[4stripes]

Thanks Marty, a build thread (if you can call assembling these foamies that) will be posted.

We made 7 flights total on today's maiden of the F15. Here are the first two (thanks to Peter!)... The wind was a challenge turning into a nasty crosswind for some of the flights. This plane catches the wind like a sail and will tip easily.
https://www.youtube.com/watch?v=wtXCUKgNwQU
https://youtu.be/xHHnc-TvVBE
The second flight I just ran out of elevator on touchdown so we removed the 21g lead weight in the nose moving the CG aft of recommended by about 5mm. Much better elevator authority on subsequent flights. The recommended stab setting was pretty close to bang on.
Every flight was timed at 3 minutes and my Gens Ace 5500mah 6S 25C packs were reading 3.78- 3.71 volts per cell using mixed throttle. Perhaps higher throttle due to the gusty winds.
We weighed the plane with battery and the flying weight is 3.94kg. Not surprisingly the vertical performance is rather weak. A loop requires flat out level full thrust or even a slight dive to complete a smallish loop. This plane is simply too heavy for 6S IMHO. Yes, it flies, but not like the T45 does due to the F15 bulk and extra weight.
The next mod will be going to an 8S setup as this plane is too nice to be a hangar queen or to just fly horizontal maneuvers.
Happy with the plane overall, but unhappy with the weight expectation and lack of 6S vertical performance.

[4stripes]

MotionRC posts specifications here that clearly shows the flying weight to be 3080g.
http://www.motionrc.com/freewing-f-1...specifications
They also show the recommended battery to be a 5000mah. Based on these spec's I never expected their "flying weight" to not include the battery weight. The FW manual is much more specific on this important fact.
I strongly suggest MRC update their site to give the disclaimer that the flying weight doesn't include a battery. A much more realistic flying weight on 6S is very close to 4kg.

[4stripes]

6 more flights today breaking that #13 invisible barrier! Glad we had light winds as I could get a better feel for the plane.
Other than scraping the wing tips the plane is holding together nicely. Expo will be added to the rudder as it tips with any turn at speed (especially when I apply brakes). The worn plastic was easily replaced with 5 minute epoxy from the dollar store.

I've moved the CG further aft to 1cm behind the recommended position and it made the plane feel much lighter on TO and landing.
This brings it to 128mm behind of where the LE joins the fuselage. My battery (Gens Ace 6S 5500mah 25C) is as far aft as possible in the bay.
It can actually be held off to a reasonable speed whereas at the stock position it would be hard to flare and would slam on without much grace.

I noticed with my two brand new packs the plane would loop out of level flight and if it had a slight dive first would do reasonably large loops. With my older packs the performance loss was noticeable (although I never noticed this in my other 6S jets as they are lighter).
Some pictures of the manual are posted showing FW spec's along with stock CG which works out to the aft edge of the forward plastic wing retaining block.

Setting my timer to 3:00 my 5500 mah packs would need between 3700 to 4200mah to recharge.

[4stripes]

video thanks to
Tim
https://www.youtube.com/watch?v=nkX-kKdbzto

[Max]

Excellent thread, Eric. Too bad about the weight.

Are you flying from grass, Geotex or ashpalt?

[4stripes]

This plane needs pavement or other smooth surface as it is very tippy on it's high narrow gear.

[Leadfoot]

Thanks for all the information and details on the F-15 Eric! When I saw the thread over on RCGroups about it, I was definitely considering it as a future purchase, as I thought FW had done a really good job with it.

The weight and gear would make it a "challenge" on a grass field for sure, so it might need a bit of reconsideration before going ahead with.

Steve

[4stripes]

I set up a CS 12 blade 90mm fan with an SK3 Fandrive 1500kv inrunner last night with a shortened shroud. The old YEP 120amp HV ESC from our departed Hawk seemed to work fine but would only produce 18-1900watts on 8S. Substituted a new YEP and the power jumped to 3100watts! Scary power that will need further testing to make sure nothing overheats or comes apart. I will add a heat sink to the motor next.

Strange that the crashed ESC worked nice and smooth but just limits the power... I will try reprogramming it to see if it can be salvaged.

[Leadfoot]

That's the kind of power my Mig-15 needs! Hopefully everything will stay together for you!

[4stripes]

The fan is now removed to upgrade for more power after 14 flights. Here is a picture showing the EDF weight.
It is a decent 6S setup and sounds great but the plane is simply too heavy for 6S power.

Here is a link to the Freewing ESC manual
https://www.motionrc.com/content/man...wing/fwesc.pdf