Engineman

Hi,
I am just finishing a new aquisition, An ARTF foamie, Alpha from Czech Republic, Corsa. Large box contains a 32" span, depron foam with hard skin, fully detailed. Only two parts, fuselage tail and wing. Geared 380 motor (Graupner can type) supplied. I am using an 8"X 6" Graupner slim Prop and an 800mah LiPoly pack which only weigs 2 oz for 11.1 volts. The whole thing ready to fly weighs just 12 oz. How can they do it. It feels quite strong and looks superb. Unusually I have not needed to make any modifications. I am now waiting for a fine day to try it out, but at 12oz I dont expect any problem except that my 11.1 volt Li Poly could destroy the motor. And a gust of wind could blow it away before I get it up.
Anyone out there flown one of these? What opinion on the power plant and prop? The shop told me that they fly superbly.[8D]

Planebeach

Hi, I have an Alfa Fw-190. I love it, its fast and fun too fly. Only took me 2 hours to finish the plane. 3 hours too cahrge the battery Dam that was a long hour.

I would recomed any Alfa or Flying Styro planes. The Alfas are faster too put into the air.

Woody 51

Don't use your 3 cell Lipo with the Speed 300 motor. A 2 cell Lipo no problems, but the supplied brushed motor is not made for a 3 cell. If you want to use a 3 cell, then go for a Brushless Outrunner, such as the MPJET units.

Other than that, the model will fly real well, like a .40 size glow powered low wing sports model.

Some tips.

The supplied control throws are way over the top. Cut 'em back to about 8 mm elevator and 6 mm aileron. C of G is critical. Make sure it is "right on the money" on the marks on the underside of the wing.

It may want to climb sharply on the 1st flight. Many of the Alfa's do. Just be on guard and ready to dial in some down trim.

Don't forget to cut some cooling air inlet holes in the dummy engine and also a warm air exit hole in the underside of the fuse. If you don't, the battery hatch will blow off as the fuselage interior pressures up.

Before 1st flight.... The motor will only be press fitted into the gearbox. As the latter warms up, especially in summer, the motor will eventually fall out as the gearbox casing material goes a little soft with the heat. It is a common problem. Causes no damage, but is frustrating. So before you go fly, smear some RTV Silicon around the end of the motor and then push it back into the gearbox. Then let it cure.

None of the Alfa's are duds. You'll have fun and then probably want another one.

Check out he following thread on the Alfa Corsair:

http://www.rcuniverse.com/forum/m_15...tm.htm#1521722

Engineman

Hi,
This morning I flew my new Alfa Models Cosair for the first time. It was a super morning for it, cold at 2 degrees, but dry and blue sky. I had completed the model and installed all the gear in the neatest way possible. Final weight came out at 12 oz.
Despite what has been said about not using a 3 cell LiPoly pack, I did as it was the only one I had. I checked all the controls and set aelerons to 50% on rates.
My pal launched the Corsair and away she went. Not quite straight and did not have enough aeleron movement, so rates off and a quick trim to fly straight and level. It was absolutely superb. The motor had bags of power and was soon shut down to about 1/2 for level flight, only using the full power to climb vertically. Being worried about the chance of overheating the motor on 11.1 volts, most of the flight was well throttled back. I also thought that being only an 800mah LiPoly, it would not last long. How wrong I was, it flew for 15 minutes, all over the sky. Fast and very slow. Handling was superb, almost impossible to stall and so steady. After 15 minutes I landed right at my feet, thrilled with the whole flight. The climb was nearly vertical and it could be flown very close in or far away. The shape made it easy to orientate.
After landing I checked the battery and found it still reading 11.4 volts. Only very slightly warm. It still provided full power, so when another clubmate wanted to see it fly, it was launched again for another 3 minute flight, after which it was losing power and was landed. Landings are so slow and controllable.

My conclusions are that this little Alfa Corsair is a superb toy. Not cheap, especially if one has to buy light servos and radio, but flies as well as most 40 size planes. Looks superb in the air. I will now buy another LiPoly. It was going to be a 2 cell 1500, but the 3 cell 800 went so well, I will stick with it. It certainly does not need a better motor, at least until I burn out the little Graupner 300. If I could afford it, I would be out there buying the Focke Wulf 190 tomorrow.

Woody 51

It won't fly any different or faster with a Brushless motor behind that 5:1 Gearbox.

So when the stock motor burns out , maybe consider a direct drive outrunner.

And welcome to the Alfa Lovers club. You should also look at their Mig15 EDF for a real blast.

Engineman

Hi again,

I agree about the motor, but I will probably buy an Axi 2212/34 when it burns out or I get the itch to improve on performance. The trouble is it does not end with just a motor, the brushless controller costs as much. I have ordered a 1500mah Kokam Li-Poly 7.4v, but am loath to try this in the Corsair. I am sure it would fly it, but I would miss the ability to open the throttle for a quick vertical climb which happens now with 11.1 volt for slightly less weight.

I will certainly look at the Mig EDF, but will it hand launch and fly slowly?

Woody 51

Hand launch? The Mig will ROG off the ground off its belly!!! (That's right, no wheels needed.)

Check out the huge Alfa Mig 15 thread down in the electric jets section.

http://www.rcuniverse.com/forum/Alfa...1931813/tm.htm

Also the MIG 15 Video on the Alfa Website at: http://www.alfamodel.cz/index_eng.htm

Scroll down to the MIG 15 and you will find the links there under "Movies"

For a Direct Drive Brushless for the Corsair, the MPJET Outrunners are specifically designed to "drop straight in" to any of the Alfa props on the exact same screw holes as the 5:1 gearbox. (They were designed in consultation with Alfa.)
A much easier conversion that the AXI you mention and with 2 cells and a 7 or 8 x 6 APC Slow fly prop, will outperform the Speed 300 and MPJet 5:1 gearbox set up with ease. Use a 12 or 18 amp ESC. Why make the conversion any harder than it has to be?

Engineman

I changed my prop to an APC 9 X 6 slowfly version. The change to my performance, using the 800mah, 3 cell LiPoly was amazing. I thought it was good before, but now it climbs vertically out of sight, but also cruises on less than half stick. In defference to the little 6 volt motor, I do not use full power much. It does not need it. As a result it still gives 15 minutes of good flight. Last flights were on a windy morning, but it remained quite controllable and did not have any problem flying in to the wind.

Still as good as new after 7 full flights. I am told that I need to grease the gearbox before it blows up! Any experience out there?

P-51B

My Feedback: (5)

For you guys flying the Alphas for a while, are there any tricks to hand launching them that we need to know.

I had a FW that I finally got to take out for maiden this weekend. It was set up with the Blue MP outrunner, 1350 TP lipo, and Castle Creations conroller. It had good power, want to pull right out of my hand. But (remember the "had"?) I gave it a reasonably level shove, it rolled hard left and became foam packing material before I could get my hand back on the sticks. It has been suggested that it may be better to launch at half throttle. Any thoughts, so I destroy its replacement?

Engineman

I have not risked launching myself yet. My pal just gives it a little shove and away it goes. Providing the controls are set as specified and you dont have the aelerons reversed it should go straight. Mine did go left on first launch, but I soon corrected the trim and have never had it again. It is best to launch at half throttle until you get away and have control, then open up and gain some height before messing about.

The secret is not to be heavy and not tail heavy. Balance it upside down as it is impossible the right way up, it topples either way and is very difficult to judge.

Sorry you smashed yours. Mine at 11,1/2 oz just floats in at walking pace, but a cartwheel can break the thing. I broke the tail off in the shop (not mine) but it was soon back using super glue.

Engineman

P-51B

My Feedback: (5)

Thanks Engineman, another recomendation for half throttle.

Busta Prop

Engineman - if you go the AXI route I suggest the 2212/20. This will give great performance with your 2 cell Lipo's and the 9X6 prop or you can drop down to an 8X6 and use your 3 cell pack for totally insane speed.

Happy Flying

Busta

Woody 51

The roll to the left is common with Alfa's. All my 3 did it as well as climbing. I trimmed it out with the TX.

Hand launching. For the P47 and Corsair, hold the model just AHEAD of the wing LE, throttle up and and launch straight ahead and may be slightly nose up, no more than about 10 - 15 degrees. No need to take a run, it will fly out of your hand. Get that launch hand onto the Tx quick as you can.

The FW-190. Hold it by the "bomb rack" underneath and launch as above

The P51. Hold it behind the wing TE and launch as above.

turboomni

Hey engineman,is the stock motor still going strong? I'm considering doing what you did or are doing hopefully. That is running the stock 300 brushed on a 3 cell Lipoly and using restraint on the throttle to only short bursts of power .

Woody 51

The Stock 300 has a reasonable life span. When the brushes's wear out, it's in the trash bin though. My 2 Alfa props now have 10 months on Speed 300's and are still going strong.

Why put a 3 cell Lipo in and run it on 1/2 throttle when you can save some bucks and prolong the motor life by running a 2 cell pack and be able to run the motor at any setting?

Engineman

Hi,

My stock motor is still going very well. It has only had about 2 hours so far, but shows no sign of wearing out. I find that using the 9 X 6 APC Slow Fly prop, performance is such that it only ever needs more than about 1/2 throttle when it is going vertical, but it is nice to have the power when I fancy a high speed pass or vertical climb. Gearbox does need greasing a little using 3 cells.

Despite that, I have this morning bought a brushless set-up. A Typhoon Micro 6/20 with a Jeti Advance 18 - 3P and an 8 X 3.8 Slo Fly prop. This combination being recommended by the UK main supplier. I almost wish I had not, because I now need to build a mount as the motor is an outrunner and the total weight is slightly up. I was getting worried using my old controller as it did not cut out until the volts were well below the 9v which is the minimum for a 3 cell LiPo. I do not expect much difference in performance, it could not be much better!, but it may run a little longer.[8D] I will let you know the result.

I did write a review for my club which is on www.hhmfc.co.uk. Probably the same review will be on AMPEER in April.

The performance of my Corsair has encouraged me to build a large version with my new Magnum 91 Four Stroke. A Hanger 9. ARTF.

Engineman

Hi again,

I have now completed the instalation of my new Typhoon Micro-6 motor and jeti Advance 18P ESC. Had to make up a new engine plate, but by reversing the motor shaft it was easy to screw the ply plate in to the same holes as the gearbox. To my surprise I found that the new set-up complete with prop and a heavier driver came out at 84g, the old set being 88, so a tiny saving in weight. Total plane weight with the 3 cell LiPoly is still 12oz. Not quite as pretty from the front as I had to cut out the dummy motor to clear the rotating motor.

I was lucky that the thing ran the correct way after soldering and the pull now measures 1, 1/2 lbs on full power. Much less noise and smooth throttling. Cant wait for a nice day to fly the thing again. It will be interesting to see how long it runs now with direct drive and a high efficiency.
[8D]

turboomni

Hey woody, The reason I'm considering using a 3 cell lipoly is because I have 4 TP 3 cell packs for my Shogun electric heli that I use.
One is a 1320 Thunder Power pack and the other 3 are TP 2100 mah packs. I would like to use these packs if possible. So actually I'm trying to save some bucks by using them! Can't afford a brushless setup right now for it as I got too much bucks spent on my heli's at the moment and just want a kick around plane when the guys at the field don't want me to fly heli's.
Engine man ,,good luck with your conversion!
Has anyone used a Thunder Power 2100 in a Alfa Corsair?

Engineman

My only worry about using the TP 2100 packs would be the increased weight, also because they are able to pump out more amps than my 800's they might cook the little motor much quicker. My 800's tended to be self regulating because of the internal resistance. That said, I am considering using 1800mAH pack which weighs 129 g. I expect the performance to drop and landing speed to rise.

Engineman

Woody 51

Fair enough. Have fun my friend.

Rocketman612

My Feedback: (85)

Ok after a few setbacks and alot of help from Woody 51 I'm back in business. Invested in the whattmeter and ran the following comparison on my Corsair setup.

MP Jet AC 28/7-30 motor, Kokam 2000mah 15C 2S pack. At Full throttle I collected the following:

APC 8x6 prop: 5,000 rpm's. 10A draw, 75 Watts power , 0.3 lb static thrust and 28.4 mph (using Thrust Hp)

APC 9x6 prop: 4,700 rpm's. 13.5A draw, 96 Watts power, 0.4 lb static thrust and 26.7 mph (using Thrust Hp)


so neither prop will tax my motor, ESC (jetti)
Looks like speed is close and the power savings of the 8x6 prop will yield longer flight times.


Pete

Engineman

Proof of the pudding is how will the thing fly! I was surpised at your low revs recorded, I was getting more than that with my standard stock Graupner 300 motor. In the air with such a light slippery model amps drop considerably. Fly it and try it.

I use a simple test rig. A piece of 2 X 1 about 3 feet long, hung and pivoted from a nail in my garage roof with a 3" X 6" light ply plate screwed to its bottom and the plane on test strapped to it with elastics. I then run it at full power and measure how far it swings the pole up. Change the prop and try again. Simple but effective. Only shows the best prop for static thrust, but my experience so far has been that if it is best in the garage, it will fly best away from my hand!

Should be able to try my new motor this weekend, weather is looking good.

Engineman.

Rocketman612

My Feedback: (85)

Flight testing always reveals the truth.

I had initially had a Kokam 1500mah 8C 3S pack in this plane but I lost the battery when I didn't disconnect it from the ESC and it went to 1V [&o] nube error. Hobby Lobby told me I'd be pulling way too much current with that setup using the 9x6 prop and suggested using the 8x6 prop. I didn't have a Whattmeter at the time and it opened a whole can of worms about static testing these systems and analyzing the data.

This will get me started and later I can always step up to the 3S pack with the 8x6 prop.

Gotta love the learning curve..


Pete

Woody 51

Yeah, Its not about prop RPM, it's all about current draw from the pack vs the packs "C" rating. A further prop size reduction to maybe a 7 x 6 will see more rpm for less current draw and therefore more duration.

Pete only had an 8C pack originally, so high current draw was an initial concern. Whether it was 2 or 3 cells, was largely irrelevant, though a 3 cell pack would have been more of a problem. However "killing" that pack neccessitated buying new ones, with a higher "C" rating.

The Alpha's are very light really and don't need all that much in the way of RPM to fly well anyway.

Jerseymac

Engineman could you post a picture or a diagram of your test jig.
I can't seem to visualize it the whole thing.
Thanks