Anti-Rotation-Arm for the Piccolo-Standard FP-Version

The basic idea

The original swash plate driver disturbed me from the outset. Since this has no proper joint, it is very susceptible to torsion (twist). First I tried to insert a correct joint:

This worked better of course, but I knew I could still improve it. Thus I designed and produced a double-sided swashplate driver, naturally with correct joints on both sides. This was the first prototype:

This functioned according to my original concept. Then it was time to optimise the prototype. I in-milled additional recesses for weight minimisation and designed the joints slightly differently. Now the final version looks like this:

              
(click on the images to enlarge)

The function

The anti-rotation arm (ARA) is installed like the original.  But by using the swashplate balls on both sides, it prevents any misalignment of the cyclic functions. Also notice this is further enhanced by the steel pin which now goes through the ARA in addition to the hub.

The installation

The result

I have flown my Piccolo with my ARA fo some time now. The rigidity of the ARA makes the Piccolo less spongelike and it reacts more precisely to control inputs. Another advantage of the improvement must be that the annoying assembly of the original part is omitted!

The production

The swash plate driver is also made from POM Delrin. All three sections are CNC-milled, thus a substantially higher accuracy is achieved than with injection moulding. POM is a stock plastic, which is very often used in the trade for mechanically stressed plastic parts. It possesses extraordinarily good sliding qualities and ideal for machine cutting. As joint pins I use steel pins ø1 x 8mm; thess are the same as those used for the attachment of the main gear.

The advantages

• Proper hinged joints, thereby less resistance    

• No imbalance, owing to their double-sided construction, thereby

• Less vibration, and

• No misalignment possible

• Increased control precision   

• The swash plate is now supported by the ARA and steel pin through the main shaft and it does not hang on the servo arms any more

• Hardly any added weight, only 0.2 grams approximately

• And not least the aesthetics: it looks simply more beautiful!

The technical data