Top-Flite 1/5th F4U Corsair ARF Group Build and modification thread
09-02-2017, 09:36 AM
#454
Join Date: Mar 2011
Location: Wilmington, NC
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So have anyone else ran into this, I am having trouble getting the center wing section attached to the fuselage,it appears that the fiberglass belly pan glued to the bottom of center wing was glued about 3/16" too far back.This causis two problems 1 It partially blocks the bolt holes so they would have to ground out to be able to get bolts in and tighten . 2, The rear surface won't let the wing set down into the saddle, so at least 3/16" would need to be removed from the back.
Or other option would be trying to remove the whole piece without doing too much damage and then properly reposition . Or I could just call Tower about a replacement section, but I already have my retracts installed with operating gear doors. So anyone have any thoughts or suggestions.
Or other option would be trying to remove the whole piece without doing too much damage and then properly reposition . Or I could just call Tower about a replacement section, but I already have my retracts installed with operating gear doors. So anyone have any thoughts or suggestions.
09-03-2017, 09:32 AM
#458
I would just re-position it. Iron down the covering next to the saddle and use a new/sharp blade and cut the covering around the edge of the saddle. The saddle is probably just glued to the covering. Take your time and work it off nice and easy. Clean off the glue and covering on the lip of the saddle, mount your center section and re-glue it back on. Moving it forward should cover most of the cuts you made to the covering except for behind the coolers which may need a bit of touch up work.
Unfortunately when you buy an arf, its a crap shoot as to how well or sloppy the plane was constructed.
Unfortunately when you buy an arf, its a crap shoot as to how well or sloppy the plane was constructed.
Last edited by Warbird Man; 09-03-2017 at 10:02 AM.
09-04-2017, 06:25 PM
#459
Join Date: Mar 2011
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well what I did was take the easy way out and cut it. I marked it 3/16" from the back and used my dremel with a cut off wheel, then sanded a slight taper on the outside of the cut off piece and a slight taper on the inside of the part still on the wing and then slipped the piece into the back, after some touch up paint the seem is not detectable , and now the center section fits right into the saddle perfect and while the bolts are still partially obstructed I can just get the allen wrench in and and tighten the bolts relatively easy
11-05-2017, 05:26 PM
#460
Hello,
I know there was some discussion about the lame rudder linkage setup in the ARF. Unfortunately for me, I installed mine before I read it. Now, I can get almost a half-inch of throw on the rudder before the servo itself moves, so I'm sure I am a candidate for flutter. I'm contemplating mounting a servo in the fin, but I don't want to chop it up trying to find the 'hole' in the framework. Does anyone know the skeletal structure under the sheeting of the fin, so I know where to cut a hole for a servo hatch? Maybe someone else has done this already? I stripped the covering off of the fuse and glassed it because it was just so saggy and ugly. I don't want all this work to go to waste because my rudder fluttered...
Thanks in advance for any guidance.
I know there was some discussion about the lame rudder linkage setup in the ARF. Unfortunately for me, I installed mine before I read it. Now, I can get almost a half-inch of throw on the rudder before the servo itself moves, so I'm sure I am a candidate for flutter. I'm contemplating mounting a servo in the fin, but I don't want to chop it up trying to find the 'hole' in the framework. Does anyone know the skeletal structure under the sheeting of the fin, so I know where to cut a hole for a servo hatch? Maybe someone else has done this already? I stripped the covering off of the fuse and glassed it because it was just so saggy and ugly. I don't want all this work to go to waste because my rudder fluttered...
Thanks in advance for any guidance.
11-05-2017, 10:15 PM
#461
Shaun, I complained to Greatplanes about the slop in the rudder and of coarse it was denied as being a problem. So I flew my plane built stock as hard as possible accepting total loss just to prove the point. What I learned about the plane was that the rudder is useless above a certain speed in flight and the plane will wag its tail at top speed. The rudder didn't flutter even with all that slop. Once your in the groove to land the rudder comes back into play and it works ok.
It's not ideal but it's not a problem as far as I've seen. I had 50 or so flights on my first fuselage until it was ruined in the garage. The second fuselage I relocated the rudder servo to a spot above the retract. The linkage is very short and the slop shifted to the wood in the rudder instead. Previously the slop was mainly in the flex of the long control rod plus the rest of the mechanics.
I'd suggest toughening up the wood in the rudder so the torque rod has no play in the wood. Also if you can, change out the torque rod to one you make from good piano wire. The wire they supply is weak and flexes which is the biggest problem.
While your in there with the rudder you can take the opportunity to update the shape to a more scale profile. It makes the shape more round and taller which won't hurt.
I've flown my mods several times with zero problems but if I wanted to go back I'd change out the stock torque rod as described above because I still have a weak rudder. There's practically zero play in the servo and short linkage now but the wood and torque rod are the last details to make a more positive rudder in flight.
Id like to see how your glass work ends up, post pics as you go!
It's not ideal but it's not a problem as far as I've seen. I had 50 or so flights on my first fuselage until it was ruined in the garage. The second fuselage I relocated the rudder servo to a spot above the retract. The linkage is very short and the slop shifted to the wood in the rudder instead. Previously the slop was mainly in the flex of the long control rod plus the rest of the mechanics.
I'd suggest toughening up the wood in the rudder so the torque rod has no play in the wood. Also if you can, change out the torque rod to one you make from good piano wire. The wire they supply is weak and flexes which is the biggest problem.
While your in there with the rudder you can take the opportunity to update the shape to a more scale profile. It makes the shape more round and taller which won't hurt.
I've flown my mods several times with zero problems but if I wanted to go back I'd change out the stock torque rod as described above because I still have a weak rudder. There's practically zero play in the servo and short linkage now but the wood and torque rod are the last details to make a more positive rudder in flight.
Id like to see how your glass work ends up, post pics as you go!
11-06-2017, 02:22 AM
#462
Thanks, Chris
Unfortunately, I not only epoxied my rudder hinges in, but also the torque rod. I suppose I can grind out the hinges and try to twist the rod out of the slot without destroying the rudder but I'd rather not. I sure as heck wonder why they shaped the rudder that way. It reminds me somehow of Herman Munster.
I'm a rudder flyer, so I'd really like to have sure and positive control, but I do feel better knowing yours didn't flutter at speeds.
Unfortunately, I not only epoxied my rudder hinges in, but also the torque rod. I suppose I can grind out the hinges and try to twist the rod out of the slot without destroying the rudder but I'd rather not. I sure as heck wonder why they shaped the rudder that way. It reminds me somehow of Herman Munster.
I'm a rudder flyer, so I'd really like to have sure and positive control, but I do feel better knowing yours didn't flutter at speeds.
11-07-2017, 06:56 PM
#465
That's good to hear. I feel like the rudder is gonna shake left and right an inch just from the engine idling! Anyway, 375 flights?!?! Geez, I've been a sponsored pilot (by three different orgs) and Rep for two others, and I don't know that I have 375 flights in the hobby! Rock on, Corsair!
11-07-2017, 08:30 PM
#466
Well, I'm confident I've got 100 plus flights on my Corsair over the last several years with zero failures and only one dead stick landing.
You may find you will be chasing screws around the plane like cowl, wing and misc screws but that's pretty scale too! Lol
The dead stick was due to using the junk spark plug supplied with DLE engines, swapped out to NGK. The only other in flight issue was a leaky pressure gauge which was subsequently removed and it's been reliable ever since.
Oh hey, big tip, replace the stock Robart springs with a softer rate spring. I made a two stage spring set like Yellow does in the P-38. The Corsair is my second mod the first was the TF Mustang. Anyway, it makes landings so much smoother. This helps keep you from bouncing on touch down even with the smoothest landing sometimes you bounce up. Check your local hardware store for compression springs that fit inside the strut.
My stack has a rubber bushing, about one inch of the stock spring and the rest is a softer spring. The plane sits with the struts about 1/4 inch from full compression.
Works great, easy to do, check it out.
You may find you will be chasing screws around the plane like cowl, wing and misc screws but that's pretty scale too! Lol
The dead stick was due to using the junk spark plug supplied with DLE engines, swapped out to NGK. The only other in flight issue was a leaky pressure gauge which was subsequently removed and it's been reliable ever since.
Oh hey, big tip, replace the stock Robart springs with a softer rate spring. I made a two stage spring set like Yellow does in the P-38. The Corsair is my second mod the first was the TF Mustang. Anyway, it makes landings so much smoother. This helps keep you from bouncing on touch down even with the smoothest landing sometimes you bounce up. Check your local hardware store for compression springs that fit inside the strut.
My stack has a rubber bushing, about one inch of the stock spring and the rest is a softer spring. The plane sits with the struts about 1/4 inch from full compression.
Works great, easy to do, check it out.
11-07-2017, 09:25 PM
#467
Join Date: Nov 2014
Location: Southern Minnesota USA
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hi shaun, i made 10-12 flights with my corsair this summer and i have really enjoyed it. i wanted to make another video explaining the upgrades needed to run the FG 90 R3 but that never did happen. i will say that i really am impressed with how solid this model flys and yes i can wiggle the rudder on my model as well but i really did not notice any wagging in the tail. on my elevator linkages in the tail i did screw them way down making them as short as possible so they werent too long acting like a torsion spring.i also epoxied the control rod into the elevator and that took up any play where it layed in the elevator slot. there was still plenty of travel in the elevator and my model flys very symmetrically big loops are awesome and with 35% expo on mid rates she responds very smoothly. chris, thats a great idea for dual rate springs. i have experienced the bounce, bounce, bounce, on landing. also after my 2nd flight i noticed all of the screws were loose on my electric robarts so be sure to lock tite or shoe glue or something on the fasteners. with my FG90 this model is an animal. it is alot of torque and vibration for it and my fire wall did crack by the motor mount box so i added 1/4x1/4 hard wood strips glued in to reinforce it. flying season is over in MN for this year but i am really looking forward to next spring! here is a short video of my model on the 3rd or 4th flight so you can see how solid it flys and there was a 10-15 mph cross wind as well.
11-07-2017, 09:41 PM
#468
Nice video, mine flies much like that, its an animal too! I'm running the RE Mod FG84 and its ripping a Xoar 24x14 at 7400rpm in flight.
Did you use the stock cowl or something else?
I didn't want to have the valve covers come thru the cowl so I used a H9 cowl and modified it a lot to work. I also cut out the firewall and built a new design that allows me to remove the engine, servo and tank in one unit. I have zero/zero thrust compensation and it flies great with no yaw issues.
What's your model tipping the scales at?
Did you use the stock cowl or something else?
I didn't want to have the valve covers come thru the cowl so I used a H9 cowl and modified it a lot to work. I also cut out the firewall and built a new design that allows me to remove the engine, servo and tank in one unit. I have zero/zero thrust compensation and it flies great with no yaw issues.
What's your model tipping the scales at?
11-07-2017, 10:00 PM
#469
Join Date: Nov 2014
Location: Southern Minnesota USA
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i used the fiberglass specialties TF-20-B cowl it was around 60 dollars delivered.i do use the factory off set for the engine and it just clears the valve covers. i have the Keleo exhaust ring and also use their baffles for the FG84-90 and she runs nice and cool even on 95 deg. days. i did add 15 oz. to the tail cone/cover to make C/G so the AUW is right @ 27 lbs. im flying the xoar 24x12 and im not sure of the rpm in flight but it makes 6100 on the ground. i really want to try the 24x10 scale 3 blade prop from aircraft international and will be ordering it @ some point this winter. i bet it would be just right.
Last edited by jagdpanther9; 11-07-2017 at 10:04 PM.
11-08-2017, 11:10 PM
#470
I should weigh mine again, 27lbs seems lighter than I recall. When I flew it with the DLE 55RA it was around 24-25lbs and the Saito plus Keleo ring is pretty heavy I want to say I'm closer to 30lbs.
Anyway, the extra weight is no problem and it wears it well. It's much more stable on approach to land, doesn't tent to float as much as before.
Im going to switch to a 24x12x3 blade too. I'm pretty sure the engine will handle the load given the performance it's showing. I'd like to put a Solo or Vario adjustable prop on it and dial it in.
Anyway, the extra weight is no problem and it wears it well. It's much more stable on approach to land, doesn't tent to float as much as before.
Im going to switch to a 24x12x3 blade too. I'm pretty sure the engine will handle the load given the performance it's showing. I'd like to put a Solo or Vario adjustable prop on it and dial it in.
11-10-2017, 05:38 AM
#474
I store mine in the corner of the basement, out of the way. The tubes and bars do look like an opportunity to snag on something, however.
On another note, can a few of you tell me what engine/prop combos you are using? I am considering some higher pitch/lower diameter sets to speed mine up. Thinking about a 22x12, and a 20x15 AT-6 racing prop and was curious if anybody has tried to go fast and if any flutter was noticed.
Thanks in advance.
On another note, can a few of you tell me what engine/prop combos you are using? I am considering some higher pitch/lower diameter sets to speed mine up. Thinking about a 22x12, and a 20x15 AT-6 racing prop and was curious if anybody has tried to go fast and if any flutter was noticed.
Thanks in advance.
11-10-2017, 07:38 PM
#475
My wings are in a custom bag and the center is stored on the wall.
My first Corsair had a DLE 55RA with a Coar 22x12 and it ran great, very fast, could hold full power and pull tight maneuvers with ease. Also, the plane flies better with a bigger prop. At 20 inches you will need more rpm or power to land unless you carry more speed. If you get low and slow your going to be behind the curve. I had this happen once with another guys H9 Corsair he under propped.
Which engine do you have?
My first Corsair had a DLE 55RA with a Coar 22x12 and it ran great, very fast, could hold full power and pull tight maneuvers with ease. Also, the plane flies better with a bigger prop. At 20 inches you will need more rpm or power to land unless you carry more speed. If you get low and slow your going to be behind the curve. I had this happen once with another guys H9 Corsair he under propped.
Which engine do you have?