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Old Sep 14, 2012, 02:17 PM
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Often junk fans with loose unbalanced blades + mounted not rigidly enough (with light packing tape and two wood screws in your case ) = destruction of fan and possibly ducting & plane

You are lucky if you did not bend the shaft on the motor - this you will find out when you mount that motor in your next fan as it's often very difficult to tell.

My advice: spend the money and get a quality fan so you can fly - instead of doing endless repairs & internet flying
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Old Sep 14, 2012, 02:28 PM
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Quote:
Originally Posted by Herb View Post
Often junk fans with loose unbalanced blades + mounted not rigidly enough (with light packing tape and two wood screws in your case ) = destruction of fan and possibly ducting & plane

You are lucky if you did not bend the shaft on the motor - this you will find out when you mount that motor in your next fan as it's often very difficult to tell.

My advice: spend the money and get a quality fan so you can fly - instead of doing endless repairs & internet flying
look.. the mounting of the fan had nothing to do with it.. really..
I balanced the fan .. it took me one 4400mah pack and 2 hours on the bench
the problem is that there was batch with very bad blades

they weighter 39grams instead of 46
they were flexing A LOT
and they even had a different colour than the good ones.

The best choice I have is a stumax rotor only. sold for 160 bucks shiped
and combine it with an RClander new housing with 11 stators OR I can remove 4 stators and make it 7 stators.
that will cost much much less.

the shaft was an 8mm one that's why it held so well
ofcourse the shaft looks nice with a naked eye.

the 4082 1600kv motor bent after this fan blown on 6s. on that one there was no balancing.. it was a 10 minute assembly

I expect that the new fan will take the beating at 3000watts. AT LEAST I HOPE.. because this L59 flies amazing. btw I balaced mine at 55mm but it was a tad noseheavy. I believe that the sweet spot should be 58mm

I will most probably have the shroud by the end of next week. I will sure test bench it a lot and watch how the blades behave.. might get my antiriot shield from work for extra protection

P,S, In the mean time good news from GErmany. my Wren 70 engine is already fixed by the Wren engineers free of charge so on monday I will have it back and by wednesday I will be flying again.

oh.. and... a new plane is also on the bench and will be ready in 1 week

http://www.rcgroups.com/forums/showp...postcount=2861
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Old Sep 14, 2012, 02:38 PM
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... I balaced mine at 55mm but it was a tad noseheavy. I believe that the sweet spot should be 58mm...
Well it seems at least you had one good flight on the CMP L-39 ...

The correct CG (four months of flying) was posted on the first page of this thread, the red line = 78mm.

Blue is CMP recommended location which is too far back, and yellow is slightly noseheavy I found out.

.
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Old Sep 14, 2012, 02:45 PM
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I had TWO ... gREAT flights
I'm talking on how the HK manual reports it.. it says go 240mm from the center towards the wingtip and then go back 66mm..
well I went back 55mm it should be close to what you have there
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Old Sep 14, 2012, 03:00 PM
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Originally Posted by pavcon View Post
...I expect that the new fan will take the beating at 3000watts. AT LEAST I HOPE.. I will most probably have the shroud by the end of next week. I will sure test bench it a lot and watch how the blades behave...
Good luck with it, it seems you have a lot of time available for testing potentially exploding setups

I think somebody said "those who cannot learn from history are doomed to repeat it" and it certainly applies to a lot of fields ...
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Old Sep 23, 2012, 01:38 AM
RAVI KOTHARI
Joined Nov 2005
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Just pushed the button on This One.

Just have access to a grass runway, will these retracts do -

http://www.hobbyking.com/hobbyking/s..._20_class.html

they seem to have larger wheels and are a little longer, wonder if they will fit...........

Any other suggestion?
Thanks in Advance.

cheers
Ravi.
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Old Sep 23, 2012, 02:31 AM
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Originally Posted by ravikoth View Post
Just pushed the button on This One.

Just have access to a grass runway, will these retracts do -

http://www.hobbyking.com/hobbyking/s..._20_class.html

they seem to have larger wheels and are a little longer, wonder if they will fit...........

Any other suggestion?
Thanks in Advance.

cheers
Ravi.
yes... reinforce the retract mounts
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Old Sep 23, 2012, 12:31 PM
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Originally Posted by ravikoth View Post
... will these retracts do ...
Ravi, not sure ... Maybe you mean these : http://www.hobbyking.com/hobbyking/s...and_L_59_.html . They seem pretty heavy (I don't trust that weight figure).

These are the ones that are made for it:

http://www.hobbyking.com/hobbyking/s...Hawk_L_59.html

and that's what I have in mine.
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Old Sep 26, 2012, 12:57 PM
RAVI KOTHARI
Joined Nov 2005
259 Posts
Thanks,
did go through all the posts with the landing gear mount issues,
am planning to redo the entire section, hopefully mine will hold.

Have more immediate issues though, The Indian Govt is taking a long hard look at the prospect of RC planes being used for terrorists activities , so they have a "Hold & verify" procedure in customs, so for now the priority is in getting her undamaged from HK, and then the scrutiny , so long way to go for now. Also HK hasn't shipped my package for the past 5 days, what is the point of ordering EMS when they let the package sit for 5-6 days (Hopefully)

Anyway it seems you & herb are the men to lead this one, sure is a great looker , hope i get her soon.

Cheers
Ravi



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yes... reinforce the retract mounts
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Old Sep 26, 2012, 01:06 PM
RAVI KOTHARI
Joined Nov 2005
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Thanks for the heads up herb, I mean these - http://www.hobbyking.com/hobbyking/s..._20_class.html

although you are right, considering how large the wheels are on that thing, the weight seems to be only 58 Gms more than the ones you have. hope its not a Typo.

Since i plan to run this on grass. i definitely am going to need larger wheels.

GAZB has them on his plane and it seems that he is happy. and those tires seem to fit , maybe with a shoehorn, but they do fit...................

L-59 main retracts (0 min 25 sec)


Cheers
Ravi


Quote:
Originally Posted by Herb View Post
Ravi, not sure ... Maybe you mean these : http://www.hobbyking.com/hobbyking/s...and_L_59_.html . They seem pretty heavy (I don't trust that weight figure).

These are the ones that are made for it:

http://www.hobbyking.com/hobbyking/s...Hawk_L_59.html

and that's what I have in mine.
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Old Sep 26, 2012, 02:33 PM
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Hi Ravi, your buddy did a nice job on the gear. What sequencer is he using?

Herb thanks for all the work on this thread. I am probably going to pull the trigger on one of these L-39's pretty soon, just have to settle on the fan package. Right now I am leaning towards the Lander 12 blade. Alloy housing 1000Kv on 8s

Cheers guy's
Dean
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Old Sep 26, 2012, 05:51 PM
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Well all I can say in general terms is that on the CMP L-39/L-59 you need to watch your WEIGHT very carefully, as this is NOT a lightweight airframe.

That applies to the retracts as well, and I don't see how a full metal set can weigh less than the plastic ones I have in mine ...

Incidentally plastic retract units work ok in the L-39 because you will punch through the wing before you break one of those ...

For a metal fan the same reasoning applies, you have to watch your weight very carefully unless you plan to have only one flight

Here the metal fan weight is listed as "TBA" (!) : http://parkrcmodels.com/product_info...oducts_id=1415

.
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Last edited by Herb; Sep 26, 2012 at 06:01 PM.
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Old Sep 26, 2012, 08:19 PM
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This was from the other forum

Well I did the maiden yesterday. I'm trying to post the video but the conversion is having technical difficulties.
First I took Pav and Herbs cg recommendations into consideration and put mines in the middle. I added 4oz in the nose. Crazy huh.
Roll out was straight and forward, she leaped off the pavement, flaps up gear up, two click of up trim, two right clicks and she was level. I'm running 7s 4000 40c packs. Ice 100. 12b. Turnigy 3025 1500kv motor. Lander style retracts.
On final gear down and whoops. Motor cut off. Reset the esc and pointed the nose down. I did a down wind landing about 400 feet. Good thing the field I fly at is about 5000 feet long
And there was no damage to the planes. I got lucky.
I put it on the logger and it stated. The temp was 314 degrees. Amps 125. 3000w. Wow. On the ground my test was 95a. 2400ws. my esc might be damage. Idk.
But I must say I love the way she flies

Thanks Herb you didn't know it but you helped out a lot
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Old Sep 26, 2012, 09:17 PM
RAVI KOTHARI
Joined Nov 2005
259 Posts
HK makes one

http://www.hobbyking.com/hobbyking/s...dProduct=11258

i do not know what he is using, you could ask him, he is on the HK l59 thread, superb job isnt it. Looks great and will cut out a fair amount of drag in the air.

also i tend to agree with HERB on the lander fan,
i too am opting for the wemotec Midi running a HET RC 650-68-1130 on a Compact 2700 10S pack. the packs only weigh about 600 odd grams and the amp draw is a measly 55 A.

Hopefully should balance my plane, if not then i will use the 3700 10S.

All the best.
Cheers
Ravi

Quote:
Originally Posted by buckaroo View Post
Hi Ravi, your buddy did a nice job on the gear. What sequencer is he using?

Herb thanks for all the work on this thread. I am probably going to pull the trigger on one of these L-39's pretty soon, just have to settle on the fan package. Right now I am leaning towards the Lander 12 blade. Alloy housing 1000Kv on 8s

Cheers guy's
Dean
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Old Sep 26, 2012, 09:17 PM
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Originally Posted by Mannyman535 View Post
...Turnigy 3025 1500kv motor....Motor cut off. ... Amps 125. 3000w....
Hi, sounds like you completely demagnetized that poor 180g $17 motor What are you thinking of as a fan replacement? that fan is an inefficient amp hog.
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