Ron,
I had warned Rotamax about surface coating and substrate issues.
I wouldn't be surprised in any way if this caused their problems.
Pity it's a great rotary engine also, copied from the NSU/Norton engine.
Aixro is a generation ahead of the Norton engine, due primarily to the
NSU/rotor/combustion shape.
George

Not copied from  the NSU or the Norton. It is an almost direct copy
of the OMC engine. Good thing you warned them George. I can now sleep
better :)

Paul Lamar
--


Paul,

You are quite right: The RotaMax engine is sure not a copy of the Norton
engine, which again is completely different to the NSU engine! Actually
the AIXRO engine is very much based on the original Norton design,
further developed by MWE/Diamond Engines. Just look at the swept volumes
of 294cc! AIXRO, Sachs (KC24 and KC 27), Norton, and MWE rotors and
seals are interchangeable when being re-balanced - as long as you don't
account for leading or trailing cut-outs! MWE rotor housings can be
fitted to AIXRO engines just as easily as water cooled Norton housings.
Actually the first lot of AIXRO engines had MWE twin plug housings...

The combustion chamber of the AIXRO rotor for instance is an exact 1:1
copy of the early Norton motorcycle engines, whereas the later Norton
engines and MWE engines had an additional cut-out in the trailing edge
of the rotor flank in order to prevent pinking at high continuous
speeds.


George,

I would be very much interested in the surface coating issues mentioned
as I am currently in the process of trying to establish a salvage scheme
for worn-out rotors, housings, and endplates for Sachs and Norton
motorcycle Rotaries, as Norton Motors Ltd shall be going out of business
before the end of next month!

Having gathered intimate knowledge of the Norton and MWE engines I
unfortunately have not yet seen a RotaMax engine for a direct comparison
myself - in particular as RotaMax have a picture copied from AIXRO on
their homepage nowadays!

Regards,

Martin.

Here are some internal pictures of the RotaMax Martin.

Paul Lamar

Martin,
I stand corrected on all counts, thanks for the clarification.

I replied to the rotary in error as I was send that e-mail to my new contact
Ron Ligeti ( aviation Engineer) who is further developing his fathers
Stratos development - currently microlight.

My limited input has been to suggest engine choices and some composite and
material specs.

To answer your question Martin I'm unsure what other engine developers are
doing, exactly. I can however tell you what some engine developers have done
in the past and are considering. As stated the primary failure mode ( in
development Al. rotor housings) is substrate failure. Mistral for example
has test every known surface finish and they all failed, primarily because
of substrate failure. Some of the very hard coating are fantastic but
brittle, without that appropriate firmness to support the, sometimes very
thin, coatings - fail.

Paul L. has regularly suggested det-gun coatings, I guess for the same sorts
of reasons, while acknowledging it is an expensive process.

Others has suggested the use of silicone particle aluminium used in Piston
Engines successfully. It has been suggested to me that the apex seal tends
to be too harsh on this finish, and they fail.

Mistral has investigated a more dense aluminium to support the coatings, but
I guess that's one of their intellectual property rights. I sure as hell
don't know what their using.

Not being a metallurgist I sometimes ponder over the matrix that
would be a good solution, my latest thought would be a matrix of Al and
ceramic nano particles. The particles themselves would stand up to the wear,
the al would wear slightly below the particles, providing oil retention and
very light particles should mix well with Al providing  greatly improved
density.

There are products out there but only research will identify the more recent
ones.
HTH
George (down under)