Posts: 81
Joined: 3/7/2004 From: Augusta,
ME, USA Status: offline
My latest seaplane, well, float plane. I wanted a glow powered float plane and thought the Hobbico Nexstar had a nice look to it and could be easily configured with flaps. I installed a OS 52 FS with a 12x5 APC and test flew the plane for 5 flights before I turned it over to Art Aube in Skowhegan, Maine for a set of his floats. I fly the plane with seven channels on a DX7 with a 5 cell 2000 mah high capacity flight battery. The water rudder has its own servo in the left float (a HS-81MG) and is mixed with the rudder controlled by a switch. AUW without fuel is 8lbs12ozs.
Takeoffs and quick and easy as it is on step very quickly and the plane will cruise in level flight at half throttle. Landings are easy also. In the air, however, it is a different story. It is not as stable as hoped. Ailerons not effective at low speeds and you need to fly with the rudder. Of course, the ailerons are smaller due to flaps which greatly aid in takeoffs. Ailerons are fine at faster speeds. There is quite a lot of dihedral in the wing. It just seems to react suddenly to roll changes in the air at speed.
I did have it flown by a real expert and we did some setup changes to throws and more will come. It has been suggested I add a subfin to increase vertical area. Thoughts??
Joe
< Message edited by jpg0529 -- 8/13/2007 3:51:51 PM >
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Joined: 12/30/2001 From: Burbank,
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Adding a sub-fin (ventral fin) will definately help. Add about 50% of the area of the existing fin and rudder. Also check and make sure there is no binding in your ailerons controls.
With that much dihedral, you have a lot of level flight stabiltity that your ailerons have to overcome to make it bank. It's a bit of work, but taking all of the dihedral out of the wing will make it handle MUCH better in the turns.
Posts: 81
Joined: 3/7/2004 From: Augusta,
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Thanks, Jim. I will work in that direction and add a fin. I do have a friend with a Nexstar and he took most of the dihedral out by bending the wing joiner rod (steel). The wing half's are only held together by the center plastic section so it wouldn't be a very hard job. He flys only from land. I will also make sure that the ailerons don't have any issues. When I flew from land for 5 flights, all was fine and it flew well but not as good as my trusty LT-40.
Again, thanks for your help.
Joe
< Message edited by jpg0529 -- 8/13/2007 8:08:41 PM >
Posts: 81
Joined: 3/7/2004 From: Augusta,
ME, USA Status: offline
quote:
ORIGINAL: jrf
Adding a sub-fin (ventral fin) will definately help. Add about 50% of the area of the existing fin and rudder. Also check and make sure there is no binding in your ailerons controls.
With that much dihedral, you have a lot of level flight stabiltity that your ailerons have to overcome to make it bank. It's a bit of work, but taking all of the dihedral out of the wing will make it handle MUCH better in the turns.
Jim
Hi Jim I have made changes to dihedral - cut it in half. I measured an angle of 170 deg at the wing root and bent the steel joiner rod so I now have an angle of 175%. Also added a vertral fin and it is just about equal to the vert fin and rudder area. Looks big!! Hope I can fly it this weekend to see the results.
This photo shows difference in dihedral and fin. Joe
Thats a great looking Nexstar! I'm hoping to make some of the changes you made to my Nexstar on floats. How did you attatch the subfin? Did you use the nylon bolts to hold the tail on when you built her,and if so how did you work around it? Can't wait to see how your next flight goes, thanks for the info-Harold
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Joined: 6/13/2007 From: , AK, USA Status: offline
Speaking of the lack of aileron's. Instead of cutting the aileron's in half and adding an extra servo, on mine I just left the dual aileron servo's on there with the wing unmodified and programmed in my flapperons on my xmiter. I don't have any of the troubles that you do. I have full control rather it is in a knife edge, or 5 inches above the runway inverted. Mine handels GREAT! It would be a good and LIGHTER solution to the problem you are having I think. Of course my two sense worth isn't any good to you now unless you are willing to buy another wing.
However I was interested in being able to put floats on my nexstar. Which ones did you use? Are they easily swapped out for wheels? I would only be flying floats for a couple of times a year.
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Joined: 6/13/2007 From: , AK, USA Status: offline
quote:
ORIGIANL: jpg0529
My latest seaplane, well, float plane. I wanted a glow powered float plane and thought the Hobbico Nexstar had a nice look to it and could be easily configured with flaps. I installed a OS 52 FS with a 12x5 APC and test flew the plane for 5 flights before I turned it over to Art Aube in Skowhegan, Maine for a set of his floats. I fly the plane with seven channels on a DX7 with a 5 cell 2000 mah high capacity flight battery. The water rudder has its own servo in the left float (a HS-81MG) and is mixed with the rudder controlled by a switch. AUW without fuel is 8lbs12ozs.
Takeoffs and quick and easy as it is on step very quickly and the plane will cruise in level flight at half throttle. Landings are easy also. In the air, however, it is a different story. It is not as stable as hoped. Ailerons not effective at low speeds and you need to fly with the rudder. Of course, the ailerons are smaller due to flaps which greatly aid in takeoffs. Ailerons are fine at faster speeds. There is quite a lot of dihedral in the wing. It just seems to react suddenly to roll changes in the air at speed.
I did have it flown by a real expert and we did some setup changes to throws and more will come. It has been suggested I add a subfin to increase vertical area. Thoughts??
Posts: 81
Joined: 3/7/2004 From: Augusta,
ME, USA Status: offline
Hi Guys... Well, I am very happy to report that the Nexstar flys like it should now!! Ailerons will now bank the plane at slow speeds and there are no "sudden" banking events as before. I still use the rudder when I fly but as I stated, you can now fly the plane with ailerons.
As for the subfin, it is attached at the rear with the rearmost plastic bolt that holds the tail feathers in place and at the front with a plastic screw just going into a tapped "CAed" hole in the fuse. I put a notch in the fin where the front plastic bolt is. Seems to hold just fine but I only have two flights on it with the mods. I built it with 3" wide 3/16 sheet balsa and glued that to a piece of good spar 1/2 x 1/4 balsa. That piece of "spar" overlaps front and rear for the mounting screw/bolt.
I bent the "joiner rod" 5 degs and everything just slips together as before but now with only half the dihedral.
As for flapperons, I always use a separate channel for each aileron servo and could easily program them as flaps for takeoff but I really like to play!! That's one reason I decide to buy that particular plane. I use that feature on my Bonnie 20 and it benefits on takeoff but can introduce a tip stall on landing if you forget them!! And as I may have mentioned, this plane flew just great until the floats were added. They are what caused the issues I had.
I had the floats installed by a friend that runs a small hobby shop here in Maine - Art's Hobbies - Skowhegan, Me. He builds his from foam, adds a hardwood mounting strip and fiberglasses them. A bunch of us up here use them and they work very well and stand up to abuse. These are 38" and he mounts them with music wire. He added hardpoints inside the fuse, drilled holes into them from the side, and the MW just slides into those holes and are held in place by a brass bracket with tie wraps. Unfortunately, the plane is at camp and I won't have access to it for photos until I return from there in several weeks. The attached photo is not that great but does show up the mounting area and the fin
BTW, the 52 OS FS is more than enough power for this plane as I fly it. Will loop from level flight. Cruise at half throttle. And I wanted it for casual flying. If I want aerobatics, I will fly my Seamaster. It excels at aerobatics.
Hello Joe: My AUW is approx. 9 lb, I used a spring scale before I took it to the lake-not sure how accurate it is. I'm still having problems getting this plane to ROW. Float to wing incedence is 2 deg, step is 1/2 to 3/4 inch behind Cof G. The day the pics were taken it was quite windy and rough. I knew I shouldn't fly but I thought it might be the last chance. So that day it lifted with no problem, but as I made the downwind turn the wind blew her down and she skipped off the water once and then caught a big wave into the float tips. You can guess what happened-tore the mounts out of the fuse which took about 2 hrs to repair. Tried again yesterday and couln't get her to ROW. The lake was a litlle less rough than in the pics but the wind was far less. Next week may be my last chance-I'm thinking I should have stuck with flying boats, might be my new winter project( looking at the LG Neptune-anyone have experience with this craft?) I'm running an OS46fx with an 11x5 prop. I wonder if I'm underpowered?
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Joined: 12/30/2001 From: Burbank,
CA, USA Status: offline
Please excuse a silly question, but in some of your photos it looks like the wing incidence is negative to the top of the floats. You do know that the wing should be 2 degrees positive to the floats, right? (In other words, the floats should be nose down vs. the wing.)
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