Rotax RPMs

Phil wrote:
On Nov 29, 3:47 pm, (Paul Tomblin) wrote:
In a previous article, said:

A quick Google search yielded this info on the engine used in the
Remos:
http://www.rotaxservice.com/rotax_en...ax_912ULSs.htm
Ok, I'm a little embarassed that I couldn't find that info myself.

Is a reduction gearbox seen as a reliability problem, or isn't that such a
big deal any more?

--
Paul Tomblin http://blog.xcski.com/
"Oh my G'Quan, they killed Koshi!" - Citizen G'kyle, Babylon Park

I don't think anyone really knows the reliability of this engine and
gearbox. It hasn't been in service long enough. I have been training
behind one in a Flight Design CT, and it is not a noisy engine at
all. When I watch a CT take off I am really struck by how quiet the
airplane is. Also the engine has altitude-compensating carbs, so
there is no mixture to mess with. In flight the engine is very
responsive and smooth. I know a lot of people are put off by the high
rpms, but if the engine is designed to run at those speeds I am not
sure that is really a problem.

I'd like to get some more information on this.
The Rotax 912 has been in production since
around 1992 and the 912ULS since 1999. Should
be information somewhere.

I've heard that thousands of them have been
sold for drones and unmanned aircraft of various
types.

My one comment on the gearbox is it has a harmonic resonance vibration
at about 1800-1900 rpm (taxi speeds) which is very noticeable. I try
to avoid that, and bump it up to about 2000, and it's nice and smooth
there.

Yup. That's why there's a yellow band on
the tach. I try to never run my engine there.