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Old Aug 01, 2011, 02:41 PM
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Not much progress besides cleaning up the proverbial rat's nest.

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Old Aug 01, 2011, 02:44 PM
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The new programming card (k-force only) has the advantage, over the older one, that it does not need anything to be plugged in into the esc (no motor, no lipo batt).

Having to plug in the main batt used to be a real nuisance .

I needed to change timing advance to 7 degrees, start to soft or very soft, brake off, and lipo voltage threshold to low.

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Old Aug 01, 2011, 07:51 PM
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cottonballs? really?LOL
that new programmer is slick, China is rapidly taking over the entire hobby!
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Old Aug 02, 2011, 12:16 AM
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Re: Building Instructions

Hi,

Thanks Herb - that is even better than I had hoped for! I will post some pics of the stripped down plane. I received two Moki fans with damaged impellers (replaced with Wemotec midi fans) with two Mega 22./20/3 motors and the older (red) Jeti controllers. I will be limited to about 4S on that setup, and may want to run on 5S. Need to test the amp draw first, as motor would probably overheat on anything more than 800w. I see that most guys are running fairly hot setups, but do not intend to fly it like a pylon racer!

Regards,

Andre
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Old Aug 02, 2011, 02:58 AM
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Hi Andre,

Mine has 6.8kg flying weight. And Im using the e-flite retracts with robart struts.
The gear has his own electric circuit, directly powered by a 2s 1000mAh pack. It is good for around 200 cycles. The System is working fine and holds up since ten flights so far. Taking off grass.
My cg is at 140mm back from the point where the wing meets the fuse with
gear up.
I am using MOKI Impeller with WeMoTec MIDI Rotors on Mega 22/20/3
with 5s5200er each side. 4.1kg of thrust.
No problems with around 1000W per Motor so far. Ampdraw approx. 55-56Amps.
Due to the low wing loading and the 4" whells all around the plane takes off from grass easily.
Even my first AW Me 262 flew with this setup with 7.4kg TOW from grass.
I personally think, you can go up to 8kg, if you have a hard surface runway.

Greets

Cat
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Old Aug 02, 2011, 01:54 PM
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Hi Andre, glad I could help.

No pylon racer with more power, just more jet-like performance Moki shrouds with WeMoTec pro rotors sounds good!

Nowadays you can get 1500W out of a $19 inrunner motor all day long, with much better efficiency than those Mega 20's :

http://www.hobbyking.com/hobbyking/s...idProduct=6526

Get some better motors !! Look at Arc, Neu, Het, Tenshock, Mega 30 and a few other brands.

And run 6S or better 8S per fan at least, you do NOT have to run full throtlle all the time
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Old Aug 02, 2011, 02:10 PM
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Quote:
Originally Posted by electricfly2002 View Post
...two Mega 22./20/3 motors and the older (red) Jeti controllers ...
Those old Jetis are very good and just about indestructible. I have a few, one still in my Spitfire

BUT, they run hot at partial throttle and are somewhat inefficient. Plus they are fixed timing, generally a bit too advanced for two pole motors.

Nowadays there are MUCH better controllers:

http://www.hobbyking.com/hobbyking/s...hless_ESC.html

http://www.hobbyking.com/hobbyking/s...idProduct=8921

Make sure you size your controllers so that you can run at partial throttle ALL DAY without ANY overheat.
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Old Aug 03, 2011, 03:02 AM
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Re: ESC and motors

Herb,

I must admit I was not very impressed with the 100A Turnigy controllers, although the red 80A Plush controllers have proved to be reliable. Hopefully the 120A and Super Brain will be better, but i would rather not risk it in a new plane (also suspect I may have the only Airworld ME 262 in South Africa)

Based on the info provided on your build thread it seems that I would be OK on the Mega 22/20/3 motors and 5S lipos (although I have standardised on 6 & 12S lipos) as I also have 2x80A plush controllers available. May be cheaper to buy new motors than new batteries! Hopefully i would be able to run some tests on the motor/fans over the weekend, and take it from there.

Just a quick comment - I noted on one of the pics that the controller was mounted in the impeller unit. Good for cooling, but it is a very bad idea to extend wires between batteries and controller ("back EMF" issues). I popped a very good controller in my Dakota that way ;-(
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Old Aug 03, 2011, 12:38 PM
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Let me put it this way : I have four TGY's (2 x 100A, and 2x 120A) and they are better than any controller I ever owned (Jeti, Hacker, Schulze, Kontronic).

The four I mention are being flown all year long without a hitch. I would not use a CC controller even if they gave it to me for free.

Yes indeed, mounting the controller in the fan is a very bad idea due to the long batt wires causing huge voltage spikes which first blow the caps and then the mosfets.

But hey maybe they never read the instructions "20cm max between batt & esc"

I suggest you use those Mega 20 as doorstops , that's where mine are (I had two in the Rafale below)

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Old Aug 03, 2011, 01:54 PM
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Herb,

Thanks for info - pleased to hear that you are happy with Turnigy controlllers - i did not have much luck with the 100A Sentilon. Subsequently found out that they are very sensitive to input voltage - too high or too low any they do not arm. Maybe i should try the new 120A controller that you recommended!

Nice pics that you posted, first plane looks very much like a F86! I am also building one from an old (unbuilt) Byron ducted fan kit, but also have no info on control surface throws, CG etc. Want to finish 262 before I start on that one though.

regards,

andre

Ps. seems that you have very nive hangar!
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Old Aug 04, 2011, 12:35 PM
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Well those Turnigy controllers are (as far as I know) actually not made by Turnigy ... The K-Force ones are made by Hobbywing

http://www.hobbywing.com/english/

http://jepe.org/jepeshop/53-controllers

and the latest Brain ones are made by HiFei

http://www.hifei.com/en/index.asp

http://lnx.electronicfly-rc.com/prod...ei.html?Page=3

For ex. JePe in Holland has been using/selling HiFei esc's for four years ...

It seems both of those companies specialize in esc electronics only.

I would say that most are "battle tested" by now.

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Old Aug 08, 2011, 01:16 PM
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The twin esc's have arrived so I can finally make some small progress ... will have to test them thoroghly before the maiden.

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Old Aug 09, 2011, 04:51 PM
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Since the esc's have arrived I could finally install the nacelles, and route the motor wiring through the wing.

I then glued and bolted both nacelles on the wing, and later installed the nacelle covering panels.

I glued the panels with silicone (as opposed to using tape) to further reduce rattling and vibration, and because paint does not stick that well to tape.

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Old Aug 09, 2011, 04:55 PM
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I was worried I might have miscalculated the length of the motor wires, which would have lead to some rather serious cursing

The length is fine though, and the esc's sit right where they should be

Now things are finally getting closer to some serious noise making ...

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Old Aug 10, 2011, 04:29 PM
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This past weekend I did find some time to work on my impressionistic rendition of the Me-262 cockpit. It is very simple, scratchbuilt out of balsa and foam, except of course for the pilot. It's called modeling, right ?

I thought I wanted it to be really light and low profile. So it would not take up too much space inside the fuse where the rest of the electronics is located, and where the escs need all the airflow they can get.

For now the cockpit tub is made to be removable, so I can take it out any time to dust it , or fix the parts that have fallen off (like the pilot ) , or even have a fancier cockpit when time allows after some test flights.

On other edfs I have there's always something that either gets loose, falls off or fades after a few flights.

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