Category Archives: Building Projects

This is a general category used for various building projects.

SSE Lessons Learned

I continue to plod slowly long on my SSE build. I have the basic construction completed and I am just about ready to start covering and final assembly. While I still have not learned how to get my builds done as quickly as a lot of the other guys I see posting on RC sites, I have learned quite a few lessons along the way.

Lesson 1: Be Selective with Kit Supplied Balsa

The 1/16″ sheeting supplied with the kit for the wing D-Tubes (the sheeted portion of the wing ahead of the spar) turned out to be a bit marginal, with a large knot running through several sheets in the same place. I ignored this and used them anyway, only to find that those knots caused a large local dimple to form between the wing ribs. Note this was not a “starved horse” kind of sagging you sometimes can get between the ribs, but more of a dimple localized around the knot. Being the fussy builder that I am, I decided to fill the dimple with a bit of balsa filler. This worked great on one wing panel, but not so good on the second, leading to Lesson 2.

Lesson 2: Know When To Stop Fussing

When fussing with the dimple on the second wing panel, I kept filling and sanding and filling and sanding trying to get the surface to blend smooth. All this filling and sanding lead me to sand the surrounding sheeting too thin, and I ended up poking a hole through the balsa. Ughh! I originally tried to patch just the local area, but this lead to another cycle of fussing. So in the end, I gave up and just carefully cut the sheeting off the outer two bays and replaced it with new wood.

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The final product is acceptable, but I do have a but of starved horse look between the ribs. This is a result of too much sanding trying to get the surface smooth. which leads to Lesson 3.

Lesson 3: Less Is More When Sanding

When it comes to sanding, always remember that less is more. You can always go back later and take another swipe or two, when you’re really convinced that you need it, but you can’t put back material (at least not easily). Even though I was careful to use a long flat bar, too much sanding leads to thinning of material directly over the ribs producing a wavy look in my wings.

I also ran into a problem when sanding out the fuselage hatch. When blending the front of the hatch smooth, I was not paying enough attention to the “other end” of the sanding bar, which in turn lead to a nasty groove being cut near the back of the hatch from the back corner of the sanding bar. This lead to another cycle of filling, sanding, and fussing (see Lesson 2), which again resulted in material being sanded too thin. In this case, I plated on some 1/16″ balsa scraps to build material back up, and then blended it smooth. You can see below that I misted on a very light coat of gray primer to help guide my sanding (i.e.; the primer is left behind in low spots).

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Once again, what I ended up with a less than perfect, but hopefully acceptable (we’ll see after the covering is applied). Which leads to the most important lesson learned yet …

Lesson 4: Any Mistake Can Be Fixed

A good friend who helped me to get started in RC once told me: “Don’t worry if you make a mistake, any mistake can be fixed”. I repeat that mantra to myself all the time while I am building, especially when things start to go bad. Mistakes are part of the building process. We all make them, even the best builders out there. Mistakes can be fixed and they can be a learning opportunities for the future. Sometimes they cost us some money (if a new part or material needs to purchased), but mostly they just impact time (and maybe a little pride) and it is part of the overall experience. Remember that this is a hobby and we do this for fun, so don’t fret if something goes wrong, just fix it!

Fan Trainer Fiasco

One of my projects from last summer was an attempt at a foamy scratch building with a Fan Trainer EDF built from Dollar Tree foam board. I patterned it after the 150% scaled up version of the plans found in this build thread: http://www.rcgroups.com/forums/showthread.php?t=426281.

This was my first attempt at both EDF and at building with foam. The building process went well and I kind of enjoyed working with foam.

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The total investment in foam was about $5 (including scrap and re-work). I powered it with a Detrum 70mm Fan combo from HobbyPartz.com which includes the fan, motor, ESC, and servos for under $50. All in, with batteries, and a 4 channel receiver, total investment was under $100.

Unfortunately, it did not survive its maiden flight. The wings were simply not stiff enough and fluttered badly. Apply enough power to keep the plane flying, and the wings flapped like a hummingbird. Back off the power, and there was virtually no control. I ended up lawn-darting and disintegrating everything from the wings forward (sorry, no picture of the damage).

Oh well, nothing ventured nothing gained. The electronics and fan escaped unscathed, so the total loss was under $10 (and a little bit of pride). I have a few ideas for how to use the fan and other bits from this attempt in a new creation!

SSE – Some Progress On the Left Wing Panel

I made some limited progress on the left wing panel today. I sheeted the upper surfaces and started sheeting the lower. In order to create a “ledge” for the leading edge sheeting to glue to, I cut a thin strip of scrap 1/16 sheeting and glued them to the inside of the leading edge between the ribs.

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I plan to use nylon wing bolts to hold the wings in place instead of the stock J-Hooks and rubber bands, so I added a backer made out of some scrap 1/8″ plywood and a 1/4-20 blind nut inside of the root wing rib before adding the lower sheeting.

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I did get a little bit of the “starved horse” look between the ribs of the upper sheeting, but other than that I am happy with the results so far. I hope to finish up the left panel in the morning and get the right panel started. It should go a lot faster than the left, as I spend a lot of time fussing about with the wing bolt mod.

SSE Wing Construction

I have been making some (slow) progress on my Sig Somethin Extra build. So far, I have the left wing ribs, spars, and shear webs glued. Need to add the LE and TE sheeting before unpinning it from the board.

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To keep the ribs square during assembly, I have been making use of 1-2-3 blocks. Normally used by machinists, they are square and flat and heavy enough (relative to the light balsa and ply parts) to stay where you put them. At $17 a pair, they are quite affordable and have a multitude of uses for fixturing during assembly.

Stella Flys!!!

I successfully maidened Stella today! Wow, she is a great flier. A few clicks of up and few clicks of right aileron trim and she was rock solid in the air.

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Definitely a bit more responsive than what I am used to, but once I got my nerves under control, I was able to bore some clean holes through the sky with confidence. I got three solid flights in with no problems – needless to say, all flights were at low rates with a a fair amount of expo dialed in. I kept it simple, just trying to get confidence and get a feel for the plane, but I can tell she will be a favorite flyer.

I was a  bit nervous about weight (all in with batteries, she is a touch over 18 oz about 2 oz over target weigh), but she seems to fly just fine. She literally leaps off the ground and slows down to a craw for landing. I always find landing on grass a bit tough with these small planes, I did nose over on two out of three flights, but at very low speed with no damage detectable.

Two very non-flying related issues did pop up though. One was the inevitable wrinkling of the darker colored Solite in the sun. Nothing major and most of it tightened up once I got her home, but a little tweaking with the trim iron to tighten up a few spots will probably be in order. The second was the prop from the other plane I was flying today poked a small hole in the turtle deck covering during the car ride home. Easy enough to patch, but hanger rash on a new plane is always a bummer.

New Build – SSE (Sig Somethin’ Extra)

With Stella almost done, it’s time to start in on my next project. I snagged this Sig Somethin’ Extra (SSE) of the classified on one of the RC forum sites a short time back. I have been looking for one of these for a while, and this one came along at the right price. Of course, I plan to convert this to electric power. I also may end up adding a full cowl to the nose (in place of the stock open design). Not sure about that yet.

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Not much progress yet. So far, just looking over the plans and sorting parts.

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Stella – Final Assembly Begins

I finally finished with the covering and have started final assembly.

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Covering the wheel pants where a a real challenge, but I ended up with a reasonably good result. This gave me confidence to try something “fancy” though (and of course that’s where things went wrong!). I wanted the top of the plastic cowl to match the blue from the top of the fuselage, and thought I could get away with a piece of blue SoLite covering to do the trick. I should have known better, but I after a bit of research, I convinced myself that it was possible and worth the try. Using and iron with a very low heat setting, I was able to attach covering to the back of the cowl.  I then thought I could carefully shrink it down with quick little shots from my heat gun … which of course resulted in a distorted cowl.

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Oh well … chalk it up to a learning experience. A new cowl (setting me a back a whopping $6.00) is on its way. This one will be left white (with maybe a press on sticker or two for trim). I know that this one is still useable, but, after all this work, I’d hate to have this one big flaw staring at me!

The rest of the assembly is going fairly smoothly. The horizontal and vertical stabs have been squared up and (re)glued, the control surfaces have been hinged and installed, and the servos and servo linkages installed, and the tail wheel installed.

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Even though the Stella is not a high-speed plane, I always worry about flutter from hinge gaps. The aileron hinge gap ended up being on the high side of acceptable, so I decided to add in a strip of SoLite along the bottom to seal off the gap. The process is easy, just hold the aileron in its max deflected position (using a bit of tape to hold it there in this case) and fold in a strip of covering (half on the wing TE – half on the aileron LE) with a nice tight crease along the hinge line.

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I also have the motor mounted and have given a trial run of all of the control surfaces. Since the motor mount is clearly visible through the wide cowl opening, I decided to dress it up a little by brushing on a quick coat of red acrylic paint.

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Left to do:

  • Mount the receiver and ESC
  • Add Velcro straps for the battery
  • Glue down the canopy
  • Mount wing and landing gear
  • Install the replacement cowl
  • Add some final trim to dress it up just a bit
  • Check a trim balance
  • Trim out the control surfaces
  • GO FLY!!!

Stella One Step Forward–Two Steps Back

I did get the wing covered this weekend, but then discovered that the horizontal and vertical stabs (which were glued in to the fuse some time back!) were out of square. I am kicking myself for not checking it when I assembled them to the fuselage, that was just plane dumb! All the laser cut parts  slip together with such precision, that I just assumed that everything would key together square. Wrong!

The misalignment became very apparent once trial fit the covered wing to the fuselage and it became obvious that the horizontal stab was not at all parallel to the wings. The vertical stab was also off, but not by as much. So, out with the razor blades and Xacto knifes to carefully cut the horizontal stab free, which I did with minimal damage (other than the covering on the stab). The vertical stab, would require major surgery to remove, so I settled for loosening it up enough to shim it as close to true as possible (not perfect, but close).

I’ve got the stabs recovered and ready to be reassembled, but decided to put it aside for now. I want to look at with fresh eyes before committing to glue (again!).

I also started covering the ailerons. I got one partially covered, but I was not all happy with how it was coming out when the “dinner bell” rang, so I ripped off the covering and decided to call it quits.

Stella Covering Continues

I made some more progress on covering Stella. I have sides of the fuselage covered and shrunk down. I did end up burning a hole the covering through while shrinking it down under the tail with the heat gun. It happened at the same time, and happened remarkably fast! The white Solite is almost transparent, so I trimmed to the covering back to the nearest structure and applied a patch. With the seem over a structure, the patch is almost invisible.

I also got the turtle deck covered. This had me a bit concerned, but came it came out pretty good. I was running a bit scarred of burning a hole again, but I just worked it slow. Finally, I started laying down the blue in front of the cockpit. The first piece came out great, but I had a bit of trouble with compound tapers in the front section, so I ripped it off and decided to call it quits for the night.

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