Tips and Tricks

April 24, 2026April 24, 2026

Adding flight pack voltage monitoring with select Spektrum receivers

I use exclusively Spektrum radios and receivers in my RC aircraft. However not all of my aircraft have smart ESCs (all are electric). Many have other brands that are doing the basic funtionality quite adequately but lack the one feature that I routinely use in all my aircraft which is battery voltage monitoring.

I’m not a big proponent of the full Spektrum chargers and batteries… that bit of added technology is not worth the cost difference for me and I don’t want to sign up to the technology induced brand lock-in that comes along with that as well. Spektrum battery prices are too high for the quality in my opinion, though I am generally a Spektrum fan when it comes to radios and receivers as well as the complementary Avian branded ESCs and servos.

Happily, Spektrum has allowed for this on many of the receivers in the form of a 2 pin port labeled (conveniently) volt! If you are looking to monitor the voltage of the flight pack which is also supplying the power (via the BEC built into the ESC) to your receiver the task is fairly simple. What is required is a connection from the positive lead of the ESC battery to that 2 pin port. There is a wire supplied with the receiver so all you need is to make the connection. This assumes, of course, that you have a capable transmitter.

There are adapters available, but what I want to document here is a simple method I’ve used successfully many times involving the use of a pin to probe this lead. Here’s my step by step.

First, grab that little two pin lead and an Xacto or similar utensil and chop of the black wire, right at the connector. You don’t have to but you don’t need that wire in this circumstance so I like to just be rid of it.

pic-cut lead

Next, get yourself a sharp, small diameter pin, your small wattage soldering pencil or iron and solder and a bit of small diameter heat shrink tubing. Strip back some extra insulation on the voltage lead and get ready to solder.

Now, wrap the wire around the pin a few turns and solder (very little will be needed) the wire to the pin.

Now you want to push the heat shrink up over the connection. This helps strain relieve the connection and covers up most if not all of the pin that would otherwise be left exposed. I like this pin with a bit of a plastic head on it as this makes it easier to push the pin into the wire.

Next insert the pin into the red wire somewhere conveniently along the lead form the ESC to the flight battery. Route the wire so there is enough play to accomodate whatever motion you need to make to plug the battery lead in. I like to connect somewhere as far up the lead AWAY from the battery connection as possible in order to limit the amount of needed motion. I used a wire tie to help secure it in the pictured case (my Flightline 64mm A-10 v3).

Now just plug in the lead to the port on the receiver (note the polarity… it is keyed so it will resist you inserting it incorrectly).

Once you have made it this far you can power up your radio and add the voltage sensor in the telemetry screen. Several pics to help you find those options below. These are from my NX-8.

You can set alarms and voltage level warnings as you please. Once the sensor is enabled in Telemetry, you will at a minimum have the following display screen available.

I hope this helps some folks out there to take advantage of monitoring your battery voltage without necessarily spending a lot of money, time or effort! Enjoy.

November 10, 2024

A sudden rash of failed HV LiPo batteries… an explanation?

Nearing the end of my normal flying season, I had begun to notice several of my batteries were hitting low voltage alarm levels quicker than expected and some warming up a bit more than I recall during previous flights. I quickly found that 7 of my 9 six cell 5000-6000mah batteries are essentially done and all 3 of my 4S 2800mah batteries are likewise underperforming.

Testing via my trusty internal resistance meter shows that every one of these packs has 1 or 2 cells with unacceptably high resistance numbers. This tracks with the observed issues.

While a certain number of failures are expected, this year seems unusual in the number of failures and the fact that many of the failures are newer packs and the largest number of them are HV packs!

So what is going on?

Well the explanation is of course a bit of science mixed with a bit of conjecture.

Here’s the data points I feel are relevant:

All of my HV batteries are 2 years old or less.
While some of my batteries are 4 years old (or maybe more) 8 of the 10 failed packs are LiHV packs. This is every LiHV pack I own.
My battery maintainence is a bit lacking.

I often leave my packs in a fully charged state between flying days. Essentially, I charge up everything a day or two before flying and whatever doesn’t get flown (typically down to 30-50%) is left charged as nothing is done until I’m getting ready to fly again. Combine that with my busy schedule this year, which means I’m flying less often and for shorter periods… and you have more batteries sitting at full charge for longer periods.

That is where I think things went south. I also believe the reason the LiHV packs were affected more than any others is that they are simply less tolerant of the abuse I heaped on them. As with anything, you don’t get something for nothing and this certainly seems to be the achilies heal of these type of packs. Sitting at such high charge states for long periods of time seems to cause more damage than standard cells treated the same way. I would suspect an electro-chemical difference just makes them more susceptible to this… more so than just being at 4.35V rather than 4.2 but I really don’t know.

Luckily, over the past few years, many manufacturers have upped their games when it comes to high quality LiPo cells for reasonable prices so I can buy some really great value standard voltage batteries that will perform as well as the LiHV packs in my application. So I think I’m going to back away from the HV packs and just purchase some high value standard packs for the coming season.

I got a bit over zealous the past year or two and overspent a bit on the LiHV packs for what I need. I’ll leave those to the high performance guys and try to find a better performance to money balance for what I need.

June 2, 2024June 2, 2024

Turbo Timber 2M SWS Part Seven – Disaster!

All of our planes have expiration dates on them, and unfortunately the Tubro Timber 2M’s clock expired on May 30th!

Here is a shot of (mostly) parts after the crash

This was very disappointing after all the time and effort I took to set this airplane up the way I wanted it. Often, I purchase a plane and just do what I think is necessary to get a few good-safe flights before deciding if I wanted to spend the time to really make it mine, but I took the route of “I will be flying this plane for years, lets do it right!” with the TT,

I have documented a majority of those changes in previous posts so I won’t rehash those here. So what happened?

I was flying my third flight of the day when things went wrong. On the first couple flights, I had been practicing some short takeoff and landings. Using take-off flaps and full throttle got me takeoffs with lots of right torque and about 2 feet of roll from a dead stop! Nice… need to work on correcting for the torque. With short landings I was making full flap touches and then slapping in reverse thrust. Not quite mastered yet, but promising! I did lose one prop to a ground strike while doing this so gave up on that manuever for the day.

Flight three, I started experimenting with the flight envelope. I made some slow passes with full and partial flaps along with some rolls, loops and other basic aerobatics. I had also made a couple of high speed passes. I had just noticed that one of my high speed passes registered 90 mph… wow. I made a nice half loop climb to about 300 feet and rolled back to upright. I then pushed down gently at about 2/3rd throttle, intending to establish a 45 degree dive back toward the runway. As I rolled in more throttle I suddenly lost control of the pitch of the airplane… I believe I made it to about 20 degrees down pitch when it pitched back up momentarily… what the???

At this point I heard what was obviously flutter of the elevator. If you haven’t experienced it, I can tell you it sounds like a loud buzzing sound and you won’t like it. I immediately pulled back on throttle and tried to level the plane but instead it simply pitched a bit further nose down and dove to the ground. She hit hard with about 60 degrees of nose down. Later investigation showed damage to the cowl (mangled), electric motor box (crushed), landing gear (ripped out), windshield, front and rear wing mount (ripped out), horizontal tail (shattered on both sides)… etc… It was pretty much a total loss airframe wise. Wings looked better but it turns out the root rib on one is broken and the other has quite a bit of compression damage on the trailing edge of the flap and aileron.

As is often the case, it is impossible to be 100% sure, but I think this is the culprit:

This picture is showing the elevator clevis as it existed when I recovered it from the wreckage.

In retrospect, I should have known that an airplane with this amount of power and speed should not use plastic/nylon clevises. I just don’t trust them at 90+ mph… Its disappointing that E-Flite didn’t use some better hardware and even more so that I didn’t think to change it out. My only excuse is I honestly did not think the TT would be quite this fast… I was thinking of it as more of a STOL airplane.

I have since figured out that the hardware is 2-56 (more or less). Its a bit sloppy when I thread a standard 2-56 metal clevis on the rod… I’d minimally use a jam nut with a metal clevis and likely I’d likely use 2-56 with bolt through ball links. I don’t think there’s a need for 4-40 as all the rods are nice and short!

I would love to get another, but I won’t spend the full spend again on a BNF. I’ll consider an ARF or 2nd hand purchase if I can find one… and in the meantime I am reaching out to Tower Hobbies both to inform them of the issue and ask if they are willing to work with me on a replacement. I don’t expect them to just ship a full replacement but I’m hopeful they give me some consideration toward the cost to do so.

If nothing else I’m hopeful they will add some sort of advisory, so that others can consider some way to avoid similar occurances in the future… or even changing out the hardware on future production runs.

Please learn from my mistake!! If you have a big/powerful/fast airplane with similar hardware… consider an upgrade.

I’ve linked the previous information on my adventure with this aircraft below. Please browse at your leisure.

Part 1 – Buying and unboxing

Part 2 – Inspection and possible modifications

Part 3 – Assembly and modifications

Part 4 – Radio setup, modifications, and repairs

Part 5 – Final tweaks

Part 6 – Flying and Analysis

April 30, 2024April 30, 2024

Building Skills as an RC Pilot

Advice for building skills as an RC Pilot

This might be my first true “advice column” here on my web site… blog… whatever this is. Hope you find it useful.

I intend this as friendly advice to those who fit the following description:

Comfortable with basic flying skills on at least a basic trainer… maybe up to a mid-level flyer who flies some aerobats or warbirds but isn’t a competitor in IMAC or scale contests, etc…
Want to improve flying skills. Either you’ve been flying for some months/years and feel like you’ve plateau’d in skills and aren’t sure what to do next or you are just comfortable as mentioned above and want to build up skills before moving onward and upward to new and varied airplane types.

So the premise here is this. The next time you are preparing to fly…. think about flying with a purpose. By that, I don’t mean to imply that you must make your flying time into something that is pure drudgery, just give yourself a goal or two for that flight. Spend just a minute or two out of your flight doing something with a purpose.

For instance, as I sat and watched some folks at the field recently I saw several pilots come in to land. Lets just say some of those landings were less than perfect. Landings are some of the first things I would encourage you to set as a goal… i.e. fly with the purpose of setting your plane down at a particular spot on the runway. At our local flying field, we have a very wide/long runway. Most of that is grass, but there is also a roughly 400’x40′ piece that is covered in geotex fabric to better accomodate smaller wheeled aircraft. At a minimum, your purpose would be to try to land on the fabric part of the runway… not the grass.

I know folks already typically try to do that, but I don’t see folks really committing to that as evidenced by the fact that many grass landings happen without a single go-around occurring. If you still have some battery left (assuming an electric powered aircraft) and the landing doesn’t look like it’s quite going to touch down “on the spot”… why not go around and try again? This is another good lesson to learn, and a good habit to get into… don’t commit to a bad landing!

A further refinement is to try to have wheels touch down (for instance) directly in front of the pilot… not just anywhere on the runway. If you really want to do this reliably, you may want to make more than one landing during your “flight”. You can also do some touch and goes. Keep in mind you don’t have to commit your entire time at the flight line to this, you can still just go out and bore some holes in the sky if that is what you enjoy!

There are many other examples I could use. How about making sure you do 3 nice smooth loops? Did the loop look round? Did the loop track the same all 3 times with no side-to-side variance or “traveling” up or down the runway so that the exit point didn’t move? Can you do it for a 20′ loop? A 100′ loop? Did the airplane appear to travel the same speed on the upline, across the top and on the downline? Do a few of these during your next flight.

How about doing a lap or two (or even a figure eight) while maintaining inverted flight?

How about making a perfect 4 sided race track pattern around the field with no difference in altitude or change in speed?

Sometimes flying with a purpose is part of the setup of the airplane. I will go out to fly with the only purpose being to test out 3 different rates on my elevator to discover what combination of throw and expo works best for me? Once I know what I like, I will set that as my default rate and either turn the rate switch off, or if I need a different rate for another reason, work on getting that setting figured out as well. This type of flying with a purpose can not only make you a better pilot as you strive to control the plane more decisively, but it can result in your plane being easier to control as well! No one needs to know the reason you suddenly look like a seasoned pro is setup related, not necessarily your awesome piloting skills!

I hope this has you thinking about ways you can fly with a purpose and improve your skills. If this doesn’t appeal to you, then, keep on boring those big holes in the sky and just enjoy!

January 21, 2023February 22, 2023

3D printing add-ons for the Freewing JAS-39 Gripen

I recently acquired a Freewing JAS-39 Gripen (Griffin for us English speakers). I’ve never had much interest in EDFs but why I have it and what possessed me to buy it is a topic for another post. For my purposes here, it is enough to say I have one and I wanted to make it look a bit more formidable by adding some weaponry, help out with balance with a little added weight to the aft of the balance point and just add some scale touches at least for display purposes.

Luckily, there are some readily available STL files. STL files are the output of a CAD program and are what you need to input to the slicer software which produces the G-code files. The slicer software parses through the STL file to decide what instructions to send to the 3D printer to create the shape and creates a list of those commands which is your G-code file. So, having the STL files means the hardest part of 3D printing what I want (the actual CAD design work) is done for me!

I printed a couple of Iris-T missiles first using some white eSun brand PLA+ filament. The Iris-T is the European equivalent to the US Sidewinder missiles. Both are extremely smart, relatively short range heat seeking air to air missiles. The Gripen can carry either but I decided to start with the more “native” weaponry. These are almost always carried on the wingtip hard points on the Gripen and since the wing tip hard points are already in place on the model, it made sense to start with something for those stations. They came out pretty well with only a little bit of stringing and just one or two very slight imperfections. I was pretty happy. There are keyhole slots in the end of the rails on the wingtips of the Gripen and there are mounting rail STLs available so I printed a few of those as well. The missiles have a flat spot designed in where you can easily glue these to the missile. Once that was done, with only a little sanding/carving/cleanup I was able to slide the missiles onto the wingtips. Here is a pic of the IRIS-T on the wingtip of the plane pretty much fresh off the printer with just some minor gluing and sanding. These are 1/9th scale just like the airplane.

There are a couple of nice things about having these on the plane. First, they add some needed tail weight. The Gripen has a very swept back Delta wing so the wingtips are far back from the desired CG so while not the ideal place for extra weight, its not a terrible spot either. Second, they cover up the sort of ugly wingtip “rails” with some nice eye candy. And third, I’m thinking there may be some wingtip strikes with the landing gear being fairly narrow as they are on many jets, so they can act as wing tip protection to some extent. I can print another missile or fin or whatever, but the wingtips of the airplane would be much harder to reproduce and replace if they get beat up or broken.

Next I tackled some Meteor missiles. These are long range, radar guided air to air missiles. In real life these things are around 13 feet long, so scale they are around 16″ long. These are massive and carry a big warhead. Imagine a telephone pole coming at you with a big bomb on the front… at multi-mach speeds! Used properly they are on par with the best such weaponry out there. With the right launch parameters and guidance these can be fired from 100+ miles away!

These are generally carried on under wing pylons on the Gripen but the model doesn’t have any built in hard points for those so I had to print out the keyholes/hardpoints and the pylons themselves and get those mounted on the plane. It took some carving in the wing, careful alignment and slowly digging a bit deeper until I had what I wanted then glued the hardpoints in. With those in place I could slide the pylons on and lock them in place then slide the missiles in place under the pylons and lock them in and bingo, we are in business. Below are some snapshots of that process and the results.

This is the outline of the mounting socket as I’m starting to remove just the skin/paint in preparation to route out maybe an 1/8 inch or so of foam so I can glue it in..

This is the socket in place.

The tape attached to the pylon is adding some pressure after the glue is in place and just starting to setup nicely. It looked a little off so needed some pressure to get it to sit level in the wing.

Here’s the whole thing after I hung a meteor on it… starting to look pretty good!

After I got this far I was down to needing sanding and painting so I started doing a bit of research and found a variety of paint schemes available and went to work. The meteors especially varied a lot, so I took a bit more license with those and stayed with the white scheme but the IRIS-T is almost uniformly and almost completely gray so I decided to reprint those so I wouldn’t have to do so much painting (I hate to paint!). Then I took advantage of where some of the color bands are to cover up some of the glue joints with pin stripe or color bands on both missiles.

Meteors (on left) and Iris-Ts (on right)

I’m sure for the true scale guys these are nothing special but I think they add a lot to the look of the airplane and the effort was not huge. For me, having the 3D printer (and the efforts of the guys who first did the design) made it possible to really upgrade the look of the airplane with minimal effort. And no one has anything that looks like these!

Of course, it doesn’t end here. I have engine inlet and outlet covers printed as well and I’m eyeing some fuel tank designs I’ve seen…

So if you are wondering if you need a 3D printer to add a little extra something to your hobby… the answer is of course, NO. But I recommend it. There’s a lot you an do that will add that little something extra to your favorite bird. I expect to do a bunch more of this in the future.

December 5, 2021

3D Printing… Handy tool for RC airplane work? Or maybe just another hobby to eat up hours!!

After a sad end for my Top Flite P47 due to radio failure, I have been in the market for a replacement and started reading about the Hangar 9 20cc P-47 ARF. While doing some research I chanced across some posts talking about printing a new cockpit for the bird on a 3D printer… and the wheels started spinning.

Of course I know that 3D printers are too expensive, take a special brand of wizardry to operate, etc… so I inquired with a friend of mine who has perhaps 5 of these magical machines. So when I asked if he would be willing or how much it might cost to print out these cockpit he response was link to a large online retailer for a 3D printer!! Hmmm… seems like a hint. Here is a link in case you want to follow me down this particular rabbit hole.

The first thing I noticed is that this particular printer (at the time I purchased it) was under $200…. far below what I had expected. After another week of research and self justification… I placed the order.

I’ll save all the trials and tribulations of assembling the printer, testing, adjustment, more testing, etc… I decided not to have a go at printing the cockpit interior immediately. Soon enough I started finding other uses for the new printer within my RC hobby. Here are a couple of examples…

First, I struggled with getting an electric nose retract to work for the tail retract of the H9 P-47. The geometry just didn’t work with the provided linkage so I began creating a replacement, and after a few iterations I came up with a design that worked for me. Being able to change dimensions and reprint or print 3 or 4 slightly different designs and test each really made it possible for me to get this working!

Here’s one of the early iterations..

And here it is installed on the aircraft for testing.

Also for the P47, there was a pattern available to help guide the wing wiring into the fuselage for easier assembly so I printed those up and installed them immediately.

Here’s the guide tube fresh off the printer…

And here it is installed in the body of the airplane.

Next, I managed to drag a wingtip on landing on my Texan II and broke one of the scale protrusions off of the underside of the wing. I shortened my redesigned unit a bit and made some minor concessions to ease of fabrication and printed a pair of replacements.

Here you can see the broken part and a replacement part being test fitted on the wing.

And here is the new unit in place after using some marker pen to add a bit of color.

Next I found the tail wheel mounting bracket of my Tundra to be somewhat weak… a known issue at the time. I found someone had already designed an alternative, so I printed up a replacement. Actually a couple!

Here are a couple alternatives I found… The top is a bit more solid and the lower a bit lighter but how well will it hold up??

Certainly many of these things take a fair amount of time to design, prototype and print. But in many cases there are no replacement parts available or there are many options but no way to know which might actually work so 3D printing provides a way to work through the options without ordering and praying you find the right part, eventually.

So the real answer here is, Yes! 3D printing is a hobby all its own and can eat up a lot of time and effort. It can also be an immeasurably useful tool for the RC modeler. If you continue to follow my posts here, you will very likely hear more about it.

January 24, 2021

Hangar 9 Carbon Cub 15cc ARF … Part 3

In part 2 of my commentary and running monologue on the Hangar 9 Carbon Cub, I mentioned that I would cover the bottom vent that I added and some other mods so I will show you a couple of those here as well as try to relate my sense of how she flies. First the build and modifications update.

Bottom Vent

Looking at the cub I realized there is not a lot of accommodation for air flow and even if it isn’t much I’d like to have at least a modicum of air passing over my batteries inside the cockpit area. So without just cutting open a whole section between formers/bulkheads in the bottom of the tail I needed another solution. What I came up with was to cut open a section in the only solid area behind the cockpit, which is the hatch for servo access. I happened to have some louvers laying around that I picked up at a swap meet so I cut an appropriate sized hole and drilled a few holes for button head #2 screws and created a nice louvered exhaust vent. It’s very nice looking (even if not quite scale!) and looks like it belongs there. Was it enough exit area… well read on.

Top Hatch blows off!

Taxiing out for the first flight on the airplane, everything seemed great. I had done a balance check, the prop seemed to be well balanced, producing a minimum of vibration, all the surfaces were moving in the proper direction and with the proper authority… Nothing left to do but fly. Unfortunately upon reaching about half throttle, about 10 feet into the takeoff roll the top hatch that I had created decided to eject. Testing a second time showed the same issue. It hadn’t been jolted loose on a bump either it was simply being swept up by some combination of the air moving over the top of the wing and the air pressure forming inside the plane as the motor forced air into the various openings in the firewall. While the louvers I had installed on the bottom of the plane might insure a good vacuum to pull some air past the batteries once she was in flight, they didn’t do enough while the plane was just starting to roll to avoid the top hatch getting popped open. For the day, I simply applied some box tape along the front and rear edge of the hatch and things were fine from that point on. For future flights I had to do something to make the latch mechanism a bit stronger. Clearly the magnets I had in place were insufficient.

Before the next flight I eliminated the magnet and screw head that I had used to secure the hatch and cut a groove in the wood and created a tab using a servo horn to form a rotating latch that would insure the hatch stayed in place. Ten or so flights later, this seems to work well.

Servo arm loose on rudder!

The final lesson re-learned on the second or third flight of maiden day for the Carbon Cub was that you should always tighten all the screws and check all of your servo arms, linkages, etc… before flying. The rudder and elevator servos are under that bottom hatch and so not observable without unscrewing and removing the bottom hatch. Apparently, when I was setting up the plane, adjusting throws and linkages and such I had neglected to make sure all of these were tight. The servo arms are metal and are a decent fit but slightly loose on the servo shaft. If the teeth are engaged there is zero slop but if you don’t tighten up the servo shaft screw the arm will slip off and rotate out of place… especially when sitting in the trailer, bouncing down the road under the force of gravity I imagine?

So 2 or 3 flights in was doing some stall turns and I was getting adjusted to just the right inputs to get an acceptable looking maneuver when it flopped out of one of my attempts. Since I was low on battery I decided to come down and check out my throws and see if I could improve on the next flight. When I landed, my plane was crabbing slightly toward the pit area so as soon as the tail dropped down to join the mains on the runway I started to feed in just a touch of rudder to straighten the roll out… It wasn’t enough so I pushed in more but nothing occurred. I was far to close to the pilot line and rolling fairly slowly so throttling up without being able to change heading was not an option, especially with a plane I had only a couple flights on and knowing someone was occupying the flight station I was quickly approaching. Instead I hit throttle kill and watched it roll up and bump the flight station. Other than a startled fellow pilot, no harm was done. He maintained focus and control of his airplane and I went down and apologetically retrieved my errant bird.

Of course as soon as I saw the rudder “freely” swinging in the breeze I dug in and found the culprit quickly. I applied just a small amount of nail polish (thread locker is known to attack some of the “plastics” used in servos… Hitec Karbonite in particular but others as well… so I largely avoid it around my servos) and tightened the screw and have had no further issues with this connection since.

Flying with the Power 60 on 6S

The Hangar 9 team recommends the Power 60 for the Carbon Cub if you are going electric and I think they have a pretty good combo here. With my 6S 5000mah packs I believe the plane is capable of handling about anything the real world plane can do, and perhaps a bit more. This does NOT include an unlimited vertical climb with out assistance from the wings but it is not far from it.

My impression is the plane flies just a little “heavy” on the wing and thus requires a bit more speed than I would like, but keep in mind I fly mostly very light, overpowered aircraft like my EF Laser on an Xpwer 35 and 12S, the Timber X on 4S, the Uproar on 4S, etc… For a war bird guy, this thing would probably feel lighter on the wing than most and most scale pilots I suspect would see it as being “about right”. You have to remember that while it has “Cub” in the name it is NOT the ubiquitous yellow J-3. It is not a floater that is hard to get on the ground but it is predictable and smooth. If you incorporate the flaps into your landings (as you should), the plane will land at a very manageable moderate speed with only a little time spent with the tail still flying after touchdown. It’s not a total kitten either in the air or on the ground but in return it is a very capable flyer and a beautiful airplane both close up and in the air.

December 25, 2020

Top Flite 60-90 size P47 ARF… Gas to Electric P4: Flying the P47 with Electric Power!

After completing the power conversion of the Top Flite P47 to electric power it was not long before I had the opportunity to put some flight time on the bird. In the course of a couple weeks I put around 10 flights on the Jug. I’ll relate some of the issues and fixes, impressions and performance information in this article. I don’t recall exactly in what order all this occurred or was measured so I’ll just hit the various topics without trying for any sort of linear time line… my memory just isn’t that good!

First, I’ll draw a comparison to my “outgoing” Thunderbolt, the FMS 1500mm P47. While I’ve always enjoyed flying the FMS aircraft and would recommend it as a smooth and good flying airplane, I prefer the Top Flite in the air.

While just a few inches larger in wingspan and several pounds heavier, it just seems to fly more like a warbird… in only the best ways.

Neither are hard to land. The FMS can land slower due to wing loading but also due to just being a lighter aircraft it tends to bounce around a bit more. The Top Flite likes to land a bit hotter, even with flaps but it settles in nice and rarely wants to bounce. The FMS may be a bit more aerobatic, but either can do anything a real jug can do plus more and the Top Flite seems to just track better and slice through the wind better. Everything it does is smooth where the FMS can occasionally be a bit more twitchy. Not terribly so, but noticeable if you fly them back to back.

Of course it may not be a fair comparison considering the power system differences but my Top Flite is certainly faster and looks it even though it is a bit larger (my experience is larger planes actually look slower). I always thought the FMS looked a bit slow in the air considering it’s a fighter plane. It certainly flies well even at slower speeds which is nice on approach but without making some changes it was never going to keep up with the Top Flite.

The other big difference between the two is flight time. Unexpectedly the bigger Top Flite can loiter much longer than the FMS. I figured using an 8S system would give me higher speed but at the cost of weight (the Top Flite is heavier even if it was only running a 6S) which would balance out and result in the same 6 minutes or so down to about 30% in the packs that the FMS typically did. I’m running the same 5000mah capacity, just more cells. Instead, as I recall, I landed at 6 minutes and had 60% left in the batteries on the first couple flights!! Now on those first couple flights, I probably wasn’t pushing it quite as much as I normally do the FMS but the flights since have convinced me to up my timer to 7 minutes and even with some more aggressive flying I am landing with 45% or more of the battery capacity remaining… I’m not really sure why I get such great efficiency but I’m going to try bumping up the prop size a bit to get a bit more punch and see how it affects things. Nothing is getting overly hot as is so I’m hoping for even more power and still having a 7 minute flight to 35% on the batteries…. we’ll see.

Aside from the flying characteristics I have made a few other changes/repairs on the Top Flite P47. After these changes it has completely replaced the FMS which I recently sold to another pilot.

First of all, I noticed that one of the flaps on the Top Flite could only extend to perhaps half of the recommended travel so I had to setup with that as the max flap throw. On the first flap assisted takeoff (with about 65% of available travel), all seemed OK but on landing with full extension I was disappointed with the effect. Other flap equipped planes I’ve flown certainly slowed up and assumed a nice sink rate where the P47 did not slow as much as I was hoping with the available travel. On closer examination it certainly appeared whomever had glued in the hinges had gotten them a bit to tight, which was causing the push point hinges to push against parts of the wing trailing edge. With some judicious trimming I got closer to 75% of recommended travel but no more. It was all I could get without cutting the hinges and starting over. Happily, it was enough that on the next landing the Jug slowed up significantly and dropped in a bit slower. I wouldn’t mind a bit more flap but it’s now very manageable on landing. It likes to land a bit fast, but that is very typical warbird like flying.

I still land a bit faster than I really have to as I’m really still just getting familiar with the way it flies and particularly how it lands. At one point that certainly bit me. We have a nice Geotex runway at our field about 250′ long and I love to land on it when I can. Partly, I just like to control the plane and land it where I choose versus just letting it land. I also feel like the landing gear is less stressed when it doesn’t have to drag through the grass. Putting the plane down “on target” is a good skill to perfect as it can come in very handy when conditions are less than ideal or when landing at facilities that don’t boast our 700′ well manicured grass runway with almost unlimited approaches! On the particular landing in question, I came down a bit fast due to some crosswinds (it’s easier to bring it down fast and maintain control all the way to the ground) and I was rolling tail high, holding a bit of rudder to offset the wind when I rolled across the one flaw in our Geotex runway… a little ridge where the grass edge of the runway used to be. This popped the plane back up in the air just long enough to carry the plane into the grass. Once in the grass I tried to let it settle in but the sudden transition from tail high rolling on grass to the same in the grass caused a quick nose down rotation as the wheels touched back down and she did a flip over on her back…. just hard enough to snap the top couple inches off the rudder! In retrospect I should probably have juiced it a bit and slowed my decent or even gone around but all in all it was ugly and embarrassing but it was a fairly clean break and an easy repair. It also broke the prop which was more expensive to fix but otherwise she was unhurt.

The other occurrence during these first flights was when the battery hatch decided to do its own “off field landing”. I was not a fan of having magnets in the front of the hatch and pins in the rear as this was built but I decided to give it a try. In order to keep the hatch in place I took the liberty of attaching a couple more magnets inside the body to increase the pull of the existing setup. This certainly seemed to help it really snap into place, but apparently that was not enough as around flight number 4 I landed with no hatch in sight! The really odd part was that I didn’t get unusually high or far away and at least 2 other people will swear they never looked away during the flight, yet all agreed the hatch was attached on takeoff and no one saw it come off but it surely was not on the plane on landing! Again, I was frustrated as the hatch was such a nice feature and creating a proper curved replacement was not something I really wanted to spend a lot of time on but I had no real choice. The new hatch now has this latch centered on the leading edge and I don’t believe it is going to part ways quite so easily in the future.

With that taken care of there are a few “clean-up” items I want to address. The cowl is a bit hacked up as it was cut to allow for the DLE-20 and of course you can’t buy a spare for a plane that hasn’t been produced in a number of years… I’ll have to figure out if I can find something available that fits, or if I will try to repair what I have.

A second item is that the cockpit is empty and I would love to find a nice pilot figure that looks appropriate in size and style. I’m eyeing some “Benchcraft” warbird busts from Motion RC. At the price, I will probably order 1 or 2 and see what looks good.

In the meantime this is simply an excellent flying airplane and a great power setup that I’m really enjoying. I’m very happy that the stars seemed to have aligned on this airplane.

May 9, 2020May 10, 2020

Spektrum connect issues… resolved?

One of my largest aircraft currently is my Extreme Flight 74″ 12S powered Laser. It is also one of my favorites due to ease of assembly at the field, unlimited vertical performance and the fact that it is capable of such beautiful aerobatics! Sometimes it even looks good when “I” fly it! Yep, the plane is certainly more capable than her pilot.

Really the only issue I have had with this plane for quite some time is on that occasion when I get it assembled and ready to fly… except the iX12 radio and 12 channel power safe receiver will not connect on power up! It’s very frustrating. It’s not that it has lost bind… I’ve occasionally gotten it to work again by cycling power once or twice or even just taking it back home and trying again… It’s was never obvious what I actually did to fix it… and sometimes it seemed nothing would. It happens very rarely and usually if I just go through a rebind process it works perfectly from that point on for a long time. This typically only occurs if the plane has been sitting idle for a period of times… week or months (like first flight of the spring) is the most likely time to have this occur.

So being as it is just getting to be good weather for flying on any kind of consistent basis here in Indiana, I just ran into this issue again! This time I was at home and had decided to tinker a bit with the Telemetry when it once again refused to talk! Power up the radio, power up the plane, pull the pin switches for both receiver and speed controller and… nothing. Everything is sitting at centers and the usual sing/buzz from the servos but no link…

I tried a couple of power cycles and still no luck so this time I decided to post on the Spektrum group on Facebook. After several posts back and forth and a number of excellent suggestions, one gentleman pointed out that the power safe receivers would not link to radio if the proper number of remotes (he even said if just the A receiver was down, that would do it) didn’t come on line and suggested checking the contacts and coating them with electrical grease to shield them from problems. An intriguing idea so I went back to the airplane and did some more testing. As I did so, I also noticed that I had not done my normal strain relief on these cables so I decide to take care of that before all was said and done.

What I found was that in fact the A receiver was certainly not linking up (no lights if I recall correctly… or at least no steady light) and once I re-seated the cable, everything linked up instantly. Repeated testing showed it all working perfectly from that point on.

I have a fair amount of pride that few of my planes crash due to “avoidable” assembly and maintenance issues so I like to track these issues down and resolve them whenever possible and then apply the fix wherever it makes sense on the rest of the fleet. This airplane for instance has redundant flight packs separate from the power packs that run the motor, nylon insert nuts on all of the ball linkage bolts, Telemetry monitored battery levels, etc… in order to make sure it is as reliable and survivable as is possible/reasonable. So I decide to see if I could eliminate this issue for good.

After collecting the necessary items (all shown here except the liquid tape) I started to work to resolve this issue.

The process went something like this… First pull the remote receiver (they are all attached with sticky back Velcro, so this is not hard to do) and the cable from the airplane. Inside the box (I’m working in the living room so protecting the furniture/carpet from harsh chemicals and spills) I spray some contact cleaner into the end of each cable connector and into the remote receiver connector. Once dry, I took a toothpick and forced some dialectric grease down into the holes on the cable connectors and then coated the pins in the connector as well. I did the same on the receiver while still installed in the airplane… luckily it’s somewhat roomy in there… and then reconnect everything and wipe away any excess that squeezes out.

That should eliminate the possibility of corrosion in the future so once all was back in place I moved onto painting on some red “liquid tape” right on the back of the connectors and onto the first 1/4″ or so of wire for each of the four cables that connect to the remote receivers. This helps to share the stress on those wires and eliminate the most likely break point for the connections. The liquid tape will flex but doesn’t allow for kinking or pulling on the individual wires. I have had a few of these wires break before but never had an issue once I applied this little “hack”. I apply this while everything is plugged in typically. If a bit gets on the receiver or over the outside of the connectors it doesn’t hurt a thing and simultaneously it can’t get in the way of the actual electrical connections if applied this way.

Here are the two plugs on one side of the receiver.

And here is one of my receivers sitting on top of the motor box under the cowl. You can see how I have coated the connection, further protecting the wires against stress and contaminates to some extent.

We will have to wait and see how this works out. I have high expectations that this problem is likely resolved and I feel very positive that this improves the likelihood that this plane will fly for years to come… or at least until I make a mistake behind the sticks!

September 9, 2018September 10, 2018

Balsa USA Bristol M-1 Part 1: Motor mounting

A while back, my flying buddy Gary gave me a Balsa USA M-1 Bristol as a thank you for some work I had done on an airplane of his… or maybe it was a few airplanes… or a bunch! Anyway, we had both seen it at a swap meet and I had admired it but he bought it. I think it may have been traded off and then reacquired at some point before it found its way to me but in any case it has been sitting in a corner of the shop for a while now and I finally picked up what I think will be an appropriate power system for it, the E Flite Power 46 and a Castle Creations Talon 90 Speed Controller. The Talon is a bit of overkill but for some reason seems to always be available at a relatively lower price point in the Castle line (my favorites). It has an outstanding BEC capability and can handle up to 6S and 90A. Castle and E Flite are among my favorite brands. The first task was to build up a good engine mount for an airplane that was kit built to mount a glow engine. To mount the motor out far enough to get the back plate beyond the cowl face means spacing out somewhere around 3″ to the back of the motor in this case. Nose weight is also not a consideration since the Bristol is so short nosed and more likely would need more weight up front if anything. Finding some 3″ spacers is difficult at best, and I like the idea of something more rigid anyway (long spacers tend to flex or twist a bit under load). To accomplish this I decided on using some shorter spacers mounting to what I refer to as a sub-firewall and then more short spacers to the X mount on the back of the motor. This assembly is very strong and uses a few easier to find smaller spacers and some rigid plywood to put the motor out where it is needed. Here are some pics showing the assembly.

Mounting plate tie wrapped to spacers used to mount speed controller.

There are a few other necessary installation tasks… servos to be mounted, an arming switch to mount, and making sure the battery can be located in a spot where the plane will balance… but progress is being made. Looking forward to flying.