Minimizing The Toilet Bowl Effect On Your Syma S107 Helicopter
What is The Toilet Bowl Effect? (TBE)
The Toilet Bowl Effect can be a problem experienced in flight
susceptible to every coaxial RC helicopter available, not just the Syma
S107 Infrared Helicopter. As the title of this page suggests, a coaxial
'copter that experiences the toilet bowl effect will somewhat, behave as
if it had been caught up in a vortex or such as when flushing a toilet.
The symptoms, are that of large circular movements whilst hovering, NOT
of rotation about the axis of the heli.
The latter effect is due to yaw problems and cannot be fixed by the methods described below
The Problem Lies With The Balance Bar...
There are many alternative, (and incorrect) theories behind the causes of toilet bowl effect on micro coaxial model helicopters, however only one - the upper section of the rotor head, probably the fly bar pivots but potentially the top blade pivots. Please note the lower rotor has nothing to do with it and under no circumstance will cause TBE. Un-balanced blades, incorrect blade tracking, and improperly balanced balance bars also have nothing to do with and do not contribute to the toilet bowl effect.
What does the Balance bar actually do?
A very basic explanation of what the balance bar does is it
automatically corrects the pitch angles of the rotor blades to stabilize
the helicopter if it is pitching or rolling giving an almost live
feedback to provide great stability.
In other words the fly bar is responsible for this "self correction" and for it to do its job correctly, it has to apply a change in angle to the rotors at precisely the correct time.
The Flybar is stiff and binding on the pivot points in the head or on the ball links going from the flybar to the rotors. The balance bar should be able to move freely with almost no resistance. It should only need the slightest touch to move it to its extremity. If the fly bar encounters resistance, then there will be an ever so slight delay in the auto correction of the rotors pitch. This will in fact cause, you've guessed it, TBE. Make sure the fly bar pivots are well lubricated with a silicon spray lubricant. DO NOT use water or petroleum based lubricants such as WD40. Using these will result in dust and dirt being attracted to the pivot joint and in the long run exaggerating the toilet bowl effect, not curing it. The other thing is when the two halves of the pivot are molded, often there is a seam where the two halves were joined. This seam can bind, causing unwanted resistance. If this is the case, then using Emory paper, smooth the joint down to reduce friction before lubrication.
- Syma S107 Helicopter Problems & Solutions
Common problems and fixes to help trouble shoot the Syma S107 micro coaxial helicopter. Including tips and hints to fix the notorious Toilet Bowl Effect...