SSP Helicopter (oz6362)

About this Plan

SSP Helicopter. Radio control helicopter model for .45 power.

Quote: "Hi Steve, Here is my one contribution, the SSP Helicopter. The full size CAD drawing is not quite the same as what was published in American Aircraft Modeler; August, 1972. The drawing is laid out more like I originally drew it, 36 x 90. AAM did a cut and paste job resulting in a 42” wide x 65” drawing and too faded.

I made some changes. The original tail rotor drive belts would slip in the cold of winter, they are now shown at ¼” wide. The tail rotor for a counterclockwise main rotor was changed to the left side, a pusher is more efficient. Also, several different views of the tail rotor were added to clarify the tail rate gyro. The CAD drawing opens slowly, may take up to a minute.

The SSP’s claim to fame is that it set the world’s first FAI altitude record of 198 meters (650 feet) for R/C Helicopters. Dahlgren, Virginia - September 6th 1971. The SSP has gone through many changes over the years and the last update back in the 70’s was the fifth revision.

In the early 90’s I tied to change its transmission cage to be more like side plates which resulted in a flimsy structure. It was set aside in pieces.

I decided to restore to SSP about 3 years ago using as many parts that I could find from the original. It is now electric powered and a pleasure to fly. The current configuration is SSP-6E – yes electric. By today’s standards, this is a 600 size helicopter."

Direct submission to Outerzone.

Update 24/3/2023: Added further articles (2. How to fly the SSP from Aug 1972. 3. Improvements & Developments from March 1973), thanks to Pit.

Quote: "Part II. Learning to Fly the SSP. By Gene Rock.

Flying a helicopter is like balancing on top of a hard sphere on a hard, smooth surface. Staying on top takes constant control inputs, but it can be done with enough practice.

Trimming: Fill the fuel tank and start the engine with an electric starter, making sure the engine throttle is on idle. Use a starter with an rpm range of 2000 to 3000 - a higher speed starter would engage the clutch causing unnecessary wear even though it would start the engine. I like to hold the model above my head when adjusting high throttle; others like to adjust the model by lying on the ground.

After high speed is set, adjust low speed so that the clutch does not engage. Again hold the model above your head and tilt the model fairly rapidly in one direction, then stop suddenly. If the main rotor gyro is functioning properly, it should take 1-1/2 to 2 seconds to become perpendicular to the main rotor shaft. If the interval is less, add weight to the gyro. Yaw the model physically (rotating about the vertical axis). The model should resist your force if the tail rotor gyro is working. Next check your controls. Make sure you have a good grip, as the force can surprise you, especially the yaw control. Have your helper move the stick slowly. If the swashplate is hooked up improperly, or the tail rotor is backwards, don't feel bad - I still make that mistake.

Tracking the main rotor blades can be quite simple if the tips are painted contrasting colors. Use an adjustable protractor or the equivalent to set the collective of the main rotor blades. An 8° setting can be used with the Enya 45 and the Murphy muffler. Start the engine and slowly advance the throttle. Observe the blade tips and adjust until they describe the same plane by rotating -20. When the blades are tracking, lock their setting by tightening the No. 6-32 x 1-1/4 in bolts in the hub.

The next step is to tether your model. Put two stakes into the ground about 50 to 60 ft apart if possible. (Weights can also be used.) Place the model in the center facing one of the stakes. Tie a cord from one side of the main landing gear to one stake and the opposite side to the other stake. Do not allow any slack. This tethering allows the model to yaw 90° on the ground but keeps the cord away from the tail rotor. The model can move fore or aft ± 10 ft and sideways ± 2 ft approximately. The model can also rise 8 to 10 ft off the ground.

Now you are ready to briefly raise your model off the ground. Again advance the throttle slowly. Play with the cyclic stick and watch the main rotor. If there is a wind, try to keep the rotor horizontal or slightly high downwind. Let the model rise off the ground and immediately settle back; if the model yaws, adjust the tail rotor collective by either the pitch arm or the servo linkage. If the tail rotor rate gyro is used, adjust the collective so the gyro remains vertical at operating speed. Remember, make your adjustments for tail rotor collective when the engine is running at a constant speed.

Next, observe the pitch. Add weight just behind the nose-wheel until the model hovers with the swashplate horizontal. The model may hover slightly nose down. it should balance about 1/4 to 1/2 in forward of the rotor shaft. (I have never had a nose-heavy helicopter,) The swashplate probably will be tilted slightly left to offset the tail rotor thrust. Again observe the rotor when applying cyclic, Does it move purely fore and aft when longitudinal cyclic is applied? If niot, rotate the swashplate. My pitch link on the swashplate leads the blades by about 100.

This entire procedure may seem long and tedious, but in time will become instinctive and will not require more than a half hour if you are already familiar with fixed-wing RC flying,

Flying: This is where the fun starts, It can also be an extremely trying time if you have a ship of your own design, for it can take up to two months to debug it. But then, nothing is more satisfying than flying one's own creation. The SSP in the configuration shown has been debugged and should present few problems.

With your model tethered, play with the controls to familiarize yourself with them while the model is on the ground, Try to taxi it. I found it difficult at first to work all four controls simultaneously. Raise the model off the ground occasionally. The easiest way to take off is to taxi to the extreme forward position and apply power - the tail will rise. Slowly pull back on the stick. As soon as the model is horizontal, neutralize the stick, or the tail will drop and it will start flying backwards. Using this procedure, you should be able to fly the model to the top of the tether. This is an exercise to familiarize yourself with longitudinal (fore and aft) cyclic. Since the tether lines are taut, lateral (sideways) cyclic and yaw are stabilized..."

Supplementary file notes

Article.
Article part 2.
Article part 3.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction