Indoor Champion

Up

 

My Indoor Champion Saga

A kit bash for small lot aerobatic flying by Greg Covey

Specifications:

bulletWingspan: 28" stock, 32" modified
bulletLength: 23" (fiberglass fuselage)
bulletFlying Weight: RTF @ 8oz. with DX-B, 11oz stock with Speed 280, and 12oz with Speed 370 motor
bulletMotors used: GWS DX-B motor, Speed 280, and Speed 370
bulletProps used: GWS 10x4.7 and Wattage 7.5x5 or APC 8x6 prop
bulletCells used: 8-cell 300mAh NiMH, 8-cell 800mAh 5/4AAA NiMH
bulletSpeed Controls: GWS 2 amp, GP C-5, and Wattage IC-15 ESC
bulletRadio and gear: GWS R4-P micro receiver and 2-3 HS-55 sub-Micro servos
bulletAvailable From: Hobby Lobby

Introduction:

The Akro Champion is a 4-channel "full-house" aerobatic streetflyer sold by Hobby Lobby. In stock form, the geared Speed 280 motor provides adequate power for simple aerobatic maneuvers. Once the power system has been upgraded, this 28" symmetrical wing plane becomes an awesome outdoor performer. I have used both 280BB and Astro Flight 801G brushless motors with great success in this model.

The basic design is not just a stick fuselage but rather a very light 1oz custom fiberglass fuselage and balsa wing covered with Litespan. The molded carbon fiber landing gear, foam wheels, spinner, and pilot all help to make this model really look like a plane with eye-catching details.

My initial design goal for this project was to reduce the weight enough to make it an aerobatic flyer for small parking lots and indoor meets. After choosing lighter power components like the GWS IPS DX-B motor, 10x4.7 Lite Stik prop, and 300mAh NiMH cells, I managed to reduce 2.6 ounces from my stock 10.6oz ship. Additionally, I eliminated the rudder servo and coupled it into the aileron linkage for ground steering and improved turning capability. It was important to me to have a steerable tail wheel for taxiing around the indoor gym for better takeoff and landing positioning.

At the conclusion of my quest to fly this design indoors over the Winter months, you will see that my final configuration ended up in a different direction to my initial goals.

Stock (Before)                                           After                                                                Change

8-cell 720mAh NiMH pack (3.6oz)            8-cell 300mAh NiMH pack (2.3oz)               -1.3oz

geared Speed 280 motor (1.9oz)             GWS DX-B motor (0.9oz)                              -1.0oz

3 HS-55 Servos (0.9oz)                             2 HS-55 Servos (0.6oz)                                  -0.3oz

Exponential:

To gain even more agility, I enabled the exponential function on my Futaba Super-8 transmitter. By using a negative exponential, I could make the ailerons and elevator more docile around the neutral stick center and still have wild throw range near the outside ends of the stick travel for loops and snap roles. It was like getting the dual rate function without flipping a switch. I initially set the aileron and elevator exponential settings to -50%.

Mounting the DX-B Motor:

To mount my GWS DX-B motor, I epoxied a balsa block to the inside of the fiberglass fuselage nose. I then mounted a balsa post through the balsa block and drilled a partial hole for the gearbox shaft. A final hole was drilled through the balsa block for the motor and wires. This made for a secure mount that would still break in the event of a direct hit on the nose.

 Lite_Champion_Firewall1_thumb.JPG (3899 bytes) Lite_Champion_MotorMounted1_thumb.JPG (3699 bytes)

A balsa firewall and post are added to mount the DX-B motor

The stock cowl fit perfectly over the mounted DX-B motor. Later on after the pictures were taken, I spray painted the distinctive orange GWS prop with black paint and masked off the tips for a nice "circle of orange" when the prop was spinning.

Lite_Champion_PropMounted1_thumb.JPG (3530 bytes)

The stock cowl and DX-B spinner are fitted as normal

Where's the Third Servo?:

By coupling the rudder into the aileron linkage, I could still have (or so I thought) my desired ground steering and also increase my turning authority in small flying areas. I used a special slowflyer control horn CH902 from Hobby Lobby that is very light and meant for a pull-pull system. I then used carbon reinforced "Fireline" to tie the rudder into the aileron linkage. Small pushrods were used to create a custom tailgear and adjusting clevis. I used a tiny 1/2" Sullivan tailwheel. The control lines connected to the aileron servo were crossed to opposite sides before tying to the rudder. Small bends in the aileron linkage rods allowed me to fine tune the rudder alignment without re-tying the lines.

Lite_Champion_tailgear_thumb.JPG (3252 bytes)

The tailgear fits through a hole drilled into the center of the horn

Lite_Champion_rudder1_thumb.JPG (3760 bytes) Lite_Champion_rudder2_thumb.JPG (3182 bytes)

The steerable tail wheel and rudder are coupled to the aileron servo

As it turned out, I did have my desired ground steering for "touring" the gym floor but the coupled rudder played havoc with my slow speed turns indoors. The resultant coupling made the plane bank and head for the floor instead of spinning around like I had imagined. I ended up removing the coupling and installing a third servo for independent rudder control.

The Finished Model:

LIte_Champion_Finished5_thumb.JPG (4612 bytes) Lite_Champion_front_finished_thumb.JPG (3010 bytes)

The finished "Indoor" Champion is 2oz lighter than stock

 

 

Initial Flight Testing:

My initial flight was with a GWS DX-A motor. I quickly realized that there was insufficient thrust for this design and after 3 flights, DX-A motor burned out. Clearly I was stressing it too much with that setup. I switched to a GWS DX-B motor and kept the 10x4.7 (Lite Stik) prop and the improvement was amazing! On 8-cells of 300mAh NiMH, the DX-B motor was drawing 1.8 amps on full throttle. This was near the upper limit of the GWS motor so I decided to add one of those GWS heatsinks for additional safety.

Lite_Champion_RTF_indoors_thumb.JPG (16462 bytes)

A revved-up Champion is ready for the challenge

Lite_Champion_Indoors2_thumb.JPG (4767 bytes) Lite_Champion_Indoors4_thumb.JPG (6792 bytes) Lite_Champion_Indoors7_thumb.JPG (4498 bytes)

The Champion circles a double full-court basketball gym

The forth flight started well but ended abruptly with a crash

Tuning the Design:

After about 4 flights in two different gyms, we managed to crash the Champion. At that point we decided that it was still flying a bit hot indoors and needed to be slowed down. After repairing my leading edge wing damage, I added another 2" bay onto each end of the wing. This would provide additional lift and drag to slow the ship a bit. My wingspan was now 32".

IndoorChampionWingBay_thumb.JPG (4507 bytes)

The new wing modifications are ready for covering with Litespan

I re-covered the wing parts using white Litespan and Balsaloc. It was my first time using these covering materials and a good learning experience. Litespan shrinks very little and the Balsaloc needs to sit for 15 minutes before using the Litespan covering and sealing iron. The trick here is to make it taught when applying the edges of the covering. In this manner, only a slight shrinkage is then needed for that tight "drum" effect.

IndoorChampionNewWing_thumb.JPG (5462 bytes) IndoorChampionNewWing2_thumb.JPG (5267 bytes)

The Indoor Champion now spans 32" across

For extending the ailerons out to the added bays, I cut scrap pieces of foam left over from my Ultra-Lite Stik project. The color and thickness of the Lite Stick foam was almost an exact match for the ailerons. The little flare at the ends gave my Indoor Champion some added character.

IndoorChampionNewWing3_thumb.JPG (4366 bytes)

Bottom view showing increased throws and cross-coupling to rudder

I decided it was time to also increase the elevator and rudder throws. Both linkages were moved out one hole so that the ailerons used the outer most servo arm hole and the rudder used the middle holes. I re-programmed my exponential aileron setting from -50% to -75% but left the elevator setting at -50%. This would help compensate for the increased aileron throws and give me wild swings at full stick offset.

Final Flight Testing:

The longer wings had indeed given me more lift and allowed me to fly the Champion slower. Once I realized that the coupled rudder was actually hindering my turning performance, I removed it and installed a third servo for the rudder control. It then flew much better and had predictable turns.

I could fly my Champion indoors using an 8-cell, 300mAh, NiMH pack but it was not aerobatic like I had wished.

For my last indoor meet of the season, I decided to switch to the stock geared 280 motor using the same 300mAh NiMH pack. Since this pack would sustain short current demands up to 3 amps, it should be fine for a brief indoor flight. This result worked fairly well, but, in the end, it was not comfortable indoor flying in a double sized basketball court.

Conclusion:

Although I had not achieved my initial goal of flying the Champion indoors with aerobatic authority, I had managed to fly it and learned much along the way. When the indoor season had ended and Winter turned into Spring, my goals for the Champion had also changed.

The Champion now fitted with a geared 370 motor

I decided that my larger wing Champion still looked great and I received many compliments on it with the hand painted pilot figure. I have since changed the power system to a geared (3.67:1) Speed 370 using an 8-cell, 800mAh, 5/4AAA, NiMH pack like that used on the Wattage Crazy Max. This power system upgrade provides both great power and duration on my now 12oz. Champion. I can easily fly this model in a small lot or field and literally float to a landing. I was very happy with the final outcome of this project even though it started out in another direction. An equivalent GWS power system with ball bearings is the EPS-300C (AS) and can be used with a GWS 8x6 prop or APC 8x6 prop.

Sometimes your projects don't always work out and sometimes goals change along the way. The important things to remember are that you can always learn from any experience and don't shy away from trying new techniques or materials. When you have fun with your R/C projects and keep an open mind, the hobby will always be a rewarding experience.

Update:

Since initially writing and submitting this article, I had an opportunity to try yet another power system on my Champion. Although I was pleased with my geared 370 setup, a new Speed 280 sized brushless motor had become available so I decided to give it a try.

The Model Motors' Aerix Mini 7 brushless motor (AC 1215/16) is the size of a Speed 280 motor but with the power of a Speed 480 motor! A Speed 280 motor has a 24mm diameter and the Aerix Mini 7 has a 22mm diameter. At 1.7oz in total weight, the Mini 7 brushless is only 0.2oz heavier than a Speed 280 motor. The shaft is Speed 400 size at 2.3mm diameter.

I replaced my Wattage IC-15 ESC with a Jeti 18-3P (JEC183) brushless motor controller but used the same 5/4AAA 800mAh NiMH pack since my maximum current draw would be about 9amps. These cells have proven to hold up better at this current level than the more popular 500-720mAh NiMH AAA cells used in Speed 280 applications.

I used an MJ MJ8009 3.46:1 ball-bearing gearbox for Speed 280 motors from Hobby Lobby. It wasn't a perfect match but it was close. I needed to drill out the 2mm hole in the pinion gear to match the 2.3mm diameter shaft on the motor. I dabbed some medium CA onto the end of the shaft and installed the pinion gear.

The motor case was a bit smaller than the Speed 280 motor that the gearbox was designed for so I wrapped my brushless motor with a few winds of masking tape until I had a snug fit.

My APC 9x6 slowflyer prop fit onto the 3mm gearbox shaft using an MJ8030 short prop adapter. At 9.5amps, I was getting 5200 RPMs on my new power system. My RTF weight using the 4oz 8-cell 800mAh NiMH pack was 13.0oz. I became excited when I realized that my thrust was exceeding my model weight!

The Champion now had incredible power to climb straight up and stop like it was sitting on a shelf of air. The combination of power, light frame, and lift from the 32" wingspan has resulted in a truly great flyer!

Final Specifications with Mini-7 Brushless Motor:

bulletAC 1215/16 Speed 280-size brushless motor
bulletRTF @ 13oz.
bullet3.46:1 MJ gearbox MJ8009
bulletJeti JES 18-3P Sensorless brushless ESC for up to 18 amps
bulletAPC 9x6 e-prop or 9x6 slowflyer prop
bullet9.5 amps @  5200 RPMs
bullet8-cells of 800mAh 5/4AAA NiMH

Karl Mecklenburg Youth Jersey went Brandon Mebane Womens Jersey the 6, 306-pound Ogbuehi with the 21st pick, despite his knee injury the Liberty Bowl Dec. nisbo says: 6 11 AM The timing of the pick is suspect, no doubt. When hung up his No. Authentic Bill Russell Jersey had five receptions for 55 yards and a touchdown against the Indianapolis Colts a Week 4 victory. Customers seeking information about a product's manufacturer's warranty should directly contact the manufacturer. One of those men was baseball legend Robinson. 2012, the Mutombo Foundation, partnership with Mutombo's alma mater, Georgetown University, began a new initiative which aims to provide care for visually impaired children from low-income families the Washington, D.C.

UP NEXT Pirates RHP A.J. The Blues controlled much of the first period and led 12 shots before the Penguins surged late to end the period with the shots tied at 13. Tweets by @1AttitudeSports Follow @1AttitudeSports Attitude Sports is the sports network for DirectorZcut. with Smith saying the crowd is going to destroy him! A five-time Pro Bowler and two-time first-team All-Pro, Smith has compiled 14 career receiving yards, and 81 receiving touchdowns. displays excellent technique and Richard Dent Jersey by keeping his Andy Janovich Jersey inside to control Smith. You the opportunities that they have to reload between, again, high draft pick this year, cap space, and even more cap space next year.

The Raiders fell 16 and watched Jack Doyle Jersey Super Bowl from home.

Looking up, he Sean Mannion Jersey teammates and coaches and trainers. Upon leaving he took up a succession of menial jobs, spent some time wandering around Europe, and finally returned to Leicester 1951. December, his league appeal was upheld and Peterson was scheduled for a federal court appeal hearing on February 6. We have to wait and where he's going to be at physically, Sullivan said. WATCH: THURSDAY'S PRESS CONFERENCES The Buccaneers' defense is shaping up to be much different than the unit that took the field a year ago. GREEN BAY JACKSONVILLE , Sept. Tarasenko said he has not given any thought to Russia's assignment Group B, considered by most the more difficult group with Sweden, Finland and North . Cause it was a tough '95 for me and probably for most of our football team. option quarterback college, Randle El threw it, caught it, and returned it the NFL, and he made big plays often. Quite the Cody Kessler Jersey origin story for a NHL mascot.

They asked me to be hitting coach . His earning potential was enormous but as well as drinking he gambled, was swindled and bought drinks all round. That's you, Mr. He plays Authentic Joey Bosa Jersey everything that he's got. This deal is supposedly sweetened Authentic Jaylen Brown Jersey by the Suns by including some Cam Johnson Womens Jersey picks.

masher1965 Curtis Joseph Womens Jersey 15 12 PM I preface this by saying I am NOT a Patriots fan and the Chiefs kick their ass this weekend, HOWEVER, is WAY OUT OF LINE here. The pair connected on a pump-and-go goal line sideline route for a touchdown, ' highlight play on offense of the game. Unfortunately for Pittsburgh, the Bruins managed to score four consecutive goals the second and third periods. Heath Miller Youth Jersey he was involved the parliamentary expenses scandal, and was reported Authentic Kevin White Jersey The Daily Telegraph to have claimed over £87 on his constituency mansion which he designated as his second home. He was closely monitoring the draft on his iPad as he prepared for Seattle's game with the Yankees. Even 12th man showed promise Mitch Morse Youth Jersey Summer League but likely rarely the court because of the line front of him. It's amazing to think that this didn't even start for the first quarter of the . 21 Maryland .

David Kocer 184: Dixon vs. To his athletes and to the world around them he is God. The only thing you can do is just sit back and relax and wait. What you feel now might not be what you feel six months from now. It seems the combine numbers he produced mixed with his experience at cornerback have Nico Siragusa Womens Jersey Authentic Bennie Fowler Jersey exaggerated impression that he is the best cover safety this draft.

@frank_seravalli @frank_seravalli Braydon Coburn was sleeping. He was ultimately granted several honors because of his integrity, character, and sportsmanship including, Gehrig Memorial Award , Sportsman of the Year , Roberto Award , Bart Giamatti Community Service Award , and World Sports Humanitarian Hall of Fame . So now for all 32 teams including the Cincinnati Bengals the off is here. In 1977, he earned his Juris Doctor degree from The George Washington University National Law Jason Witten Jersey He needed that. Worst-case scenario: The Indians have depth the bullpen, but injury to , Shaw or would not go over well. You can always change the information you share with us by editing your profile. With that mind, going out and grabbing a netminder free agency or MLB Jerseys China via trade might be the only way for to Nike NFL Jerseys China improve goal. It is expected to pass just east of Jamaica Authentic Tony Dorsett Jersey Authentic Bishop Sankey Jersey over or close to the southwestern tip of Haiti late Monday or early Tuesday. --When Brent Burns Womens Jersey a fly on the ceiling, was it flying upside down all the time, or was it flying right-side up and flipped over at the last possible second? When you're the backup at a position, there's times -- like Alvin didn't get a Larry Warford Jersey of reps last week at guard and he Eddie Goldman Youth Jersey there and was able to play his butt off, Greco said.

The only difference would be Cheap Jerseys Paypal that those particular receivers relied on NBA Jerseys For Sale route running and using their body to get open. He has learn a lot from Jennings and yet still trash. According to , Jakob Poeltl Baseball Jerseys Cheap is hoping that he can pattern his game the after Chicago Bulls forward Pau Gasol. If he pans out, you can look at his signing as a key ingredient to a championship Celtics squad.

It's different teams that's right there on the cusp of winning that Super Bowl or really contending for that Super Bowl, Dansby said, and I feel like I'm their missing piece all those situations. The Royals beat the A's 6 at home on Cheap Jerseys Paypal Free Shipping night:


The Quick Wholesale Jerseys De La is extremely unlikely to take the hill before mid-, and not be completely effective upon his return, so monitor Wholesale NFL Jerseys progress from the safe distance of the waiver wire. He also tied the MLB record for most grand slams a age 24 or younger. I would have beards. You 't have to look at analytics to that. It's pretty clear is nowhere close to the Nike NFL Jerseys Supply type of numbers he put up during his 2013 Pro Bowl campaign, although the 49ers probably would have parted ways with him Cheap Game Jerseys if that was the intent. Eight are still on the roster and several could play significant roles this .

Ninkovich did the Cheap Jerseys Paypal same for the Patriots. 144 catches, 1 yards, 17 TDs, 32 , Nike NFL Jerseys Cheap 4-year, $46M, $24M guaranteed.
Our pitchers it, infielder Carson Shaddy Nike NFL Jerseys China said They are all about spin rate now and the word you hear from them Cheap NFL Jerseys ‘Velo,' . The 19-year-old rookies quickly followed the lead of Jones and 2015 Calder Trophy winner Ekblad adapting more quickly to the NHL than elite defensemen of previous generations. The Hornets likely won't have update on 's status again until after shootaround Saturday morning, but playing high altitude Salt Lake City may not help the point guard's condition.