Buzzard Bombshell Electric Conversion and Mods

About a year and a half ago I picked up this wonderful high wing balsa old timer at a swap meet.  I did not know what it was but I'm a sucker for an inexpensive balsa old timer, especially a three channel high wing.  He wanted $25.  I offered $15.  He threw in a motor, esc, and two servos and we settled for the $25 he was asking!  I was a happy camper.

After some time and a bunch of Internet searching, I finally discovered that what I had bought was a plane called the Buzzard Bombshell.  The original design was done and built by Joe Konefes in 1940  with about a 72 inch wing span.  It was intended as a free flight as RC gear was way too expensive for most people.  This plane was designed to head up as high as so many ounces of fuel would take it and then glide for as long as possible (Joe flew his for over 49 minutes at the 1940 NATS).  To help with extended glide times they incorporated large tail surfaces that helped with lift and moved the CG to 50% or more back from the leading edge.  With the heavy motors of the time, this made for an interesting stubby nose look.

Mine was a more current and smaller version that was intended for 1/2A power sources.  It looks like it was setup for a Cox .049 judging from the mounting holes in the firewall.  Now by smaller I mean about a 45 inch wing span and still a good size plane.

Didn't realize that these cluttered photos were the only ones that I had at the time I posted this.

I'll take some better ones as soon as I get some time.

A couple of things that I really liked about this plane is that the builder did a pretty good job of construction and covering, but also, I see no oil residue and so don't think that a motor was run on this plane let alone even mounted.  I don't think it has ever been flown.

The first thing I looked at doing was to figure a motor mount

You can see here the holes for the original motor mount.  Fortunately the builder install blind nuts from the back side.  I just needed to figure out what size they are and how to go about using them.  They are oddly laid out so I can't directly use them and I'll need an adapter.

You can see the blind nuts in this photo.

I decided to use a circle of 1/8 inch plywood.  I would drill holes to line up with the engine mount holes and then drill holes to fit the electric motor mount.

I lined up the disk from the back side so that I could transfer the mounting holes from the front side.

Here is what I came up with.  I started counter sinking the holes so that I could use flat head screws so that it will fit flush against the firewall.

Here are the parts that I came up with to create my motor mount.  I ordered some aluminum stand offs from an online source and screws and washers from my local hardware store.  As I recall all of the threads turned out to be a standard 10-24.

Here is how the stand offs will fit with the electric motor x mount and the original motor mount.

This is how it would look with the longer stand offs.

Here is the new round plywood mount test fitted in place.

I needed to ream out the x mount slightly to fit the new screws.

Now the screws fit fine.

Here are the different stand offs and screws that I used.

Here is how it would look with the long stand offs.

This is how it would look with the short stand offs.  I like this look better, it puts the propeller closer to where it would have been with the originally designed gas motor.

I used different amounts of washers behind the x mount arms to set down and left thrust angles.

Here is the end result.

Now I need to start looking at where and how to mount the battery, ESC, and the two servos before I can get this thing back in the air.  These will be done in future updates.

Thanks for stopping by my blog.  Please feel free to post comments, good or bad, and be sure to come back and check for future posts.

$5 Durifly Ryan STA(M)

Ok, maybe it will not turn out to be $5, but it started that way.  I was browsing Hobby Kings bargain bin items and under the $0.99 bin I found all of the critical parts for the Durifly Ryan STA(M)!  I was really bummed to find out that the engine cowling and parts kits, while not $0.99, were out of stock, but I can live without those.  I'm not so much looking for a complete, complete deal here, I just want something that I can have fun flying, looks reasonably good, and relatively cheep.

So, here is what I ordered.  One set (yes, set, right and left) of wings, one fuselage, one cockpit, one rudder, and one stabilizer.  Each was only $0.99!  So, ok, this will not come out to a $5 build as I did have to pay shipping and HK is smart enough not to let you order too many $0.99 pieces without ordering something else (I had to split this into two orders!), so shipping cost me about $28, or about $14 each order.  But still, I'm only about $35 into a $150 plane, so far.

I did already add two 9g servos to the wings (about $4 each).  You can see them installed into the wings in these photos.

The really good stuff (besides the parts being CHEAP!) is that everything was already covered, all movable surfaces were already hinged with control horns and stoppers, and the rudder has the tail wheel installed.  All very nice indeed!

The not so good stuff, the wings came without the spare (that seemed really odd!).  So I had to make one using a lot of educated guessing (but I got it done).  The rudder was a little kinked about mid way, right where the balsa color changes.  I have no engine cowl.  I have no landing gear, wheels, or pants (I'll make a set but don't plan on making the pants), the cockpit section came without the dash decals, the manual (as sparse as it was) is no longer available (luckily someone posted photos of theirs on RCGroups), and the hardware kit is no longer available (this included all of the linkage, screws, support wires/string, wing mounting screws, and misc. hardware).  I will also have to provide two more servos for the tail surfaces, a 25Amp ESC, a 3530 1100Kv motor, and a 10x6 prop.

So far I have the wing spar made, the wing halves epoxied together, and the aileron servos installed.

This photo shows the wing spar that I cut from 1/8 inch plywood.  I measured the depth of the slot in each wing to come up with an estimate for it's length.  I measured the angle of the wing roots to come up with an approximate dihedral angle.  I carved and sanded until it fit and the two wing roots came together nice and flush.

I then put a liberal amount of 5 min. epoxy into each wing root spar opening and covered the root faces with a thing layer of epoxy.  Then I slid the left side of the spar (yes, it has sides to match the wing) into the left wing and then slid on the right wing onto the right side.  Then I taped up the bottom side good and flush (lower photo) and then pulled the top side together nice and flush and secured with tape (upper photo).  I left this to sit over night.

Here is what the parts look like so far.

Check back again and find out how this new project is coming together and as usual, thanks for stopping by my blog.

Please feel free to post comments, good or bad, and be sure to come back and check for future posts.

SD Card Extension Mod, Turnigy 9X

I love the new sound mod that I did for my TG9X transmitter!  One big problem that I have with it is that it's such a pain to update the sounds!  Because of how I opted to do this mod (the way almost everyone has done it) I have to open my transmitter every time I want to update any files.  What a pain.  Then I noticed one day that it's possible to get SD card extensions.  This is a cable where one end plugs into the existing SD card slot and the other end has another card slot for you to locate somewhere.  So I hunted down the best deal (because, you know, I'm cheep) and ordered one.  So now the rest of this is a review of what and how I did my mod.

This is just the back view of my transmitter getting ready to take the screws out and crack it open.

Here is the view of the micro SD card extender that I bought.  I wanted the flat ribbon cable but should have paid closer attention to the length.  You'll see later how the length affected the install.

 Here is a closer image of the insertion end.  Looks good.  You can also see from this view how wide the flat ribbon cable is.  I might have also paid closer attention to this and found a narrower one.  What was not obvious from this view is that the circuit board material that it is made from is thicker than the micro SD cards.  While it still fit in, it was very snug and did not "click" in.  It just stays in by friction.

Here is the socket end that will have to be mounted somewhere.  It too was larger and thicker than anticipated.  I tested inserting a micro SD card and it works just fine.

Here is my radio open with the first look at where everything is and what I have to deal with.  Lots of wires from the programming cable to the jumble of wires for the MegaSound board.

This is another closer look.

And yet another closer look.  We can easily see now the micro SD slot that we will be working with.  It sure has been a pain to open my radio every time I wanted to update a sound for a new plane or option.

This view is just holding the radio programming cable out of the way to see what kind of space I have to work with.  After looking things over, I decided this would be the best location for the SD slot end to mount.  I really wanted to mount it on the side, but with all of the socket connectors (all the white ones) and the MegaSound board on the other side, it would be too confining.  So, I reluctantly went with a bottom mount.

This view is of the mating side showing how the battery box from the other half might interfere with mounting in this location.  Since it is just under flush with the rim, it should not be an issue if I stay below the rim of the mating side.

Here I have outlined the area that I need to cut out to accommodate the socket end.  I made sure that it would be clear of the stand and above the curvature and still well below the rim.

I started by drilling small holes inside the lines.  I just used whatever suitable small drill bit that I had.  I could have just as well used a larger size and just drilled them down the middle.

Here is the end result ready for cutting in-between the holes.

I just used my utility knife and worked at cutting the ribs.  It took some time but finally the center was cut free.

Fortunatly this plastic, while tough, carves nicely.  It took some effort, but was nice to work with.  As soon as I could, I broke out the files and cleaned it up and to the lines.

Here is the final test fit of the socket end.  Nice and snug without pushing in on the sides of the socket end.

Here is how it looks from the other side.  You can already see that I will have to do some folding and manipulating of the ribbon cable to get it to the SD socket on the MegaSound card.

here you can see how I started to layout the ribbon cable.  It was so long that it had to make a few runs back and forth across the radio.  I also put a ruler along the bottom stands to make sure the socket end would not extend below and interfere with sitting level.

Here it is hot glued from the back side.  You can also see how I folded the ribbon cable.  I creased it to help fit better as well.

Here I started to add some hot glue from the outside to ensure as secure mount.

Here it is all done and put back together.  I didn't think that I would be happy with the bottom mount but I have changed my mind.  I realized that if it were on the sides, my hands might inadvertently cause problem, but on the bottom, it is out of the way but easily accessible when needed.

I have already used this about twenty times as it is so easy to add and mod sound files now.  I am really happy that I did this upgrade.

Thanks for stopping by my blog.  Please feel free to post comments, good or bad, and be sure to come back and check for future posts.

Wing One Rebuild (Say that fast 5 times)

This beauty was my next project!

This wing came to me from the second owner who had not actually done anything with it.  He reported that the original owner had flown it with some sort of pod on top that housed the battery, electronics, and motor.  The pod and what was contained were no longer with this wing.  It did show signs of having been flown but was still in really good shape.

Here I started to take the covering film off of the trailing edge of the section between the elevons.  I started to do this because I knew I would need to take this section out to be able to move the motor forward.  I wanted to move the motor forward because I also knew it was going to be hard enough to get the CG right without the motor being so far back.

Here is a closer look after I had cut the trailing edge balsa lose.  I also have the motor/prop combination that I intend to use and the start of a motor mount/firewall.

Here I'm getting an idea of how things will line up.

Here is how I originally thought everything might lay out.

To provide for some flexibility in the power system (in anticipation of crashing), I decided to use a block of stiff foam to mount the firewall.  I cut out the covering film where this foam block will be glued down.

I decided to use Gorilla glue to secure this block as it would expand into the foam as well as adhere to the wood and foam of the wing.  Also, Gorilla glue is more flexible than epoxy (remember the anticipated crashing?).  I used the popsicle stick to help spread out the glue.  I did not show these steps, but I also spritzed it with water to help activate the glue and then held everything in place with masking tape.
(Our cat Dewy is trying to get in on the action)

Here is all of the pieces glued in place.  I made sure to have the motor wires run over the top just because I though it would make it easier to connect up.  Also, you can see the slight up tilt in the motor.  This was done to keep the thrust line pointing to the center of mass.  If you do not do this with a pusher, you will get pitching up or down when applying power.

After doing some CG work (I used an online CG calculator for flying wings to come up where the CG should be for this wing.  I think I used one of these: wingcgcalc and fwcg), I realized that the battery would need to mount like this to get the CG right.  I centered the battery and then traced around it and dug out the foam about half an inch down.  I did not want to go too far into the foam so as to maintain as much strength as possible while still providing a good battery mount.  You can see that I glued some bamboo skewers into the long corners of this cutout.  I also wrapped a strip of velcro around each of these.  I thought that these would help reinforce the foam and help to secure the battery.  This actually worked very well.

Here is a closer look.

 Here the battery is strapped in.

Here I am out for the maiden flight.  A friend who is a really good wing pilot got it up in the air for me and then handed the controls over after he trimmed it out.  Thanks Richie!

If flew great and he was easily able to launch it and trim it out.  I came down a bit hard on a landing and loosened the glue on the firewall.  I just used a couple of rubber band from front to back to secure it and that is what you can see here.  I did this because I was not ready to go home and really wanted to continue flying!

(Editorial Note: I am not condoning the flying of damaged airplanes in any way!)

  It flew great just like this for two flights.  Then I came in rough again and encountered the damaged prop and completely broken loose firewall that you can see here.

Here it is again all rebuilt and ready for another day of flying.

I have been really impressed with how durable wings can be.  I have continued to fly this wing just as it is for many flights including some nasty crashes.  My worst crash was at a pretty good speed into a street curb.  The crash destroyed the battery and broke the hinges on one elevon and the related clevis.  I have since replaced the battery repaired these and flown it again.

Thanks for stopping by my blog.  Please feel free to post comments, good or bad, and be sure to come back and check for future posts.