rcpattern

My Feedback: (45)

My initial plan was to go skiing today. No one else here wanted to go, so I put skis on my plane and did what I could.

ramirez76

fantastic Arch

this is testing my winds today .. only a WORD: OUTSTANDING

ramirez76

HELP ME .. I HAVE DONE WITH THE PICTURES: (

nosram

Arch,
Two more question, sorry?!?!
On the rudder and elevator I will use S9151 and S9650s, respectively, that I have.
For the aileron I have a choice of S9252 or HS5245MG (61oz.in), these I also have. The HS will fit in the wing, whereas the S9252 will sit proud. Do you think the Hitecs are powerful enough? I really don't want to go and buy 2 Futaba 9551s unless I have to. Also the Hitecs are about 3/4 oz lighter.

There is one more question!? I didn't feel comfortable running 5 digital servos off the Hacker speed controller, so I plan to use a Castle Creation 10 amp BEC. Is it OK to run this off the main battery, or should I use a seperate small 2 cell LiPo?

Thank you very much for your help and advice,
Norsam

rcpattern

My Feedback: (45)

Nosram,

Your servos will work fine on the ailerson. You wont have any issues. You don't need a huge amount of torque on the ailerons. I personally am running a separate battery, but I know others who are using the BEC with no problems. Either way works. Personal preference really.

Arch

ramirez76

I used a separate bec (economic turnigy 7A)

john agnew

Arch

How did your battery perform in the cold weather? Did you notice any difference in performance?

regards

John

rcpattern

My Feedback: (45)

John,

It was 31 degrees F here Saturday. I did nothing special to them, they weren't preheated or anything and I had no power issues. My batteries are kept in the garage along with the planes, so they arent heated. It doesn't get as cold as it does outside, but I'm not doing anything special to keep them warm. I had the same thing happen in November with the 2m at a contest when it was in the upper 30's in the morning. What I personally have found is that you don't get the jumpiness at the beginning of the flight, but the power seems to be more consistent from beginning to end. Really didn't notice much drop off from beginning to end. I had this conversation with Mike Mueller a few months back, he isn't convinced that batteries have an issue when cold and he keeps his cool in the summer. They seem to have a much flatter discharge rate if they start off cooler. I'm not saying its right or wrong and not out to start an argument, but I wont make efforts to preheat my packs any longer. Seems to me if they start off cooler, they will finish cooler and my packs haven't even been warm when I've landed in colder weather, but still had more than enough power. Maybe not the ballistic power I would have if the packs were warmer to start, but they don't seem to have a steep drop off if they start cold,

Arch

Velco

Arch the feeling you have is absolutely correct. Page 44 from Hacker 2010 catalog 

http://www.hacker-motor.com/img/katalog/Hacker2010-2Auflage-web-44-46.pdf 

is confirming what you say.

If it is below 15C degrees outside I keep my batteries in the car and possibly heated by the sun. I still like the oomph a fresh batteries can give.

Velco

koakiss

ok guys i made up my mind about the power system, i am using the scorpion 4025-12 with castle ice 100 speed control. will use the bec in the castle because it looks to be stable enough. will have both 16x10 and 17x8 props ready and may buy a apc 16x12. was thinking of going with HK stuff but at the end was not able to get a peace of mind with the chance of getting a falty something and crash, so will just be getting the prop turnigy ultra light from HK. for the ele servos i am looking at align 520 and Gotex GD 9257 and as for the rudder and the aliron it will be Alturn USA AAS-645LMG or something still looking. may at the end go with futaba.

DaveL322

In the last 5 years, I've done a lot of data logging with ambient temps ranging from 30F to 100F, with lipo temps starting between 35F and 115F. Temp of the lipos absolutely makes a difference in the amount of power they produce. In general, I'd say every 20F in temp change is worth 5% change in power (watts), and it varies depending on the exact cell chemistry/construction and temp range.

Bottom line - I preheat lipos to ~60F when the temps drop below 50F, and I keep them in the shade whenever it is warmer than 70F. The ducts for cooling air to the lipos in my planes are separate from the cooling ducts for the ESC and motor. As the ambient temps drop, I start blocking cooling air to the lipos to keep them ~115F at the end of a flight.

In general, lipos are more efficient at higher temps - resting voltage is higher, and voltage under load is higher. This is basically why the power curve of the lipos seems flatter when used in the cold - they are making less power and are less efficient when starting the flight cold, and then relatively increase in power and efficiency as they heat up (which to an extent balances the normal drop in power as the discharge progresses).

It is best to not subject lipos to extreme cold (below freezing) - any water present in the cells (from manufacturing, hopefully minimal if any) can freeze and damage the cells (water expands as it freezes). Charging should not be done in extreme cold as a "peak" of 4.2 volts per cell at 30F is actually comparable to higher voltage (4.25, 4.3, 4.35, I don't know the exact value) in higher temps, and excessively high voltage can damage the lipos.

Regards,

Mastertech

My Feedback: (31)

So basically, if I'm at a comfortable temp the Lipos are happy. If I'm cold or hot the lipos are not happy campers either.

Tim

stmdk

hey guys

i just got my kit... im very impresed by the quality of Sebart !!

i will try to put in further time some pics of changes i will do or some usefull tips for the assembly.

P.S: the box dimention are:

L: 147 cm
W: 49 cm
H: 19 cm

nosram

Arch and all,
Happy Holidays to everyone.
I got my plane, very impressed. Covering is excellent.

OK I have a couple more questions:
1) If using a pull-pull for the rudder, what did you guys do for a rudder horn? I am guessing that you somehow joined the 2 horns together. If so I would worry about its integrity. Please offer some suggestions?
2) The manual suggests 40° throws, with D/R set to 30% for normal flying. I will never try to fly 3D with this plane, and only intend flying pattern. By doing this I will have lost 2/3rds of the servo accuracy. So what throws do I need for pattern flying?

Thanks in advance, Happy new Year,
Nosram

koakiss

oh you lucky lucky people. gona get my straight from sebart, can not locate one near my location, hope the shipping wont be a fortune. i got the rest of the gear though. over spent a bit for the scorpion 4025-12 and the castle ice 100.

desertrider49

My Feedback: (5)

I also used the pull-pull, here's what I did. Lay out all control horns and you will see three sizes, I used the large ones for the ailerons, the middle sized ones for the elevators, and the small curvey ones for the rudder. I dry fit the rudder control horns and with a super sharp xacto blade cut out the covering from under where the control horn sits on the rudder. When I was happy with the fit I squirted some carpenter's wood glue into the slot and then CA'ed the conrol horn in place with a tiny drop on the exposed wood. I then turned the rudder over so the control horn was on the bottom and let the wood glue seal from the inside. Wood glue takes a day to dry so the next day I did the other side in the same manner. The rudder horns seem quite strong.


As far as throws, you need very little. I maidened mine today, and I'll measure tomorrow for you and tell you what I ended up with. Found out one aileron was bent so it didn't fly that good.

Cheers
Randy

nosram

That's great info, thanks Randy.
I will be very interested in the throws that you used. What a shame that you have a warped aileron, hope you can fix it or get a replacement.
Did you use the kit supplied fixtures for attaching the pushrods to the servo. I think I will use ball joints, I don't like the idea of a threaded retainer being the bearing surface. Added to that you have to assume that loctite will keep the nut on the thread! Ouch I don't like that, but I guess it works?
Nosram

desertrider49

My Feedback: (5)

Hopefuly, I can use my heat gun on the aileron and get it back in line.

Yes, I used the supplied hardware, at least the good ones. I use the CA method of securing the nuts. Put a drop of CA on the thread of the screw and let it dry, then you put the nut on and it won't vibrate off. Remember too, there won't be as much vibration as a nitro or gas engine. and obviously, an ounce of prevention is worth a pound of cure, after the maiden flight I check every nut and bolt and screw to make sure they are tight.

nosram

Back when I used to make my own planes I would have to use a heat gun, or my mother's electric fire, to straighten out warps. Generally they were down to my building, but sometimes the shrinking power of moisture followed by dope took over. That's my excuse
Please let me know what throws you end up with?
Thanks Nosram

banez

Regarding aileron servos I was almost decided to get Futabas 9551s but then due to current lack of funding, I decided to try to fit DS821s I already had so that it not only works properly but also looks nice. As you may remember DS821 does not fit nicely in the wing but sticks out of the wing more than I can tolerate.

That required some "exacto-knife and glue" work on both wings, and I was lucky to have a friend and scale master builder Mirce to help me fix it.

We removed planking between the two ribs, just beside the original hole and glued couple of hard-wood sticks as a support for the cover holding the new mount for the servo.
The rest of what we did is simple, couple of wood blocks glued to the cover, servo screwed into the blocks and servo arm sticking nicely out of the wing.


I think pictures will descibe it better than my English :-)

















Note that this is not a finished "product", I'm going to put some carbon fiber-like sticker over the cover and screw it in the wing like that.
Now that should look cool I think!

desertrider49

My Feedback: (5)

Now that I see Banez's pictures, no, I only used the usable ball links that were supplied. I went with ball links on both ends and bought some threaded rod and cut to length.

desertrider49

My Feedback: (5)

Just measured my throws. Keep in mind I only had a 5 minute flight with a warped aileron so it wanted to roll to the right. I have both the ailerons and elevators at 8 degrees. OR, looking at the radio settings, I have the end points at 100% and on low rates I have 25% with 40% expo. I only use high rates for the stall turn and I'll probably set them at 75% with 40% expo, but I try not to use the elevator and aileron in the manuver.
As far as rudder, it's at 60% low rates for snap rolls, and 75% high rates for stall turn.

Hope to fly again Friday, I'll post results after that if you are interested. Your results may vary.

nosram

Randy,
That is great info. So 8° each way on elevator and aileron. Your picture looks just like my plane! I went down the hobby shop this morning and bought a packet of Dubro ball joints and 2-56 all thread. I couldn't bring myself to use the supplied hardware. Also some of the supplied ball joint were very tight. Generally a good squeeze in a vice, or pliers, will free them up. The squeeze deforms the plastic a bit. I am a lot happier with the double ended ball joints. Did you also fit a Sullivan tail wheel? I plan to,
You are lucky to be flying, the weather in Houston is dreadful this week,
Nosram

pattratt

My Feedback: (1)

Banez
A quick observation. You are betting the life of your aircraft that the knurl screw holding the Aileron linkage to the servo arm is not going to vibrate loose! I know electrics don't vibrate as bad as Glow but my 50 + year experience says sooner or later it will come loose!!
Happy New Year!
Dick

desertrider49

My Feedback: (5)

Yep, 8 degrees each way.
Glad I can be of some help. This is my first electric plane so I'm doing a little flailing around too.
I used the tailwheel from the ARF, except I cut a "V" groove in the edge of the rudder where the wire goes up and into the rudder and epoxied it in place.

We are getting one day of nice weather then two days of rain. At least we have the snow capped mountains for the background of Rose Parade picture.