Saturday, February 7, 2009

Easy Star + Ailerons + FMA Co-Pilot = Awesome!

F0r some time now I have been taking aerial photography and video from my Easy Star. With the brushless upgrade, the plane can easily carry 5 - 7 oz of extra payload. One problem is keeping the plane nice and level for good video and photos. To solve this problem I have been eying the FMA CPD4 Co-Pilot. For around $70 you get an infrared sensor which distinguishes the temperature difference between the sky and land, and controls the ailerons and elevator accordingly to hold the model level. Being a sucker for gadgets I decided to give it a try.

Though I have read other posts from people who used the CPD4 with elevator/rudder only, I wanted to use ailerons for better stability. I followed the lead of Ian from rcgroups.com who very thoroughly documented the process of adding ailerons. I used Hitec HS55s for servos and standard park flyer control rod hardware. I adjusted the aileron size and location a bit. I cut them 12 inches long and 2.5 inches deep starting 6.5 inches from the wing root.

The Easy Star's upturned wingtips are designed to keep the plane level which means the plane will fight you a bit when trying to turn with ailerons. In the above mentioned post Ian flattened the tips; but for this application I want the plane to be as stable as possible. For regular flying with the CPD4 off, I mixed in some rudder with the ailerons on my TX. This makes the turns nice and smooth and in my opinion better than with the stock rudder only setup.


With the ailerons working well I began installing the Co-Pilot. The directions are very thorough which is a real plus. As far as physical setup, the biggest decision is where to place the CPD4 sensor. The weight is not the issue and would have no noticeable effect on the center of gravity
(CG). The sensor needs a clear view of the sky in 4 directions. The traditional setup is on the wing or bottom of the fuselage, but the design of the Easy Star does not lend itself to this setup. I followed the procedure for the special application setup which calls for mounting the sensor diagonally and switching the position of the number 3 switch on the Co-Pilot. After some thought I decided to mount the sensor on the tail boom. Partially to get it out of the way and partially to use up the long cable that came with the kit. I mounted the sensor with velcro which seemed to work fine. The Co-Pilot computer tucks nicely up in the nose of the aircraft and velcros easily to one side. Following the instructions I plugged the copilot into the receiver and servos and went through the initial setup procedure. I would highly recommend plugging the remote into a spare proportional channel on your TX/RX if you have one. This allows you remotely control the sensitivity (gain) of the co-pilot.

Flight Report:

The instructions include a pre-flight checklist which I highly recommend adding to your regular checklist. There are several unfamiliar steps that you don't want to miss. Before every flight you need to calibrate the co-pilot to adjust it for your flying site/weather conditions. Based on the calibration you get feed back on how good the conditions are for the co-pilot--on this particular day I got a 5 out of 10 which seemed to work just fine. Even before take-off I was immediately impressed to see the co-pilot correct any movement away from center. All the control surfaces were perfectly reacting to return the plane to level.

Thinking in my head this must be too good to be true...I decided it was time to take off. For take off I turned the co-pilot off using the dial on my transmitter. After I was several mistakes high, I turned it up to full..and instantly the plane leveled out. It still couldn't believe it so I put it to the test and began a series of turns using only the rudder. Just as you would expect, the Easy Star made nice (wide) flat turns with the co-pilot providing the appropriate input with the ailerons to keep the plane level. To have a little fun with the system I turned it off and put the plane into a steep spiral dive. As soon as I turned on the co-pilot the plane almost instantly returned to level. Even with the co-pilot on you can still use the ailerons and elevator, just be prepared to provide alot of input to override the system. The co-pilot really shines during landing. I chopped the throttle and used the rudder to line up the plane. The co-pilot holds the plane perfectly level as you come in for a landing, all you have to do is a little flare at the end!

Final Thoughts:

Flying over water, ice or valleys can reportedly cause some problems for the system. The site I fly at borders the SF Bay which is definitely a large, cold body of water. I took the plane over the Bay a few hundred feet or so and did not notice any degradation in performance. As far at the co-pilot goes, it is great for aerial photography/video as the plane is level for good shots and you have the freedom to put more thought into taking pictures rather than flying. The co-pilot is not a replacement for good flying skills, and though it could be used to help a beginner, I think you are better off learning using a buddy-box or simulator. Alternativly you could go the route I chose which is a really tough plane (easy star) and plenty of glue ;) That said, the FMA Co-Pilot is a nice to have extra and worth every penny!


Sunday, January 11, 2009

Maiden of my new Parkzone Trojan T-28 PnP


After much deliberation, I decided it was time for a new plane. My first aileron plane was the Estes Air Force One, though it isn't very maneuverable and I wanted something I could really use to increase my skills. I decided the Parkzone Trojan t-28 Plug and Play (PnP) was a good choice due to its flying characteristics, sturdy foam construction, and overall value for the price. The PnP model includes the assembled and painted plan, servos, 25A ESC, and Parkzone 480 brushless motor. All that is required is the TX/RX and battery.

There is not much to mention in the way of building, all that is required is to insert the horizontal stabilizer and snap in the main landing gear. The nose wheel is secured with a screw. The only modification I made immediately was to snip off the E-Flite battery connector and solder on a standard Deans plug.

Flight Report:

The maiden flight was successful, though a little hairy at times. The plane is the most responsive of any I have flown so far and truly flies where you point it. Though the plane is stable, it would not make a good first plane as there are no self correcting proprieties. I think this was a good choice for my 3rd plane (not counting the estes jet). The ground handling properties are excellent with the triclycle gear though I plan to swap out for larger tires to make grass strip take offs easier. In the air I tried a few loops and rolls, and even manged to pull off a fairly decent immelmann turn. I am looking forward to experimenting and adding new aerobatic moves to my repertoire. Right now I am working on pulling off smooth landings and putting the plane right where I want it. I manged to rip both main landing gears off during separate hard landings. They were easily glued on and stronger that before. I would recommend this plane to anyone looking to improve their skills beyond 3 channel rudder/elevator. If you already have a 4 channel radio and battery, you can't beat the $160 price tag which includes servos, ESC and a brushless outrunner. One recommendation, get a radio with dual rates if you can. Right now all I have is a basic 4 channel and it was very touchy at first...something that dual rates can help with. Happy flying!

Saturday, September 27, 2008

Estes 747 Air Force One Upgrade and Flight Report


I finally got around to finishing the upgrade on the Air Force. I'll jump right to the end and say it was worth it! I took it out for the maiden flight this morning and had a blast flying it। Even better, it came home in one piece.



The Modifications:

To anyone who has tried to fly the Estes 747 in its stock configuration, god help you. It is basically uncontrollable and I would not recommend it. For the upgrad, I used a Hitec 3 channel receiver, Great Planes 35 amp brushed ESC, and a Thunder Power 3S 2100 Lipo battery.

I started by finding the CG of the plane with the battery and electronics installed. You'll find the CG is roughly on the two large circles under the wing.

Next I disassembled the plane and removed the stock receiver and ESC. All that is required is to clip a few wires and the stock electronics are out. I did not bother removing the power switch.

With the electronics out, I cut the ailerons and elevator. Based of other postings on the internet, I decided not to add a rudder and have been happy with that decision so far. For the ailerons, I initially cut them 1.25 inches deep, 9 inches long, starting 3 inches in from the wingtips. After the first flight, I decided they did not have enough authority. I ended up cutting them an additional 3 inches towards the center making the total dimensions 12in X 1.25in. If I had it to do over again, I would probably cut them deeper, possibly 1.5 or 2 inches. Once the ailerons are cut out, cut approximately a 45 degree angle on the downward side to allow the ailerons to travel in both directions. I cut this angle free hand and would probably have done better to use a guide to make the cut cleaner. With the angle cut, I attached the ailerons to the wing with hinge tape available from your local hobby shop or Tower Hobbies.






For the elevator, I made two cuts straight across at 1.5 inches deep. I gave some thought to making the cut parallel to the trailing edge, but decided not to complicate things so I cut straight across. Repeat the procedure from the ailerons to cut the 45 degree angle and reattach them to the plane with hinge tape. In order to make both sides of the elevator move in unison, you need to join the two sides. I cut a short piece of servo wire and bent it 90 degrees on both ends. I pushed the servo wire thought the end of the tail and glued it in place on both sides of the elevator. So far this worked out well, though I am keeping a close eye on it before and after each fight.







The next task was to install the servos for the ailerons and elevator. The aileron servo installation was straight forward, just cut out about half the depth of the servo and glue in place. I used Dubro servo hardware and ez connectors to rig up the ailerons. I made a small slit in the wing with an exacto knife to hide the servo wire.
For the elevator servo I decided to put in on the top aft of the fuselage and rig the control wire to the top of one side of the elevator. I routed the servo wire through the inside of the fuselage. If you take cut out the rear hatch on the fuselage, you will find it is easy to route the servo wire up to the center wing area.

With three servo leads now terminated at the center wing area, it is time to rig up a wiring harness for the 4 electric ducted fans. I essentially made a pig tail connection, that is soldering all the positive wires together, then soldering them to a short wire with a standard bullet connector at the end. I did the same for the negative wires. Its not the prettiest, but it does the job. For my electronics placement, I put the receiver in the small electronics bay sandwiched in between the two wing halves. I had to enlarge it a bit to accommodate all the servo and motor wires. I put the ESC down below in the old batter slot, and covered it with packing tape for protection. I routed the battery connector side of the ESC through the top of the electronics bay which required cutting a small whole.





The last step was to find a suitable location for the battery. I can't remember the website, but I ended up using someone's idea which was to carve out a cavity in the top of the fuselage, essentially in the top bulge on the 747 (you know, where the 1st class lounge is!). I am using a 2100 lipo which meant I needed to take out quite a bit of foam to accommodate the batteries size. This step is critical as you need to place the battery in the correct location in order to get the CG balance right. I taped the battery to top of the plane, moving it forward or backward until I got the correct location. Once the CG was set, I traced around the battery and commenced melting out foam with my soldering iron. I did this is small stages, frequently checking to see if the whole was deep enough. Once the battery compartment was created, there was still one problem to solve. The forward post used to join the two wing halves is directly under the battery. In order to provide enough clearance, I again used my soldering iron to melt about half of the thumbscrew down. This seemed to work well, and everything fit together nicely. If you look in the picture above you can see where I melted down the thumb screw.



Flight Report:

For the maiden flight I chose not to use the included bungee launch system. Instead, another flier was kind enough to give it a hand launch while I worked the controls. The takeoff went well, only dipping a bit before pulling nicely in a scale like fashion into the sky. The 11.1 lipo obviously helps out, though it is certainly putting more voltage to the motors than in intended 8.4V. This can be mitigated by minimizing use of full throttle while cruising. I found 1/3 to 1/2 throttle allow you to cruise at a nice level altitude. Turns were good, though on the initial flight I found the ailerons lacked much authority, requiring a lot of deflection to bank the plane. I extended them for subsequent flights to a length of 12in which helped quite a bit. For turns all that is required is to bank the plane and use a little elevator to push the tail around. Landings are easy, I found the plane glides well and had a tendency to overshoot my landing area. Flight times with the 2100 lipo where about 10 minutes. I found on subsequent days the plane was difficult to fly in windy conditions and noticed quite a bit if horizontal wobble. All in all, this is a fun plane to fly once the proper modifications are made. The looks are great as is the sound from all 4 engines. Happy Flying!

Saturday, August 16, 2008

Easy Star Brushless Upgrade

Its been almost a month now since I upgraded my Easy Star to a brushless motor. It was an excellent decision and I have been flying it almost exclusively since the upgrade. My main reason for upgrading was a desire to turn it into an aerial video/photo platform. At the moment the only camera I have (for plane use that is) is the Oregon Scientific ATC 2000 camera. This is the same one I tried with before with the stock configuration that resulted in a crash. After doing a lot of online research, here is what I ended up with.

Motor: E-flite Six Series 2000Kv Brushless Inrunner
ESC: Great Planes C-35
Prop: APC 6X4
Battery: Lipo 3S 11.1 2100mAh
Futaba 72Mhz TX/RX

I went back and forth on the motor and if I had it to do all over again I might have gone with the 2700Kv version of the motor, but the 2000 works just fine. The full up weight is 27oz. The motor is a drop in replacement as the dimensions are almost the same. The trickiest part of the upgrade was to cut out the old motor and cut the top seam to allow the motor wires to be put back in the original channel. Once that was done, it was just a matter of installing the rest of the electronics and checking the CG.

Maiden Flight: Well lets just say it is well worth checking the rudder servo to be sure things are moving in the right direction. After a few false starts I learned this lesson! With everything hooked up right I found it flew very nice. Take offs were easy and the plane quickly climbed high enough to be a speck in the sky. Through several flights I found the flight time to be 15mins plus with good throttle management. 25-50% power is sufficient to hold level altitude. The motor will not allow for unlimited vertical but according to some of the calculator software it can theoretically do about 40mph on level flight. One of the biggest advantages is the ability to fly in higher wind (10-15mph). The extra power really helps penetrate the wind and keeps you flying.

After a few flights unloaded, I decided to strap on the video camera. I made a quick mount by gluing the helmet mount to a piece of 1/8th inch plywood cut to fit in the cargo bay with the canopy off. I ended up cutting a foam wedge to elevate the camera and point it down the nose of the plane. I secured the camera by putting three rubber bands around the camera and fuselage. The total weight with the camera is 33oz. In order to balance the plane I ended up putting the battery on top of the center of the fuselage (where the wings meet). I secured it with a rubber band and velcro. This setup seemed to work well. I have flow about half a dozen times so far and am very pleased with the performance. With a good hand toss the plane dips a bit but easily gains speed for a good take off. Once at the desired altitude 50% power or so will hold level flight. Landings dead stick are a snap even with the extra weight. If anything it actually makes it easier to land as the plane comes down quicker shortening the area needed for a landing. The trickiest part is learning to fly smooth and level to make good videos. I feel like this has greatly improved my flying ability and been fun as well. When funds allow I plan to by a small digital camera and install an extra servo to start doing aerial photography.

For anyone looking to do a similar upgrade, feel free to email me with questions.






Super Cub Aileron Upgrade

Now that I feel comfortable flying the Super Cub with 3 Channels I decided to give ailerons a try. I won't go into great detail on the build as I followed Dave Smith's blog . The toughest part for me was getting the angle smooth on the bottom side of the aileron to allow it to travel down. Also, I ended up re-cutting the ailerons from 1" to 1.5" deep. I used an old, slightly damaged wing to provide the larger ailerons. I decided to do this as it was clear after the first flight that 1" provided no authority in the air. Also, I went back and forth on whether to reduce the wing's dihedral. In the end I did try to flatten the wing out by putting on book on it over night.

Flying Impressions:

In all honesty it doesn't fly as well as I hoped. I think my ailerons may still be too small and the dihedral too great. I have run into what I believe is "adverse yaw" which means the plane tends to yaw in the opposite direction of the intended turn. To learn more about this well known effect, read this link. This effect can be countered by coordinated the turn by applying rudder input. I find that I can do decent turns by using both rudder and aileron as well as up elevator. I can't make the plane to aileron rolls, likely due to the aileron's fighting the wing's dihedral which was designed to self right as it is a trainer. All in all it is still fun to play around with and should give me some aileron experience for future planes. I may try messing around with the dihedral more at some point to see if that helps.

Here are some pics with the original 1" ailerons.


Sunday, June 1, 2008

Hobbyzone Super Cub with an Oregon Scientific ATC2000 Camera

With the increased power of the Lipo battery (3S 11.1V, 2100mAh) I decided to give Oregon Scientific ATC2000 a second try. I used the rubber band helmet mount and some Velcro to secure it to the battery door. If you bend the landing gear in a bit there is just enough clearance between the camera and the ground. The full up weight with the camera is around 32oz. I of course chose a windy day to try this, but what can you do, its always windy! The take off was a little wild but once I got it under control it flew very nicely. It of course flies much heavier which means you need more throttle to maintain altitude and a longer roll out for take off. Landing wasn't too bad, I kept about 1/4 power almost all the way in and killed it just before landing. This was also in part to the strong wind I was landing in.

Here is the video, the actual quality is better but you tube made it a little choppy:

Saturday, May 24, 2008

Upgraded Super Cub on a windy day

Today was the first flight of the Super Cub with all the new parts in place. Even though the clouds were ominius and the wind was blowing 10-15 my co-pilot and I decided to press on. For reference my co-pilot is 1.5yrs old but his little fingers are great on the stick ;)


Plane Details:

Stock Motor and Prop
Futaba Pars2 Receiver
Futaba 4 Channel 72Mhz Transmitter (bought TX/RX off Ebay)
Great Planes Electrifly C35 Brushed ESC
2 SG90 9gram Servos (Bought off Ebay from Hong Kong for dirt cheap, $5 each)
Thunder Power 11.1 3C 2100mah Lipo Battery
Deans Connectors
New paint job using foam safe spray paint from my LHS.

The installation of the new eletronics was straight forward with the most coplicated being learning to soldier the Deans connector onto the battery. As the new LiPo battery is larger I decided to put the reciever in the batter compartment and tape the battery in place inside the fusuleage. I may end up switching this around but it will take some modification of the exisint battery box.

The paint job was frustrating and didn't come out quite like I wanted. Though the paint is foam safe I found that it didn't bond very well. Even the gentlist of scratch will chip the paint off. I used the lowest tack masking tape I could find and still it would lift the paint of. I will have to go back and do touch ups on the areas that didn't survive the tape.

Flight Test:


This was the windiest day I have flown to date but let me just say it was fun. The new lipo battery given this plane new life. I don't know how using this battery will effect the motor in the long run as the stock battery is only 8.4V vs. 11.1V. I am trying to mitigate this by not using full throttle very often. I found that 75% throttle was more than enough to rise off ground (ROG) in a short distance. Once airborne into the wind the plane shot straight up and climbed at an incredible (scary) rate. For the first minute or so I though I would completely lose control as the plane gained altitude and bounced around wildly. I looked at my co-pilot sitting comfortably in his stroller and he looked as concerned as I felt. I decided to reduce the power to 50% and I found the plane leveled off and began to stabilize. For the next 15-20 minutes (forgot to record the exact time) I flew a nice pattern slowly on the upwind side and faaassstt on the downwind leg. It was fun playing around with the throttle so the plane basically stood still on the upwind leg. Eventually as with all flights I decided I should stop putting it off and try to land. This was tricky with the wind and I aborted my first attempt. With the old battery I would usually give it full throttle to do a go round, so this time should be no different, right? WRONG! When I applied full throttle into the wind the plane shot up and was almost half way through a loop before I reacted. I figured I had two options, try to complete the loop, or abort....both seemed risk as I was low to the ground and have never done loops at low altitudes. I decided that I would stay with the loop and try to fly out of it. I did this of course knowing that there was a good chance I would hit the ground nose going way too fast. Luckily I made it through and recovered in time to go around and make a reasonably nice landing. I practiced my landings in the wind a few more times and was pleased with the results. A couple of times when I landed harder than I wanted to my co-pilot exclaimed "Uh", leaving out the "O", as he does because he is eccentric (or because he is a toddler). I definitely recommend the LiPo upgrade as it gives the plane much better power and longer flying times. Keep in mind that you have to replace the stock electronics before swiching to a LiPo battery as it is designed for NiMh batteries.