LX 64mm SR-71 Blackbird on 4S 12-Blade Power Setup

[Aros]

A soft spot in my heart goes out to all those RC pilots still flying these LX stealth birds...Takes true commitment. :)

[Bearcat]

A soft spot in my heart goes out to all those RC pilots still flying these LX stealth birds...Takes true commitment. :)

I love my F-117-- easy flyer but it could be better...better foam, landing gear....

[Jpahemi1]

Aros
I discovered the SR thread on RCG a week ago and finished it last night. At 30 pages in I decided to go for it and found a V2 kit version on the BH site and bought it. They shipped it the next day with no shipping charge. At 50 pages in was starting to question my judgement. Somewhere between page 50 and 122 I back to all in.

I’m currently building a Park Flyer Plastics B-58 and I ordered four 64 mm fans from Motion but I’ve decided to use two of them in the SR. I also have a new Eagle gyro. I have a good runway at our field so I’m going to keep retracts.

I read this thread so I know what esc and 4s pack together from Motion.

I’d like to add the thrust tubes, whale tail and rudders do you think that’s ok. What mods if any are you still using. Any and all advice is welcomed
thanks
John

[Aros]

Hi Jpahemi1, welcome to Club Habu! Sounds like you are well on your way. I would do the whale tail and thrust tubes for sure. Make sure you have a nice inrunner setup. My Don's Wicked setup years back was fantastic but he stopped making them. Just remember to have your CG dead perfect at recommended and keep your pitch throw maxed and your roll throw limited. Matched with a really good power setup you will have plenty of success. Just keep your eyes on it at ALL times as orientation can be a real bear real quick. (In my efforts to retain scale appeal I refused to paint stripes on the bottom sometimes to my detriment, lol).

Please post your progress/photos/video here when you can and good luck!

[Jpahemi1]

Aros
I appreciate to quick reply. I’ll be using the Freewing 64 mm fans on 4s just like you did. I’ll post pictures for sure.
thanks
John

[Aros]

Hi John, just to be clear I didn't like the power of my Freewing 12-blade setup. Even with the upgraded 4S it was never "zippy" like Don's Wicked setup was. If you don't mind just chugging around in pattern flight it's okay but I was underwhelmed with the performance overall. If I were to do it all over again I would search for a more robust 64mm power system.

[Jpahemi1]

Thanks Aros, my eyes are not the best and your video with the 12 blade fans looked like something I could keep up. Do us still fly yours?
I saw Lance Campbell fly his yellow aircraft SR every year at Superman with Dynamax fans and OS Engines. He always did a great job but it sure was roll sensitive. The crowd always went nuts when he flew and he always got a round of applause when he landed.
Can you give me any advice on the Eagle 3 gyro besides mounting it at the CG.
John

[Aros]

Hi John, no I sold my last one months ago. I am hoping Freewing comes out with one. (Crossing fingers)....

The Hobby Eagle A3 is a nice, cheap gyro that works great for this model. I mounted it in the receiver bay and it worked really well. Highly recommended!

[flyjets305]

Hello, its nice to see this post is still active, I just purchased the SR-71 it was on sale from BH (i dont know if i can mention the competitor's name) so i couldnt resist, I am going try flying it
stock with 4s 2200mah battery, definitely gonna use a gyro. Aros, and others are very brave hand launching this bird, I will be taking off from paved runway.
I purchased this particular plane because of the history, not because of the performance of this model, If I wanted super fast or more maneuverable there are other planes out there.
So with that said I will fly it stock set up, I like flying scale. Aros mentioned he had the FW 64mm 3300kv motors in it. I saw the video and that looked plenty fast for me .Again, depending
on how it flys stock, I will consider installing FW 64mm that I already have or FMS 64mm3150kv which is super fast . Hope to be able to maiden next week!

[Aros]

Welcome to The Squawk and Club Habu flyjets305! You sound like you have the proper mindset going into this model. Indeed it won't be performance that dazzles, but just flying a Blackbird is worth it alone since this LX has remained to this day the only RC foam SR-71 to ever be mass produced. Let us know how the maiden goes and please take video if you can. Good luck!

[Jpahemi1]

Flyjets
mine is the kit version and it’s perfect for me. You get the foam parts, a fan no motor and the mechanical retracts. The Freewing 64 mm fans fit perfect. I just order the Freewing A-10 dual Esc, six 9 gram servos, and 4s 3600 batteries. I putting the Eagle AL3 gyro right in front of CG 78 mm
Lets share as we build

[flyjets305]

Jpahemi1, I will also be using that gyro, i just wish the battery and Rx and gyro would have been located on top of the fuselage instead of on the bottom. I will have to see how much room there is, but i will start with 4s 2200 lipo. i would like to see how it flys stock first, and will post maiden flight soon.!
did anybody add some carbon fiber to strengthen the connection where the cockpit and body attach? it just seems like that would be a good idea,

[Jpahemi1]

Flyjets
Have you read the 122 page thread on Rc Groups yet? It’s a good read. The nose joint typically breaks off at the joint. I’m still figuring that out, I’ll post pictures when I figure that out.

Aros
control throw question. Did you stick with 15 degrees on the elevon for roll and 25 elevator function?
on the whale tail was that also at 25 degree

Thank
john

[Aros]

I can't recall the precise degree of deflection I went with but the key is minimal roll and maximum pitch for certain. In my early years of flying (crashing) this jet I had no clue what I was doing. I had waaaaaay too much roll throw, no gyro, trying to fly it like a normal jet...Yeah, went through a lot of airframes back then, lol.

[flyjets305]

Jpahemi1 I just received my plane today, and overall pretty happy just wish they would have addressed some minor details. But specifically, how in the world can you put a 4s2200 battery
in the battery bay, there is no way it fits ??? with out cutting something.
also, i would like to put a gyro in, but where do you put that so it is lying flat?
do you have it set up as ELEVON in your radio? thats how I have my, but i cant get the gyro to work. any suggestions? but especially about how to fit the battery?

[flyjets305]

follow-up to my previous post. I guess i cant use the ovionics battery unless i make some modification.. but my Zeee 4s2200 fit snug but they fit. I used the glue that was provided in the kit
to glue the fuselage together , I hope it holds. i didnt add any carbon fiber reinforcing like i wanted but lets how it goes.
I was able to get my gyro working and i have layed it flat on the bottom of the cage as it closes. i will secure with zip tie. It may be to windy tomorrow to maiden, so may have to wait till next week.
will report then.

[Aros]

I always had to heavily modify the battery bay to make my choice of battery(s) fit. A lot of cutting/dremeling. For gyro I used the receiver bay aft of the battery bay. Space is indeed at a premium in this model. Elevon is the setup for this bird but it depends on your gyro programming for how to get it to work properly. CF rods work great at the joint but my last few airframes I actually didn't bother. If a hard landing caused enough stress to break the seal it was always easy enough to glue back together cleanly. Good luck and God Speed!

[flyjets305]

Thank you Aros, I wish you had some pictures of the battery bay mods.
John, lets see your battery bay, and what size battery you will use?
I dont plan on using anything bigger than my 4s2200mah batteries, unless, i get less than 2 minutes, but if i can get 2 1/2 to 3 minutes I will be happy. luckily, I have some Zeee 2200mah lipos that just fit without any mods.Using the 78mm CG per instructions, the plane sits level for the most part I can make it till nose heavy or tail heavy,which is alittle concerning, because obviously nose heavy is better. but the battery placement is fixed so you cant move the battery forward or back to adjust CG, I cant even image that this was supposed to have used a 3s battery, there is no way the CG would have been correct. I am going to zip tie the gyro to the bottom of the cage @ the Rx box, it seems to function so we will see. i have to wait for some calmer wind, so maiden wont be this week. but will post video

[Aros]

Here's a few of the photos I could find in my archive. Not all these are of the same model...Keep in mind I converted most to hand-tossers so they were heavily modified. As for batteries, I would often just hold them in place using nothing more than Gorilla Tape (and lots of it). The knicks and dings were easily dealt with using Testor's Flat Black. Good as new! LOL!

[Jpahemi1]

Flyjets.
I’m out of town when I get home I’ll post some project pictures. Right now I have installed the elevon servos and worked on the mixing. Next up is make thrust tubes