Alpina E - RC Groups
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Jan 15, 2007, 11:03 PM
Registered User

Alpina E

It's the dead of a Minnesota winter so time to build my Alpina!

Like many others have done before me, I will convert this one to electric.

I will build for an Aveox F-12 LMR motor/gb, 100 amp Aveox ESC, and 12 GP 3300 mah swinging a 17x11 prop. Why? 'Cause that is what I got! Sure there is more powerful, but this should work acc. to my calculations and others who have run similar. Refer to Tom's work here on the ebay Ventus - he reports greater than 45 degree climb at 10 pounds auw using a similar prime mover.

My kit is already covered (thanks, Kevin!) so that will save a lot of time, money, and hassle. It is the "4001 carbon master edition", fwiw.

My first dilemma to solve is the what wing servos to use. The only servos available here in the US that fit the included trays are Multiplex digitals, list price $99, best price available is $62. Well, I am not about to drop $375 for servos so I searched for a replacement servo that can fit in the trays. I was advised to try the Hitech HS-5245 digital. This led me to the HS-225, the analog version available in both metal gear ($27) or nylon ($22). Torque of 55 oz-in is acceptable for this model. I bought one from the LHS to test-fit. It fits beautifully with some small mods to the tray and servo. Excellent...

I will buy four 225-mg servos for flying surfaces and 2 nylon-geared for the spoilers.

Next up is servo selection for the rudder, elevator, and tow release....
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Jan 16, 2007, 02:05 AM
Tragic case
davidleitch's Avatar
I have seen bad drift in Hitec 225 servos and several others have reported the same in the sports plane forum. The 5245 work well for me and I use them regularly,but I took the 225's out of a sports plane. YMMV
Jan 16, 2007, 08:38 AM
Registered User
Andy W's Avatar
I would recommend digitals also, especially in the wing (tail is not so critical). I'm coming around to the more precise holding capabilities..
Jan 16, 2007, 10:08 AM
Registered User
Thanks for the tip. Perhaps I'll go for digitals in the ailerons and maybe the flaps too. They should work fine for the spoilers.

Jan 16, 2007, 11:27 AM
Registered User
Andy W's Avatar
It's not that they are needed for precise control as flaps, but for holding the correct camber setting (even if none is used) during "regular" flight conditions..
Jan 16, 2007, 10:51 PM
Registered User
After a lot of questions to my local club and a review of the specs from Tangent I went for the 225 mgs on the ailerons and flaps, nylon 225's for the spoliers, and three HS475 HB for the R, E, and tow release. $190 shipped.

Call me cheap but I have a 15 m ship to save/pay for!

Jan 17, 2007, 11:44 AM
Electric Airplane Junkie
bhchan's Avatar

I use the Multiplex Mini servo in mine. Do a search with the key word "alpina" in the electric sailplane forum and you will see a few electric alpinae(?) there. Most did not mention the servos.

Warning about the GP cell. They like to be ran HOT. If the cell cools down too much, they will not perform. I used 2200 on mine( 20 of them), For long flight in cool days, I run the motor once in a while to keep the cell warm. No problems with the cells cooling in days with temp over 85... You can check it by running the motor with a cool pack(let it sit for 30 minutes after charged), and a hot ( 90+) pack right off the charger.

Also about launching, find a good launcher that can run and throw the plane level (at the same time!! ). Or make a dolly to launch the plane,(the same search will review some dolly designs too) it is a bit large to launch it by yourself (for me anyway). With the lower pitched prop and lower(!) power level, a good throw is important.

Good luck and let us know how goes!

Brian, an EAJ
Last edited by bhchan; Jan 17, 2007 at 11:47 AM. Reason: can' t type or spell
Jan 18, 2007, 05:27 AM
We come in peace.
Synth's Avatar
The hs125's fit real nice and they are cheap to boot. Your going to love the Alpina.
Was my favorite bird until some jerk ripped it off. My power setup was similar to yours.
More cells less amps though. The Alpina handles the extra weight with ease.
Good luck with yours.

Jan 18, 2007, 10:01 AM
Electric Airplane Junkie
bhchan's Avatar

There is plenty of room in the wing , why bother to go with the smaller servo? I believe in get the biggest that fits!!

I like the toughness of themetal gear, but like the tightness of the nylon gear.

Brian, an EAJ
Jan 18, 2007, 03:15 PM
We come in peace.
Synth's Avatar
I had to trim the arms of the 125's. They are plenty strong on 5 cells and have metal gear output shafts. Also very easy to get parts for.
Feb 20, 2007, 05:53 PM
70 is the new 50
bobthenuke's Avatar
NOt to change the subject, but I just brought my Alpina Carbon Edition home and am comfounded by two issues not explained in the instruction book. First, I have no instructions to assemble the spoilers...the parts are there as well as the frame factory installed in the wings, but before I start "popping" these things together I have no idea what goes where. Also, there's mention of a brake and a wheel is provided as well as some mysterious plastic parts, but again I'm at a loss with nothing showing these.

Wold anyone reading this thread have some answers or pictures for me?

Thanks so much,

Feb 20, 2007, 06:24 PM
Electric Airplane Junkie
bhchan's Avatar

Sorry, mine have flap, no spoiler. And no wheel. You don't need a wheel. I just put tapeon when i need to land on hard surface. It really did a number on the carbon prop blade if the balde is in the wrong place.
Brian, an EAJ
Feb 21, 2007, 12:21 AM
70 is the new 50
bobthenuke's Avatar

I know I don't need a wheel, but I'd to have it. The idea of a wheel with a brake on it while landing in the desert sort of appeals to me; my scale gliders have a wheel and they work well, brake or not. I'm not planning on putting a motor in it.

Feb 24, 2007, 12:47 PM
I'm All Thumbs
AirBornOne's Avatar


Hi Nuke,
Here is what I have at the moment.These are smaller than yours but assemble the same.

The recent HS 125 servo thread in the slope forum has Really turned me off re: these servos.What has been your experience?
HS-125 servo thread

Looking forward to your updates.

Feb 24, 2007, 02:27 PM
We come in peace.
Synth's Avatar
I have never had a problem with the 125's. I did read the threads on these servo's.
I guess iv'e been lucky.


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