SMALL - SMALL - Telemetry SMALL - Radio
JD-Slow-Thumbs's blog
Posted by JD-Slow-Thumbs | Dec 18, 2014 @ 07:02 AM | 968 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 | 1,334 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 | 2,267 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 | 1,749 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 | 919 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
Posted by JD-Slow-Thumbs | Nov 21, 2014 @ 09:40 PM | 1,505 Views
We often hear complaints about Local Hobby Stores closing up shop, and the loss of these assets to the hobby-community. Yes I still like to see and touch what a new product is like, but the prices that I am finding are usually more than I want to pay. (Generally I have turned to scratch building foamies instead of ARF clones),

Compare To Camera Stores
Once upon a time I regularly went to camera stores to get not only film but developer and print paper too (yes I had my own darkroom). Then it became that I just needed film, because it was less hassle let somebody else develop my film and make enlargements. After digital photography became popular I stopped going to camera stores because photo-quality inks and papers could be found cheaper at office supply stores, lately I have been going to Office Depot for my “photographic” supplies.

How Soon Do You Need It?
Recently I went to a LHS looking for some small inexpensive batteries so I could fly my new model the next weekend (as a beginner I do not need the premium). At the LHS one battery cost $23, via mail-order I got three batteries plus shipping for $21, and all it took was wanting them in a week instead of this afternoon.

Plan Ahead And Stock Up
Another influencing factor, the cost of shipping from mail-order encourages people to plan ahead and purchase more than one battery or prop at a time, so people will tend to stock up on three or four batteries and a half a dozen props. When I decided to get into...Continue Reading
Posted by JD-Slow-Thumbs | Nov 21, 2014 @ 02:15 AM | 1,446 Views
To Club Or Not To Club – Many activities naturally form into leagues like; bowling, baseball, soccer, while other activities do not have a lot of formal structure like; jogging or fishing. Some of the activities that naturally form into clubs and leagues are competitive sports.

The larger heavier planes made of balsa with nitro/glow engines naturally need real flying fields and clubs to buy and maintain them. If your foamy can be hand launched or take-off from a driveway, then you don’t need a lot of formal-structure/club/league.

Annual Budget versus Annual Cost Of Membership – After your initial investment in a trainer, transmitter, charger, extra-batteries, etc… you can buy an additional ARF every year for $150 or less and think that you have it real nice and luxurious.

Some clubs are cheaper and some clubs are more expensive, I live half way between two clubs, one club costs $83 (AMA 58 + club-dues 25) the other club costs $233 (AMA 58 + club-dues 70 + initiation-field-fee 105), both of these clubs are considered cheap compared to a $300 club. People have always been value conscious, lately more people have become more frugal. Now if the budget says that you can spend only $100 per year, then the local club becomes a lot less attractive. You can get a cheap micro-airplane for around $100 or build your planes out of DTF, and you will not have to join a club to fly them, thus saving yourself one or two hundred dollars a year. These new micro pilots are just about invisible to the mainstream club fields. (BTW if you can only spend $100 per year, then you might not last very many years in this hobby). (BTW I belong to the cheaper club at $83/year and I love the camaraderie and sharing at my club).

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 21, 2014 @ 01:36 AM | 1,402 Views
Apartment Sized Hobby – Many of us have/had a nice garage to keep our hobby stuff in and a workbench to clutter up, and many of us live in apartments where we have to clean off the dinner table that we borrowed and put away our stuff at the end of the every evening. Park-Flyer size and Micro-size airplanes and Small quadcopters that come in a box the size of carry-on luggage is a much better size for apartments.

I just figured out that I have about twenty cubic feet (20cu-ft ~ 2 cu-meter) of rc stuff plus a six foot folding table/workbench. For a fun challenge, the next time you look over your rc stuff try to estimate how many cubic feet it takes up, it might surprise you.

Thanks for reading

Update to a reply on 3-11-2014
Posted by JD-Slow-Thumbs | Nov 21, 2014 @ 01:10 AM | 1,373 Views
Customer Expectations – User Friendliness.
Thanks to the generation that put men on the moon, and thanks to the generation that learned to program their VCR's. The “Younger Generation” has enough familiarity with using computers, programming VCR’s, playing video games, fiddling with cell phones and GPS navigation systems; that they/we have acquired some confidence around technology and consumers now expect a higher level of user-friendliness. The $50 quadcopter that I bought a couple months ago was more “user-friendly” than the $120 Bixler that I bough just a couple years ago, the quadcopter flew for ten minutes on my first try versus the Bixler which crashed in ten feet on my first try. Technological advances such as piezo-gyro flight stabilization systems and other anti-crash technologies and crash resistance is one of these “user-friendly” features that can make a big difference in converting visitors into newcomers into hobbyists. Technology and price are fast catching up with these perfectly reasonable customer expectations.

Thanks for reading

Update to a reply on 3-11-2014
Posted by JD-Slow-Thumbs | Nov 21, 2014 @ 12:17 AM | 1,344 Views
While looking for foam for building airplanes, foam without skin/coating or very easily removed, and not so much better as bigger/thicker...

I found a new source of foam from R-Tech available at both HomeDepot and Lowes in Los Angeles , it is white styrofoam with plastic skin on one side and aluminum foil skin on the other side which I can peel off easily and consistently. Available in the following thicknesses 0.50 , 0.75 , 1.00 , 1.50 , 2.00 , and always a little thin of the nominal dimension so bring your measuring stick.

Unlike the more popular foam core products like Dollar Tree Foam or the blue or pink Fan Fold Foam which are extruded, this still has mostly distinct Styrofoam bubbles.

I use this stuff for fuselages, my larger (medium) sized receiver and batteries fit into either the 1.5 or 1.0 inch thicknesses, now I am buying skinnier batteries and receiver to try to fit into the 0.75 thicknesses for fuselages. I have not yet tried any of this for wings, they do not seem to have a 1/4 inch size.

The only drawback is that it comes in 4x8 foot sheets, and I have to cut it down to fit it into the backseat of my car so that I can get it home.

Good luck and
Thanks for reading
Posted by JD-Slow-Thumbs | Nov 20, 2014 @ 06:58 AM | 1,360 Views
In response to recurring discussions about the value of keeping a “Relationship” with a vendor.
?Do I want a relationship with a vendor? --> No and Maybe

Primarily I want my purchases to work like a “Bic-Pen that writes first time, every time”. I want my Receivers, Batteries, ESC's, Motors, and Servos to “work first time, every time”. I mean who needs tech-support or customer-service if it works.

Now I think it is cool that the Local Hobby Store usually stocks spare parts like wings and fuselage for the Super-Cub and T-28 and others. But this is to address defective flying (pilot error) not defective manufacturing, and this kind of vendor support is appreciated and worthy of a relationship. (I am too cheap to buy the ARF's, but if I can buy a “Known-Good” wing for under $20, then my semi-scratchbuild/Franken-Plane creations get to fly a little sooner).

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 17, 2014 @ 02:14 AM | 1,784 Views
In response to recurring general questions of:
Kit vs ARF vs RTF, and Balsa vs Foam, and Fuel or Electric. - - (Kit = box of parts, ARF = Almost Ready to Fly, RTF = Ready-To-Fly).

I see three general phases to peoples RC hobby flying:
1 – Initial Entry Point, lessons at a local flying club, or Do-It-Yourself.
2 – Beginner / Intermediate skills, where most of the action is.
3 – Special aircraft and special skills.

After the initial entry point, in phase 2 - Beginner-Intermediate-Skills, when people are ready to invest in the hobby and buy not only the next plane but the batteries, charger, transmitter, transmitter-batteries that they plan to use for the next few years, and invest more time into the hobby to learn skills. At this point I think that most people want to buy ARF's that are manufactured to a "known-good" status, so that they can concentrate on improving their flying skills. Theoretically foam comes out of the mold needing very little labor to finish adding the controls. Theoretically a balsa ARF that is assembled in a factory by someone who has built hundreds of similar models will have consistently very high quality. Also for a trainer it is not good to be the first one on the block to have a particular model of plane, good choices of trainers include models that almost everybody has experience with like, Apprentice, SuperCub, T-28, etc... Trainers are mass produced and mass distributed and priced for the masses.

Regarding...Continue Reading
Posted by JD-Slow-Thumbs | Nov 16, 2014 @ 01:54 AM | 1,720 Views
This is one of my 80-20 statements, that you can do 80% of your flying with 20% of the transmitter options. That you can cover the beginner / fundamental skills in RC-Simulators, and for that matter also RC-Fixed-Wing, RC-Helicopters, and RC-Quadcopters,

After spending considerable time in the three main free and low-cost RC-Flight-Simulators; FMS, RC-Desk-Pilot, and ClearView; I have formed the informed and experienced opinion that only four (4) channels are needed for over 95% (98%) of the planes and features of these simulators. I spent a lot of time wondering why so very few models were available that used channels five and six of my 6ch-USB-Transmitter, it is because you only really need four channels to fly around.
4 Channels will cover the beginner / fundamental flying skills needed for:
Fixed-wing Powered planes with Yaw (rudder), Pitch (elevator), Roll (ailerons), Throttle.
Fixed-wing Gliders, Coaxial Helicopters, Fixed-Pitch Helicopters, and QuadCopters.

Yes, you can quickly think of ways to outgrow these limited models with; flaps, retractable landing gear, flaps, flaperons, differential-ailerons, and other tricks; and helicopters that have Collective Pitch. But AFTER you have mastered the fundamentals and you are ready to spend hundreds of dollars on the advanced models and the advance simulators, then you should also be ready to use an advanced transmitter, probably your real transmitter with your custom mixes configured the way you like them.

With the above in mind, I recommend the E-Sky 4 Channel USB simulator for the entry level simulator controller.

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 11, 2014 @ 01:45 AM | 1,384 Views
Many people are asking “Why have QuadCopters become so popular?”

First the big reason.

When a newcomer is initially investigating this hobby, he wants to know if he will have fun doing this. So that first aircraft is going to be an experiment and a GAMBLE to see if he can get the hang of rc flying. Obviously it is easier to gamble $50 on a RTF QuadCopter than $200 dollars on an RTF Airplane (plus AMA membership, plus club membership).

(Many people here talk as if choosing this hobby is like choosing a college-major or career or sport and that the answer to this decision is pre-ordained. Somehow our advice to potential newcomers always seems to be about getting the “right” stuff like transmitters and chargers that are totally appropriate for second year hobbyists but might be less appropriate for a person that is still wondering if he is even going to “like” rc flying.)

Next the smaller reasons.

Smaller Footprint – QuadCopters can fly very nicely in backyards, front-driveways, basements, auditoriums, parking-lots, etc... You do not have to pack up your plane and accessories and drive an hour to a useable flying site. If you want to get in a flight in the backyard before dinner, it is easy to do. They are a very good size for life in the suburbs.

Apartment Sized Hobby – Many of us live in apartments where our "workbench" is the dinner table and we have to put away our stuff at the end of the every evening. Small quadcopters and...Continue Reading
Posted by JD-Slow-Thumbs | Nov 10, 2014 @ 06:06 PM | 1,349 Views
My nephew, while in high school wanted a career as an airline pilot and was planning to earn his Private Pilot License in the summer after his graduation from high school. For Christmas 2012, I sent an RC-Simulator-USB-Transmitter (Dynam-6-Channel) and a lengthy e-mail (very abbreviated here).
Welcome to RC Flight Sim-ing,

I sent a USB Controller so that you guys get to try out RC Flying for free, to see if it is your cup of tea, and to see if you can keep a model flying for more than a minute, before spending serious money on a model that can crash.

Simulators In General: The newest free RC Flight Simulator is RC DeskPilot, it has several airplanes but is new enough to have only one scenery. The best low-cost simulator is ClearView, it has several planes and helicopters and a few sceneries available. The oldest free simulator is FMS (Flying Model Simulator) and has many planes, many helicopters and many sceneries, and old enough to need the consumer to find software utilities to get it to run in newer versions of windows. Tower Hobbies is the biggest distributor of RC stuff in America and along with their RC Airplanes they also sell what is regarded as the best rc flight simulator called REAL FLIGHT, lots of airplanes (from the Tower Hobbies catalog), lots of helicopters, lots of sceneries, and costs a couple hundred dollars. Horizon Hobby is the second biggest distributor of rc stuff in America, and along with their rc planes also sell a very good...Continue Reading
Posted by JD-Slow-Thumbs | Nov 04, 2014 @ 08:01 AM | 1,911 Views
I went to the AMA convention in Ontario (Los Angeles) since I live in the Los Angeles area, and while I was there I picked up a small quadcopter on closeout sale. I think that I upgraded the battery before I even flew it

The one that I bought had the little rings around the propellers (propeller guards or whatever they are called). This little guy was fun to learn and practice on, I could do my little hops, hover, scoot around, land on the table, practice figure-eights . And with the propeller guards I could even gently bounce into things like my garage door. Guys this is the new best entry-point into RC Flying, an overgrown kid can have fun while learning how to not over–control the aircraft and learn orientation by practicing figure–eights. Great Fun ! - - JD-9

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 04, 2014 @ 07:29 AM | 1,841 Views
About this time I was reading many Threads/Posts/Discussions where experts made comments about lesser pilots that almost never used the rudder on their 4 channel airplanes, and although the planes maybe could have flown a little more gracefully they seemed to fly more than adequately. I decided to see if I could tell the difference, so I built a plane, using over-sized foam board, without a separate Vertical-Stabilizer–Rudder, now the fuselage was a skinny vertical rectangle with large flat sides which should handle the yaw–stabilizing function.

Since I still was not good at gaining control of the transmitter after hand launching airplanes, I asked a friendly guy to pilot the transmitter/plane while I launched it. Big mistake, he flew it straight up, and as it was about to head back over the pit area with spectators he cut the throttle and let it crash straight down about fifty feet. At least the yaw issue (left/right) worked the way I thought it would, but it must have had a serious pitch trim problem to loop up like it did. - - JD-8

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 03, 2014 @ 01:51 AM | 2,410 Views
I was at a FunFly-And-Swapmeet and I picked up something that looked like fun. It was a Phoenix EDF, I mean how could I go wrong for $40 ? Well, I already knew it was a kit, but when I got it home I discovered that the servo-to-surface linkages consisted of five pieces per set, a bent wire going to the servo-arm, a piece straight wire for length, a piece of heat-shrink to join these together, another bent wire going to the control horn, and another piece of heat-shrink to join those together. Since I did not want to run a heat-gun next to foam fuselage-wing, I replaced the linkage system. Add a couple batteries and my $40 plane looks more like $60. Went really fast! Fun while it lasted - - JD-7

Kit vs ARF, in my opinion $0.25 worth of better material and $0.75 worth of labor to assemble this plane would have made for a much better experience. For only a dollar more, I will be glad to let somebody else assemble the plane into an ARF (Almost Ready to Fly) !

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 02, 2014 @ 01:38 PM | 1,895 Views
I was noticing a pattern where on a hard landings that the fuselage would break close to where weight was attached to the fuselage, near the tail (empennage) and near the nose with the motor and battery. My next invention would be the addition of rubber-band springs to the tail and to the “power-pod” hoping to improve the survival of the transients found in hard landings. This would also be my last 30 inch wing made of DTF for a while. - - JD-6

Thanks for reading
Posted by JD-Slow-Thumbs | Nov 02, 2014 @ 12:55 PM | 1,536 Views
I noticed that I was starting to go through airframes (generally wings lasted longer), so I started working with DTF Dollar Tree Foam. My first invention featured a built-up wing (Armin-Wing?) and a single big wheel, named after the “BigWheel” tricycle. Theoretically the single big wheel was more than sufficient for supporting the weight of the airplane, however the wings could never stay lever for that first second that was needed to gain some aerodynamic authority needed to obtain the “self-control” needed to continue the take-off without dragging a wingtip. I also learned that Dollar Tree Foam is not substantial enough for a wheel to rub against an axle.

Concluded that I needed less weight, so … the next the next variation went on a diet and lost the big wheel, it flew a little better. This is when I put on order a proper volt-amp-WATT-meter for experimenting with propeller-motor-battery combinations. - - JD-5A and JD-5B

Thanks for reading