HobbyKing.com New Products Flash Sale
Closed Thread
Thread Tools
Old Apr 22, 2013, 11:28 PM
Registered User
United States, VA, Virginia Beach
Joined Apr 2013
28 Posts
Help!
F-35b stovl

Hello everyone, my new project is to build the Marine Corps version of the F-35 which has VTOL capabilities. I understand this is a pretty hard concept to put into RC planes. Been working with some coworkers brainstorming on how to make this work very easy. VTOL is the main part of the project and then transitioning to conventional flights. I will be starting with EDF and later on move on slowly to a turbine engine. The design is projected to be 50" long with a 35" wingspan. I was told to make it bigger due to the complexity of details going into it (minimum 5' wingspan). I am hoping to find a custom RC kit shop to build the model for me. Been reading a lot of the blogs in here and getting a lot out of it. I am open to lot more suggestions. Thank you.
louisjunior is offline Find More Posts by louisjunior
Sign up now
to remove ads between posts
Old Apr 23, 2013, 11:13 AM
Registered User
Ran D. St. Clair's Avatar
United States, CA, Sunnyvale
Joined Dec 2006
1,094 Posts
Louis,

The group here loves to help people and we love to see them succseed. That being said, you are not on a path that is likely to get you there.

Yes, a fully functional F-35b is possible in model form, but it requires lots of time and money, and some of the most skilled model designers and builders in the world.

If you want to give yourself a fighting chance, then start small and cheap, not large and fragile. Build your own models out of foam and tape and carbon fiber, because you will be building, and rebuilding, many times along the way. Start simple and ugly, and be prepared to learn 100 ways that don't work before you find one that does. Give yourself a chance to have some success and fun along the way.

If you aren't already an experienced RC pilot, then buy a simulator, and a basic RC trainer plane. Go find a local club and get some help learning to fly. Also get a small quad-copter and learn to hover. This stuff is all tons of fun by itself.

Now evolve your design from stuff that already works, like a quad copter. It may not be anything close to true scale, and it might have propellers, but at least it will fly, and you will learn, and have lots of fun in the process.

If this is a passing whim, then forget the whole thing. It will take you years to achieve, and the only way to stick with it that long is if you are enjoying the journey.
Ran D. St. Clair is online now Find More Posts by Ran D. St. Clair
Old Apr 23, 2013, 04:26 PM
Registered User
Joined Oct 2004
2,911 Posts
Also, check this forum's history for the number of F35 attempts that never got in the air.
Brandano is offline Find More Posts by Brandano
Old Apr 24, 2013, 01:24 AM
Registered User
United States, VA, Virginia Beach
Joined Apr 2013
28 Posts
Thank you for the feedback. Work on F/A-18 allday and love it. I will follow on the advices.
louisjunior is offline Find More Posts by louisjunior
Old Apr 26, 2013, 08:58 PM
Registered User
United States, VA, Virginia Beach
Joined Apr 2013
28 Posts
I am starting the 1st prototype this weekend. It will be designed with foam and beginning with just the vertical takeoff and landing moving on to hovering. Not that it is simple but I conceive the VTOL part been a lot harder than the conventional flight reason why I am starting with that (I may be wrong on that). I will definitely have progress pics update. One thing we are debating on here and would like to have more views on is weather I should use duct fans or props for the lift system. I'm probably going to have them mixed up and try different configurations but what I'm getting from others experiences, props will give me that hard push at the beginning but more stable when up v/s duct fans with a slow push off but harder to control.. Any thoughts on this?
louisjunior is offline Find More Posts by louisjunior
Old Apr 27, 2013, 07:46 PM
Registered User
Ran D. St. Clair's Avatar
United States, CA, Sunnyvale
Joined Dec 2006
1,094 Posts
Ducted fans are a poor choice for anything VTOL.

Momentum physics says for a static device (helo rotor, static propeller, EDF, etc.) says the ideal minimum power required for thrust T is: P = T (T/2*rho*A)^1/2, where P=power, rho =air density, A=disk area. So you can see, as the disk area increases, the power per unit thrust can decrease to zero in the limit.

In other words, an EDF can be made to work, but it will consume more electrical power to produce the same amount of thrust. It's basically a gross mismatch for your application, like using a sports car to move furniture.

The inly good reason for using an EDF in an RC VTOL it to make it look more like a scale jet of some sort. Beyond that it is a triumph of style over function, and the laws of physics will punish you for it.
Ran D. St. Clair is online now Find More Posts by Ran D. St. Clair
Old Oct 27, 2013, 11:11 AM
Registered User
United States, VA, Virginia Beach
Joined Apr 2013
28 Posts
I have a Multiwii Pro Flight controller w/MTK gps as shown in the link below. I can't get the gps to work. Can somebody help me with this?
http://www.hobbyking.com/hobbyking/s...dProduct=39478
louisjunior is offline Find More Posts by louisjunior
Old Oct 28, 2013, 09:19 AM
Registered User
Joined Nov 2012
186 Posts
Try use a ardupilot or kk2.0. These are easy to program
Joel_Vlashof is offline Find More Posts by Joel_Vlashof
Old Oct 28, 2013, 09:21 AM
Registered User
Joined Nov 2012
186 Posts
Quote:
Originally Posted by Ran D. St. Clair View Post
Louis,

The group here loves to help people and we love to see them succseed. That being said, you are not on a path that is likely to get you there.

Yes, a fully functional F-35b is possible in model form, but it requires lots of time and money, and some of the most skilled model designers and builders in the world.

If you want to give yourself a fighting chance, then start small and cheap, not large and fragile. Build your own models out of foam and tape and carbon fiber, because you will be building, and rebuilding, many times along the way. Start simple and ugly, and be prepared to learn 100 ways that don't work before you find one that does. Give yourself a chance to have some success and fun along the way.

If you aren't already an experienced RC pilot, then buy a simulator, and a basic RC trainer plane. Go find a local club and get some help learning to fly. Also get a small quad-copter and learn to hover. This stuff is all tons of fun by itself.

Now evolve your design from stuff that already works, like a quad copter. It may not be anything close to true scale, and it might have propellers, but at least it will fly, and you will learn, and have lots of fun in the process.

If this is a passing whim, then forget the whole thing. It will take you years to achieve, and the only way to stick with it that long is if you are enjoying the journey.
I agree
Joel_Vlashof is offline Find More Posts by Joel_Vlashof
Old Oct 29, 2013, 04:15 PM
Registered User
Joined Sep 2010
163 Posts
Louisjunior:

VTOL type aircraft are perhaps the most difficult "scratchbuilt" aircraft to deal with. Like the others who have given their opinion, recommend you do your research and layout your processes on how you are going to accomplish the 3 phases.
Then find out from others, will it work based on their experience or opinion.

For instance, using EDF's. Unless you have a lot of experience, wouldn't recommend it. Spooling up(compared to props) is a big issue( yes, I have tried it) dealing with VTOL. Will it work, it could, if you have experience and know what your doing. I have designed, flown a EDF STOL F-22 and that was quite a handful. Best to start with props. The other key is to build light, yet strong, to handle the stresses from going one stage to another.

Anyway, welcome to the group.
aero1960 is offline Find More Posts by aero1960
Old Oct 30, 2013, 05:30 AM
Registered User
Finland, HKI
Joined Apr 2013
179 Posts
Quote:
Originally Posted by Ran D. St. Clair View Post
Louis,

... Give yourself a chance to have some success and fun along the way.

...
Thats why we have RCGroups. You might split whole project into small pieces. Someone just build mockup aircraft and introduce it here. It's very accepable I think. Or you might build your test bench and introduce it etc. Someday you might challenge best designers/builders here. Then it is expected some pretty tough criticism. But don't worry it's all intresting.
MrJan is offline Find More Posts by MrJan
Old Aug 08, 2014, 09:29 PM
Registered User
United States, VA, Virginia Beach
Joined Apr 2013
28 Posts
Decided to build it myself..
louisjunior is offline Find More Posts by louisjunior
Closed Thread


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log F-35B Lightning II VTOL –Scale Composite Build <Updated: Aug 15> pg.4 Mustang5 Electric Ducted Fan Jet Talk 102 Jun 21, 2014 03:56 PM
Build Log F-35B Lightning II VTOL - Scale composite build!!! G-force237 VTOLs 221 Sep 09, 2013 07:00 AM
Discussion Lanxiang F-35B vtol??? alphacenturi Electric Ducted Fan Jet Talk 3 Nov 16, 2009 08:35 AM
3D view of the X/F-35B? themagicman Electric Ducted Fan Jet Talk 1 Apr 21, 2004 04:31 PM
Interesting X-35B STOVL test video Thomas B Electric Ducted Fan Jet Talk 6 Apr 21, 2001 05:54 PM