JC's Planes and Projects

There is no need to go into the details of constructing this ARF. Anyone with a kit or two under their belt will be able to get good results. I will just detail the changes and modifications that I made. To start, I used Dubro nylon hinges on all surfaces instead of the supplied CA-type hinges. I used Pacer Hinge glue to mount the hinges and found it to be very strong and easy to use and clean up. Testing shows that the hinge will break before the Pacer glue will give way. Don't use this hinge glue with Robart Hinge Points as some have reported that it will not set.

I also used a Sullivan tailwheel and bracket. The bracket is very easy to mount and has work flawlessly on three previous models. As with most ARFs, the main wheels are small. I up-sized the mains from 2.75" to 3.25". My grass field can get spongy during peak growing season and larger tires really help. There is ample room in the wheel pants for the larger tires. Since I was using a gasoline engine, I used a smaller Sullivan 10-oz. fuel tank.

The above photo shows a fairly tight tank compartment even with the small 10-oz fuel tank. The CAP models do have short noses! Just behind the firewall the black ignition module is visible. An "L" bracket was constructed of light-ply and lined with latex foam. Velcro straps hold the module in place. In back of the ignition module the yellow covering of the ignition battery is visible.

In this photo is the small black rectangular micro switch with red wires. The red nyrod in back of it is the actuator. A servo pushes the nyrod and kills the power to the ignition. Remote kill of gasoline engines is required at IMAA events and recommended by the AMA. It was necessary to use this method because the MVVS has no choke and I installed it with the idle stop mechanism intact.

Here is the MVVS mounted using the included aluminum mounts. You do not have to re-drill the mounting holes; the pre-drilled holes in the firewall are adequate. I slid the MVVS as far forward on the mounts as possible to obtain 6.125" between the thrust washer and the firewall. Note the red nyrod throttle pushrod. The end of the nyrod has a 2-56 stud onto which a Dubro ball-link is affixed. I could not find a ball-link to fit the one on the throttle lever so I just cut a notch and split the Dubro link. This allows it to slip over the ball. This attachment has proven to be robust on the test stand.

The Bisson muffler fits very well inside the cowl. Note the use of the MVVS exhaust spacer between the Bisson muffler and the cylinder. This spacer comes with the MVVS engine and is useful here to provide adequate clearance between the muffler and aluminum engine mounts. Also note that the fuel tubing to the carb is neoprene. The tubing is routed between the muffler and cylinder and may get hot. Tygon will melt if in contact with the muffler, neoprene won't. All fuel tube connections are secured with small nylon tie-wraps.

Note that the covering has been stripped away below the firewall. It was replaced with a light-ply plate with a hole to allow the spark plug wire to loop underneath the firewall and into the tank compartment where it attaches to the ignition module. I did a lot of head scratching before I decided on this installation. It appears robust and keeps the plug cap and wire pointing backwards for a more attractive cowling.

Working carefully and patiently, you can achieve an attractive cowling job. Of course, start without the plug cap, or even without the spark plug, and it will make positioning of the cowl over the engine easier. You will need to create clearance for the idle stop, carb, cylinder, plug cap and wire, and the switch and charge jacks. I also put two holes on the top of the cowling to access the high and low-speed needles. Spinner is a Dave Brown Vortech 3" unit. You will need a 10mm diameter adapter for the MVVS engine.

The muffler is easily enclosed but will need clearance for the pipes. The photo above shows how I achieved this clearance. Excellent exit area for cooling air is evident. Note the cutout for ignition switch and charge jack. I mounted these items as far forward as I could to keep them away from the RX electronics.

Here is the finished cowling. It is secured to the airframe with 6-32 nylon screws instead of the supplied metal screws and grommets. The screw holes are drilled and tapped into pieces of 1/4" aircraft plywood pieces inserted inside the fuselage. Tap the holes, wick in some thin CA, allow to set, and then tap them again. Note a small hole was drilled in the cowl to accommodate the fuel filler tube. It is just a "T" off of the main fuel line and plugged with a Dubro aluminum plug. After filling, it just snaps back into the cowl.