. Here are some of its features.

It has an arm that pivots onto the gram-scale and can swing up to change propellers.

It has a pivot plate (for lack of a better name) that needs a weight to hold it flat.

It has a small platform on top of the pivot arm for the battery, watt-meter, ESC, and receiver to sit on.

I use my radio transmitter to control the throttle.

The pivot-arm weighs down onto the gram-scale,
The propeller's thrust also pushes down on the gram-scale,
The gram-scale has a “Tare” function which comes in handy.

In order to get useful gram measurements with the scale one must get a single point transferring weight to the scale. For the first year that I used this setup the “single-point-transfer” was approximately half the length of the arm giving me close to a 0.50 factor for converting measured grams to grams of thrust. The first...Continue Reading
Posted by JD-Slow-Thumbs | Dec 14, 2014 @ 11:53 PM | 2,386 Views
I attended the Drone Expo here in Los Angeles and had a good time visiting the exhibitors booths and seeing some of what is happening in the world of civilian drones (predominately multi-rotors). There were many exhibitors and I think thousands of attendees, a very good turnout for a first time exposition. About a quarter of the drones there were the larger versions capable of carrying the heavier Hollywood cameras. There were a few software vendors that would take your mapping data and, cloud it, integrate it, and analyze it for you). There were several vendors selling the smaller drones and services for them. There were very few vendors with fixed-winged platforms. I missed out on the speakers, because I had just worked all night the night before.

I have asked the organizer for official links to:
Their exhibitor list,
Count of attendance / tickets sold,
Links to videos and/or transcripts of the speakers and panel discussion.

Thanks for reading

I put the discussion in MultiRotor Talk

DRONE EXPO – DEC 13, 2014 – Los Angeles Memorial Sports Arena
by UAV Systems Association –

(the following information from the above website retrieved 12/14/2014)
Sponsored by: (sales, support, aerial filming)
UAV Systems Association –
3D Systems (3d printers)
Rotor Drone...Continue Reading
Posted by JD-Slow-Thumbs | Dec 13, 2014 @ 08:50 PM | 3,263 Views
Just got back from visiting the LA Drone Expo (Los Angeles). Great exposition and a lot bigger than I anticipated, exhibitors came from all over the country. Attendance was very good in the thousands. At this expo I am seeing a lot of interest and in what drones can do from a commercial perspective.

I will update this note later after I have had time to process all of my brochures, flyers, and business cards.
Posted by JD-Slow-Thumbs | Dec 11, 2014 @ 12:31 AM | 2,737 Views
I saw that somebody had a question that re-ingnited the tractor-vs-pusher debate and this time I joined in.

I remember reading about this Tractor-vs-Pusher debate in at least one probably two magazines for full sized real world planes for home builders. (EAA Sport Aviation magazine, long ago issue). The authors debated the pros and cons of the following:
Efficiency of propeller,
Efficiency of wings for lift,
Effectiveness of control surfaces,
Noise in the cockpit,
Noise to the ground,
Directional stability.
And for full sized planes they concluded that pushers were 7-10% less efficient than tractors, due mostly to propeller efficiency. Historically in full sized plane it takes about 100 horsepower to go 100 miles per hour so a 10% loss in power slows you down significantly.

1 - As already mentioned Dieffenbach did some fantastic work showing that propellers want clean air.
2 – Apparently there is still a debate about what wings need more, fast air or clean air, and fast air is generally preferred.
3 – Effectiveness of control surfaces especially the elevator, the elevator definitely needs abundant airflow in order to have control / elevator “authority”, the ability to change the planes direction as the pilot commands.
4 – Noise inside the cockpit to pilot and passenger would be less with a pusher, they use some serious headsets as a countermeasure for engine/cockpit noise.
5 &#...Continue Reading
Posted by JD-Slow-Thumbs | Dec 08, 2014 @ 02:34 AM | 2,174 Views
I would like to suggest an idea for FPV get-together events, FPV-Mini-Golf !!!

My concept would be for a group of FPV'ers to get together and rent some time at a local miniature golf course for a private party. Rent part or all of the mini-golf course and have some fun following the course for 18 holes and land at each hole. The landing sites would start out very easily as a wide bulls-eye pattern on the ground and become progressively more difficult as a smaller platform above the ground. Prizes or bragging rights to the winners, and feedback to pilots for how good they really are.

The platforms could take the shape of naval-aircraft-carriers (folding table) or skyscrapers (tall box).

Sponsors could bring inflated bouncy-house type obstacles/landing-zones to regional events. Using inflated objects this could even be done at indoor venues such as basketball, hockey, indoor-soccer, golf-dome.

One of the keys to this concept would be for it to be a “closed-course” where full-sized airplanes should-not-be, like below treetop level or four feet above a neighborhood putt-putt-golf.

Sure would be nice if somebody could post video of FPV-Mini-Golf ...

Thanks for reading

The discussion is over here