RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Paul,

That looks great. I was wondering the same thing about the exhaust. Also, If anyone has a lead for a nice tail hook I'd appreciate it.

I have to sand those CF rods for the bearings as well. It looks like mine did come with everything I needed in the tube department. I agree somewhat about securing the vertical stab but overall I feel good about the stock setup. One thing I was thinking about was the former in the fuse that mounts the stab. With a few years of service small cracks may develop in the fuse where the former is mounted so I may doing something a little different there. I don't think it's a failure point though. All and all this aircraft is going to look incredible. If your out and about the state this year with yours we'll need to hook up.

Ken

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

tail gear/feathers (cont)

Tail gear (cont)
This plane is so big, I've decided to mount the tail wheel gear onto the tail gear instead of running lines to the front and mounting the servo in the usual spot. I'm figuring about 1.5 oz of extra weight but with a big radial up front, I don't think this should be a problem.

pic 1:
I used a re-enforced cut off wheel in a dremel to cut the piece of aluminum between the two lightening holes on the bottom support of the gear. The metal is 1/8" thick so I don't think that I've compromised the structural integrity by removing this small amount of material.

pic 2:
I mounted a Hitec HS-225MG (64 oz metal gear) to some 1/8" thick ply by putting one side of the servo mount on top of the ply and the other side of the servo mount on the bottom of the ply plus another piece of 1/8" thick ply to get the proper angle to the wheel control arm (I also put the brass grommets in upside down on the one side).

pic 3:
I drilled/tapped 4/40 X 3/8" button head screws through the ply and into the aluminum frame.

pic 4-6:
Finished product.
She worked great on a test run with the transmitter.
I used 2/56 screwed ball and socket on one end and 2/56 clevis's on the other end.
To work on the servo mount, I removed the 'C' clip, pulled the pin out and the whole bottom part of the retract swings out for easy access (the clip/pin can be seen in the last picture).

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Service tray.
The CG is 6 1/2" from the LE of the wing so I mounted the kit provided service tray so the center of the tray is in the center of the CG.
Since the fuel tank is mounted on the top side, this will keep the fuel weight centered over the CG.
The sides of the tray taper to fit the inside of the fuse.

pic 1:
I find a scroll saw with an 'easy to remove' top blade the easiest to cut holes in ply.
I drilled holes at each end of the hole and slip the blade in to cut each slot.
These hole slots are to hold the fuel tank and receiver.

pic 2:
I used some 1" triangular balsa stock to hold the tray to the fuse.
One side needs to be sanded to be in alignment with the fuse wall and the service tray.
I had to sand off about a 3/8" taper for proper alignment.
My 8" band sander made quick work of this.

pic 3:
The balsa triangular stock was first epoxied in and then some 1/8" thick ply was epoxied to the triangular stock.
The ply providing the necessary 'tooth' for holding the service tray to the fuse.

pic 4:
Home depot has some nice 6" long velcro strips that interlock with each other to make nice long strips.

pic 5:
A dubro 50 oz tank strapped to the top side of the service tray.

pic 6/7:
Eight hex head servo screws used to hold the service tray to the triangular stock.
I'm using JR's J922 power safe receiver.
I plan on mounting two 6 volt/5000 ma battery packs to the front fire wall.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Service tray (cont)

pic 1:
The ball bearing from Boca arrived today.
It's an exact duplicate of the ones that came in the kit.
You know your plane is large when ball bearings are needed for moving surfaces!

pic 2/3:
I installed the air valve and servo for the functional canopy.
The gear/door air valves are mounted in the center wing.

pic 4:
I also cut more slots to presently hold the three battery packs (two for receiver and one for ignition): if nose weight is needed for balancing, I will move the batteries to the fire wall.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Outer wing (cont)

pic 1:
I wanted to make the outer wing alignment tube removable (for future maintenance) so I drilled/tapped for a 2/56 screw to hold the inner aluminum tube to the outer FG tube.

pic 2:
I used some flex guard split seam covers over the flap/aileron extensions.
HD or local auto store sells the split seam covers.

pic 3/4:
I cut the covers that go on the inside edge of the outer wing.
They go between the main wing sleeve and front hinge.
I believe they are to stiffen up the front edge when they are epoxied into place.
I also believe that comparf put the finished side on the wrong side as I was having trouble getting them to fit until I put the rough FG side showing as in the picture. Even if I'm wrong, they won't be very noticeable since they are on the inside edge of the wing.
I'll be painting them the same green that I used for the cockpit.

========
Making extension wires.
While at a flea market (planes) I picked up some 20 gauge extension wire this week end from radicalrc
http://www.radicalrc.com/shop/.
Most heavy duty wire that I've found is 22 gauge so I thought this would be great for those long runs with big torque servos.
If you want multiple connectors, like molex, you can contact Doug Miller:
[email protected].


pic 5:
The male and female assembly parts come in separate packages and it's a good idea to keep them separated to avoid confusion.
Interesting: the metal connectors that go inside the female plastic houses are male ends (and vise versa).

pic 6:
I strip off about a 1/4" of sheathing and then crimp the two prongs over the bare wire and then crimp the two prongs over the sheathing.

pic 7:
The business end of the crimper.

pic 8:
The 'crimp' side faces the holes as when you push the wires in, there are small plastic hooks that snap down when the metal ends are pushed into the plastic.
The outer plastic cover is then pushed over the inner plastic plug.

pic 9:
One female side done (also showing parts needed).

pic 10:
The male plastic end uses the metal connectors that are female and, as with the female assembly above, push the connectors in until the small plastic tabs snap into place.

pic 11:
Wire stripper from HD.
There's probably a much better description of how to do this somewhere out on the web!

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

inner wing (cont)

Main gear (cont):

pic 1/2:
Here's what I had to cut out of the surface to get the gear to fit.
Two notches are also ground into the side of the wood mounts to allow two large bolts on the gear to pass.
Some of the inner beige sheathing was also ground away and a little of the LE of the wing to get the gear as far forward as possible.
The LE is hardwood so remove very little as I'm sure that is part of the main gear mount support.
note: that one notch on the center, left side is not needed.

pic 3-5:
With the minimum amount of surface material removed, I had to first tilt the right, front side of the gear down, slide the gear forward and also putting the right, back side of the gear down and then, finally, putting the left side of the gear on the wooden mounts.
This had to be done with the retract in the down position.

pic 6:
A black felt tip marks the inside corner of the gear that needs to be trimmed to allow the CF door cover to lay flush on the wing.

pic 7:
Only a 1/8" clearance between the tire and back of the wheel well.
Any door supports cannot be placed in the center of the back of the well.

pic 8:
CF door assembly lays flat.

pic 9:
Corner of gear cut off with a re-enforced cut off wheel.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Sam,

I thought Darrell made those retracts for your specific Corsair and had a deal with Comp ARF to supply the gear to it's customers. It seems to me like he just used the same gear he custom made for mine and decided to pass it on to you. Doesn't seem right that your having to do so many mods just to get them to work. I'd call him up and let him know what is going on.

Barry

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Inner wing (cont)

Main gear (cont)

pic 1:
Right side.
The basic outline to be cut just follows the outside edge of the wooden mounts and across the back of the LE spar.

pic 2:
A razor saw to cut the surface wing and a hack saw to cut the three layers of 1/8" thick ply (some good size quality ply that I'll throw in my scrap box!).
The notches in the wooden mounts for clearance of the gear bolt heads are 1" back from the back of the LE spar.
The inside surface edge has the two notches in the same place as the two mounting holes.

pic 3:
Recess in the beige 'backing' material at the right front in the picture to allow room for the gear.

pic 4-6:
dry fit.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Inner wing (cont)

Main gear (cont)

pic 1/2:
I drilled/tapped #6X32 bolts into the 3/8" ply.
(#8 bolts are a little too large)
The oleos align up perfectly with the wing.
I've got a slight bulge on the top of the wing from the gear pushing down so I'll have to add about a 1/32" thick ply between the gear and wooden mounts. The opposite end of the rotating ball (for rotating the retracts) had to be cut down about 1/8" so it wouldn't hit the inside top wing. Tolerances along the front edge are very close so small shims and/or grinding may be necessary to get a good fit since moving the retracts back means cutting into the back of the wheel well.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Inner wing (cont)

Main gear (cont)

pic 1:
To the right in the picture are the 1/32" thick plys to raise the front of the retracts so the one edge of the retract doesn't push on the top wing surface.
The left retract, outside mount needed an additional 1/64" ply.
As mentioned previously, this includes cutting off 1/8" of the end of the shaft that rotates the gear plus 'rounding over' the shafts end.

pic 2:
I routed the air lines through a small crack by the CF spar.

pic 3/4:
Gear covers dry fitted.
As mentioned previously, there's little spare room between the front of the gear and the bottom wing surface and the doors covering the wheel and oleo.

pic 5:
Notches were needed on the door covers around the hinges.
I finished drilling/tapping into the 3/8" wood for the rest of the gear mount bolts (#6-32).

=============

pic 6:
Also, as previously mentioned, only three screws are needed to remove the outer wing: two on the main folding mechanism and one on the hinge at the LE of the wing.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Engine area

Fire walls
Two kit provided ply fire walls need to be epoxied to the nose of the fuse (one inside and one outside).

pic 1:
The surface roughened up with 80 grit sand paper and then cleaned with alcohol.

pic 2:
The fuse and well as the ply was epoxied and some weights to hold the ply to the fuse.

pic 3:
Epoxy and micro-balls poured around the parameter to strengthen the transition from the ply to the fuse and prevent any future cracks from developing.

pic 4/5:
Fuse put on its tail and let gravity hold the outside ply to the fuse after the epoxy was applied after using 80 grit and alcohol to clean up the fuse surface.

===============
Inner wing (cont)

Main gear (cont)

pic 6/7:
Air tanks.
Some 3/8" thick ply used for the tank cradles and 1/8" thick ply connects the two cradles.
Some holes drilled into the top of the center wing to give the epoxy some tooth to hold the tank cradles to the wing.

pic 8:
A robart large tank velcro'ed to the tank cradle.

pic 9:
A video initial test run of the main gears.
I will need two large tanks for the gears as two cycles on just the mains consumed 30 pounds of air.
I'm thinking two large tanks on the center wing for the mains and tail wheel and one large tank in the fuse for the doors and canopy.

main gear test video:
http://www.rcuvideos.com/video/F4Uco...geartest01-AVI

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

I was missing my rudder hardware and comparf et al (Larry, Andreas and sales) got my hardware delivered very quickly: cool.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Sam,
have you decided on power for this bird yet?

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

I'm hoping for an RCS 250 radial (might as well go the whole 10 yards!).
I don't have too many choices: it appears that any twin engines will have to have holes on each side of the cowl for the spark plugs.
Cowl width is about 12.5".
(wonder if I can get some of that 800 billion stimulus package money!)

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Yo Barry,
I just saw your post (your post was posted just a minute ahead of mine so I missed it).
The retracts looks like they are made for this plane.
There's very little room in the wing for the retracts and since Darrell doesn't have an actual wing to work from, I'm quite happy with the results. The small mods are only minor.
Since comparf puts all the parts into a jig and molds the wing around all the ply parts, just a 1/16" movement while forming the wing can make a difference on how the retracts fit.
With the high quality of the comparf kit and retracts, I am quite happy with the results: this is the best combo set of ARF/retracts that I've ever had (especially with a 'one of a kind' folding wing: which Darrell also made). I think we'd be 'hard pressed' to find such quality in another manufacturer's kit!

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

ORIGINAL: samparfitt

(wonder if I can get some of that 800 billion stimulus package money!)


I think I saw a provision in there for your radial on page 892, paragraph 3, subsection 2c, yup, there it is , RCS 250 for your Corsair.

Looking good !!!

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Sam,

I got lucky and bought a 3W 200 cc twin for mine and now they discontinued it. It was the narrowist twin I could find in that size of even down to 150 cc. With my cowl being about the same as yours I have room for the plugs and leads. There is about 1/8" to 3/16" clearence on each side. If your cowl is 12.5 inchs wide it would work if you could find one NIB for sale. Although I wish I could of afforded the radial but just couldn't and still can't swing the extra dow. The sound alone of the radial makes it worth the extra money. Oh well so much for the sound of mine. Beleive me I think Darrell is a master at what he does but I thought you were having more trouble with the gear than you actually were I guess.

Barry

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Center wing (cont)

Gear doors:

pic 1:
My scroll saw did a nice job on cutting the doors out of the CF panel.
I used a black felt tip to outline where I wanted to cut so I didn't accidentally cut along the wrong panel line and set the scroll speed to the slowest speed possible.

pic 2:
Since the door panel assembly is three dimensional, I used a 3/4" thick block of oak to hold the panel off the scroll table but still kept the panel from chattering.

pic 3:
I used metal cutting blades but went through seven blades as that CF wears the teeth down quickly.
I could only cut about 6" before the blade was 'shot'.

pic 4:
The CF panel assembly over the wheel well.


pic 5:
The manual indicates that only the front part of the panel assembly is suppose to be used to cover up the retract mechanism.
I may opt to use the whole panel as the CF outline is about an 1/8" larger hole than the wheel well and this would give a nice lip for the doors to rest against in the closed position.

pic 6:
With the three door covers.
The two side doors will be fastened using the kit provided hinges.
The front door will be hinged at the front to the panel and a rotating brass wire will hold the top of the door to the front of the oleo.

pic 7:
There would be a edge showing along the wing but I may be able to bevel sand it so it's not noticeable.
The outside edge won't be noticed since it aligns with the edge of the wing.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Sam,

Did that panel come with the kit? If so it was good thinking on Comp's part.

Barry

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Barry,
Yep, the panel is kit provided.
The whole back is all CF so there's no chance of these babies warping (or breaking).
Because of all the CF, that's another reason I'm considering using the whole panel that surrounds the doors: Everything would be extremely strong. Another reason for using the whole panel is that all the doors are raised another 1/16" from the surface of the wing: with tolerances so close, the extra 1/16" would be a nice buffer from the retracts. The panel is also on the bottom of the wing, which will never be seen.
Scuttlebutt has it that the comparf owner is from Germany but now lives in Thailand: With the owner being at the plant every day where the products are produced, I'm sure he has tremendous control on keeping quality control very high plus it makes it much easier and faster to make changes/updates/improvements in the product.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

COOL!!!

Barry

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Center wing (cont)

Gear door assembly (cont)

pic 1:
The two black felt tip lines (panel lines) are where I am cutting to separate the front, removable door assembly from the back, non-removable door assembly.
The front door assembly needs to be removable for gear maintenance.

pic 2-4:
I've now got both gear door covers cut in all the pieces required for assembly.
After cutting everything on the scroll saw, I manually sanded all the straight sides on my 8" belt sander and used 80 grit tacky sand paper on a paint stick to sand the rest of the sides.
The CF comes off quickly so no power tools are needed for sanding and manual sanding gives better control (always easier to take more off than add it back on!).
I labeled all parts to avoid any confusion.

pic 5/6:
I used masking tape to align the front door to the front cover, and, then used a #54 drill bit to drill holes into the CF and, finally, used #0X3/16" screws to hold Dubro's heavy duty hinges with cotter pins (#257) to the door and panel.
A notch was cut in the door for the hinge pin location.
In the manual, it appears that the front of this panel was cut off: I'm keeping this panel as one piece for two reasons: 1) the screws holding the hinge to CF is very strong so the screws won't pull out, and 2) the front edge gets 'butchered' in order to get the retract in the wing (see pic 7) so the panel, as one piece, will cover this up.

pic 7:
A notch in the front of the wing is needed for the hinge which allows the panel to lay flush on the wing.

pic 8:
The front removable panel was screwed to the wing using ten #2X3/8" screws: most of the screws were put where there is ply under the wing.

pic 9:
The panel will have a more visible edge along the front of the wing but I don't think it'll be very noticeable when painted and viewed from the top.

pic 10:
The difference of a 'spot' on the gear cover directly over the oleo mount moves about 1.5" from the UP to the DOWN position so I'll have to work on the best way to attached the door to the oleo without binding.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Center wing (cont)

Gear doors (cont)
Well, it's 1:30 am here: was too close to getting the front door resolved to 'hit the rack'.
It'll took quite awhile to figure out how to get a flush closing door.
The retracts come with two 4/40 bolts screwed into the front of the oleo.
There's only about a 1/2" of space between the bolts and the surface of the door: too close for any connection between the two so I found a location on the back side of the oleo using a brass 'L' bracket.

pic 1:
Here's the brass L bracket: the two holes are for mounting on the front of the oleo and I put a ball socket on the side.

pic 2:
Front view (gear down).
As you can see, I had to drill three sets of holes before I found the correct spot for the front door control horn location.
The lower right is the final location (will be putting two more #0X3/16" screws to hold the control horn to the front door).

pic 3:
side view.
I soldered some brass wire to the ball socket and connected the wire to the control horn on the door.
Actually, the control horn is half of a sonictronic hinge: I like using them as the thin arm flexes which allows me some 'wiggle room' to get a tight door fit.

pic 4:
In the UP position.
I'll be putting some light ply as a lip along the sides of the wing to give the front door a place to rest: The lip will also allow me to put a little stress on that flexible control horn arm to get a good tight fit.

ps: after looking at the picture, I may have to make a new bracket that is U shaped and put another ball socket and control horn on the other side of the door to keep the wind from racking the door when it's in the down position.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Center wing (cont)

Gear doors (cont)
Today, I got the left side front door panel assembly done: just a mirror of the right side.

pic 1/2:
Masking tape to keep the front door and panel in alignment with each other while the dubro hinge was screwed on.

pic 3:
The brass bracket with ball link screwed onto the oleo plus the front panel screwed onto the wing.

pic 4:
Down position.

pic 5:
Control horn/ball link assembly.

pic 6:
UP position.

pic 7/8:
On the right front door/panel assembly, I epoxied some 1/16" thick ply to the panel (center/right in picture) so the front gear door can easily be flush with the panel in the UP position.
I was thinking that I would need a lip on both sides but one seems sufficient.
The sonictronic hinge for a control horn is working nice to keep a little tension in the UP position when resting on the 1/16" thick ply lip.
Also, the front door seems pretty firm with only one control horn so, presently, it will stay that way.
On the left bracket, I made it 'U' shaped and drilled a hole on the opposite side to save time if I have to add another ball link.

RE: COMP ARF 110" F4U ARF WITH FOLDING WING ASSEMBLY
 

Center wing (cont)

Gear doors (cont)

pic 1/2/3:
Now that the front door installation is complete, I can work on the back two side gear doors.
I'm still opting for using the CF parameter panel with the back side doors.
The negative is that I'll have an edge showing on the inside (see pic 3) as well as along the back but no one will ever see it.
The positive is that I can attach the doors to the extremely strong CF panel, I can install the doors at the work bench and any future maintenance can also be done since I'm also opting to screw the panel to the wing versus gluing it in place.
Another positive is that since the hole in the CF panel is about an 1/8" larger all the way around the wing hole so I get a natural lip to hold the doors in place in the closed position.
Having the doors rest on the wing also gives me another 1/16" that the doors are away from the oleo where the tolerances are very close.
Also, in the future, if the wheel should start touching any edge, I can remove at least 1/8" of wing material that forms the the lip.
I first taped the outside panel to the wing.
I then used a felt tip marker (using my finger as a guide) to draw a fine line along the edges that needed sanding so I'll have about a 1/16" gap between the doors and panel. I used the wood paint paddle with 80 grit sandpaper to manual size the doors to the panel.

ps: not sure why I'm making the door edges so precise: I'm the only one that's going to see it!