PBY Catalina

January 27, 2015

All shiny again!

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January 27, 2015

Today my replacement plastic parts arrived … a new canopy and a new hull shield.  It wasn’t too hard to pry the old shield off, and the new part is already to slap on.

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January 26, 2015

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Here is a quick snapshot showing the new orange color on the engine cowls, the upper side wing tips, and also notice the tail stripes have been repainted orange (originally red.)  I’m just waiting on a replacement canopy which will hopefully arrive tomorrow and I should be able to completeley reassemble the model and re-maiden it after the crash.  Oh, I also have soldered up the led landing lights and will have those illuminated now just for fun.

January 23, 2015

Repair status update:  The crash repairs continue at a slow but steady rate; I am hoping the result will be better than ever!

Here is a picture showing the motor nacelle damage.  This has now been reglued and is as strong as ever.

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The next picture shows the repair process of the wing center pylon. This got shredded when the wing ripped off.  2 pieces have already been attached in this picture (with a battery on top to weight it down) and I am holding the final piece in it’s approximate location.

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My repair plan includes adding some orange color to the engine nacelles, the top of the wing, and the tail for enhanced visibility.  In the next picture I have removed the cowls before painting them.

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Now we see the cowls painted orange and reattached.  I think the final result will look nice if I can get some orange stripes on the wing tops and tail and do it cleanly.  In this next picture you can also see a view of the repaired wing center pylon (with some white filler that still needs to be painted.)  I found some flat gray spray primer at the hardware store that is a pretty close match to the factory paint, but it is cheap paint and covers poorly and requires a couple coats.

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I have ordered a replacement canopy and replacement forward hull shield because these thin plastic parts were substantially damaged in the crash.  Grayson hobby had these parts in stock for $9.99.  If you are frustrated because nitroplanes.com is always out of stock of the airplane or part you want, check out grayson hobbies online.  They have a wide range of dynam stuff.

January 4, 2015

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More detailed damage assessment:

  • The fuselage center wing mounting pylon is pretty shredded.  I’m hoping I can glue the parts back together to get the shape, and then do some reinforcement to get the necessary structural strength.
  • The right wing tip float broke off.  I’m strongly considering a mod to convert this model to retractable wing tip floats.  There are a few people on youtube that have done this and it turns out pretty cool.
  • The canopy got shattered into dozens of bits.  I need to either buy replacement plastic parts or carve a replacement from something.
  • The left engine nacelle got completely ripped off.  I think this will go back together again ok with enough surface area to be structurally sound.
  • The right front bottom of the nose took some damage I just now noticed.  That’s probably something I can just glue back together and it will be ok.
  • I am thinking about getting out my can of orange spray paint and doing an outboard section of the top of the wing in high visibility orange (and maybe a couple other bits while I’m at it.)  Part of the reason for the crash was that I completely lost orientation on the model, and part of the reason for that (I think) was flying an all gray model on an overcast day.

January 3, 2015

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I went out to fly this off the lake this afternoon (frozen this time of year.)  I did one good flight, switched batteries and midway through the 2nd flight some winds started to come up a bit. Then I did the unthinkable … I lost my perspective/orientation with the model, executed one of those dumb thumb moves, and corkscrewed it right in.  It’s been a long time since I’ve had a crash I couldn’t blame on mechanical, electrical, or weather factors.  This one was just dumb thumbs and it was over before I could figure it out.  Now I’m really bummed.  Here is a picture of the wreckage I carted home.  Major damage includes the center wing pylon sheared off (foam/structural), the canopy shattered to bits, one of the wing tip floats broke off (plastic part broke), one of the engine nacelles broke off, and probably a few other odds and ends I’ll find if I dig in further.

I think the engine nacelle and center wing pylon will be repairable.  I don’t know what I will do about the canopy … maybe I can buy a replacement?  Same with the wing tip float mount?  I suppose I’ll set it to the side for now.  Usually after a few days I start to get a bit curious and dig in and often a lot of the damage is quickly repairable.  Some of it might be a little harder though … guess I’ll post a repair log if I think I’ll be able to fix it up and fly it again.

June 21, 2013

This is the PBY from nitroplanes.com.  It is a relatively big airplane compared to most ‘foamies’ these days with a 57-7/8″ wing span.  It is also a twin and a seaplane.  I have nothing but good things to say about it.  For the cost and the effort to assemble it, it looks really great!  On the ground, in the water, in the air, sitting still, water taxiing, flying … it just looks great.

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I purchased the PBY in January of 2012, so my first flights were off a snow covered lake on a bitter cold January afternoon.  I fly it with a 2200 mah 3 cell battery and that provides tons of flight time … probably pushing 20 minutes or more of relaxed flying.  Relaxed is the key word. There is nothing white knuckle about flying this airplane.

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One of the fun things I did this day was to snow taxi downwind a bit, turn back around into the wind and give it about 3 notches of throttle.  It began to slide across the slick snow and pick up speed slowly.  Little by little it accelerated and before I thought it would be ready to fly, it slowly lifted off on it’s own.  It passed in front of me about eye level, still climbing out at a very slow, very scale looking flight speed.  There are moments that are so perfect you always remember them, and in the context of flying RC airplanes, this was one of them.2012-04-19

She handles water operations just as effortlessly as flying off snow.   There is a little park with a dock at one corner of this lake in walking distance from my house.  It’s a perfect place to go fly a park-flyer seaplane on a nice calm summer evening.  The twin engines, the big wing with slow flight characteristics, smooth water handling … it just makes for a calm, relaxing fun evening of flying.  At the park, the PBY always seems to attract an audience too.

If you are into aerobatics, the catalina can do all the basic loops, rolls, inverted flight, wing overs, etc.  It can, but for some reason, I’d rather watch it do slow, scale, near perfect fly-by’s all evening long, mix in some touch and goes off the water … it’s really pretty!IMG_20120811_111738

For whatever it’s worth, the Catalina has plenty of power to do dry grass takeoffs from the RC club field.  I try to be extra careful keeping the wings level on landing so I don’t catch one of those wing tip floats.  The ground is a little less forgiving than water.

Just to summarize.  This is a very scale looking airplane.  It has a big fat wing and is lightly wing loaded (just like the real thing.)   It can fly amazingly slow in the air.  If you just want to enjoy a beautiful scale looking/flying aircraft, this one is hard to beat!

Sonic 64

Hobbyking Sonic 64

This is 1230mm (48.4″) wing span flying wing.  It is powered by a 64mm electric ducted fan.  It is a simple build and flies great!

Here are a couple pictures before the maiden flight (temperature was about +18F, winds were calm, skies had a medium thin overcast.)

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My one gripe about the Sonic 64

Of course we buy airplanes like the Sonic 64 because they are inexpensive, quick to assemble, and fast to get out to the field and up in the air.  It doesn’t hurt that they look great and are a lot of fun to fly!  But in the case of the Sonic 64, perhaps it is a little too inexpensive.  The servos that came with the kit were utter garbage.  One of them was completely useless and unsafe to fly.  It couldn’t hold a position, and it had a lot of trouble with it’s potentiometer.  The other servo probably could have been able to fly safely, but not fly well.  I submitted an RMA to Hobbyking where I purchased this ARF, and to-date they have not responded with an “initial evaluation.”  Typically the stuff I get from Hobbyking works and meets expectations, but this is pretty poor customer service to not even acknowledge my RMA request after a week and a half of waiting.  So I gave up, dug out the original servos, and replaced them with Hitec HS-55 servos.  These are $10 servos and far better than the $0.50 servos that came installed with the kit.  Unfortunately the servo leads on the Hitec servos were shorter so add two $3 servo extensions.  And finally add the cost of some glue to install the servos properly … altogether that added about $31 to the cost of the airplane … and Hobbyking still has yet to respond to my RMA.

Servo Installation in foam wings

My new favorite glue for installing servos into foam wings is: E6000 (available at Michaels and probably lots of other places.)  It is not a quick dry cement (let it dry over night) but the result is solid, it seems to be foam safe, it dries clear, and according to the video it’s pretty easy to cut through with a knife to later separate the glue joint.
I ran up to Michaels last night and got a small tube to try on my Sonic 64 and I’m really pleased with the results this morning.  I’ve tried different techniques over the years, but I’ve had hot-glue and double sided tape be wiggly or just pop out.  Epoxy is a bit too permanent when you are talking about cheap servos … E6000 seems to be a really good balance between creating a solid glue joint between a servo and foam, but then being able to separate it later if needed.  Here is an in depth how-to video (not mine) with a bunch more explanation.

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Variants

This same design is sold under the name “Neptune” by Nitroplanes.com (but was out of stock when I was interested in ordering it.)  The manual still has at least one reference to Neptune that hadn’t been updated. 🙂

Launching

The Sonic 64 is hand launched.  This can be a little tricky if you are flying by yourself or need to get help from someone who doesn’t have a lot of airplane hand launching experience … so be cautious, things can go wrong quickly.

The manual suggests running the throttle up to about 50% (that feels about right) and then running 2-3 steps and giving it a good firm level throw (wings level, nose level, throw direction straight and level.)  I had one good launch, one bad/failed lauch (no damage, whew!), and a 2nd good launch on my 3rd try.  I noticed the left wing would really drop quickly.  I made every effort to make a straight level through, but maybe my technique is flawed?  Maybe there is some torque or spiral thrust issue going on?  Hopefully I can learn to do this more reliably on my own.  Often I’m out flying by myself, and then no offense to any of my fellow RC club members, but many of us don’t have much hand launch experience.

Next time out I think I may try to run the throttle up a little higher (maybe 2/3rds) and try to release it on an upwards trajectory … maybe 15-20 degrees up?

Flying

My maiden flight was on a dead calm afternoon and the Sonic 64 flies beautifully.  It is stable, tracks nicely, and responds well to control inputs.  It has no rudder, but it can do all the bank and yank type aerobatic maneuvers you can think of.  I attempted a high altitude stall to see what kind of craziness would happen and it was boring … it just dropped the nose and kept flying.  I’m sure I could get it to spin if I stalled it out in a steep turn, but I didn’t want to push it too hard on my first time out.  One thing I did manage to do was a sequence of really graceful wingovers.  I could fly a fast eye level pass, climb out steeply, and then as speed bleeds off, roll into a bank (maybe 10-20 degrees) and hold that as you run out of airspeed.  The airplane naturally does a wing over and comes back flying right past you the other direction.  It’s really graceful.  If you hold the throttle fixed through the maneuver, it tends to kick you over just a bit faster when you are at the apex and have minimal aerodynamic control and the thrust starts to dominate.  If you pull the throttle back at the apex, then it’s a bit more lazy and graceful.

I was flying a cold day (+18F) so the air was relatively dense.  As a result, top speed didn’t seem too fast, even though the motor was really wound up.  I expect on a warm summer evening it will zip by much faster in hotter, less dense air.

Landing

The Sonic 64 is a flying wing and behaves exactly how you would expect.  It has a relatively long, flat glide, and if you carry any speed over the threshold, it will glide forever in ground effect.  So there really isn’t anything difficult or unexpected, just be ready for a fairly long, flat approach and be ready for it to carry during the flare as it wants to just keep flying forever in ground effect.

Conclusions

This is a great flying, inexpensive airplane that goes together quickly (probably an hour or two maximum.)  It is appropriate for a moderately experienced sport flyer.  It’s also a big bundle of fun and looks really cool in the air.  However, I am now aware that if I do have any problem with something ordered from Hobbyking, I shouldn’t have high hopes for their customer service and for their response times.  That’s unfortunate because I actually like Hobbyking otherwise and everything else I’ve bought from them has met expectations.  In this case the problem was easy to fix (yeah model making skills) but that was an extra chunk of money out of my own pocket.

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Polaris Ultra

Manufacturer: Model Aero

Design: Polaris Ultra

Web sitehttp://modelaero.com/product/POL-ULT.html

Summary: Pretty awesome airplane

Model Aviation also has a nice review of the Polaris: http://modelaviation.com/modelaeropolarisultra

My story is that I missed one of the model aero sales by a day or two so I emailed the owner to see if I could sneak in my order late.  He replied that he had a couple unpainted polaris arf’s and he’d be willing to give me a package deal on one of those.  So I figured it couldn’t be that hard to paint a foam model and off I went.

The aircraft arrived completely unpainted. The foam was white, and even the plastic parts were just clear.  I test fit a few of the pieces and it sure was looking pretty cool even without paint:

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The assembly process is pretty straight forward and the instructions are good.  It’s perhaps a bit more work than some of the newer foam arfs.  It took me a couple evenings (including the extra work of painting.)  But, there was nothing too difficult.  I chose to mount my elevator servo externally to simplify the install.

Because I was painting the model from scratch, I got to make all the choices.  That is good and bad.  I decided to try to keep things simple and roughly follow the original scheme.  I happened to have flat gray primer in a can, and then I ran to the local hardware store and picked up a can of bright red.  So those were my two colors.  The cockpit and dorsal vent got painted flat gray.  The cockpit piece is removable for swapping flight batteries so it was easy to get a nice clean edge there.

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Painting the color was a bit more work.  I’d never done this before, not exactly, so I had to make things up a bit as I went along.  It turns out that if I hit the foam surface hard with the spray paint, the propellant would melt the foam. That wouldn’t be a good thing.  Same problem with the primer.  I did some googling and water based spray paint exists, but I didn’t have it in hand.  I found some test foam and it turns out that if you start by lightly dusting the surface from a good distance (maybe 18+ inches) from the surface.  This lets most of the propellant evaporate off before it hits the foam, and as the dust accumulates the surfaces is more and more protected.  So I did this trick with the primer and then later could paint normally over that with the color layer.

I decided to use electrical tape to mask the paint areas.  This was good in the sense that it didn’t seem to bleed too much, but bad in the sense that it was too sticky and pulled some of the shiny foam finish off when I removed it.  That’s hard to notice though so I guess it wasn’t a complete disaster.  I layed down my exact lines and then masked off with newspaper after that.  One thing I discovered though is that the spray goes everywhere.  It managed to sneak through some cracks I thought were sealed.  Again, not perfect, but not too noticeable on the final result so I guess it’s not the end of the world.

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After painting the color areas, I went back with 1/2″ electrical tape and used that as edge trim to hide paint edge and tidy things up.  Again, not perfect and kind of crude, but I think it turned out pretty sharp in the end.

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I painted the bottom of the wings flat gray to differentiate them from the top, and with the 1/2″ black tape on the edges I think it set it off and made it look pretty sharp.  I’m happy with the result.

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Here is the end result.  The canopy is glued on, the cowl is painted red and attached.  3-bladed prop looks great.  The decals are applied in the final shot.

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I don’t have any flight videos or pictures yet, but I did do the maiden flight. I waited and waited (almost a month) for decent weather and finally got a day with almost dead calm winds here in MN.  The Saturday after Thanksgiving was the day.  There is a small lake across the street from my house and this time of year it is frozen.  Fortunately due to early extra cold weather, the ice on the lake was thick enough to walk on safely.  So I put on my boots and headed out to find sunshine, upper 30’s, and dead calm winds.  It was later in the afternoon, but the sun was still bright.  The first flight went perfect.  It needed a bunch of clicks of right trim and a couple clicks of up, but once I got her dialed in, then WOW!  She really flies spectacularly.  I love how you can pull high alpha in the turns to make them extra tight.  She tracks and handles so nicely, like she is on rails.  She looks so sweet in the air!  Take offs from the snow were amazingly smooth.  I was flying on some tired old 3S batteries, but honestly that was plenty of power and plenty fast for the area I was flying.  It is a relatively long model so it is extremely stable in pitch.  It is all around really wonderful … looks and flies spectacularly!

 

 

Smart Trainer Photo Shoot

Design Observations

I really like the looks of this aircraft.  It is a unique combination of design choices that I think should provide a nice balance of good flying qualities and lots of aerobatic capability.

It calls itself a trainer, but it is not a “learn to fly” trainer.  Instead it positions itself as an entry level pattern ship.  It is light weight which means it should maneuver effortlessly and not have bad habits.  It has long lines so it should fly like it is on rails.  It has thickened wing tips so it should have excellent slow speed characteristics and be adverse to tip stalling.  Oh, and it also has all the design elements you’d want for effortless knife edge and inverted flight.  The aircraft has a semi-symmetrical airfoil.  Most aerobatic planes pick a fully symmetrical airfoil, but in my opinion, across the flight regime that this aircraft covers, the choice of airfoil shouldn’t make much difference.

While I am grounded and waiting for the snow to melt around here I took a couple pictures:

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I am hoping this will be a fun airplane to go out and cut up the sky with classic pattern style aerobatics.

 

Aerosky 185 Photo Shoot

 

Photo Shoot

Don’t look too closely, but take a few steps back and I think she looks pretty nice.  I love the older style 185 tail and the tail dragger configuration.  The relatively large wheels help me imaging this is a bush plane intended to get in an out of rough strips.

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It is still winter here in MN and our ground is still covered in a foot of snow at least.  I’m hoping the snow melts quickly so I can get out and maiden this airplane soon!

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Yup, she looks pretty sweet I’d say!

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Aerosky 185 Build Notes

I was interested in the Aerosky Sky Trainer 185 because it looks a lot like a Cessna 185.  It has the 185 tail and is setup as a taildragger.  Technically the rear window is not correct for a 185, but there are a lot of things you could nitpick if you really wanted to go there.   The other interesting aspect of this kit is that it includes a full set of float for water operations.  I live near a little lake so I am hoping this will fly well off water on a nice calm summer evening.

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In this post I simply want to hit the questions/issues I ran into with this aircraft.

Rear Fuselage Extension and Tail Surfaces

First off, the instructions say “glue” on the rear fuselage extension piece.  I don’t hae a tip for getting this exactly lined up.  I lined up the stickers exactly, but that put the horizontal stab out of alignment with the wing.  Use a bit of caution and planning and measurement here.  Maybe consider installing the wing first so you can align the tail with it.

The instructions do not say glue on the horizontal & vertical stabs, but they provide no bolts/washer so I assumed the only way to install them was with glue.   That is fine, but the instructions seemed to imply something else.  Again, I recommend bolting the wing on before gluing the tail surfaces so you can try as much as possible to align the horizontal stabilizer with the wing.

Now my biggest frustration so far is with the wing hold down bolts. Only one actually lines up well enough to get it threaded easily. I messed around quite a bit and I think I can get 2 more lined up, but the fourth is just really off kilter or something.  The bolt tries to cross thread on the blind nut whenever I start it … frustrating!!!
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 Wing Mounting

I did manage to get the wing bolted on ok. The factory installed blind nuts did not line up well which made this a huge pain.  I just had to fiddle with it long enough I guess. I managed to push out one blind nut in the process of try to get the bolt started which was a setback to the process.  It took quite a while to get the bolt reseated, but I managed to get it all together in the end.

Power System

I’m not impressed with the quality of the 3-bladed prop … looks like cheap molded plastic. Anyone know the pitch on this so I can replace it with something decent?

I’m also not impressed with the glue on foam spinner.  The instructions have you glue it on, and it takes quite a bit of fiddling to get it centered so it doesn’t wobble terribly when it spins. That’s another thing I’d love to replace eventually if I keep and fly this airplane regularly.

Pro-tip: Don’t glue on the spinner until after you’ve hooked up the ESC to the motor and have all your wiring tested and tucked away.

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Landing Gear

The landing gear and control linkage installation has been straightforward … no major gripes there.   In the online videos I didn’t like how nose down the aircraft sits on it’s floats.  I noticed the extra gear provided with the floats is a bit taller than the main gear to account for the fuselage being a bit more slender as you go rearward.  I swapped these and used the bigger part for the front in hopes that this will help the aircraft sit a bit more nose up (scale-like) on the floats when I finally attach them.

I think this airplane will be ok. It’s not high on the quality or fit & finish scale, but it was relatively cheap and on clearance.  I think it will look good in the air and from a few feet away. Just don’t get out the microscope or start nitpicking too much.

RC Aircraft Precision Balancer and Work Stand

This morning I whipped together a “precision aircraft balancer” (like the Great Planes “C.G. Machine”.)  I built it out of $5.57 worth of PVC pipe and connectors from Fleet Farm and it probably took me an hour at the most.

The Plan

Here is my concept drawing:

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Shopping List

Here you are looking at $5.57 worth of PVC parts purchased locally.  The one flaw in the original design is that no one locally sold those 3-way corner connectors.  Maybe they don’t even exist?  So I made an on the fly design change while I was shopping.  The new design uses a “T” connector and a 90 degree elbow with 1.5″ long pieces of pipe connecting them.  The parts list is: 8 x 90-degree elbows, 4 x “T” connectors, 14′ of 1/2″ PVC pipe (in 2 10′ sections.)  I went with 1/2″ PVC and that is plenty strong for my needs, but 3/4″ PVC would work just as well and make the stand a bit beefier.

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Construction

Cut the straight sections and fit it together.  There is no rocket science, but do remember “measure twice, cut once”.  Here you can see the parts starting to come together.  How exciting! 🙂

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Finally here it is all put together:

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You might imagine that if the parts are only friction fit together, the two rails could flop over if you placed a heavy model on top.  So what I did was use PVC cement to glue the joints between the “T” connector and the 90 degree elbow connectors at the base.  I left everything else just friction fit so I could potentially take it apart for transport/storage.

Finished Stand

Finally, here is the payoff picture of the stand in action!!!  Yes, those are Christmas decorations that have not found an off season storage location.

IMG_20130625_101909Modifications

There are a variety of modifications that could be made to the design

  • Add pipe insulation to the top rails to help protect your more fragile models
  • Go with bigger PVC (like 3/4″) to make a beefier stand.
  • Drill a vertical hole into the top rail to insert a peg.  (A bolt with a rounded head with a nut screwed most of the way in makes a nice drop in peg.)  Make marks on the top rail in your favorite units.  Now you have a “Precision C.G. Machine” and saved yourself $50 at the hobby shop.  Personally I would suggest locating the peg about 1/4 to 1/3 from the rear along the top rail (not dead center) so it’s easy to just place the aircraft forward and use it as a stand without removing the pegs.
  • If you add balancing pegs, make them drop in/removable and tether them to the rail with dental floss so you can use the device as a stand without worrying about scratching or denting your model with the balance pegs.
  • Adjust the dimensions.  I built this for a flying wing with a 16″ wide fuselage so I made my stand really wide.  I also made it pretty tall to accommodate setting the aircraft on it inverted (leaving room for the vertical fins.)  If you have a different aircraft in mind, it might make sense to adjust some of the dimensions … but don’t make it too tall and skinny or it’s likely to blow over in the wind at the field.
  • Do an image search for Escher and instead of making an aircraft stand, try to build some sort of perspective/perpetual work of art.

Sold the P-47

I sold my P-47 on craigslist today.  I liked it, but for whatever reason, it wasn’t my favorite to fly and I’ve got my eye on something else … but I need to free up some space first … !  I really enjoy flying my PBY though … I need to set up a category and post a few pictures of that soon!

More wing related repairs

I encountered two more issues that I needed to address:

  1. The cheap retract servo stripped out.
  2. The rear wing hold down threads stripped out.

I replaced the retract servo with a much higher quality hi-tech metal gear servo and spent about 10 minutes fiddling with end point adjustments and linkage lengths to try to get non-binding operation and minimize the servo buzz.

The stripped rear wing hold down threads was a bigger problem.  I tried to glue a nut to the back to replace the cheap plastic threaded plate, but just made a mess of things, got glue on the threads, etc.  Just a big mess that was hard to deal with due to it’s location and inaccessibility when things are lined up and put together.  So I went old-school — found a “blind” or “t” nut (like you use when kit building to anchor firewall mounts, wing mounts, etc.) and found a matching non-metric screw (my hardware store doesn’t sell metric t-nuts.)

So that’s it — no pictures, but the repairs are complete and the bird is airworthy again — at least until the next cheap part strips or breaks. 🙂

P-47 Wing Repair

The Hobby-Lobby “Hun Hunter” P-47 seems to have a small design flaw.  Because of the size of the wheel well required for retracting the gear, there is not a lot of foam material along the leading edge of the wing in this area.  At the thinest point, it’s pretty thin. The wing is subject to cracking in this area — starting at the leading edge and proceeding through the middle of the wheel well.  There is a carbon spar in the wing so the wing isn’t in any danger (I don’t think) of coming off in flight, but it does create greater flexing and makes me nervous.

It seems that any landing that is less than perfect has potential to crack the wings.  I can grease in a sweet landing now and then, but once in a while everyone bangs in a little harder than they intended.

In an attempt to repair this problem “permanently” I cut two small pieces of glass cloth, about 5/8″ wide by 1 – 1/2″ long.  I then used a mixture of slightly thinned 12 minute epoxy to glass in this cloth.  The picture below shows the outline of the tape along with the rough location of the crack (in green.)

The tape blends in pretty well once the epoxy saturates it, although the epoxy will cure a bit yellowish.  This takes away from the perfect scale appearance of the aircraft I’m sure, but what are you going to do?  I want to be absolutely rock solid safe in flight.