HobbyKing.com New Products Flash Sale
Reply
Thread Tools
This thread is privately moderated by jackerbes, who may elect to delete unwanted replies.
Old Oct 10, 2012, 10:33 AM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,619 Posts
Quote:
Any recommendations for simple and free drawing software?
Google Sketchup is pretty good. I'd be interested to hear of any good competition.

nickchud is online now Find More Posts by nickchud
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 10, 2012, 10:39 AM
Jack
USA, ME, Ellsworth
Joined May 2008
16,683 Posts
Some here have found the free (or at least free in the beginning) SketchUp app to be good enough for the simple drawings we usually need here. I am not an expert on or with it but there is some help here from guys that are darned good with it:

Using google Sketchup for modeling... With practical examples - http://www.rcgroups.com/forums/showthread.php?t=920416

How do I make plans using Google sketchup? - http://www.rcgroups.com/forums/showthread.php?t=1376826

Drawing, CAD drawing, welding, flying RC, being happily married, having obedient children, and well-trained dogs. What do all of those have in common?

The harder you work at them the better your results are!

Jack
jackerbes is offline Find More Posts by jackerbes
Reply With Quote
Old Oct 10, 2012, 11:05 AM
Reap the wild wind
headlessagain's Avatar
Bristol,UK
Joined Feb 2007
3,912 Posts
Here's a short video of my depron KFm-4 Funbat "ultra" flown close in at 50% power then WOT. Super stable as you can see and has a really good glide. Main wing in 6mm and steps 3mm top and bottom
Radio control Funbat Ultra 10thOct12 (1 min 14 sec)

Andy
headlessagain is offline Find More Posts by headlessagain
Reply With Quote
Old Oct 10, 2012, 12:47 PM
rcflyer
UK
Joined Jun 2010
843 Posts
Looks like a nice one Andy, what are the mods you made to make this then?
rcjim11 is offline Find More Posts by rcjim11
Reply With Quote
Old Oct 10, 2012, 02:17 PM
Registered User
Joined Nov 2007
1,760 Posts
Thomas, thanks for the info on the power train. Do you think this would fly well on a 2S system -- perhaps with a 7" prop? Or, do you need 3S and high speed?
Flyboy Steve is offline Find More Posts by Flyboy Steve
Reply With Quote
Old Oct 11, 2012, 12:40 AM
Registered User
davereap's Avatar
Ashford. Kent. England
Joined Feb 2005
6,798 Posts
Sketchup is an easy program to use and its very clever..much neater than pencil and paper and quicker once you've played with the program for a while, you can do 2D lines very quickly , and go on to make a full 3D model if thats what you want..
All my drawings are done in sketchup...and in my previous post the sketchup file for my version of your radius is in the zip file..it took about 10-15 mins to draw up.

Try downloading sketchup and my zip file, then load up my drawing and correct it to suit your build..
having a problem to work on, like the changes will get you learning faster..
http://www.sketchup.com/intl/en/download/index.html the basic version is free.. the pro is time restricted...
My
You will realize I am just as much a sketchup fanatic as I am a KF fanatic... however, on using sketchup, although I can very quickly do basic line drawings, I have a long, long, way to go to make use of its full potential

Power for the radius... my setup is a 7x3.5 on a 800mAh 3 cell and a 1700kv motor.. this is drawing about 7-8A at full power and hovers at 1/2+ power...so my max speed is going to be less than Thomas, but it will go vertical just fine..
My AUW with an 800 3 cell is 9.5 oz.... total area 1.8sqft... so 5.3ozsqft..

When going to 2 cells use a fairly high kv motor and prop it to suit, but dont expect the same max speed as thomas unless you take the motor's kv well high..
Your choice of power setup obviously depends on what you want it to perform like, My site is a sport field at the bottom of a park,so I tend to restict my models in top speed so as not to scare the pedestrian trafic..

The funbat is another good simple to build model, it reminds me of the much earlier obilex sloper and its layout is similar again to the radius, like a lot of our models it uses similar ideas, with changes of shape to produce a nice new model.. It then just depends on whether you like straight lines or curves...
davereap is offline Find More Posts by davereap
Last edited by davereap; Oct 11, 2012 at 02:23 AM.
Reply With Quote
Old Oct 11, 2012, 01:12 AM
Reap the wild wind
headlessagain's Avatar
Bristol,UK
Joined Feb 2007
3,912 Posts
Quote:
Originally Posted by rcjim11 View Post
Looks like a nice one Andy, what are the mods you made to make this then?
Central fin and more streamlined fuse - see this post http://www.rcgroups.com/forums/showp...&postcount=912
Andy
headlessagain is offline Find More Posts by headlessagain
Reply With Quote
Old Oct 11, 2012, 02:06 AM
rcflyer
UK
Joined Jun 2010
843 Posts
Cheers, what are you planning to use the funfighter motor in now?
rcjim11 is offline Find More Posts by rcjim11
Reply With Quote
Old Oct 11, 2012, 02:13 AM
Reap the wild wind
headlessagain's Avatar
Bristol,UK
Joined Feb 2007
3,912 Posts
I might build a 800mm flying wing to run on 4s KFm-4 of course.
headlessagain is offline Find More Posts by headlessagain
Reply With Quote
Old Oct 11, 2012, 09:52 AM
Registered User
Thomas B.'s Avatar
Germany, Nordrhein-Westfalen, Cologne
Joined Mar 2012
505 Posts
Steve, the Radius should fly well on 2s if you choose right motor/prop combination.
Thomas B. is offline Find More Posts by Thomas B.
RCG Plus Member
Latest blog entry: Water Rocket glider
Reply With Quote
Old Oct 11, 2012, 10:17 AM
What could possibly go wrong?
nickchud's Avatar
Market Harborough
Joined Apr 2006
3,619 Posts
Dave
Quote:
It then just depends on whether you like straight lines or curves...
I don't know if I'm right, but it seems to me that the radius type of wing is incredibly tolerant and easy to fly, both slow and fast. I wonder what the drawback is and why it's not used for 3-D planes like Extra, Edge etc?

Nick
nickchud is online now Find More Posts by nickchud
Reply With Quote
Old Oct 11, 2012, 12:23 PM
AMA 353531
rdeis's Avatar
United States, CO, Colorado Springs
Joined Aug 2003
6,543 Posts
I'd guess that the circular sweep gives it very nice stall behavior just like a delta wing has.

The disadvantage is lots and lots of drag at higher angles of attack, which makes it more difficult to carry energy through your maneuvers.
rdeis is offline Find More Posts by rdeis
Reply With Quote
Old Oct 12, 2012, 01:05 AM
Registered User
davereap's Avatar
Ashford. Kent. England
Joined Feb 2005
6,798 Posts
Deltas and circles are very good fliers and will do most everything, with the exception that they are poor/difficult for easy knife edge.. conventional shapes like the extras and yaks etc are much easier...
I am not sure on the aerodynamics, but isn't sweep back often equated to dihedral.. so many degrees sweep = so much effective dihedral... and as effective dihedral works as stability to bring the model back on to level flight, it makes it difficult to keep a knife edge in flight..And when you use the rudder to hold the nose in Knife edge it will roll the model rather than just yaw it..
Circles and curved back leading edges work similar to sweep back.....

Ive tried both but as I am not a competent 3D flier I found it impossible to hold a knife edge for more than a few seconds.. I can however hold it with the conventional 3D models
It is I know possible to do and can be aided by mixing opposite aileron in with the rudder, but I have never been that bothered..Its far easier to use a conventional shape for 3D

Speed ranges..all our KFs have excellent speed ranges, it is one of our models flight characteristics that using the steps does improve... From a good top speed whizz, they can be slowed, going slower and slower with no bad tendencies till you get them stopped and go into that parachute maneuver....Ive found that true enough whatever the shape of the wing..
davereap is offline Find More Posts by davereap
Last edited by davereap; Oct 12, 2012 at 01:38 AM.
Reply With Quote
Old Oct 12, 2012, 04:29 AM
Registered User
davereap's Avatar
Ashford. Kent. England
Joined Feb 2005
6,798 Posts
After looking at the obelix I have decided to make my own sloper version in a KFm9 format..
One model hanging on my wall and one I am not using is a BIG V wing, It was ok but nothing special, and my newer mini gliders are well out performing it..
So the knife is coming out and the V will be converted into a close approximation of the Obelix but at 56" span ...
I took some measurements and did a quick sketchup drawing, working out where the mods will have to be made... and luckily it wont be a difficult remodeling job..
davereap is offline Find More Posts by davereap
Last edited by davereap; Oct 12, 2012 at 05:43 AM.
Reply With Quote
Old Oct 12, 2012, 12:51 PM
AMA 353531
rdeis's Avatar
United States, CO, Colorado Springs
Joined Aug 2003
6,543 Posts
Quote:
Originally Posted by davereap View Post
I am not sure on the aerodynamics, but isn't sweep back often equated to dihedral.. so many degrees sweep = so much effective dihedral... ... ..And when you use the rudder to hold the nose in Knife edge it will roll the model rather than just yaw it..
Oh, I forgot about that!

You're exactly right, sweep will couple roll into the yaw.

It makes the airplane feel very well behaved for the sort of sporty cruising around and punching holes in the sky a lot of us tend to do (which is why so many of us like it), but I can see that making knife edge flight really tough.
rdeis is offline Find More Posts by rdeis
Last edited by rdeis; Oct 13, 2012 at 09:58 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Idea 40" Depron Dynamite, Kline fogleman Depron build dougmontgomery Hand Launch 636 Jul 12, 2014 06:29 PM
Cool Here is my KFm-5 DLG GLider (Kline-Fogleman) dougmontgomery Foamies (Scratchbuilt) 151 Apr 21, 2014 09:08 AM
Discussion ** Kline-Fogleman Airfoiled Flying Wing ** Tony65x55 Foamies (Scratchbuilt) 3945 Apr 08, 2014 10:40 AM
Video Kline Fogleman Airfoil on a flying wing Tony65x55 Electric Plane Talk 3 Jan 30, 2009 07:37 PM
Discussion Kline-Fogleman Airfoil on a flying wing Tony65x55 Modeling Science 1 Aug 20, 2006 11:14 AM