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This thread is privately moderated by Herb, who may elect to delete unwanted replies.
May 31, 2012, 07:34 PM
Never fly an A model anything!
jayb1rdz's Avatar
Herb, the HK version is now in stock and shipping. It's unlikely to have the wing strengthened at all. In your opinion, can the retract rails be strengthened from under the wing by adding ply blocks and webbing? Or is going through the top of the wing the only way???
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May 31, 2012, 09:05 PM
In the pipe 5 by 5...
urrl's Avatar
I decided to table the 12 blade for now and replaced it again with the 5 blade. I must have done a better job of making sure the ducts were sealed because now I can loop better and it really feels faster with the 6S 5000mAh batteries.
Jun 01, 2012, 02:50 PM
Lithium Member
Herb's Avatar
Quote:
Originally Posted by jayb1rdz
Herb, the HK version is now in stock and shipping. It's unlikely to have the wing strengthened at all. In your opinion, can the retract rails be strengthened from under the wing by adding ply blocks and webbing? Or is going through the top of the wing the only way???
Hi Jay,

Yes I think the HK one has most likely exactly the same wing, and therefore the same problem ...

Yes the retract mounts can be strengthened, I did some of that initially but then had to do some more later.

I also believe all of it can be done from the bottom, without ruining the appearance on the top wing.

If it is done right (ply doublers on ribs and spars, reinforced shear webbing, epoxy & glass or fiber on the joints, laminating epoxy on the top sheeting close to the retracts etc.) then very little weight is added.

The crucial point is to SPREAD the load and make everything nice and rigid.

The BVM F-86 wing below is a good example of how it's done.

.
Jun 01, 2012, 05:28 PM
Never fly an A model anything!
jayb1rdz's Avatar
Herb, thank you for being so generous with your experience. It would be a shame to let an attractive model get hangared due to fear of landing or worse wrecking through poor design.
Jun 02, 2012, 09:31 AM
In the pipe 5 by 5...
urrl's Avatar
Flew seven packs this morning. Loops, inverted circling, barrel rolls, touch and go landings. She seems faster now even though only 6S 5blade. I think reinstalling the ducting made a difference. Love this jet. I'm thinking of buying another CMP jet.
http://www.scaleflying.com/BAE-HAWK-...F-_p_2506.html
Jun 03, 2012, 07:17 PM
chillax! It's only a Hobby
1moparman1's Avatar
Quote:
Originally Posted by urrl
Flew seven packs this morning. Loops, inverted circling, barrel rolls, touch and go landings. She seems faster now even though only 6S 5blade. I think reinstalling the ducting made a difference. Love this jet. I'm thinking of buying another CMP jet.
http://www.scaleflying.com/BAE-HAWK-...F-_p_2506.html
I have one of these too
still in the box, might get to it in a few
the paint and color looks great!!
Latest blog entry: Hk cri cri
Jun 04, 2012, 10:13 PM
Registered User
So guys I have the 10s 90mm HK fan - is there any reason not to put it in the L-39?
Jun 05, 2012, 06:56 AM
Registered User
Also... anyone checked out the gear that comes with the pnp version offered by Aerodyne/Scaleflying?
Jun 05, 2012, 12:38 PM
In the pipe 5 by 5...
urrl's Avatar
A few things happened during my five flights for the day. First I caught a defective rechargeable Tx AA battery which can disconnect intermittantly. A $6 battery could have destroyed a $600 jet. Though it was brand new it was defective. Then during or after my third flight I lost a flap servo. Then one of my elevator servos became unglued. Not sure whether it was during flight or not. Hopefully what does not destroy the L-39 will make it stronger.
Jun 05, 2012, 05:12 PM
Spektrum Fan Club
SlayerNZ's Avatar
Quote:
Originally Posted by morgusmax
So guys I have the 10s 90mm HK fan - is there any reason not to put it in the L-39?
Same here, I ordered the 10cell version as well
Jun 07, 2012, 09:21 AM
In the pipe 5 by 5...
urrl's Avatar
Check the flap hinges now and then. One conecction on each flap was loose; one actually came out, that's how i discovered it and used some epoxy on both. I need to slow down, been running thru 5 packs on this jet daily for about two weeks.
Jun 07, 2012, 11:11 AM
Lithium Member
Herb's Avatar
Quote:
Originally Posted by morgusmax
So guys I have the 10s 90mm HK fan - is there any reason not to put it in the L-39?
Quote:
Originally Posted by SlayerNZ
Same here, I ordered the 10cell version as well
Whatever you put in there make sure you watch your WEIGHT as the wing can't take much stress

I use a very lightweight fan combination (WeMoTec Midifan).

Quote:
Originally Posted by morgusmax
Also... anyone checked out the gear that comes with the pnp version offered by Aerodyne/Scaleflying?
Yes, https://www.rcgroups.com/forums/show...67&postcount=3

.
Last edited by Herb; Jun 07, 2012 at 11:16 AM.
Jun 08, 2012, 02:53 PM
Registered User
The weight issue is a tough one. 10s and the alloy fan will add quite a bit. Decisions decisions!
Jun 08, 2012, 03:38 PM
Never fly an A model anything!
jayb1rdz's Avatar
I suppose, if you are going to open the wing to strengthen the retract rails and attachment points, you might as well add straight spam wise as well.

The wing surface area looks as though it could handle the loading.

Herb, is the problem the engineering or the surface area? I was planning 7s 3800s Mega 1400 kv in the Mach all alloy.
Jun 08, 2012, 06:01 PM
In the pipe 5 by 5...
urrl's Avatar
Does anyone know what scale our models out? I'm looking for some Breitling decals and want to be sure of the scale.
http://www.hobbyshop.cz/shop/1-72-de...-72-decal.html

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