ESM F4U Corsair 50cc 85" Wingspan ARF

Specifications from Manufacturer

Wing Span: 85"
Wing Area: 9.39 sq. ft
Wing loading: 44.5 oz/sq.ft.
Gas Engine: 50 to 60 cc
MSRP $699.00 (US) as of 10-2013

Specifications for this built

Gas Engine: DLE 111cc Twin-cylinder with standard mufflers
Elevator Servo: 1 x
Aileron Servos: 2 x
Rudder Servo: 1 x
Flaps servos: 4 x
Throttle servo: 1 x
Air Retracts Servo: 1 x
Air Retracts: ESM (2 for main and 1 for tail wheel)
Main gear Doors Servos: 4 x
Receiver:
Power Management:
Master On-Board Ignition switch
Optical Radio controlled ignition cut-off switch
Receiver/Servo Batteries: 2 x Fromeco Lion 2400mAh
Ignition Batteries: 1 x Fromeco Lion 2400mAh

Overall finish

The exterior finish of this ARF is very good with built in panel lines, mat paint job. The interior is spacious.and the designed servo area will work for most applications. The elevator, rudder and tail wheel use string pull/pull system, You can see more details in the official (ESM) PDF manual at this link.

Changes and modifications

For my particular ARF I perform the following changes and modifications.

Replaced

Replaced all oem links with heavy duty Dubro ball links.
Replaced all air lines wit Robart air lines.
Replaced retracts air valve with Robart heavy duty valve.
Replaced all air line plastic connectors with Robart.
Replaced most hardware with SAE hardware from RTL Fasteners.
Replaced the oem wooden dowels with a larger diameter hard wood dowels.
Replaced the oem wing bolts with larger steel hex cap bolts and blind nuts.
Replaced original main gear axles (4mm) made out of very soft material with 8mm stainless steel studs.

Modified

The original firewall had a left thrust line so some modifications are made to fix this issue.
Re-enforced the firewall "tube" (see manual and fig. 1 and 2) )with extra fiber-glassing. Added also in front of the origan firewall an extra layer of hardwood and everything were tide down with bolts and large "fender" washers (fig. 3). Just wanted to make sure the 111 cc engine will not "depart" from the plane!
Created a hatch on the fuselage belly between the tail wheel and the wing.
Re-finished 2 main gear doors because they were painted and finished on the wrong side!

Figure 1


Figure 2

Figure 3

Engine

This model is specified for a 50cc Gasoline Engine but later on when the landing gear, servos and auxiliary equipment installed to achieve the correct CG I would had to add more than 10 lb. of weight! At that point I decided to use a bigger engine for adding weight on the nose A DLE 111cc twin cylinder gas engine was purchased and installed (figures 4).


Figure 4

Landing Gear

The ES M air retracts look very beefy; at least most of the parts (figures 5, 6 and 7) .

Figure 5


Figure 6

Figure 7

The weak links are the axles and the scissors. The original axles bent after the 1st landing and we manage to straiten them by hand! I replaced them with stainless steel (could not find harden steel of these dimensions) 8mm stand-offs (figure 8). Of course I needed to drill bigger holes on the wheels.

Figure 8

Landing Gear Doors

The package included the 3 piece doors for the main gears and the hardware for the piece that attached to the wheel strut with the number. The 2 main doors had no hardware so I had to create hing points and fit the 2 servos to operate them (figures 9 and 10).