Fly RC

December 30, 2016

P38 conversion to “standard” 2 blade props… The plan.

As I think I mentioned in my last post, I really dislike the idea of having the 3 blade assembly on the Motion RC/Flightline RC P-38 being held together by the plastic back plate of the spinner and self tapping screws set into that plastic. In order to eliminate this, I started looking at options.

I first thought I would simply purchase some one piece 3 blade props… but upon further study I realized that the spinners supplied with the kit were customer made and would not directly support such props. Finding spinners that were appropriate would be possible but expensive and for all that expense I’d still have 3 blade props which are not my favorite from an efficiency perspective…

My next thought was that perhaps I just purchase the 2 blade spinners and props from Motion RC that are provided as part of their sport power set? The only issue is that the props are 12×8 two blade versus the 12×7 three blade set that is the standard set. I want something approaching the same load and speed profile as the original if at all possible. So the root question is what size and pitch prop in a 3 blade is most similar to the 12×7 stock 3 blade prop?

A bit of research revealed a loading factor can be calculated for any prop with the following formula:

PL=D*D*D*P*(square root(B-1) where PL=Prop Loading, D=diameter, P=pitch, and B=blade count.

Using this formula to calculate the loading factor of the stock props and then comparing to similar calculated factors for 2 blade options plus or minus an inch or two should give some propeller options that would be suitable.

In the course of measuring to see what options were possible due to ground clearance (I estimate anything up to a 14″ diameter would be reasonable) I found that the factory prop is actually about 6.25 inches in radius. Based on that I adjusted to a 12.5 inch diameter for my reference point.

After loading in several prop sizes it became obvious that a 12×8 two blade was a far less appropriate match than a 13×8. The 13×8 is less than a 1% load differential from the reference point while the 12×8 is 22% less load. This means that the 12×8 propellers available from Motion RC just aren’t suitable for my purposes… not with the stock motors. Based on past experience, it is highly likely that the difference between the stock prop and any other manufacturers similarly sized prop will vary by far more than this small percentage just due to blade shape and composition so, no guarantee but I think it will be close enough for my purposes.

This means I need both standard and reverse pitch 13×8 props and spinners. Note that the spinners must be be cut to match the pitch direction so just 2 standard spinners won’t work here either. Looking into all this, it appears the cost to get this all done is not exactly going to be cheap… So maybe a flight or two with the 3 blades is in order to determine just how much I dislike this setup! Maybe the plane will fly poorly enough that I won’t really want to spend the money… 🙂

Just as I was about to hit “publish” on this post I was assembling the propellers for both the green and silver aircraft when I had a problem that added yet another wrinkle…

As I was putting in one of the final screws on the final propeller assembly (for my green bird) one of the screws sheared off before it even got tight against the prop! Here’s a picture of the result:

I’m a bit concerned, wondering if the other screws are all this weak? Just when I was thinking maybe these assemblies would be OK… This did not add to my comfort level. I’m really in a quandary now as to which way to go.

December 19, 2016December 21, 2016

P-38 assembly… going slow but some progress

With the recent move to a new house, time in the shop has been minimized but that is starting to change and I had time recently for a couple sessions.

Session one started with some of the structural assembly. Motion RC has provided an assembly video and between that and the manual we got most of the screws in the right holes on the first (OK, second… maybe third) try. Well at least I guess we did. If you decide to get one of these I highly recommend you go through the video and the manual a few times to figure out which screws go where before you assemble anything. Luckily (or maybe by design?) The screws are all the same diameter so even if you use the wrong ones, you aren’t permanently expanding the holes in the plastic and messing them up so that swapping them around later doesn’t create a big issue! Likewise the wiring runs can be confusing. Take special note that there is an extra wire on the port side which is where the landing light is located. We got both the nacelles, the horizontal stab and the center pod all tied together and the wiring runs done during the first session mostly by just following the video.

Let me take a moment here to add in some commentary on the ease of assembly. The manual that comes with the airplane is a bit confusing (thus the video I suppose). Most of the manual seems to be redundant information since a lot of the document is dedicated to installing the servos and landing gear and similar information on topics that are unnecessary since these things are already done for you! I appreciate the extra work that has already been done for me but then why do I need instructions on how to do it? I initially tossed the manual to the side and just started to work from the video, but it gets very tiresome trying to play a section/stop and backup and try to find the same section again to be sure what I thought I saw was correct… I’m convinced I could work much more quickly from a standard written document than from this video. After a while I went back to the video and kept the manual handy as a secondary reference. It has some information about linkage lengths and screw sizes that are somewhat easier to find in the case that you need to double check anything.

Some other oddities with the video… What other “Comprehensive build video” includes such vital information as “Matte/Flat finish paint for enhanced realism”? I already bought the plane and don’t really need the commercials. It looks like you could skip the first several minutes or at least condense them to a list of parts that should be in the box. Also, if you are making a video rather than creating a quality manual, wouldn’t you think some voice over commentary to explain things would be included?? I mean, the video does actually include sound… it’s just that for some reason the producer of the video decided to use only text embedded in the video to impart information on which screws to use where, etc… I can hear the clicks and scratches of the screws being tightened but no actual instructions are provided as part of the audio track. Someone suggested to me that this is more universal (for non-English speakers) but the overlaid text is in English so that doesn’t seem to be the reasoning either. Maybe I’m just a throwback but I’d really much prefer a well written and illustrated manual that takes me through the actual steps that I need to complete the aircraft, rather than this somewhat bizzare video. OK, rant paused… back to the build.

Both of the aircraft in the shop got to this same stage of assembly on the first evening but for the next session I pressed ahead only on the green model (mine). For that session I enlisted the help of another flying buddy. Steve helped assemble linkages for all the control surfaces while I wired the various connections to the provided “control module” or whatever you want to call it.

Pause for rant 2…. I hope this isn’t the start of a pattern. The part I’m referring to looks sort of like a receiver. It’s encased in blue plastic and acts as a distribution point for the many, many, many… wires that you have to connect, as well as a sequencer for the gear doors and landing gear. It also provides one light connection that is strobed, 1 that comes on when the gear deploys and the other 2 are solid and all are labeled Light!? OK, extra credit for coming up with the box which encapsulates a few Y connections (but not all), a sequencer and the lighting controls… and then I take all that back for making me comb through the document (which labels it wrong!) and then finally just testing it myself or reading a few hundred posts on one of the two active threads that I’m aware of in order to find the actual layout of these light plugs. Oh, and before I forget it is clearly labeled but double check your polarity on those light connections… they are opposite the servo plugs that they rub up against!! OK, second rant finished.

After all that was done, I got the receiver bound to the bird and plugged in more wires… did I say there were a lot? Here’s what it looks like once you get it all connected and routed.

I’m not fond of this spaghetti bowl of wires either but their just seems to be no good way to tame them without some major rewiring. I’d do that if this was a $3,000 aerobat but for a standoff scale foamy I think I’m just going to live with it as is.

We then attached and mechanically adjusted all the linkages. This took a bit of doing since you can’t use much of the radios sub-trim when you have 2 or 4 connected servos on most channels. Nothing wrong with that… I recommend you always get your servos as close to perfect as possible by using mechanical means rather than radio settings. Just be ready to spend some time as you will need to do this for most every linkage and again the P-38 has a bunch so it can get tedious to get them all correct.

In a follow up session we did this same thing for the Silver bird belonging to Kelly. During the process we realized there were some wiring errors where things were plugged into the module (this is when we figured out all the lighting) as well as a retract wire that had been routed in a “non-optimal manner” which made it more difficult to get the wires all plugged in and the module tucked into the center pod.

Also between sessions 2 and 3 we went ahead and converted to the new “upgraded” oleo style struts. My experience with war birds is that you want all the help you can get absorbing landing forces without tearing up the structure, landing gear struts, etc… so these seemed like a deal at only $40 for the set. The two main gears were pretty much a drop in change. The only hard part is making sure you don’t strip out the set screws that hold the struts into the retract unit. About 15 seconds with my soldering iron in the whole prior to loosening each one did the trick nicely. Flightline/Motion RC did provide several new set screws with the new struts. Kudos for that. The new tires look better as well as being marginally larger which is always welcome. In both cases, I found that keeping the struts as long as possible (there is a very small amount of up and down space available within the groove cut to receive the set screw) helped with any tendency for the tires to rub or bind when moving in and out of the wheel wells.

The nose gear was a bit more of an adventure as it is held in place with an almost microscopic “C” clip. A new clip is provided for this as well, which is probably for the best as the chances are you will either bend this beyond further use or lose it when it flies off as you attempt to remove it. I had two to do and I encountered one of each. This is the modeling part, right? I managed to drop the replacement on one of them as well so was left scrounging for a replacement which I found in the bottom of a spare screw and nut drawer. (It’s not called Jack’s house of everything for nothing… my wife calls it hoarding… tomato/tomato).

Here’s the new strut in place… maybe its even worth chasing tiny c-clips around on the carpet! It sure looks nice.

During the course of all this I have had to disassemble some parts of the airplane in order to re-run wires and correct wiring errors on both birds. It’s a challenge to get done correctly and extra hands were a big help during the “re-work”. This is not a first ARF for sure!

I still have to do the linkages on the silver bird but then we will be back to equilibrium on both. There is still a lot to do but they are starting to look like airplanes and the Xmas holiday will afford me more time to get some shop time so I’m hoping to get them finished up soon. I am considering changing over to 2 blade props on my Lightning, but Kelly is going stock with his. The idea of screws in plastic being what holds the three blades in place makes me uncomfortable and I don’t want to spend a fortune in time and money looking for proper 1 piece props (with reverse pitch for one) and having spinners cut to match etc… So will probably find some simplistic replacements. I like 2 blade efficiency anyway if the ground clearance is available and I think it is.

Hopefully, I’ll have more updates soon.

November 18, 2016

The P-38s are here!!

As I got more involved with RC aircraft, I always wanted a twin engine aircraft… and in my book the only twin worth considering was the P-38 lightning. I have always thought the P-38 was a gorgeous aircraft and I kept an eye out for a chance to purchase a nice example but there were a few issues with acquiring one. Remember this was before the advent of high quality ARFs and certainly before low cost, high quality electric power systems became the norm so the only P-38s available were very large, very heavy gas powered craft with equally impressive price tags! Smaller glow powered versions were few and far between partly because keeping two glow engines in sync has always been a challenge and I would assume partly due to the difficulty of designing an building an aircraft as structurally complicated as the Lightning.

For instance, designing and building a light and rigid boom assembly with the landing gear location limiting your options for structural integrity in the wheel well area would certainly be challenging. And of course everything about the craft is round and tapered, making for additional challenges for the builder… especially if you wanted to create something close to the scale outline. Lots of beautiful curves means difficult to form from Balsa, glue and covering.

Lucky for me, the days of stronger foam, carbon fiber reinforcement and inexpensive electric power systems is upon us! Enter the Flightline RC P-38L available through Motion RC. Since these first became available a few months ago, my buddy Kelly and I have both been watching the various on line forums for reports of both build quality and the air handling of this latest iteration of an RC version of the Lightning. Reports seemed mostly positive so after he hinted for several months that we both should have one I recently texted Kelly with the phrase “I want the green one!” It only took about 3 days after that before Kelly arrived at my shop with two fairly large boxes. Here are a couple shots of the unboxing:

2016-11-10-17-21-47-opt

And here is the workbench (all 12′ of it!) covered in P-38 parts!!! Now that is a bunch of airplane parts….

At first impression I can say that these things are pretty impressive. For $349, you are getting what seems to be a fairly strong airframe with two motors, two speed controllers, 9 servos, 3 bladed props, spinners, decals for 4 different aircraft, servo linkages, etc… Basically it looks like EVERYTHING you need to fly except batteries and a receiver. Yes, as widely reported, you can certainly see the foam cell structure through the paint. This is especially true of the silver model as it has a higher gloss/luster to it. Scale aficionados will doubtless be displeased but the overall lines are very nice and I am not trying to win any scale contests here so my initial impression is that they look pretty good.

I’ll post more as I get to assembling. I’ve already ordered the upgraded landing struts (they seem like deal for $40 for the set!) and my receiver is on order as well. I expect to be posting again soon as I don’t think I can stand to let these lay around here for very long. Christmas just came a month or so early!

July 4, 2016December 16, 2016

Using my Hero 4 GoPro Session and the Carbon Cub to search for a downed RC Glider

Recently one of my flying buddies (George) lost one wing panel on his glider while sailing along over the cornfield adjacent to our field. A couple of us who own multi-rotors with decent cameras were called upon to go on a little airplane hunting expedition. Unfortunately, my only available batteries for the quad (a 350 QX) are a bit weak and I was concerned that with the expected distance to cover, I would have a hard time getting enough time over the search area to be effective. Also, at that distance, the QX was going to look very small and I just don’t have enough time flying it to be comfortable at that distance. On the appointed day of the big search I arrived at the field and started planning some way to get out there and do a decent search. Starting out at the very edge of the field or perhaps even staging in a bare spot somewhere further out were considered but in the end I decided to hold out a bit until my friend Martin arrived with his much more capable Yuneec Typhoon H.

In the meantime, I decided it might be fun to do a survey of the field with the Carbon Cub and GoPro Session. I had a vague idea that if the aircraft was sitting high atop the corn stalks I might have a chance of getting a glimpse! Even if we did see it in the video it seemed unlikely to do more than confirm a rudimentary vector to look on and perhaps a little more refined idea of how far off the field, but since it involved flying my cub… So shortly after I had the Session mounted and a fresh battery installed in the cub and away we go!

I angled the camera down 60 degrees or so and then started the video and took off over the corn. I made three passes out and back along the line that the pilot reported his lost plane. 5 minutes later we fired up my laptop and started playing the video and carefully advancing a second or two at a time and looking on the video for anything that didn’t look like corn and especially anything white (which is the predominate color of the down airplane).

So here is a short clip of that flight… I highly recommend full screen for this one.

Did you spot it? Here’s a single frame with a bit of help on what to look for.

If you want to go back to the video around the 39 second mark you can probably pick it up for yourself now that you know what to look for. Also notice that later in the video as I pass over the edge of the field you can get a line on where you would have to exit the field to find the downed craft!

In fact, after viewing the video a few times and following the row where we saw the plane out to the edge of the field and marking that spot as best we could… I walked out into the corn with one other person and we found it as soon as we got out far enough into the field. In fact I walked to within 2 rows of corn on my first attempt and had no trouble finding it!

At this point I have no idea if we were just lucky or what. It helps that the plane is mostly white… a military camo pattern would have been tough!! I do know the video created by this camera is pretty amazingly detailed. What your seeing here is very compressed version but even in this clip it is possible to spot that nice white spot in the corn!

For those who are interested, we were able to recover all but the one wing panel which we didn’t spend much time looking for after we realized the aircraft was pretty much destroyed in the wreck. With what we had it what fairly obvious what happened that caused the wing to collapse. After a stern talk with the ground crew (George mumbled to himself for a while) we were assured this particular error would not happen again! 🙂

The GoPro Hero 4 is an awesome little camera with all of the quality you expect from the folks at GoPro packed in a small little cube that can mount on a variety of RC planes in many ways. It’s significantly lighter and smaller than the full size bodies with very similar quality video output. It is NOT an FPV camera… it is a great way to record the action and then view/edit and enjoy the awesome airborn views. Here’s a link:

And if you need a great platform to carry it the carbon cub is hard to beat. It can fly slow (almost walking speed with the flaps dropped) or move along briskly and carrying the camera has little to no affect on it’s flying characteristics. Here’s a link for that as well.

The Carbon Z Cub isn’t perfect… it has some paint peeling issues, the main gear mount could be sturdier and the motor has been known to occasionally give up the ghost… I’ve documented all that in other posts here… but I still recommend it because it just flys so darn well and it’s just a blast to fly. Add in top notch support from Horizon and you have pretty good airplane.

Anyway, it was fun and felt good to help a fellow flier get his airplane back. Even staring at video of the corn passing underneath the plane was interesting. Who doesn’t like a good video from an “elevated” perspective. Hope your search patterns yield equally good results. I’ll try to post some more soon on other interesting projects and happenings at the field. Until then, happy 4th of July! Or as we always called it at my house… “Happy dad’s birthday!”

May 23, 2016

Conversion of the Telemaster 40 to Electric Power – Part 3

When is the 300th flight a maiden? Telemaster 40 returns to flight once more!

Since the last update about 6 months ago, I finished up the covering job on the Telemaster and got all the servos and radio gear back in the old Telemaster 40. The usual challenges of hindging, recovering and getting control horns back in place kept me avoiding these somewhat onerous tasks but once I got past some of that and got close enough to see the finish line I quickly finished her up and it was time to put her back in the air.

Here it is after the final decals were applied, screws tightened and radio system installed.

One of the common tasks I ran into when I went to reinstall the servos was to rerun the servo wires out into the wing bays. Of course I should have run those when I had the covering off but of course that thought didn’t occur to me. First, I applied the servo clips (how can you attach extensions to servo wires without those?) to insure the wires stay together.

Then I grabbed my custom servo wire guiding tool (patent pending) and thread the wires back in there… This tool is quite complicated (a string and a nut) and customizable by picking out a longer string or a smaller or larger nut! Here it is in action.

Tie your servo lead to the end of the string, fish the nut down through the wing and pull the wire though… presto!

With the 3700 6S on board the plane now weighs approximately 7lbs. Figuring the original 5.5lb weight (approximately) and adding the on board fuel weight (maybe 3/4 of a lb) means it has gained maybe 3/4 of a lb flying weight. This is a bit more than I wanted but this plane flew so light that I think an extra couple pounds would leave a flyable airplane but I admit I would like to keep it as light as possible. I fully expect the power system to be able to handle up to about a 9lb airplane to at least “hover” if not “pull straight out of hover” levels so it may be that the extra weight won’t cause a problem.

So, with all that in mind, off to the field to meet up with several of my flying buddies and see how it goes. This is the third covering scheme on this aircraft. It started off base white with some red and green highlights and then after I needed to do some maintenance that caused much of the red and green to exit, I decided over a white bread sandwich that red, yellow and blue polka dots were the answer. Now along with the conversion to electric power, I went to a combination of transparent yellow, white and checkerboard black/white. While all had their appeal, the new scheme is my favorite.

The first flight session went remarkably well. The new hatch gives ample access to the battery area and there is plenty of room to shift the battery to achieve any desired balance point. In addition it appears to allow for plenty of air flow and the magnet (which I had been concerned about) is keeping the hatch in place nicely. After the last flight of the first day, I noticed the engine had started to move. Upon further investigation I realized just how loose it was! Here’s a shot showing some of the issue.

Not one of the mounts is still tight! Two of the back screws are completely lo0se inside the body and one of the front mount screws is missing! Yikes! In the back of my head, as I looked it over I remembered thinking I would go back later and apply thread locker and re-tighten these mount screws. Such is the danger of spreading out a job like this over close to a year span. Later never quite arrived… until after these first few flights. I got lucky that no damage resulted.

Once home, I pulled all the bolts and added some thread lock before re-tightening and she was ready to go again. Next trip proved that the airplane still flies as well as ever. The added weight doesn’t seem to hurt, maybe even helping in somewhat breezy conditions. It seems to fly well with anything from my smallest to largest 6S batteries, from 3200 to 4500mah. The 32/3300 packs give me a safe 5 minute or more flight with the 4500 netting an easy 15 minute flight. Short takeoffs with flaps are easily doable with slow lazy flight being the real forte of this old but dependable platform. The plane will pull straight up indefinitely with any of the packs as well so float flying, glider tow and carrying my RC jumper all seem doable. This is a great start.

The 300th flight… or just the latest maiden flight. Anyway you look at it, the Telemaster continues to perform well. When I opened that box of sticks ~15 years ago… who would have guessed!

April 30, 2016April 30, 2016

Carbon Z T-28 Recommended modification

As I may have previously mentioned, my flying buddy Kelly has one of the big E-Flite Carbon-Z T-28s. He has trouble wiping the smile off his face when he’s doing one of his usual low speed, flaps down, no bounce, land like a butterfly with sore feet touchdowns. With the AS3X keeping things even more stable on breezy days, this thing is just smoooooooooooooooth.

We initially had some nose gear issues (replaced) plus we added some Multiconnex and there was an issue with the flap hinge cracking (the flap/wing surface is the hinge) which was rectified with some Blenderm style wound tape/hinge tape. As I recall, when we applied the tape we also replaced the wing control linkages. Everything about them is undersized for this big aircraft and some folks have had small issues… others not so small.

So after an early spring flight recently, I guess we shouldn’t have been surprised when the rudder linkage lost it’s center pin. Funny thing is we bought the additional parts way back then but never installed them. It’s funny because it wasn’t the elevator that quit working!! Kelly was able to get the airplane safely back on the ground and I have just finished manufacturing the replacements for both the rudder and elevator.

As you can see the original is just plain scrawny looking and our replacement is only 2-56 rod. I consider even that small for this size plane but since they are so short (kudos for that E-Flite) 2-56 is sturdy enough I suppose.

The moral of the story however is if you are going to buy the big T-28, I would highly recommend you just go ahead and buy the hardware and replace all the flight linkages (6 short rods and your favorite clevises) before it even leaves the ground. One less thing to worry about!

While you’re at it, order the Multiconnex (see that post here) and really make it easy on yourself!

March 29, 2016

BD-5B first flight… and almost last!

Let me just start out stating… when you get to the part of the manual where Aeroworks tells you to balance the BD-5B… and even tells you definitively “Do not skip this step! ” I highly recommend you just move on and leave that ’till after the first flight. This way you will have a much more exciting first flight and it certainly is more likely that you will be able to more easily transport the aircraft back home… I doubt you’ll need a very big garbage bag to carry what’s left. Unless you really want to fly it twice without repairs? I guess that’s one way to go, but if you are a thrill seeker not-balancing is a great way to go! Ask me how I know.

Ok, so maybe you should balance the plane… I opted out of that part so let me tell you a bit about my maiden flight.

It was a nice Sunday morning with the temperature approaching 60 degrees at noon. The wind was a bit brisk for an airplane this small and light (8-12mph) but it was pretty close to being down the runway so not terrible. After loading up and securing a 3S 2200, I dutifully checked all control surfaces which responded appropriately. Thinking back I recalled that I had checked the throws against the recommended and dialing in my usual (fairly aggressive) exponential settings. I even made sure I was in low rates as I expected that at speed this little ship would probably be a bit more sensitive that most that I fly. All looked good so after a quick taxi out on our Geo-textile runway I lined up into the wind and started rolling.

It took a bit longer to rotate and a bit more elevator too (note to self… maybe check to make sure the nose isn’t pointed down slightly??) but then it jumped into the sky and with a little down elevator it… dove for the ground!! Yikes, pull back up and it’s climbing like crazy again… After letting it gain some altitude it became a constant battle to maintain altitude and herd the plane around while constantly trying to find a mix of throttle, elevator and attitude that would smooth out the roller coaster ride. After trying several combinations, and barely recovering from several stalls and one trip to the far reaches of my visual range, I realized it was time to admit that there was nothing that was going to keep this plane flying level and try to figure out a way to get it back down in one piece… or at least a minimum number! Having used every trick that 20 years of RC flying experience has taught me to get to this point… it was time to just line it up, react and hope for the best.

On approach now and trying to outguess the roller coaster ride. Keep in some throttle to avoid any stalls until about 3 feet off the ground and here comes the seemingly inevitable plunge… A last second drop of throttle and simultaneous full up elevator just as it hits the grass with only a little bit of nose first down angle. Holding my breath but it looks like nothing too serious. The structure is apparently intact with only the nose gear pointing back a bit more than when it left the ground. All in all, I wasn’t unhappy with the end result. Just with the mistake that made this such a fight!

Here, you can tell where the wheel contacted the bottom of the body!

And this is back of the nose gear mount… You can see the wood split and allowed the landing gear “bearing” to rotate back

You may also be able to see that there is a groove that looks like there may have been a retainer of some sort but if it was ever there… it’s long gone now. So I created one using a washer and after re-gluing and clamping the wood to restore it to perhaps stronger than original, here is the result.

When I reinstalled it, it seemed as good as new.

Finally, I put the airplane with battery installed up on the stand and not at all surprisingly it took 3 ounces of extra weight were the battery sits… which is far forward… to get it to balance as recommended. No wonder it was such a handful! That equates to about an inch behind the recommended balance point. So the lesson, in case I had any remaining doubts, is “Always double check the balance!“.

To correct this, I can either throw some lead in there or drop in some extra milliamps… Normally, I would go for more battery capacity but I have no use for 2500-3000 3S batteries so I will likely just secure some lead and give it another try. At this point I am lucky to have a plane to fly a second time so I don’t have much to lose. I used all the skill I had and then got just plain lucky to get it down in one piece. Looking forward to a much less frantic flight!

February 11, 2016

Aeroworks BD-5B – final touches and photos

Did some final work on the BD-5B this evening. Here are a couple photos… still pre-flight.

You can see the Pitot tube (which I love on this plane) along with some of the decals in this shot.

The rear end of this plane has some bite! That spinner (stock) is nice looking and the APC 7x6E looks great and certainly seems to produce some push… at least sitting on the bench.

This view shows the interior which is admittedly cramped and messy with all the goodies stuffed in the right places to make the balance come out as specified. You can see the 2200mah 3S LiPo on the right (tucked into the nose). The tubes coming out from underneath it are going to the pitot which feeds pressure to the airspeed sensor which is tucked in the back (left/upper in the picture) part of the area under the canopy. Hidden under the wires in that same area is the Variometer as well. The Castle speed controller is velcro’d on to the sidewall at the bottom center. At the bottom left of the photo just behind and below the speed controller is the telemetry receiver with the g force sensor attached to it. Just in front of the servos, just peaking out from under the servo tray is the Spektrum receiver.

This may be a bit of over instrumentation for this little bird but once I see the data I can always pull some or all of it out… except the pitot/airspeed as it just looks to good to lose it! Hurry up spring… I need to get a few flights on this bird. 🙂

February 6, 2016February 11, 2016

Aeroworks BD-5B… Assembly

Over the past couple weeks I’ve been working on several projects in the shop as the weather in Indiana has not been especially hospitable for flying. It has been quite a bit warmer than in most years past for the time of year but still not up to my standards for comfortable flying. Sometimes the temperature tempted me but those mild temps usually came with gusty strong winds so no flying lately for me. The good side of that is it gives me some time to work on some projects in the shop!

The latest is the Aeroworks BD-5B I just finished putting together. Mine is pretty close to stock with only a couple small exceptions. On mine there is a pitot tube sticking right out of the front of the nose… which is about the only visible difference. I actually like the look of it on this air frame. Other things that are not exactly per the directions are:

E-Flite DS76 servos instead of the specified Hitec 55s… I like the 55s just fine but as speedy as this thing is likely to be I like having extra precision and torque of a digital.
In addition to the pitot for airspeed, I also have a g force sensor, variometer (altitude and altitude rate of change), temp sensor around the HiMax motor body, and voltage monitor at the pack as well as from the receiver bus.
I chose the Himax 2815-1400 per the written instructions which seems to be rated for quite a bit less power than the E-flite motor now recommended on the Aeroworks web page… I hope it will be sufficient.

I still have to setup the control surface throws and exponential settings but everything else is pretty much buttoned up at this point. Centering and direction of surfaces has been set. I need to apply the decals and any other final cosmetics I want to add and I haven’t picked up the propeller yet, but that is about all that is keeping it from graduating from static model to aircraft at this point.

There were a few minor annoyances when assembling… Belly pan fit could have been better, Canopy could extend down just a bit more or maybe have a structural frame added to help it fit better/keep its shape. Also, I am not a huge fan of the extensive use of the EZ type connectors where only set screws are keeping the control rods from slipping… Much prefer ball joints, standard pin clevises, Z-bends… really most other connection types! I may think about replacing some of those either before the first flight or shortly after if all seems to go well. Just seems a bit “under” designed for a plane that is going to (I presume) move along briskly as I expect this to.

My bird is 29 ounces with a 3 cell 2200mah on board. With the Himax 2815-1400 and an APC 7x5E or similar, I expect about 150 watts which should give me decent performance… 85mph? more? We’ll see soon. I am a little concerned if this will be enough, plus I have never flown a pusher and the lack of airflow over the surfaces at lower speeds (no propwash) has me thinking that landing this might be a bit more interesting. Only one way to know for sure!

I have had this ARF sitting on my shelf for a couple years but until we got a geo-textile runway recently, it just would have been impossible to take off or land without risking damage. Now, with a place to fly, it is finally going to get its chance to soar! Once I dot the last i and cross the last t and get a flight or two I will take some actual pictures and do another post on how it actually flew.. or didn’t!!

January 17, 2016September 7, 2018

Balsa USA 1/4 Scale Cub – Part 4 More Mods – Rudder Shape.

Another modification I recently accomplished on the Cub is to reshape the rudder. Again, I have decided to just look at the general outline of the aircraft. I realize that when covered, some of the “ribs” will not be in the right place and anyone looking closely will be able to tell this but in the air I doubt anyone will be able to tell! They will see the outline, which I hope will at least be suggestive of the real Super Cub!

So here is what I did. After careful comparison of the shape of each I decided that just a bit of a change to the trailing edge of the rudder would take care of the primary difference between the J3 and the Super. Besides… I’m always happy to have a little more control surface! In order to accomplish this I decided I would just laminate a new trailing edge.

Here’s the process. To start I used my balsa stripper to create some strips of the proper width from a sheet of 1/16″ balsa. After a quick sand to make a slight flat spot at my “start” and “stop” areas I pinned down the rudder and used some thin CA to tack down one end of the first strip.

I then bent the stick to shape and tack glued down the other end and then trimmed of the remainder with my Xacto knife.

I then added two more layers of stripping. On each one I used some wood glue between the layers and then tacked it in place with pins and some thin CA to insure it didn’t move before the wood glue set.

Once finished with the third strip, I added some additional support at the point where the existing “ribs” would have contacted the trailing edge. With just a bit of sanding to round things off a bit and to taper the new material at the ends and mate it up with the existing structure, the final shape was complete.

The structure is quite strong and once covered I think most folks will find it to be a fair match to the outline of the real Super Cub.

There is plenty more to do in order to get this bird finished so… more to come!