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Posted by JD-Slow-Thumbs | Dec 07, 2015 @ 11:36 PM | 1,568 Views
Well I got a chance to try out my catapult and it was totally wimpy I think there is too much friction in the “pully” system where the bungee cords' cloth covering goes around stationary eye-hooks. At the field I could not get it tightened-up enough to get a decent launch. After all that work building that catapult, I ended up hand launching after-all. So much for calibrated consistency.

The test glider, my JD-12, is a delta front with a squared off back, using a KF-step of 3/4 inch, swept back 30° bilaterally, 30 inches wide, 20 inches nose to tail. (20x30 that sounds familiar from somewhere). The airframe itself, just the Blue-FFF and R-Tech foam and a spritz of 3M-77 adhesive and 3 inch wide packing tape weighed only 104 grams. To represent the weight of the electronics and miscellaneous hardware I used a roll of pennies. Did you know that a roll of pennies weigh about 130 grams. Anyways my all-up-weight was 234 grams which is real close to the probable registration threshold of 250 grams. I have a 40 inch wingspan version where the foam air-frame only weighs 124 grams.

Between the wimpy catapult and 15 mph gusts I did not get very far with my experiment. I was lucky to get a reasonable Center-Of-Gravity figured out. I think. For an easy throw, it floats along very nicely. But for a hard / fast throw, it curves up, stalls, and nose-dives. It leaves me wondering if the Center-Of-Lift can change depending on airspeed. Or it might just be that darned gusty wind.

Here is a picture.
Thanks for reading.
JD

Requires Further Research !
.
Posted by JD-Slow-Thumbs | Dec 05, 2015 @ 12:33 AM | 2,325 Views
I think that I see something special in the Kline-Fogleman stepped airfoils and since I love to experiment I decided to do some experimentation to test some of my theories. In a earlier discussion BMatthews suggested that I build gliders for my testing. He also suggested building a system to get a consistent “Throw” so that flight times and/or flight distances could be compared. Good idea.

I spent last weekend building a catapult with a 30° slope, and ran out of weekend before I could try it out. During the week I decided that 30° was too steep and too tall, so today I modified it to be only 15° slope and not so tall. This had the added benefit of fitting into my car easier.

My catapult is based on 8 foot long twin rails, that are 3 inches apart in this version, with a 15° slope. I used 2x3 inch boards from Home Depot and some leftover plywood for the basic shape, and 1/4-20 carriage bolts and matching fender washers and wing-nuts for ease of re-assembly at the flying field. In this version the rails are 3 inches apart to accommodate my two HP-SuperFly's (EasyStar derivative) and my two Air-Hogs-Titan's. This rail separation will also work good with my experimental deltas once I add small “keels” to them. In my next version of this catapult I will probably use forks that hold the rails about 9 inches apart to accommodate planes with 8 inch propellers. The forks that set the rail separation are modular / swap-able. I almost forgot to mention that it uses a long bungee cord to accelerate the aircraft. The bungee cord started out life as a cargo net from Harbor Freight.

Here are a couple pictures.
I plan on trying it out tomorrow.

Thanks for reading.
JD
Posted by JD-Slow-Thumbs | Dec 04, 2015 @ 11:42 PM | 2,004 Views
I think that I see something special in the Kline-Fogleman stepped airfoils and since I love to experiment I thought that I would build a tabletop-wind-tunnel to test my theories.

Well … I started out asking for suggestions for cheap telemetry, and, ended up getting a quick education in wind-tunnel design, and came to the conclusion that I would not get very far using any blower compatible with the 15 Amp 115 Volt house current in my garage.
http://www.rcgroups.com/forums/showthread.php?t=2513381

HugePanic suggested that I setup my experiment on top of my car so that I could get 60 mph airspeed without the hassle of buying a motor plus blower with large cubic-feet-per-minute and then fine tuning the turbulence out of a wind-tunnel. I will probably get around to a car-top experiment later.

BMatthews suggested that I build gliders for my testing. He also suggested building a system to get a consistent “Throw” so that flight times and/or flight distances could be compared. Good idea. I liked it enough to start down this path next.

Thanks for reading.
JD
Posted by JD-Slow-Thumbs | Dec 04, 2015 @ 08:41 PM | 1,532 Views
Quote:
Originally Posted by Ldm View Post
I see this the most feasable in the pharmacy segment. Small packs, light weight, urgent deliveries of meds etc .
I saw this and gave a response worthy of a Business Major

I totally agree with pharmacy deliveries. - From a regional hospital or pharmacy to smaller satellite hospitals and nursing homes. Everyday, nursing homes and small hospitals need something that they do not already have. Currently regional pharmacies need to own a fleet of cars/vans and hire drivers, usually to make once daily delivery routes, (I remember, order by 3pm and receive it by 8pm, the backup plan is a local pharmacy and local taxicab company).

The reverse would apply to medical lab-work getting picked up from outlying doctor offices and going to a central / regional medical lab. Again this is currently typically a once daily pickup route with the lab providing overnight service so that the doctor can deal with the answers the next morning.

Also I can see a lot of businesses wanting to get their afternoon small shipments to the FedEx terminal after the standard 3pm pick-up time.

So Yes, I can see a few commercial applications for drone delivery and pick-up service. Actually I see fast pick-up, so that you do not lose a cycle of once-daily service to be the most urgent business demand. So far I am not seeing the demand from the consumer sector.

Can any of you all think of any more high volume commercial needs for drone pick-up / delivery service.

Starting to get more interesting,
JD

P.S. Someday it would be interesting and fun to place an order for hot pizza and cold beer and receive it by drone.

But I think the chances of ordering anything off the beaten path like "Rotor_Drone_Magazine" or "Model_Airplane_News" or a book like "Drones_for_Dummies", would result in a message saying "Not-Available-For-Drone-Delivery".

The discussion is over here
http://www.rcgroups.com/forums/showt...2554855&page=6
Posted by JD-Slow-Thumbs | Dec 01, 2015 @ 10:35 PM | 1,770 Views
While weighing the elctronic components for my Sub-250g-Flying-Machine, just for fun I decided to weigh my Smart-Phone, and it weighs 222 grams ! (LG-VS880 with crash resistant cover).

This is giving me a little perspective on just how Freaked-Out The Establishment Is.

I bet that somebody here has a smart-phone that weighs over the 250 gram threshold.

Thanks for reading.
JD

"Establishment", for a guy way over thirty, I sure am sounding like a dang hippy.

Discussion is over here
http://www.rcgroups.com/forums/showt...5#post33336815

Recently the DOT/FAA commissioned a task force to make suggestions for how to implement national registration of “Drones” including traditional R/C-Airplanes, so that a crashed drone could be traced back to its owner, and among other things they recommended that anybody operating a drone over 250 grams be required to register as a “Drone-Operator”. In response to this situation many people in this forum are very unhappy about it and really going nuts about it. Meanwhile I am only a little unhappy about it and I am currently developing scratch-built-foamies intended to fit under this 250 gram threshold.
Posted by JD-Slow-Thumbs | Oct 07, 2015 @ 12:10 AM | 2,377 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
JD
Posted by JD-Slow-Thumbs | Apr 05, 2015 @ 03:58 AM | 2,763 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 | 2,947 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.
JD

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 | 3,376 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
JD

The discussion in the Radio forum is here
http://www.rcgroups.com/forums/showthread.php?t=2367187
Posted by JD-Slow-Thumbs | Mar 09, 2015 @ 01:23 AM | 2,815 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
http://www.rcgroups.com/forums/showt...4968&page=2&&&

Thanks for reading
JD
Posted by JD-Slow-Thumbs | Mar 04, 2015 @ 01:11 PM | 2,791 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
JD
Posted by JD-Slow-Thumbs | Feb 24, 2015 @ 03:03 PM | 3,437 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
JD

The Poll with discussion is over here in Scratchbuilt Foamies
http://www.rcgroups.com/forums/showthread.php?t=2355400
Posted by JD-Slow-Thumbs | Feb 19, 2015 @ 01:29 AM | 4,509 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:
http://www.rcgroups.com/forums/showthread.php?t=2351069

Thanks for reading
JD
Posted by JD-Slow-Thumbs | Feb 03, 2015 @ 12:51 AM | 3,899 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
JD
Posted by JD-Slow-Thumbs | Jan 26, 2015 @ 09:54 PM | 2,907 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
JD
Posted by JD-Slow-Thumbs | Jan 19, 2015 @ 09:44 PM | 3,343 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 | 3,268 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.
JD

Here is information for the R-Tech foam that I am experimenting with,
http://www.rcgroups.com/forums/showthread.php?t=2289454
Posted by JD-Slow-Thumbs | Jan 12, 2015 @ 05:46 PM | 2,313 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.
JD

edit - Here is information for the R-Tech foam that I am experimenting with,
http://www.rcgroups.com/forums/showthread.php?t=2289454
Posted by JD-Slow-Thumbs | Dec 30, 2014 @ 02:14 PM | 3,148 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
JD

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 | 2,757 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,
http://www.knifeedge.com/forums/showthread.php?t=30989

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

Thanks for reading
JD