Official Freewing 90mm F-15C Eagle Thread

[John Bergsmith]

I put three more flights on the F-15 on Sunday. Balanced at 125mm, it still feels slightly nose heavy. I did some research in this thread and didn't realize they had weight in the nose, so I can get that out and see how it changes the C/G. Speaking of the nose cone, I need to modify it so it's removable, or just glue it on. You barely touch the nose cone and it falls off, I'm surprised it doesn't come off in the air. Other than that, the F-15 flies great on the 4068-1835kV inrunner.

I have no idea of the overall speed, however I do have an interesting comparison. A club member took off his L-39 powered by the FMS 80mm when I was flying the F-15. I was flying at slightly above half throttle, he was at full throttle catching me from behind. Soon as he got close I went to full throttle and pull away from him with ease. We did this several times. Also had a test between an L-39 powered by the FMS 80mm and an L-39 powered by the Freewing 3658-1857kV brushless inrunner, but that's for another thread.

[Phantom]

I put three more flights on the F-15 on Sunday. Balanced at 125mm, it still feels slightly nose heavy. I did some research in this thread and didn't realize they had weight in the nose, so I can get that out and see how it changes the C/G. Speaking of the nose cone, I need to modify it so it's removable, or just glue it on. You barely touch the nose cone and it falls off, I'm surprised it doesn't come off in the air. Other than that, the F-15 flies great on the 4068-1835kV inrunner.

I have no idea of the overall speed, however I do have an interesting comparison. A club member took off his L-39 powered by the FMS 80mm when I was flying the F-15. I was flying at slightly above half throttle, he was at full throttle catching me from behind. Soon as he got close I went to full throttle and pull away from him with ease. We did this several times. Also had a test between an L-39 powered by the FMS 80mm and an L-39 powered by the Freewing 3658-1857kV brushless inrunner, but that's for another thread.

Um...is this an FMS to FW comparison? Or an 80mm to 90mm comparison? Apples to apples, oranges to oranges and all that?

[John Bergsmith]

Um...is this an FMS to FW comparison? Or an 80mm to 90mm comparison? Apples to apples, oranges to oranges and all that?

Nope, just an overall speed comparison between an F-15 using 4068-1835kV inrunner and the L-39 running an FMS 80. So no need for apples or oranges. :)

[Johnnyrabuse]

Hey everyone, I just ordered the inrunner version. Is there a link to a post with anything additional besides the manual? best CG, throws, flaps mixing? Looks like folks are liking to land with no flaps?

I can only speak for myself

I fly a little nose heavy I have zero issues with both full and half flaps

Can land nice and slow Flair's great no flaps it's a little hot with a long roll out

Unless I have a good headwind then it's a non issue
I have the inrunner version 6s

If I fly balanced with flaps it's a little tippy and slightly tail heavy it tends to float to much then pancake

another thing I set my timer 2:30 land at three and it's close ...

On 5000s


Anything over 300 and its a gamble I'll either hit low voltage or blow a cell

That's mixed throttle most of the flights 3/4

Next time out I'll fly 6000s they fit

[C17loadmaster]

I put three more flights on the F-15 on Sunday. Balanced at 125mm, it still feels slightly nose heavy. I did some research in this thread and didn't realize they had weight in the nose, so I can get that out and see how it changes the C/G. Speaking of the nose cone, I need to modify it so it's removable, or just glue it on. You barely touch the nose cone and it falls off, I'm surprised it doesn't come off in the air. Other than that, the F-15 flies great on the 4068-1835kV inrunner.

I have no idea of the overall speed, however I do have an interesting comparison. A club member took off his L-39 powered by the FMS 80mm when I was flying the F-15. I was flying at slightly above half throttle, he was at full throttle catching me from behind. Soon as he got close I went to full throttle and pull away from him with ease. We did this several times. Also had a test between an L-39 powered by the FMS 80mm and an L-39 powered by the Freewing 3658-1857kV brushless inrunner, but that's for another thread.

Removing the weight in the nose will aid in stopping that from being an issue. I ended up keeping just the fiberglass outer shell and ditching the foam that was in the nosecone. I did glue some magnets back on to the fiberglass to keep it removable. It’s rock solid now... and would require quite the impact to break free.

[djmoose]

So I decided to bump the rudder and see what the plane did. That is where all the wobble is coming from!! It did some wonky stuff when I touched the rudder! So the rudder or vertical stabs are the reason for the rock.

Hey guys, I had a great maiden and 3 additional flights on the F-15....and I was puzzled about the wobble when using rudder...but I'm glad to hear that someone else experienced it as well. Does anyone know how to get rid of that without a gyro?

[Ks.jetflyer]

I'm starting to build my arf+ version. Going with the new style fan and 1650kv outrunner. Went to mount the fan unit, but it won't fit. Does anyone know if freewing changed the outside diameter of the new fan compared to the older fan? Won't fit in the fuse or the hatch cover.

[Ks.jetflyer]

found

[DCORSAIR]

I'm starting to build my arf+ version. Going with the new style fan and 1650kv outrunner. Went to mount the fan unit, but it won't fit. Does anyone know if freewing changed the outside diameter of the new fan compared to the older fan? Won't fit in the fuse or the hatch cover.

So, you got the 90mm F-15 and the new inrunner fan unit won't fit? That is strange to me, I upgraded mine to the 1835kv and it was a drop in fit, what or how would yours not fit?

[Ks.jetflyer]

So, you got the 90mm F-15 and the new inrunner fan unit won't fit? That is strange to me, I upgraded mine to the 1835kv and it was a drop in fit, what or how would yours not fit?

It's actually the outrunner version. It wont fit down in the fuse. Mounting tabs are about 3/16 above the rails. I have 2 of the newer version fans, neither one will fit. I got the arf+ version.

[John Bergsmith]

It's actually the outrunner version. It wont fit down in the fuse. Mounting tabs are about 3/16 above the rails. I have 2 of the newer version fans, neither one will fit. I got the arf+ version.

Something doesn’t sound right. I just assembled an arf plus version because I already had a HET 4068-1835kV. It fit with no problem.

[Ks.jetflyer]

Would not fit in this one. I taped sandpaper on the shroud and with some elbow grease got it to fit. All the foam removal was on the sides below the mounting rails

[gooniac33]

Hey guys, I had a great maiden and 3 additional flights on the F-15....and I was puzzled about the wobble when using rudder...but I'm glad to hear that someone else experienced it as well. Does anyone know how to get rid of that without a gyro?

It helps using an aileron to rudder mix. but it will always kinda be there.

[djmoose]

I would love to see an updated version, blue board, 8S....and an F-15EX body!



https://www.airforcemag.com/first-tw...by-early-2021/

[mshagg]

After months of umming and ahhing I finally came to terms with the fact I'm a scale guy and pulled the trigger on the high performance version. Assembly was easy as you'd expect. Put some carbon reinforcement through the nose as it was sagging just under the weight of that nosecone lol.

Currently have it set up with an X8R, although toying with the idea of going for an AR636 I have here. I reckon I can make the airbrake and flaps work somewhat independently on the same channel with some mechanical adjustment to the flap servo/pushrods given the airbrake doesn't deploy until around 1400us on that channel, and get away with 6 channels.

im unlikely to use the airbrake but I'll be damned if I pay for all of that lovely scale fidelity and don't at least have it on a switch lol.

What's the consensus on gyro stabilisation for this bird? I'd be giving up voltage telemetry that I find a pretty important data point on thirsty jets.

[DCORSAIR]

After months of umming and ahhing I finally came to terms with the fact I'm a scale guy and pulled the trigger on the high performance version. Assembly was easy as you'd expect. Put some carbon reinforcement through the nose as it was sagging just under the weight of that nosecone lol.

Currently have it set up with an X8R, although toying with the idea of going for an AR636 I have here. I reckon I can make the airbrake and flaps work somewhat independently on the same channel with some mechanical adjustment to the flap servo/pushrods given the airbrake doesn't deploy until around 1400us on that channel, and get away with 6 channels.

im unlikely to use the airbrake but I'll be damned if I pay for all of that lovely scale fidelity and don't at least have it on a switch lol.

What's the consensus on gyro stabilisation for this bird? I'd be giving up voltage telemetry that I find a pretty important data point on thirsty jets.

I used the airbrake all the time on my F-15, sometimes I would pop it up on final but usually right when I touched down, I had it on a seperate switch though, but I think it would work great along with the flaps, I did that on my FW T-45, put the slats and flaps on one channel, worked great, I didn't use a gyro on my F-15, but I could see where it would help the F-15, it seems to wobble around a lot in windy conditions, other than that it flies great.

[mshagg]

I used the airbrake all the time on my F-15, sometimes I would pop it up on final but usually right when I touched down, I had it on a seperate switch though, but I think it would work great along with the flaps, I did that on my FW T-45, put the slats and flaps on one channel, worked great, I didn't use a gyro on my F-15, but I could see where it would help the F-15, it seems to wobble around a lot in windy conditions, other than that it flies great.

Thanks for the input. To be honest if there's a breeze around I'm likely to grab a stabilised sport jet from the hangar rather than a scale 90mm - so that probably answers my question right there.

[mshagg]

Alright so i know gooniac is running a gyro in this plane - can i ask for a hint on gains? Maiden flights were awesome this morning, much better than i expected after reading so much about it being a flying brick lol. Effortless grass performance and wasnt even that rough on the batteries. I'd be surprised if there's a cooler sight than the landing light of an F15 shining away as she settles in on a nose up final approach. Love at first flight, really.

But she was pretty wobbly in the breeze, so I'll swap in the AS3X receiver. Im guessing go hard on the aileron gains, maybe yaw, but pitch axis doesnt seem to need a lot.

[rifleman_btx]

I'm thinking about getting this plane now, it's not discontinued is it?

[MikeT]

https://www.motionrc.com/collections/rc-jets/products/freewing-f-15c-eagle-90mm-edf-jet-pnp

https://www.motionrc.com/collections/rc-jets/products/freewing-f-15c-eagle-90mm-high-performance-edf-jet-pnp?lshst=collection

Nope both just just out of stock.

Mike