Lanxiang/BlitzRCWorks F-22 thrust vector mod (Full Version)

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tankertoad -> Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/13/2009 2:48 PM)

I'm starting this thread to show my thrust vector (TV) mod on the Lanxiang F-22. Off the top of my head, I can think of about 5 different places to pick up this jet; Banana Hobby, eBay, BP hobbies, Hobby City and Easy Tiger. There are probably many more. Mine was purchased on eBay as an ARF. I shy away from the RTF stuff because I don't trust the components,

Here's my set up:
Fan/Motor: Eflite Delta-V 15/Eflite BL15 Ducted Fan Motor, 3600Kv
ESC: Eflite 60-Amp Pro Switch-Mode BEC
Battery: Flightmax (Zippy) 4s1p 2650 20C (get about 4 min of hard flying)
Servos: (4) Eflite 7.5 Gram DS75 Digital Sub-Micro Helicopter Servo on ailerons and elevators, (2) Eflite 7.5-Gram Sub-Micro S75 Servo on TVs
RX: Spektrum AR7000 (I planned to mix everything through the radio, but got lazy and used a GWS V-tail mixer on Y adapters from the aileron and elevator channels to mix in the TVs.)

Wing Span: 850mm / 33.5"
Fuselage Length: 1230mm / 48.4"
AUW (my set up) 3lbs

Overall impressions:

My ARF came with fixed gear, but I fly off grass so hand-launching is the way I go. Plus, gear seemed like an afterthought in this model. The hardpoints for the mains weren't very strong. I tried to maiden off the gear, but both hardpoints popped out of the foam. Unless you are flying off smooth pavement, I wouldn't use the landing gear.
The styrofoam is soft. Mine sustained a fair amount of hanger rash during the build and first few flights. If you are belly landing on patchy grass or dirt, you may want to glass the belly.
The waterslide decals look nice, but they didn't stay stuck for long. I covered the tailflash with Minwax polycrylic to protect it. All my stars and bars came off so I printed some off the parkjets.com site to replace them.

It flys great. It's stable and does all the scale F-22 maneuvers. I'll try to get some video in the future.

More on my build later...




tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 8:51 PM)

OK step 1 - Get the parts. I knew ball studs and links would be easy to find in the heli section of my LHS. I used parts from a Blade 400 and some carbon rods.
Here's the list:

EFLH 1437 Ball link set (1) (you will need 8 links)
EFLH 1418 Bell Mixer Arm and Pushrod/Link set (2) (you only need the 8 ball studs from this set)
Carbon fiber rod and carbon fiber tube (size shown in the photo)
Great Planes small pivot point hinges



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 8:56 PM)

Step 2 - Cut out the TV paddles at the scale location. Try to get them as square and even as possible. Perfect geometry is key to this modification.



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 9:16 PM)

Step 3 - Notch out the areas in the photo. They provide clearance for the linkages to travel. The front of the notch starts at 28mm back from the cut (hinge) line and ends at 48mm back to give you a 20mm wide gap. They are only about 3-4mm deep.



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 9:25 PM)

Step 4 - On to the paddles. Bevel the edges of the hinge lines. You'll notice I marked each paddle to identify the the location from where it was cut. Next,mark a line parrallel to the hinge line right at the point where the paddle starts to form a triangle so that your line is the base of the triangle. MAKE SURE it is square with the hinge line. Next, I used a drill bit and carved a channel in the paddle while ensuring it was square to the face of the surface and right on the line I marked. Last, use the carbon tube and ball studs to make a pivot rod for the channel in the TV paddle. Total length of the pivot rod with studs installed is about 58mm. Once those were glued in, I filled and sanded over the pivot rods to ensure smooth airflow over the paddles. In fact, the entire inlet and exhaust (including the TV paddles) of this model is covered with clear packing tape to reduce drag.



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 9:46 PM)

Step 5 - Install servos. I installed two micro servos right in the channel molded for the vertical tail. There's a step in the foam that is a good place to ground the edge of the servo to make sure you get both servos in the exact same location. Next, notch out the tail in the area where the servo will protrude. Also, make a hole for the servo lead to go down through the fuselage to meet up with the leads from the aileron and elevator servos.



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 9:57 PM)

Step 6 - Make links from the carbon rod and ball links. Mine are about 38mm in length. The key point here is to find a length so that when your paddles are installed on the jet, they form a perfect square (top and bottom paddle, left and right link) and the inner surfaces are even with the exhaust duct (once again, to prevent any drag). Install two pin hinges in each paddle and install all links. Get everything lined up to make the holes in the fuselage where your pin hinges will go. Again, make sure it's all square and even left to right (you will now see why you cut those channels in the sides of the fuselage at the exhaust duct.) Dry fit everything before you glue your hinges in. Make sure not to get glue on the elbow of the hinge (some people dip the elbows in vaseline). I put a little teflon on my hinges and links to ensure everything moves smoothly.



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/19/2009 10:11 PM)

Last step - Install control horns on the top paddles. I used hardwood backers (made from epoxy stir sticks) on both surfaces of the paddle to sandwich the foam before I installed the control horn. I also added a little carbon strip imbedded lengthwise in the top paddle to make sure it was strong enough for the abuse. Do all this BEFORE you glue in your hinges! I did it after the fact and it was a pain. Make pushrods and connect to your servos.
My radio mix uses a V-tail mixer on Y-adapters from the aileron and elevator channels.

I may have missed something in this post so, let me know if you have any questions and feel free to improve on the design. Good luck!!


PS - My F-22 does all the scale Raptor Demo stuff (backflips, cobra maneuvers, etc.) I'll try to get some video up once I find some easy to use software for my Sony HD camera. Any suggestions?



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (7/28/2009 2:01 AM)

Just ran a 4s1p 3200 25C. The jet carried it well with hardly any need to re-trim from the 2650 battery. It made for a little better performance, but the extended run time (5+ min) was the biggest benefit.



sheik480 -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/16/2009 6:35 AM)

Nice setup man! How long did that go together?



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/16/2009 11:35 PM)

Maybe a few hours above the normal time to build it as an ARF. Not sure what it would be like for the RTF version.



sheik480 -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/17/2009 12:16 AM)

Cool. How is performance affected?



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/17/2009 12:54 AM)

If you go to the Hobby Lobby site and look at what their SU-34 can do in the video, my F-22 will do the same. On the front side of the power curve, it's a VERY stable EDF jet, so adding the TVs made it do exactly what I hoped it would do. (Cobras, flips, etc) It would probably be capable of high alpha flight, but it tip stalls pretty wickedly, so I would suggest a gyro on the roll axis if you are looking to do it. I may add one later, but now I'm busy converting an E-Flite Super Airliner into a KC-135.
I hand launch with no problems and it's very easy to land.
The additional weight is nearly a non issue since I didn't add the gear to mine. I compensate for any CG issues (I doubt it makes much difference) by running a slightly larger battery than if you get the RTF version.
It's a great mod. It impresses everyone who sees it fly. Now if I can just get someone at my club to get an SU-34 so we can go head to head :)



sheik480 -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/18/2009 3:32 AM)

Awesome! Nothing a little genius can't 'fix'! I think I'll be looking into this mod...



tankertoad -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/18/2009 1:20 PM)

Great! Please keep this thread going with your version of the mod. Are you doing the ARF or the RTF? If you are going ARF, BP hobbies has them stocked in the US. Banana has the RTFs.
I also added some finger-holds to the bottom for hand-launching and can post pics if you are going sans gear.



sheik480 -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (9/18/2009 11:20 PM)

Heh heh, I'll let you know in a couple months. I had a terrible time this summer and it'll be a while before I pay off my credit cards, especially with the jacked up rates. [:'(] But when that does happen, I think I'll go with the RTF and keep the landing gear. But until then, all I can do is imagine...



b8oven -> RE: Lanxiang/BlitzRCWorks F-22 thrust vector mod (1/5/2010 9:59 PM)

On a somewhat unrelated matter, Banana sent me a 6-channel Lanxiang radio with a jet I ordered. Of course, no instructions on how to bind receiver to transmitter. Anyone ever tame one of these things? Thanks. (You can reply to my email :
b8ovenbest@yahoo.com




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