RC Groups

RC Groups
    Waterplanes
        Discussion Beriev Be-200 for EDF-40: long delayed project complete!

#1 Thomas B Jun 01, 2010 05:37 PM

Beriev Be-200 for EDF-40: long delayed project complete!
 
2 Attachment(s)
About 4 years ago, I started a BE-200 for twin brushless EDF-40s. fter much procrastination, it is complete at last! I put it back in the front of th queue for SMALL 2010, which starts this week.

Not certain it will get off the water, but I think it has a fighting chance. If not, It will still be a fun sport scale model to enjoy.

This model is a little hard to catagorize for RCG....it fits scale, waterplanes and EDFs...:)

Link to original thread here, woith some of the old progess photos:

http://www.rcgroups.com/forums/showthread.php?t=521103

#2 jimmycashley Jun 02, 2010 05:39 PM

Nice job--it looks pretty, especially for a Russian design. Some of theirs look a little cobby to me.

#3 Thomas B Jun 03, 2010 10:45 PM

I dunno,,,,it is generally considered that the Russians have designed a lot of really beautiful and striking aircraft....some that come to mind at the Tu-16 Badger, the Backfire, the Bear...as well a the Be-200!

Got the first flights in on the Be-200, including some at SMALL in Little Rock today....it REALLY flys nicely!

#4 cracksmeup Jun 04, 2010 05:57 PM

I LIKE IT, not to many guys modeling that . keep up the great work thomas. joe

#5 Fast Freddy Jun 06, 2010 08:11 PM

:)Beautiful Thomas! Looking forward to your maiden, and that's off the water! Videotape it if you get a chance as there are not many rc EDF seaplanes out there.

#6 meatbomber Jun 07, 2010 10:29 AM

the biggest question is now :

DOES it ROW ? :)

Sure hope it does, it`s a beautiful model !

#7 Thomas B Jun 07, 2010 08:17 PM

will be trying it off the water shortly...:) after flying it off the grass, I think it has a good chance of doing an ROW, perhaps with a tweak or two on the step and the tip floats.

Here is video of the little BE-200 in action:

http://www.rcgroups.com/forums/showthread.php?t=1256915

#8 Richard N Aug 09, 2010 02:10 PM

BE-200 Flight Pictures at SMALL 2010
 
3 Attachment(s)
There are a number of pictures of Tom's BE-200 in flight at SMALL 2010 in this post in the SMALL 2010 thread here:

http://www.rcgroups.com/forums/showp...&postcount=202

Richard

#9 Richard N Aug 09, 2010 02:18 PM

BE-200 on Water
 
9 Attachment(s)
These are pictures from Tom's first attempts at ROW from a pond near his home. It didn't have enough grunt to get unstuck but did have good water handling and did do an LOW.

Richard

#10 Thomas B Aug 09, 2010 07:02 PM

1 Attachment(s)
Had another go this past weekend at the Fort Worth Thunderbirds Float Fly with shorter tip float struts...the originals pictured above were far too long.

Did noticably better, but still not quite enough ponies to get it up on step and away.

It did take off nicely with a start in the grass, to get up to planning speed by the time it hit the water...cheating, but still farily satisfying. Did 5-6 touch and go landings...short touches...:)

Does need a water rudder...or at least differential thrust.

Richards pics show the need for some spray rails along the sides fo the forwar fuse...rather like the real one has...;) I still think it has a chance of unassisted ROW with some more mods....might have to try to vent the step as well.

Our float fly photographer failed to get any pics other than a few of the model taxiing, but I did like this one of it going past a tugboat model that was there. It shows the short tip float struts.

#11 parkcityskier Aug 10, 2010 07:56 AM

Beautiful rendition of the BE-200. Regarding your problems with defeating the suction of the water and not being able to do a ROW, I have some thoughts. To me, the root problem is not being able to generate enough angle of attack and lift from the wing, to overcome the step design. With a scale design, this is pretty hard to redesign. Likewise, increasing the angle of incidence of the wing would be impractical. One solution would be the use of flaps on the wing. Another redesign, of course, but how about trying using the ailerons as flaperons? It might be worth looking into with another seaplane that you might have to see what adverse problems you might encounter using ailerons as flaperons if your ailerons are not full span, as on your BE-200.

#12 lake flyer Aug 10, 2010 08:58 AM

I agree with PSF , if you can take off from grass you should have enough power to ROW .

If your airfoil is semi sym or sym , you need more AofA than you do for Clark Y type airfoils .

You have built a beautiful model , I have thought of building one of these , but haven't got arround to it yet .

The "to do " list keeps getting longer !!

#13 Thomas B Aug 10, 2010 11:29 AM

The surface tension of the water is a larger effect than the quite low drag of short grass on the fuse. As I have posted, there are still some options around of adding a secondary step or larger step. Given the volume of water sheeting over the fuse, I also think spray rails will give some useful benefits.

The airfoil is a Clark Y variant, with a little washout in the tips and a couple of degress of positive AOA at the root.

The model has never quite gotten on step yet, so no way to know if the scale fuse design will allow it to rotate off the water, or not, once it gets on step.

I was already thinking about drooping the ailerons a bit, if it will not get off once on step. Will have to add a second aileron servo, as I have only one at present.

Never thought it would come close to taking off the water as I designed it...it was really a fun little scale jet for grass operations. But, who knows..It just might be possible.

#14 Richard N Aug 10, 2010 11:57 AM

1 Attachment(s)
This is what it needs.

#15 Airboatflyingshp Aug 10, 2010 05:19 PM

Lovely job Thomas, I agree about the spray wave if you look at close ups of the original its got substantial if thin spray rails about there. Increasing the step a little and turbulance ahead of it should dencrease the stiction. You will get there, definately cool.


All times are GMT -5. The time now is 10:42 AM.