Sean Tucker aerobatics in his new Challenger III Biplane

Sean Tucker aerobatics in his new Challenger III Biplane cutting ribbons at KHWY on 5/19/11.

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).

Figure 9

Figure 10

I used an EMS Gear and Door sequencer for scale movement of opening and closing the gear doors and retracting the landing gear.

... to be continued

Lynsel's Bristol Giant Scale biplane

HD Video on Vimeo

This is a great detailed giant scale RC (remote controlled) plane flown in the Tomcats (SCCMAS) air filed.

How To rebuild a DLE 55 cc engine

In the next few days I will complete the rebuild of a DLE 55cc engine after a crash. The only visible damage to the engine is a broken cooling fin and the throttle shaft was sheared off from the carburetor. The plane crashed nose first from a high altitude so even if the shaft looks straight without x-ray or other methods I cannot tell if any microscopic fractures are developed due to the crash.

WARNING:  The following procedure assumes that you have some experience disassembling and assembling engines. If you have not done this operation before seek help from an experience air-modeler who have worked with this type of engine. Also, by disassembling the engine you most likely voided the warranty.

The following parts except the carburetor are replaced as a precaution and probably not absolutely necessary. Due to reasonably priced DLE parts I decided to replace the following parts.

• Complete crankshaft (includes connecting rod) for $39.99
• Both main roller bearings (front and back) for $9.99
• Walbro carburetor due to broken throttle shaft for $39.99
• Gasket set for $5.99
• Screw set for $5.99
• Woodruff Key for $1.49

DLE 55 parts after disassemble and clean

Cylinder and carburetor are removed.

 DLE 55 Gaskets (bottom left gasket not part of OEM gasket set)

The circular gasket is custom made and goes between the carburetor

 and Troy Build Models (TBM) Small Velocity Stack.

Use a pulley extractor to separate the propeller hub from the crank shaft.

From Top clockwise: Reed valve gaskets, Reed valve spacer, spark plug, piston pin retainer clips and reed valve.

1. Remove the spark plug.
2. Remove the 2 bolts holding the carburetor and reed valve assembly. Probably the gaskets between the carburetor, reed valve and engine body will brake so make sure you order a new gasket set.
3. Separate the reed valve  from the reed valve spacer and carefully examine the reed valve petals. Be careful not to break them petals. If any of them are missing or cracked you will have to replace the reed valve.
4. Remove the 4 bolts holding the cylinder.
5. Gently separate the cylinder from the main body. Do not twist the cylinder too much when removing it from the main body because it can catch the piston ring and brake it.
6. Remove the 4 bolts behind the main body and gently separate from the crankcase from the back plate.
7. Using a long socket unbolt the crankshaft extension were the spinner bolt goes.
8. Remove the propeller hub and careful not to drop the Woodruff Key.
9.  With a plastic tipped hammer gently hit the crankshaft from the front until it is removed from the engine case.
10.  Check the bearings (front and back) for smooth rotation. If any "scratches" are identified the bearing should be replaced. They come in pairs so may as well replace both in this case. I like to warm up the crankcase in a toaster oven for 15 minutes at 450 degrees Fahrenheit and makes the bearing removal easier. Use wooden or plastic dowels to remove the bearings from the case without damaging the bearing seats.
11. Install the new rear bearing on the crankshaft. To make the operation easier I put the crank shaft in a zip-lock bag and put them in the freezer for a few hours. Now the bearing should slide much easier in the shaft. Insert the spacer sleeve in the crankshaft.
12. Insert the crankshaft from the rear. To make the operation easier I put the crank shaft with the installed bearing in a zip-lock bag and put them in the freezer for a few hours. I also put the front bearing in the same bag too (for the next step). Now the bearing should slide much easier in the body.
13. Insert the front bearing from the front of the crankcase. If the crankcase is warmed-up in the toaster oven for a few minutes it could make the installation even easier. Make sure the bearings are fully seated.

Pictures and more details of the rebuild will follow.

Ruby's Hawker Sea Fury RC Nitro

Below is Ruby's new Hawker Sea-Fury RC model plane powered by a Nitro OS 120 AX engine. This ARF (Almost Ready to Fly) model is from CMP.

2011 Tomcats (SCCMAS) Airshow

Below is a compilation of images and videos from this years Tomcats aka SCCMAS Airshow.

Some more photos from the event's night flying below:

 

Walter's amazing light show

Startship Enterprise

Startship Enterprise actually flies!

Leo's Tow Cobra

Check out the amazing details of this Bell AH-1 Tow Cobra RC helicopter.

The mechanics are from an Align T-Rex 600E and the fusalge is from Century Helicopters.

Also in a video below