Throttle cables to ROTAX 912A2

"As to recommending a type, personally I would avoid Teflon coated cable."

Hi Des,

Please expand on your statement😈

G’day Sean,

I certainly don’t profess any expertise and as I said, as a personal choice, I would avoid them. Others will disagree. In my experience with machinery other than aircraft, PTFE coated cables provide something of a sugar hit with smooth operation when first installed but more quickly deteriorate toward poor performance with the coating wearing and or breaking down causing increased friction and in some cases clogging of the cable. IMHO, a good quality uncoated stainless steel cable properly installed and maintained, will provide a long lasting low friction control.

Peter has been in touch with the aircraft manufacturer so I’m sure he will receive guidance that will improve the performance of the throttle control and comply with the local authority requirements.

Cheers.

Sean Griffin wrote:

I find the McFarlane cables to be unnecessarily stiff - much preferer a lighter duty cable.😈

The McFarlane cables seem to be by far the most popular Rotax throttle cables I have seen on this and other forums.

McFarlane make all sorts of cables for aircraft. 

From my perspective their throttle/choke cables are a carry over from those made for LyCon.

They work but are over-specified for the Rotax range and are over costed for non certified aircraft.

Motorcycle grade cables will do the job just as well (no reduction in efficiency/safety)

You can purchase 2-3 motorcycle grade cables for around the cost of a McFarlane.

Seems to me that where the owner/maintainer has the choice (experimental) many are seduced by the perception of higher quality/functionality from a source promoting their product as aviation specific. Often there is no practical basis for this perception.

To each his own.😈

"......PTFE coated cables provide something of a sugar hit with smooth operation when first installed but more quickly deteriorate toward poor performance with the coating wearing and or breaking down causing increased friction and in some cases clogging of the cable"

Sorry Des, cant agree.

All cables of this type (carburettor/choke/ manual brakes) will wear out. The wear is concentrated on the outside of a bend. A straight cable, not subject to undue dirt, will last for many many years, almost indefinitely.

The biggest problem with cables lined with a friction reducer (PTFE, plastic) is people lubricating them - definite no no! The combination of lubricant reacting with the lining and dust attracted, kills a lined (modern) control cable.

Lubricant on the old style(McFralane?) likly helps the movement of the inner cable. I would still be concerned about the lubricant attracting dust - perhaps a dry lube like graphite may be the way to go?. 😈