Swashplate Ball-Modification
The basic idea
The desire for more precise control inspired me to improve some things on the
Piccolo. I thought that since every swash plate I had seen had a ball joint, it
had to be possible to implement such a thing on the Piccolo. This ball joint for
the swash plate has made the largest improvement in the flight characteristics
of my Piccolo so far.
The function
The ball joint is built into the center of the swash plate. It reduces the
gap between the swash plate and the main rotor shaft from 0.5 mm to a few
hundredths of a millimetre. Also, the axial slop is virtually removed. Thus a
substantially higher control accuracy is achieved compared with the original. In
addition, influences by air turbulence or ground effect are reduced to some
extent.
After three prototypes I finished the final version, which is illustrated
here.
The installation
|
|
The ball joint can be fitted without much
modification of the swash plate. All you need for the installation is
three twist drills of 4mm, 4.5mm and 5mm diameter. The already existing 5mm-hole must be only drilled trough the whole length. |
The result
I flew my Piccolo with the swash plate modification for some time and feel
happy that the optimal solution has been found. This is also often acknowledged
by other happy Piccolo pilots.
This is why all larger helicopters have a ball joint!!!
By the way, I have also supplied some swashplate ball joints to Hornet fliers,
apparently they fit the Hornet perfectly. I have not tried it myself however,
since I do not own a Hornet.
Please visit http://microhelis.homestead.com/index.html,
by John Kallas, for more information.
The production
The ball socket is machined from POM Delrin and the ball is brass. Both
sections are CNC-turned, 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 is ideal for machine cutting. Likewise, brass possesses
very good sliding and lubrication characteristics.
The advantages
Slop from the swash plate to the main shaft is eliminated, thereby
much improving control accuracy
It also fixes the swash plate in the axial direction
The helicopter can be better controlled in the ground effect
The helicopter reacts faster to control instructions
Hardly any added weight, only 0.2 grams approximately
Simplifies hoovering
And the swash plate looks more like a real swash plate.
The technical data
|
Ball-diameter: |
4.6mm |
| Outside diameter: | 5mm |
| Inside diameter: | 3mm |
| Height of socket: | 2.9mm |
| Weight: | approx. 0.2 gram |
| Ball material: | Brass |
| Socket material: | POM-Delrin, white |
