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.

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.

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!

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.  
Motor attached to sub firewall
Sub firewall bolted to firewall
Mounting plate tie wrapped to spacers used to mount speed controller.
With the cowl in place
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.

Dumas Windy… now “This sucker’s electrical!”

After swapping in the power system from an E-Flite Timber, the Windy seemed to be ready to go but then I started to notice what sounded like a stutter on startup and sometimes even at higher power settings.  I did some research and found a lot of speculation around causes. 

Some report that connection issues cause the problem.  It seems a poor connection on one of the 3 wires coming from the speed controller can be to blame.  Others claimed it was a setting in the speed controller (timing) that creates the issue.  As best I could determine the connections on the motor end seemed fine so I tried re-soldering the bullets on the speed controller, then replaced the wires entirely but neither made a difference.  Since the motor is fairly inexpensive, I decided to try that next and placed an order.

While awaiting the new motor, I did some research and tried to program the timing on the 40A ESC that comes in the Timber.  I didn’t consider this to be a very likely scenario as most Timber’s don’t seem to make this sound but I thought I’d give it a try.  Based on my experience… don’t bother!  I have programmed several brands and types in the past and I tried to follow the published directions to no avail.  After researching on-line, I have found that this is the experience of all but a lucky few with this ESC.  Remind me to bypass the E-Flite line of speed controllers in the future.

Unfortunately, in my experience, E-Flite tends to have an appalling lack of information on the products installed in many of their ARFs.  This makes it very difficult to pick an upgrade part or replace a failed component, especially in the case of a part that is difficult or impossible to acquire from the manufacturer.  I am quite fond of the “Power” line of motors however, but I usually stick to that product set and avoid the motors that come only as part of an ARF.  I only tried this one as it was so inexpensive.

In any case, after the new motor arrived I tested and found it made ZERO difference!  Back to the drawing board.  The next step was to get a new speed controller.  My “go to” on speed controllers has always been Castle Creations.  In my experience, not only has the quality of the Castle products been high, but they offer many features that your average ESC doesn’t come with.  With the Castle ESC, I can get real time or recorded telemetry, programming either through my radio or via a cable to my laptop plus features like a throttle cut switch.  Yes, they are one of the more expensive manufacturers but I think they are generally worth the extra dollars.  Of course I am always looking for a discount!

A few days later I found a good deal on a 50A Phoenix Edge.  With a little extra overhead in the current handling capability plus the ability to handle up to 8S, programmable setting concerning timing, braking, etc… along with telemetry capabilities, etc… (I like to be able to move my gear on to other projects down the road) I cashed in a gift card to help soften the blow and made the purchase.  

After soldering on the appropriate bullets and power connectors, I tested with the Castle and the motor purred like a kitten… or screamed like a vacuum cleaner gone berserk once the  prop was affixed!  Since this controller is not water proof I decided to take some precautions.  First I hid it away in the pod to shield it from most water and second I did a quick water resistant treatment with my handy bottle of Corrosion X.  I have had good luck with components treated with Corrosion X being dunked (complete submergence)  and continuing to run so it has become my go to for insurance against water damage.

Here’s the dunk process to apply the Corrosion X. 

   

Then I let it drain for 10 minutes or so.

After a quick wipe with a paper towel to remove some excess from the wires I nestled it in the top of the pod with some foam around it to keep things snug

Then I buttoned it all up and tucked the wires well away from the propeller!

In testing with a 4 cell battery, the Windy was able to taxi around on my short carpet in the shop and readily pick up speed and turn.   I am looking forward to getting some test runs on the snow and later at the pond.  Best guess is that I may have a bit more power than before… I’ll try to at least add a comment here after some testing.  Wish me luck!

 

Re-Programming the AR636a in the E-Flite Timber

Please read Part II (located here) when finished with this post… it has vital information if you are reprogramming as I did!

After a dozen or so flights on the Timber I started thinking it was time to either replace the receiver with a non-SAFE/AS3X model or find a way to disable the SAFE mode (which I will never use) and be able to at least switch off the AS3X mode.  There is a fair amount of contradictory information out there and apparently there is no reliable way to tell which AR636A can be adjusted and to what extent.  Some, you can adjust the rate gain and priority but not the heading (this seemed to be the case on the Timber) while others apparently are locked down.  It wasn’t clear to me if I could setup the receiver from the Timber to keep the safe switch selectable as well as have multiple AS3X settings or not…  

I did find one place saying you could “upgrade” the code on some of these receivers and basically bring the receiver back to standard AR636 functionality.  Of course there are all sorts of warning that you are on your own if something goes wrong.  Since I’ve got a new receiver sitting on the bench ready for install… I decided to take the shot.

So I went into the Spektrum web site and registered my AR636 so I could download the code.  When the site took the serial number successfully I was heartened that just maybe this would work.  After viewing a few videos about how to program the receiver I decided to just go forward with sending the code and see what happened.  The software recognized the 636 SAFE receiver and allowed me to download the code.  To do this using a PC you will need the USB cable.

Here’s a link in case you decide you need one of these.

I immediately went in and changed a few settings and quickly thereafter the SAFE mode was lost for good!  No big loss for me… would be nice to be able to reactivate that somehow just in case I wanted to sell this plane but it seems unlikely I would do that… it will likely crash or be cannibalized at some future point.  Hopefully thousands of flights from now.

I now have all the settings set to zero gain for all three (switch selectable) modes… as well as taking away a couple servo reversing settings.   So I have effectively converted the the 636a to a dumb standard receiver!  Well actually it seems to be equivalent to a 636 now with expo, channel assignment and reversing and all the “gyro” settings available.  I can see where this would be really nice for someone with an inexpensive radio that didn’t have all the expo, assignment etc… already available.  For now I’ll just use it as a standard receiver and be happy with that.  Looking forward to flying the Timber without the stabilization to see how it goes.  Will be nice to see what the air frame and my skills can do without any help from the receiver.

Eventually I may re-institute some of the stabilization settings on a switch in case I want to do some “poor condition” flying and need a safety net or perhaps if some other folks want to get a flight or two in on a stabilized aircraft.  I kept an export of the original settings so hopefully, I can go back and re-import the original settings if I want to.

Looking forward to getting a flight or two on it soon to test it out.

Extreme Flight 74″ Laser – Build nearly complete

The Extrem Flight Laser has been in the shop now for about a month and I’m finally getting close to flying status!  My final items to complete are to get the speed controller and receiver installed, do the radio setup and then go back through and do final checks on bolt tightening, gluing any joints that need it and seal all the hinge gaps.

Overall, the instructions and included hardware seem to be good quality and short of flying it, I am pretty happy with it so far.  I’m going to get a bit nit picky over the next couple of paragraphs in hopes that this will help anyone else who is working on putting together.  There are a few shortcomings in the instructions worth noting and a couple tips I can pass on as far as what to do (or not) that may prove useful.   So here is my summary of the good, the bad and the ugly of building this ARF.

First off, when installing the control horns you need to remove some covering in order to get a good glue bond.  The instructions for this are pretty good but I would recommend a couple of ways to make this easier.  First, when drawing around the control horn base in order to know where to cut, I suggest a white board marker.  They are easier to wipe off with just some alcohol or window cleaner.  Also when removing the covering I remove only to just inside the line so that the base plate actually slightly covers the edge of the material.  This helps ensure that the material will never peal up around the horn and the result looks very professional.  Secondly, not only here but pretty much anywhere you need to remove covering… I highly recommend use of a soldering iron.  With minimal practice you can move at a rate that doesn’t char the wood underneath but just melts the covering.  It also seals down the edge as you go.  I find this method far superior to use of a razor blade or Xacto knife.  Extreme Flight’s manual mentions this option in one place but then often says to use a blade in many others.  I’d stick with the Soldering iron in pretty much all cases.

While on the subject of control horns, for some reason I got two sets of of rudder horns with no explanation as to why or what I might want them for… still don’t know.  In any case, I would install these dry and mark them once you measure for proper centering.  The “barb” on one side that I thought would end up against one side of the rudder to aid in alignment… does not seem to be any such thing and I don’t know why it is even there…  Just be cautious that you get the centering correct here.

One preference/ nitpick of mine is the tail gear mounting method.  I’m used to having blind nuts embedded but this gear mounts only with wood screws.  I would love to have the blind nuts as I think they result in a stronger mount.  Hopefully this mounting method will be strong enough.

The next note I made while building was regarding the rudder pull-pull mechanism.  First, if you have never put one of these together before you should go find a step by step instruction set that will walk you through everything you need to know ’cause what is in the manual for the Laser is not that!  If you’ve done a couple you probably will have no issue with this one.  One odd note is that they specify to crimp the aluminum tube with side cutters???  If your side cutters are worth a darn and you squeeze firmly you will end up cutting that tube and probably the cables themselves clean through.  A standard pair of pliers works quite well, thank you.  Don’t use side cutters!

Next, I noted that the instructions for installing the wheel pants had a couple of shortcomings.  First, when they have you drill a hole, they do not tell you what size hole… you can figure it out of course but it would be nice if they just told you… sorry I didn’t write it down or I would have provided that here (silly me).  Also when they have you install the blind nuts it required an excessive amount of force to get the little sharp prongs to push into the wood because the back of the wood inside the wheel pant has a fairly heavy coating of fiberglass/resin which necessitated a pair of channel locks to get the prongs to penetrate!  I felt like I was risking a good amount of damage when I did this but that is what it took to get them to embed flat…  and you need it to lay flat to keep it from rubbing against the rim/tire.

One error I ran into as I mounted the motor is the stated distance from the front face of the motor box to drive washer should be 6-3/8″… My ruler says it is actually 5-3/8″!  If you extend it to 6-3/8″ the cowl will not go back far enough to mount.  Luckily, I checked before I got things mounted.

OK, that’s about it.  Everything else seemed straight forward to me and I appreciated the packaging of the parts (individual bags with labels for each set of pieces).

I’m looking forward to getting started flying soon and the real test will be flying characteristics and how well she holds up over time.  Looking forward to messing with setups, props, batteries and telemetry to see what works best.

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.

AndHere

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!  ūüôā

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!”

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.

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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!

P-51 Redtail… More progress. Wing repairs progress.

Further work is occurring on my quest to reassemble the Redtail without spending significant dollars and simultaneously lightening it up a bit in the hopes of improved flying traits.

The latest is around the port side (that’s left if you were to sit in the cockpit of the P-51 facing forward) main landing gear mounting area and wheel well. ¬†That area took significant damage during the abrupt meeting between the retracts and beans at about 35mph! ¬†Yep, that is about stall speed… or at least is was that day.

Here is a sequence of pictures showing the progress. ¬†Most of this was simply measuring, cutting, fitting and a fair injection of TLAR engineering methods to try to get something put back together that will stand the strain. ¬†TLAR… you know… “That Looks About Right”!

After cutting out the sheeting and getting rid of the various splinters and unidentifiable fragments here is what I was left with.

 

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I cut away even a bit more before adding back a bit of structure… ¬†Rebuilding the rails so that the screws have something solid to bite into required some temporary bracing…

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Then I started building the actual rail structure and piecing them together with an eye toward making sure there was some interlock to help add some strength.  This rail notches into the rib and creates a lip for the rear rail to rest on.

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Here, all the rails are in place and all of the mounting screws have been drilled and put in place… lots of advanced TLAR to get the placement right (I hope).

 

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Then came the puzzle of re-sheeting around the fiberglass wheel wells.  I cut the existing sheeting back to expose a bit of the top of the spar and then pressed the sheeting down over the fiberglass to give me a cut line.  This created shapes like this ones.

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Then I added some small “railing” to catch the sheeting and give me some glue surface for the larger span of this piece of sheeting. ¬†There was also some reinforcing and rebuilding of the ribs that contact the wheel well that had to be done.

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Here are the pieces going into place.

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And the final bits of woodwork are glued in.

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From here is will just be some recovering work, though I have considered adding a bit of light fiberglass reinforcing underneath the landing gear mount area… ¬†We’ll see.

Next up is finishing up the covering and the last of the repair work on the fuselage.