Official Freewing 80mm EDF F-86 Sabre Thread

[Jim Talley]

Haven't flown my F-86 in quite a while. Took it out this morning and did 4 beautiful flights. What a great airplane!! Gonna take it out again tomorrow along with the A-6 and twin 64 A-10. Life is good.

Jim

[Oxotnik]

I visited an RC Club yesterday, in my hometown, and flew several planes, including the Sabre. It was my first time flying on a paved runway, narrower and shorter than my home grass field. Takeoff from a paved surface was definitely easier, as I was able to rotate much more quickly than on grass (no surprise there). For landing, though, I had to wave off the first three approaches, then had to land on my fourth (as I was almost positive that I'd be out of battery after one more climb-out). With super-human concentration, I put the plane down just off the centerline, a little faster than normal (as I had a bit of crosswind), and I thought that the dang plane would never stop the roll out. All in all, it was a very fun day flying (also flew my FlightLine P-38 and Freewing FW-190A) and I made some new friends.

[Topshot19]

how is wing removal for transport with this jet?

[T-CAT]

Even though wing removal is easy with the four screws and plastic joiner, it's a pain to reconnect all the servo leads and ensure they get reattached perfectly out of the airstream since a plastic tube halves separates the wiring connections and the intake. It's a jet I would prefer to keep in tact because of this.

[e4dragongunner]

Agreed!

[Beeg]

Oxotnik, now that you've got some time on your Sabre you may want to experiment with doing what you can to move the CG back. It lands, takes off and flys a lot better with a more aft CG. If your interested. It's great model either way.

[e4dragongunner]

Hey Beeg, What is the alternate CG from stock? Thanks :-)

[Beeg]

Some guys are running 200mm with the "tail sit test". If you search the tail sit test in the Sabre thread at RCG there is much discussion about the various CG's folks are using. Without adding weight I think I have mine around 170-180mm but I run 6000mAh batts so it's hard even with my ESC moved out of the way and batt shoved back against the foam cross member to get it much further aft. Most guys have to add weight to the tail.

you can start here.. https://www.rcgroups.com/forums/show...0#post31279337

[Oxotnik]

Oxotnik, now that you've got some time on your Sabre you may want to experiment with doing what you can to move the CG back. It lands, takes off and flys a lot better with a more aft CG. If your interested. It's great model either way.

I have moved the battery back another inch or so. I removed the battery retainer and carved out the bottom of the canopy/battery hatch. The CNDL 6S-4K is still too fat to move all the way to the back to the bay. The Admiral 6S-5K is a little wider and thinner and can be moved further back. I do want to the push the CG a little farther back, hoping that the F-86 will rotate a little more quickly. The Sabre will take off from grass, but it certainly helps if I can hit a bump to help it get airborne. LOL

[e4dragongunner]

Excellent
Many many thanks!!!

[Oxotnik]

After flying my Sabre twice today. I noticed that the grub screws holding the struts on are not tight. The struts do not rotate, but they move (extend/shorten) about an 1/8". I couldn't break the thread lock with my hex tool. What's the trick to break the thread lock? Heat the grub screw with a soldering iron?

[Porkster]

After flying my Sabre twice today. I noticed that the grub screws holding the struts on are not tight. The struts do not rotate, but they move (extend/shorten) about an 1/8". I couldn't break the thread lock with my hex tool. What's the trick to break the thread lock? Heat the grub screw with a soldering iron?

Yep, a little heat should do the trick

[Oxotnik]

I killed my Sabre today. I'd moved the CG back, so that she would almost stay on her tail when the tail was pushed to the ground. The takeoff, climbout, and flight was great. She gave me no indication that she may be tail heavy. I even pulled some rather tight Immelmanns, and if she were close to being tail heavy, I've have expected her to snap roll out of the high-g half loops. As you can see in the video, I was turning onto the downwind leg, gear deployed, when I lost her. As I was coming onto the downwind, she was in a descending 90° bank (a maneuver that I've done a million times with no problems), but when I gave her the commands to level out, she was unresponsive and stayed in the diving turn, becoming a spiral of death. It felt like a brown-out, but I'm having trouble buying a brownout because I was using a standalone UBEC. I've dropped gear in turns like that, without incident. Maybe a combination of dropping gear (adding drag), throttling back as I was setting up landing, and having the CG farther back than I've ever flown her before. I'd appreciate your thoughts. If I dumb-thumbed it, I'm not afraid to admit it.

[Evoman]

I killed my Sabre today. I'd moved the CG back, so that she would almost stay on her tail when the tail was pushed to the ground. The takeoff, climbout, and flight was great. She gave me no indication that she may be tail heavy. I even pulled some rather tight Immelmanns, and if she were close to being tail heavy, I've have expected her to snap roll out of the high-g half loops. As you can see in the video, I was turning onto the downwind leg, gear deployed, when I lost her. As I was coming onto the downwind, she was in a descending 90° bank (a maneuver that I've done a million times with no problems), but when I gave her the commands to level out, she was unresponsive and stayed in the diving turn, becoming a spiral of death. It felt like a brown-out, but I'm having trouble buying a brownout because I was using a standalone UBEC. I've dropped gear in turns like that, without incident. Maybe a combination of dropping gear (adding drag), throttling back as I was setting up landing, and having the CG farther back than I've ever flown her before. I'd appreciate your thoughts. If I dumb-thumbed it, I'm not afraid to admit it.

As soon as it I read your post I had a good idea of what may had happened. I have experienced the same thing while flying my F-86 Sabre but in the DCS flight simulator several times.
This is referred to as an aggravated stall. It would mostly occur when doing sudden turns.
Here is a good video that explains it and teaches how to recover from one.

[Oxotnik]

It didn't feel like a spin to me, but it did seem to be entering a spiral, as it went behind the trees. I'd certainly been pulling 90° bank turns during this same flight, without any indication of a stall. Maybe pushing my CG back AND dropping gear in that turn caused the turn to become unstable. I'll think about it some more. Thanks for your thoughts.

[Oxotnik]

Evo,
I've watched the video a zillion times. The gear dropping, caused the problem. There's no doubt in my mind about that. When the gear deploys, the nose noticeably drops. I'm now agreeing with you. I think that dropping my gear while in a steep bank, triggered an unstable event. I think that I enetered a spin, as you'd suggested. I was so low and dropped behind the trees so quickly that I couldn't see the plane long enough to stabilize the descent.

Thanks again for the thought/pointer. Even though it's a bit embarrassing to admit to dumb-dumbing, I'd rather know what happened and learn from it.

[Evoman]

I know the feeling of wanting to know what went wrong. When it first happened to me in the simulator I did not understand what had gone wrong. But after several stall spins I learned not to bank the F-86 too much at lower speeds or sudden banks and dives that would suddenly reduce airspeed. When ever I get my Freewing F-86 I will be mindful of this tendency and try not to upset it. From what I hear the Mig-15 was notorious for this type of tendency if flown near its stall speed and then banked.
Here is a good video of a Mig-15 flown in the DCS simulator demonstrating this tendency and how to recover.

[Model jet juggernaut]

Flight from two sundays ago

https://youtu.be/n1xqbKXPUrM

[seaviper]

Man I'm sorry to hear of the Sabre going down. I know how that feels. Looked like a stall to me. It was quite slow in the turn. Typical of swept wing birds. Live and learn.
I stalled my F5 at low altitude in a high G turn earlier this year.

[RPC]

Hi....... I'm placing an order today for the 80mm F-86.....I'm currently flying with Turnigy 4000 and 5000 6s 60C batteries.....can someone tell me if these batteries will fit in the F-86 without modifying the fuselage.....please advise.....Thanks.