----- Original Message -----

From: Russell Duffy

To: Rotary motors in aircraft

Sent: Sunday, January 01, 2006 6:45 PM

Subject: [FlyRotary] Single rotor running- Tracy questions

Greetings,

 

Below are two days of log entries.  The first will be a repeat, if the message I sent to the list 24 hours ago every decides to show up.  Hopefully this message won't also go into the void that intermittently appears to exist between Bellsouth, and Lancaironline.

 

Tracy,  on my older versions of the EC-2, there were two default settings.  One was setting everything to zero, and the other was setting it to what you have on the RV-4.  I looked through the new manual at the hanger yesterday, and again today, but just couldn't find the procedure to set the EC-2 to your settings.  There was only the mention of setting to the zero defaults. 

 

Now it's possible that I missed it, but I did find my old cheat sheet for the procedure, which was basically the same, except turning the cold start switch on when doing the reset.  In retrospect, I did this on mode one of the the A controller just before noticing that the A controller seemed dead.  Is this procedure for setting the defaults to your values no longer valid, and did that cause the A controller to wig out for a while (mentioned in the log)? 

 

Also, I think I've mentioned this before, but I'd REALLY prefer to have the manual for the EC-2, and EM-2 in electronic format.  I could search for this default setting question, rather than having to read through the whole manual (quickly, and probably missing what I'm looking for).  I could also easily print a copy for the hanger, and home, rather than having to shuffle a bunch of paper through the copier.  I would venture to guess that almost everyone on this list would feel the same way.  Is there any possibility of posting these manuals on the web page?  You could change the revision number when new features are added, and put the date they were added. That would let people figure out

 

I'm hitting send now.  Let's see if it shows up.

 

Cheers,

Rusty  (1-1-06 5:45 pm)

 

 

 

12-31-05 

 

Made the first attempt to crank the engine today.  This turned out to be a good news/ bad news event.  The good news is that it fired up instantly, and everything seems to work.  The bad news is that it’s rough as a cob :-0

 

It would appear that my worst fears about the torque reversals with the RD-1C drive have come true.  I didn’t notice the rpm, but the engine barely made it over the speed the starter turns it.  In fact, the starter stayed engaged a couple times, because the engine didn’t accelerate enough to push the gear back.  Did I mention that’s it’s rough :-)  It just shook the living crap out of the plane, but the engine mounts work well. The main gear of the plane was actually jumping slightly off the ground.  Good thing I was sitting in the plane, or it really might have been interesting.  

 

While the engine was running, no amount of throttle changes anything.  It’s simply impossible for the engine to accelerate out of this mode.   BTW, this is EXACTLY how the 912S used to behave on this plane.  If you didn’t crank the engine with enough throttle opening, it would get stuck in the gearbox shaking mode, and the best thing you could do was shut it down, and try again.  Rotax came out with a  “slipper clutch” to eliminate the problem on the 912S.    

 

Next step will be to remove the prop, and try it that way.  Eliminating the rotational mass of the prop should make it better, if not eliminate the problem altogether.   If that works OK, then I may have to try a different hardness of rubber dampeners on the redrive thrust plate.  If it doesn’t work, then I’ll likely pull the drive itself off, and try it that way.   

 

1-1-05

 

Much better today.  It appears that some dumbass marked my pulley wrong :-)   Tracy says to put a new mark on the pulley that's 35 degrees BTDC, and set the static timing to that.  The RB pulley has 4 equally spaced marks on it- 10 ATDC, TDC, 10 BTDC, and 20 BTDC.   Realizing that these are 10 degrees apart, I measured the distance, and then figured out what one and a half times that distance would be.  This new distance would be 15 degrees, and if I put it beyond the 20 BTDC, I'd be at 35 BTDC.  Unfortunately, when you have the pulley turned around backwards on the workbench, and put the new mark on the OTHER side of the existing marks, it becomes 25 ATDC.  When I set the static timing, I set it to my new mark, which I "knew" was right, so the timing was retarded by 60 degrees.  Amazing it ran at all.     

 

The good news is that it runs much better now, even with the prop (didn't try without it).  There is still going to be a resonance issue with the redrive I believe, as there are a couple RPM's that go into the same rattle mode that I used to get around 1100 RPM on the 13B.  The worst was around 2400 RPM, and it also seemed rough around 3000, but not as much rattling.  I didn't run over about 4000 rpm, or more than a few minutes,  since I suspected I still had a bit of an oil leak, and didn't want to make too much of a mess. 

 

There was oil leaking at the fitting on top of the front housing, which I use to feed the redrive.  This is really a metric fitting, but 1/8 NPT seems to fit well.  I ended up removing the fitting, and installing a new one, with some miracle gray RTV for good measure.  Unfortunately, it leaked plenty during my few minutes of running.  I had the plane tied to the wheel of the company van, and it is completely covered in oil.  I do mean the whole van, not just the wheel :-)   I bet it's really only a half pint or so, but it sure got spread around by the prop. 

 

I also had an odd case where the A controller seemed dead.  The injectors wouldn’t click when I pushed the set button, and the engine wouldn’t fire.  The B controller worked normally, but switching to A while running killed the engine dead.  After I turned everything off,  checked for leaks and such, then turned it all back on again, the A controller seemed to be working fine.  It’s now as if there’s no problem at all.  There's a long time before I could ever consider flying the plane, so I'll just watch to see if this returns.

 

I need to finish eliminating the leaks, then run it enough to purge any air from the cooling system, and verify that all is well as far as cooling goes.  At that point, I can give auto tune a try, and then see if I can make some sense out of the torque reversal induced vibrations.