busarider29

My Feedback: (4)

I have the Alpha Corsair and I attempted to fly it a couple of times this past winter with no success. My girlfriend would hand launch it for me, and upon launching it, it would immediately begin to torque roll to the left, I then would compensate with right aileron and I think I would overcontrol and shortly thereafter it would roll into the ground. Luckily there was quite a bit of snow on the ground during these first flight attempts, so damage was minimal. Well, there is no snow on the ground anymore to cushion a crash so now I'm scared to give it another go. I'm running a 2808 Axi (I believe thats the name of it) brushless motor with a 3 blade prop, 2 cell Kokam Li-Po battery.
What would be the best way to launch. I was thinking of actually giving it a hard throw. My girlfriend was just kind of tossing it lightly and letting it "fly" out of her hand, almost like letting a bird fly with a small boost from your hand, if thats a good analogy. Also, what are good settings to have the control throws set at and Expo settings. Like I said before, I think I was overcontrolling. Any advice would greatly be appreciated. Thanks, Don.

euromodels

Are you sure about your AXI motor? 2808 is too big for this plane. We have a few of them flying, the first one with a geared 5:1 Speed300; other fly with the blue MPJet outrunners. No problems at all.
Good luck.
Zed
www.euromodels.com.au

Woody 51

The best AXI for this model is the AXI 2208/20 and 9 x 6 prop.
Anything bigger and you will have a constant problem with torque yaw.
The tendancy to roll on initial launch is common but once trimmed, they fly quite straight.
Recheck you motor size and if it is a 2808 series then downsize it to a 2208/20.

The 3 bladed prop will also give some problems. The Flying Stryo models with their scale props are all terrible when it comes to torque yaw.
A 3 blader may look scale (when it is still) but once its turning, no one can tell how many blades the prop has on it.
Try changing to an APC 9x6 Slow Fly 2 blader, which is the prop ALFA designed the model around. Just pop the 3 bladed one on for looks when the model is on the ground.

busarider29

My Feedback: (4)

Thanks guys. I know I was a little larger than the recommended size when I purchased the motor but that was because I was planning on running the 3 blade. I'm going to downsize the prop to a 2 blade. I wasn't full throttle at launch, probably 3/4.......will that still pose a problem with the 2808?
One last thing, what are your recommendations for control surface throws and expo/dual rates??

Thanks,
Don

Woody 51

It is essential that the models C of g is spot on where ALFA indicate. You will find the C of G marks on the underside of the wing. A small slot, parallel to the wing LE.

Alfa's are sensetive to C of G. It can be a couple of mm forward, but do not take it any further back.

The control surface settings given by ALFA in the instructions are way over the top

Assuming the C of G is spot on the indicated marks, elevator about 8mm and aileron about 7 mm should be more than sufficient. If it is forward, add a mm or 2 to elevator.

The 2-3 mm "up" on each aileron is advisable, to help counter tip stall at slower speeds.

Exponential is a personal thing. I use 30% on both, but I know of others who use more and others less. It's your call.

If your using a bigger motor than specified, you may need to consider a slightly bigger prop to soak up the extra power. Consider either a 9 x 7 or 10 x 6.

Don't try and land it "trainer " style (no power and full up elevator) or it will stall and "Splot!"

You must keep some power on and "fly it" ONTO the ground.

Good luck.

busarider29

My Feedback: (4)

Thanks Woody. I know it was somewhat difficult to balance the Corsair. I had to move the battery as far forward as I could get it and it was a real squeeze to get it where I needed it, as there's not a whole lot of room. I'll be sure to balance it "dead nuts" before I fly it again. From your advice, I can see that I was WAY OVER the top on the surface throws. I'll have to correct that too. I believe the 3-blade that I have on it now is a 9 x 6. Maybe switch to a 10 x 6 two blade? I just ordered some plans this week for a bungee cord launcher that's on rails. It's not the Jet Launcher from Hobby-Lobby, its more for prop planes. I guess some of the scale combat guys use them. I'm going to build that and use it for the next flight instead of having someone hand launch it. I read on here in another thread that hard, brisk throws to help it gain sufficient air speed is better than giving it a light toss and letting it fly out of your hand. Hopefully this will also help with the hard left torque roll that I'm experiencing as well.

Woody 51

You should not need a cat launch for any of the Alfa's, including their EDF's.

My 2 Alfa Props are only Speed 300 powered (9 x 6 APC and 5: 1 gearbox) and literally fly out of my hand. Full throttle, a light toss with nose about 5 degrees up and they are away.

There is a website somewhere that suggests launching them undearm. Don't!
The extra height from an overarm throw is a great asset.

Study the video's on Hobby Lobby's website and just follow those guys. They have the method right.

A 9 x 6 three bladed prop should be o.k. once you have the model trimmed out, but the AXI 2208/20 is still a better solution. An even better one is the Blue MPJET Outrunner spinning an
8 x 6 or 9 x 6. It is tailor made for the Alfa Props. No torque yaw problems and great performance

Woody 51

You should not need a cat launch for any of the Alfa's, including their EDF's.

My 2 Alfa Props are only Speed 300 powered (9 x 6 APC and 5: 1 gearbox) and literally fly out of my hand. Full throttle, a light toss with nose about 5 degrees up and they are away.

There is a website somewhere that suggests launching them undearm. Don't!
The extra height from an overarm throw is a great asset.

Study the video's on Hobby Lobby's website and just follow those guys. They have the method right.

A 9 x 6 three bladed prop should be o.k. once you have the model trimmed out, but the AXI 2208/20 is still a better solution. An even better one is the Blue MPJET Outrunner spinning an
8 x 6 or 9 x 6. It is tailor made for the Alfa Props. No torque yaw problems and great performance.

If its any consulation, my Alfa P47 carries 8 grams of lead ballast on the front firewall to get the C of G right and I am using a 2 cell, 2200 Ma/H Lipoly in that! Don't be afraid to ballast your Corsair up, it will handle the extra weight no problems. We are only talking 2/5ths of stuff all here.

Old Shep

busarider29
Avoid the bungee! It simply isn't necessary for any of the Alfa models....like Woody says, study what the HL guys do on their videos...handlaunching isn't rocket science. I'm not expert enough about electrics to comment on your prop selection...my Corsair flies just fine with the brushed motor and the stock 2 blade prop. I do have a liPo battery however. Keep after it; the Corsair is a wonderful airplane in the air, slows well for landing, maneuverable, etc. Good luck!
Old Shep

busarider29

My Feedback: (4)

Thanks guys. Okay, I'll study the videos from HL more and iron out all the details on the Corsair and give it another go. I guess I could still build the bungee launcher and use it for a 1/12 combat Hellcat that I still need to build.

Woody 51

A cat launcher is a handy item to have, especially if you ever add an EDF to your collection. Just not needed with ALFA's.

busarider29

My Feedback: (4)

Well guys, I decided to try and get my Alpha Corsair in the air again. First attempt since my last post back in April. I vowed to stick with my original motor/propellor set-up which is an Axi 2808 with a 9 x 6 3-blade prop. I hand launched it at about 3/4 throttle just like the video showed on the HobbyLobby website.
Well, after a few seconds battling the torque yaw and finally getting it under control to where it was flying on the wing, it flew great!! Boy, it's a blast to fly and looks great in the air. The motor/prop combination I've got gives it all the power and then some. I put a functional rudder on my Corsair and it works really nice. Went out a second time and same thing, fight the torque yaw at launch until she's level and flying. That torque on launch is a bear but once she's flying, no problems. I guess it would help if I had someone launching it for me instead of trying to do it myself.
This is my first electric and although its a blast and all I have to do is go to the local school yard to fly, I get one 7-8 minute flight and then its 2 hours on the charger. That sucks! With my nitro planes I get four 12-minute flights before I have to take a 30 minute break to charge, then its back in the air for 4 more flights. I've got a 3-cell Kokam Li-po also. What sort of flight times should I expect to get out of that?
In conlcusion, this little Alpha Corsair flies great, and looks awesome in the air, especially on a low, high speed fly-by.

Woody 51

The number of cells in you Lipoly won't determine the flight time, but the Ma/H rating and the actual current draw of the motor will.

The current draw is in turn, determined by the size (diameter/pitch) of the prop you are using.

The instructions that came with your AXI should have that information printed in there somewhere.

What Ma/H rating is the Kokam pack you have?