Dave Smith

A couple weeks ago I sent my Spektrum AR6000 receiver to Horizon Hobby’s service department because it was losing bind on the ground (especially in cold weather). Oddly, I could never reproduce the problem on the bench. It only happened at the flying field, and only on hand launches. Very weird. I was nervous that I would destroy my plane if it ever lost bind in the air, so I finally decided to send it in for service. I didn’t have much hope that Horizon would be able to see the problem since I could never make it happen on the bench, but they graciously took my word for it and replaced it free of charge. All I paid was the $5 to ship the receiver to them, and they replaced it and shipped the new one back to me free of charge. This was after they failed to reproduce the problem after 15 attempts. Way to go Horizon! I’m now a loyal customer for life.

P.S. Larry Weddle did the service, and decided to send me the new AR6000. Good work Larry!

Finally a successful maiden flight! Here are some post-maiden photos of my T-28 Trojan from ParkZone.

This tiny dots to the right and left of the cockpit mark the Parkzone recommended center-of-gravity (2.5″ back from leading edge, measured 1″ out from the fuselage). I moved it forward by about 0.5″ and it flew better.

On my first flight, the elevator was trimmed way too far up, leading to a near-death experience. I landed it, fixed the elevator sub-trim, moved the CG forward 0.5″ and it flew beautifully. In your pre-flight checklist, be sure to verify that the elevator is totally level (co-planer, to use geometry terms) with the horizontal stabilizer forward of it.

This shows my battery compartment and where I positioned my 2200mah battery pack to balance properly. I used velcro to secure the battery to the floor of the battery compartment.

To fit my battery as far aft as I did, I needed to remove some foam from the bottom of the cockpit:

This is where I mounted the ParkBEC as an insurance policy against the included speed controller’s crappy BEC. Since this is a switching BEC, it produces a lot of electromagnetic interference, so you want to put it as far away as possible from your receiver and antennae. Even though it creates lots of EMI, it creates virtually no heat, since it is very efficient at stepping voltages down.

My last landing was gorgeous. I even held a 10 degree flare during final approach that really greased it in for a smooth touch down and roll out. However, the left wing must have caught something hard (a particularly hardy blade of grass perhaps) that pulled the left landing gear right off. Nothing a bit of epoxy won’t fix:

What a great flyer. This is truly a bank-and-yank plane and is very easy to fly. The motor provides adequate lift to climb out at 45 degrees all the while showing no sign of slowing. The vertical is limited to about 30 or 40 feet from flat flight, and the roll rate is very very slow and non-axial. It flies just slightly better than a brushless HobbyZone Super Cub with ailerons. I think I need to increase my aileron servo travel to get some really good rolls. I will probably also mix in some differential to make the rolls more axial and pattern-like.

Oh, and I’m fairly certain that in a few months, it’ll be time to upgrade the motor for insane speed and unlimited vertical.

Well, I upgraded my L-39 jet’s motor and re-maidened it. I don’t want to give away the ending but it wasn’t pretty. The new motor was fantastic. It bolted in with no modifications to the plane, and provided lots of thrust over the stock motor. It was great.

The added thrust helped control the plane. Without it, I would have been toast out of the gates (like last time). The take off was uneventful other than the 90 degree right roll on launch and the first turn which almost crash landed the plane right into the adjacent road. Yikes! Here’s the video:

Everything was going okay, but it was extremely twitchy and stall happy. I think it’s too heavy, cause I was fighting to keep it aloft the whole time. I held my own for a few minutes, and then the low-voltage cut off kicked in. The motor must have been pulling more juice than I realized. I was up wind, which was a problem because the wind was blowing at about 10-15mph. Nevertheless, I managed to bring it in for a nice soft landing. Well, “soft” is relative. The plane touched down at the same spot where the only obstacle in the whole park was sitting: a sideways metal pole. Oops. Here’s the video and crash site photo:

You can’t tell very well from the pic but both the wing and horizontal stabilizer are bent, because they went under the poll while the rest of the plane went over it. Not pretty.

Oh well. Live and learn. My battery was badly puffed (due to the low voltage and high amp draw I’m sure), but it subsided back to normal. Not sure if I trust it for another flight yet, but I will definitely be keeping it in an ammo box and carefully monitoring its voltage before I use it again.

Thanks Cliff for filming!

After nearly one year and hundreds of flights, it’s finally time to retire the F27C Stryker R/C plane. This wasn’t necessitated by the plane or a crash, but rather my stupid attempt at modifying the airfoil to get it to roll faster. I learned the hard way that I am not an aeronautical engineer. The Stryker has been a great plane. It outlived two motors and at least 4 devastating crashes. Until I modified the wing, it flew like new. Here are some pictures to commemorate its service:

Elliot loves this plane, especially now that he can toss it around and see it flip and flop:

This is one beat-up airplane. The motor mount area of the foam got ripped out several times, and repaired very easily. The roughed up underside is due to all the concrete landings it endured behind my office building:

Here’s Elliot giving it one last throw to the ground:

I noticed that the wing tips are very rubbery and soft after all the flexing I must have put it through flying it at 70mph. What a great plane.

A moment of silence please.

That is all.

One word: crash.

I put a heavy battery in my new L-39 jet, knowing that I would eventually upgrade to a beefier motor that could make the thrust I’d need to move the heavier battery around. I was confident that it would fly stock, even with the heavier battery, because I had seen this video of it flying with my same battery on the stock motor.

I launched it three times, and the first two times it hit the deck about 20 feet out. You’d think I’d be smart enough to quit then, but I figured I just wasn’t throwing it hard enough. So I got a running start, and gave it a good solid chuck. I got my fingers to the elevator stick just in time to pull it up and out. It flew great. Did some big long circuits on low rates. Then I went for the gusto, flipped to high rates, and pumped out a wicked fast roll. This thing rolls fast! Very nice! However, coming out of the roll, a wing dipped. I think I must have been dangerously close to the stall speed. I couldn’t recover in time and it went full throttle into the ground. Elevator was ineffective, and it was all I could do to keep the wings level as it went in. Thinking back, I should have lowered the nose to gain some air speed. These jets are very different animals since there’s no prop wash over the control surfaces to help direct the plane. I mean, there really is no prop wash at all. All control authority comes from air speed.

Damage Report:

The left wing broke and fuselage broke. But never fear. I’ve already repaired it, and I have my new motor on order.

This time I’ll wait until the new motor arrives before I try any hot shot stuff.

Here’s the flight video. Please forgive all my “dang it”s after the crash. I was a little upset, needlessly so, of course. I was fine afterwards. The whole plane only cost $99 (including fan and motor), so hey, it’s easy and cheap to repair.

My good friend Cliff (a.k.a., Darth Elevator), strapped a digital video camera to his Slow Stick airplane this week and filmed me flying Randy’s Stryker around. The video captures both the Stryker take off and landing, and lots of crazy stunts. After seeing myself fly it from this angle, I’m surprised Randy lets me fly it at all. The video has been edited down to only include the shots where the Stryker is visible on camera. Here’s the video:

Spring is in the air in Salt Lake City, so it’s finally warm enough to get back into R/C flying. To that end, I ordered the new Electrifly L-39 electric ducted fan (EDF) jet. It’s getting great reviews, and I’m excited to fly it. I’ve read that the stock brushless motor is underpowered, so I’m looking into motor upgrades. I’m considering the HXT 2040 4850kv from HobbyCity.com, which ought to be a bolt-on replacement for the Ammo 3500 inrunner the plane comes with, but I’m worried it won’t give an appreciable power boost.

Stay tuned for more info, but in the mean time, check out this video of the L-39 flying with a pair of F-27 Strykers (which I have also built and flown, if you follow this blog):

And here’s the official Electrifly advertisement for the L-39:

I put together a $22 Hobby Lobby Yak 55 Profile this week, and it’s great fun. This is by far the most aerobatic plane I’ve flown. Here’s my power setup:

Here are a few videos of it in action

The takeoff

Sorry about the shaky cam at the beginning. Notice that it just jumps vertically out of my hand while rolling at about 3 rolls per second. Pretty awesome:

Some Stunts

This video shows lots of fun stuff, knife edges, loops, snap rolls, flat turns. Lots of good stuff.

Landing

This one mixes in some fun rolls and then the landing. The landing is a tad abrupt, but it works. I need to work on throttle management in my landing approaches because it just falls out of the sky if you dead stick it.

That’s all for now. Stay tuned for more photos of the plane up close so you can see how I put it together.

Here’s the video of the Easy Glider maiden flight:

Since then, I’ve had about 4 more flights, and they’ve all gone very well. The only mishap was when the canopy popped off during my last flight, and landed in the nearby river! The wind was good to me, though, and blew it over to the edge, where I was able to retrieve it. Sometimes, mother nature really is on your side in this hobby.

I finished the Easy Glider today, and took it out for its maiden flight. Here’s the setup:

• Motor: Tower Pro 2908-10 brushless
• ESC: Tower Pro 30A
• Battery: Hextronik 2200mah 20C
• Prop: 9×4.5 (will upgrade to a folding prop later)
• Servos: Hextronik 9g servos
• Radio: Spektrum DX6 with AR6000 receiver

The plane took a little longer to build than expected, mostly because I ordered the non-electric version so I had to dig out lots of foam to accommodate my battery and motor. I had a hard time fitting all the servo cables under the canopy, so I flew without it the first time. Here’s what the plane looks like:

When I launched the plain, it flew up at about 45 degrees without any sign of slowing down. I was impressed. After an altitude of about 100 feet, I killed the motor to see how it would glide. I must have pulled back too much on the elevator, because the left wing stalled and it started to roll over. Experience taught me how to handle this, so I let the nose fall down to get some airspeed, and rolled out of the stall. Then, I decided to climb a bit, and that’s when the firewall tore loose of the foam. Fortunately, I had put a layer of packing tape over it to double secure it to the fuselage, so it didn’t fall out of the sky. I was able to pilot the plane down with no problem. Any maiden flight with a good landing is a good flight, and this was no exception. I came down with spoilerons, and I’m not sure I could have come down in time without them. I would have overshot my runway by a factor of about 3.

I’ll post some video later.