Xfly Models B1B Bomber 70mm

[Evan D]

I’ll say it once more XT and EC are not compatible and if you decide to plug one into the other it’s a stupid decision. Kallend said in a pinch you can spread the pin to make a better connection but DON’T DO IT. In the picture are two types of pins used, these are both EC5 pins. The one on the left is what he’s saying to spread and yes I guess if you did it would make a connection but it’s just not designed to be used that way. I can’t believe a professor actual even suggested it. What’s next, missing that machine screw to hold your wings on, use a wood screw, it’s close enough?

XT90 and EC5 are not compatible. The pin on the XT is 4.5mm and the tube on the EC is 5.0mm. Don’t do it.

[Elbee]

Eeep!!

Aros, there is nothing good going on there except the wings stayed onboard. Cheeez und Krakers, Bro. Best, LB

[Coconut]

BBBBAD BAD, BAD to the SPAR!!!

[Coconut]

The wing is on backwards .

[kallend]

Eeep!! I sure hope there's spars! But it does look like (in the video) there are none?? Holy catfish. I'll check for sure along with the bearings...Thanks!

Here's the video:

It's hard to see from the video but it looks to me during the take-off roll that the dihedral is coming from the wing root area (the pivots), and is not flexing in the wing itself as would be expected if a spar was missing. At 0:09 the wing itself looks quite straight but it is definitely angled up from the root.

[Aros]

Eeep!! I sure hope there's spars! But it does look like (in the video) there are none?? Holy catfish. I'll check for sure along with the bearings...Thanks!

Here's the video:

[F106DeltaDart]

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

The other thing to check would be the bearings embedded into the wings. They may have missed adding the bearings on the bottom side of the wings. Having only one set would result in something looking very similar.

[F106DeltaDart]

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

I wonder if you got a QC fail where the factory sealed the wings up without putting in a spar.. it’s the only explanation I can think of that would result in that.

[Aros]

Congrats Aros! On mine, following Jeremy's build video, I used the 16mm screw in the center and the 6mm screws on the flanges. I didn't have any noticeable dihedral on my (albeit brief) first/last flight.

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

[jetpltrich]

Should be like this.

[GliderGuy]

The dihedral reminds me of the Concordia sailplane….Aros’ B-1B doesn’t look right.

Congrats on the maiden!

-GG

[F106DeltaDart]

Good report RudyD54 thanks!

I successfully maidened mine over the weekend. I'll post the video later today. I actually did connect the XT90 to the EC5. I wrapped some Gorilla Tape around the connectors and it held fine after two sorties. Although I admit it was not ideal and a bit risky. The connectors were WARM after the flights. I got my adapter so I will be using those moving forward. The maiden was decent although I forgot to retract my takeoff flaps which would explain why she felt sluggish at full throttle (smacks forehead). Landing is a breeze. You could probably dead stick her in. When I swept the wings it felt wonky a bit. Seemed to not want to track straight and bank to the left so I quickly brought the wings back out.

The wings had a ridiculous dihedral so I was hoping to get someone's advice...When you mount that metal bracket piece to the pivot point mech, did you use 16mm length screws for all of them? The manual confused me...Looks like two are a 6mm and the other is 16mm? Perhaps that would explain the dihedral? Not enough "meat" going into the holes?

Congrats Aros! On mine, following Jeremy's build video, I used the 16mm screw in the center and the 6mm screws on the flanges. I didn't have any noticeable dihedral on my (albeit brief) first/last flight.

[Aros]

Good report RudyD54 thanks!

I successfully maidened mine over the weekend. I'll post the video later today. I actually did connect the XT90 to the EC5. I wrapped some Gorilla Tape around the connectors and it held fine after two sorties. Although I admit it was not ideal and a bit risky. The connectors were WARM after the flights. I got my adapter so I will be using those moving forward. The maiden was decent although I forgot to retract my takeoff flaps which would explain why she felt sluggish at full throttle (smacks forehead). Landing is a breeze. You could probably dead stick her in. When I swept the wings it felt wonky a bit. Seemed to not want to track straight and bank to the left so I quickly brought the wings back out.

The wings had a ridiculous dihedral so I was hoping to get someone's advice...When you mount that metal bracket piece to the pivot point mech, did you use 16mm length screws for all of them? The manual confused me...Looks like two are a 6mm and the other is 16mm? Perhaps that would explain the dihedral? Not enough "meat" going into the holes?

kallend I didn't actually check my CG location manually. I simply went off the photo of my friend who was using the exact same Admiral 6000. He took a photo of it in the tray and I simply emulated that and it worked great. So I still need to find out where my CG is at for when I want to try different batteries.

Here's the portion of the manual I was referring to...And get a load of that dihedral!!

[kallend]

Since it was reported elsewhere that the wingtips are weighted, I checked to see how much the CG moves when the wings are swept back.

I set the CG at the 81mm mark (by the lip of the intake as shown in the set-up video) with the wings forward. When I swept the wings the CG had shifed back to 105mm, a shift of 24mm (or an inch).

So just be aware that when you set up your model's CG at the 81mm mark (or wherever else you think it should be), be sure that the wings are in the right place.

[RudyD54]

My flying buddy RudyD54 maidened his B-1 yesterday and helped me maiden my Bronze Tiger Eurofighter. I believe he put on 5 flights with the B-1. Some were a little "wonky" as he was dialing it in but did comment that when the wings are swept back, it likes to dive and full elevator hardly brings it up. He's a very accomplished pilot and an electronics guru and to me, with some odd tendencies, it seems to be challenging yet interesting to fly but definitely lands super easy at least on grass. Hopefully he'll chime in here and give more coherent comments.

Haha, I didn’t realize you took this pic. I’ll copy and paste what I wrote in the other forum here:

After maidening mine today, I’m convinced that the gyro in the B1 is some form of heading hold gyro. It acts just like one and would explain why trimming is a bad idea and it “self trims”. It’s more like it continues in whatever direction/attitude you put it in.

It took me a while to find a CG where things felt ok. For me it’s roughly a few mm forward of the picture I attached earlier where I was pointing out the intake lip.
This is where wings out felt the most stable, but at the expense of a lot of elevator authority with the wings swept. Wings forward the B1 is sensitive on pitch, and requires very little throw to toss around while wings back requires full elevator input to make a rather wide banked turn. It’s an odd sensation akin to flying two completely different models. I was able to improve the wings swept pitch authority by pushing the CG back, but that created a very touchy beast with the wings out.

Honestly I feel like the internal gyro is just not setup ideally for this model. It’s “adequate” and will get the job done, but I feel like it’s the product of trying to make things easy to setup as it negates trimming, multiple flight modes, gains, etc. that are required on the Freewing F-14 for example. After 5 flights, I think the wings out mode needs more expo, less travel, and much higher pitch gains, and wings swept needs more throw. These things may have already been tested, and may have not worked, but that’s the best way I can describe what improvements I think can be made.

I’ve got a Spektrum AS3X receiver in there which currently has the gyro disabled but I’m going to go ahead and try using it instead, as well as using flight modes and the necessary mixes while putting the elevator channel directly to the receiver so I can get more throw.

Aside from that above the plane is very cool, and I did enjoy flying it. We have thick green grass at our field this year due to the constant rain over the last month that’s not cut very low, so the takeoff roll was pretty long, I’d say about 300 feet with flaps. I may add a few more degrees to see if I can get some more lift.

Landing is a breeze, she settles in nicely and glides for a while.

Weather is terrible here for the next couple of weeks so it’ll probably be a while before I can get her out again but I’ll report back once I test the changes.


Here’s a short vid of the maiden:

https://youtu.be/MDirmOZOqDg

[Hugh Wiedman]

Well, to say the least, this was not how I was hoping the maiden flight would end… Spent hours setting things up exactly per Jermey’s videos and thought I’d give the stock flight controller a shot for the maiden flight and maybe bypass it later. A word to my fellow B-1B pilots, approach flight with wings swept very carefully, and be ready to bail out of it at a moments notice.

The aircraft was configured with a 6S 5800 battery towards the aft side of the battery compartment, balancing at intake lip per the setup video. Controls all centered mechanically, no trim or sub trim as per the videos. 2 RC geek Center burners were also installed.

The take off was uneventful, and it flew pretty well with wings out. Maybe a bit tail heavy in that configuration, but not bad. The stock gyro was doing a good job overall. 2 normal patterns were completed before I was confident to try sweeping the wings. I swept the wings on downwind, and attempted a turn to stay in the pattern.

This is where it all went wrong. With the wings back, I found myself at full up elevator just to maintain level flight, and heading out towards the lake at the end of the runway. I gently attempted to coax it into a turn, with a bit of elevator, aileron, and rudder, but it was bleeding altitude. I then tried to get the wings back out, but by this point it was diving out of sight behind the tree line. Found it 10 ft away from the water, just as you see on the shore.

Pretty much everything in the nose was destroyed, including the battery and my 9 channel Spektrum receiver. The aircraft itself is pretty much a write off. Only the far aft tail section survived intact.

My flying buddy RudyD54 maidened his B-1 yesterday and helped me maiden my Bronze Tiger Eurofighter. I believe he put on 5 flights with the B-1. Some were a little "wonky" as he was dialing it in but did comment that when the wings are swept back, it likes to dive and full elevator hardly brings it up. He's a very accomplished pilot and an electronics guru and to me, with some odd tendencies, it seems to be challenging yet interesting to fly but definitely lands super easy at least on grass. Hopefully he'll chime in here and give more coherent comments.

[kallend]

I've seen people put the XT into a EC. It goes but doesn't make a good connection.

I use an adapter but in a pinch you can slightly spread the pins of the male XT so it makes a tighter connection with the EC.

[Evan D]

I've seen people put the XT into a EC. It goes but doesn't make a good connection.

[SanExup]

My mind went to the part where he mentioned an XT90 to EC adapter. I use them but I zip tie the XT to XT side together. I've seen them get sloppy loose in a short amount of time.

[Evan D]

XT90 and EC5 are not compatible. The pin on the XT is 4.5mm and the tube on the EC is 5.0mm. Don’t do it.