Mailing List flyrotary@lancaironline.net Message #53648
From: Bill Bradburry <bbradburry@bellsouth.net>
Subject: RE: [FlyRotary] Re: Most stupid question here ever...rotor position
Date: Wed, 26 Jan 2011 14:16:13 -0500
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

Mark,

Yes, I got my contactor from B&C here..

 

http://www.bandc.biz/intermittentdutystartercontactor.aspx

 

it has a built in spike suppressor diode in it.  However, I am also using the solenoid that came on the starter, and I don’t think that there is a spike suppressor diode on it.  I will have to look as I can’t remember.  Is your set up much different from this?

 

Bill

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Wednesday, January 26, 2011 2:06 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Most stupid question here ever...rotor position

 

Bill,

 

I take it to mean the solenoid, not the motor.  Here is Tracy's post...

 

<quote>

Basically, anything that has an inductive load (relay, solenoid, etc) and is switched on and off should have a diode clamp unless the something about the design requires none.

 

BTW, aside from the diode clamps, all those relays and contactors introduce more possibilities for routing problems in electrical systems.  Yes, I know the theoretical reasons for having contactors and relays in aircraft but I didn't use any at all. 

 

Electronic engineer's mantra:

Every wire is a resistor.
Every wire is an inductor.
Any two wires are a capacitor.
Any two wires are a transformer.
None of these components show up on a schematic.
All of these components affect circuit performance.
Nobody gets engineer jokes at a cocktail party.

 

Tracy


<end quote>

 

Mark


 

On Wed, Jan 26, 2011 at 12:07 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Mark,

Are you talking about the primary of the starter solenoid?  Mine has diodes across the primary.  Isn’t that supposed to catch the spikes??

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Wednesday, January 26, 2011 11:05 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Most stupid question here ever...rotor position

 

Chris,

 

Yes, overthinking problems is easy to do.  I typically lean toward underthinking problems.   

 

I was going to stop by on Saturday, but I experienced a corrupted MAP table incident just prior to departure.  It didn't dawn on me initially what had hapened.  But as soon as I looked at the map table I knew that it had been corrupted.  I reloaded the factory table and it fixed the immediate problem.  Now I just need to figure out why it happened.  Tracy suggested it may be a spike eminating from the starter solenoid. 

 

Mark 

On Wed, Jan 26, 2011 at 9:47 AM, Chris Barber <cbarber@texasattorney.net> wrote:

Mark,

 

Thanks.  That is what I was thinking but then I started over thinking it.

 

Now I can focus on the other tasks at hand.  Again, I believe it to be timing related.  When I turned the CAS, retarded I think (clockwise), it seemed to crank a bit better on B.  So, like I said, I may be a tooth off. At least it is a starting point.

 

Isn't this fun.......:-\

 

Chris


From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Mark Steitle [msteitle@gmail.com]
Sent: Wednesday, January 26, 2011 9:06 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Most stupid question here ever...rotor position

Chris,

 

The rear rotor will only fit one way as dictated by the eccentric shaft, stationary gear and rotor housing.  So, don't disassemble the motor again... unless you just need something to do with your spare time.

 

Mark

On Wed, Jan 26, 2011 at 8:50 AM, Chris Barber <cbarber@texasattorney.net> wrote:

This may be the most stupid question posed on this site. 

 

Ok, first the update on my loss of compression in my rear rotor housing.  I tore open the engine and everything looked really good, except, as expected, the springs for the apex seals had been flattened.  Upon reflection, I also remember removing the rear spark plug a while back and recall I replaced it due to the plug removed looked damaged.  At the time, since the engine seemed to be running ok (event though difficult to start), I didn’t think too much of it.  However, now I realize that it was a clear indication of detonation.

 

Seems like a no brainer now, but sometimes I gotta be hit across the skull with the obvious.  Flame suite on but in the tradition of John Slade, I do wish to post my failures to help others learn and to hopefully finally get it.

 

Anyway, I got everything buttoned up and got it to start last night.  I reset all the EC2 parameters to the factory defaults. It did not run well.  I could not even get it to start on the A computer, and it started after a lot of extended cranking on the B computer.  It did not run great on B.  My suspicion is that the timing is off.  The B computer was tuned a long time ago and has not been updated.  I plan to do a static timing check this evening if I can get out to the hangar.  I have gotten that process down pretty good now.  I think I may be off a tooth on the crank angle sensor.  I think a combination of a lean mixture and bad timing may be the predominant factors in my detonation problem.  I had a friend point out the obvious in that the pinging I may have thought I would hear would not be too likely with the noise of the prop.  DOH!

 

I did do the EC2 check and the injectors are clicking dutifully and I saw strong spark on all plugs.

 

Ok, here is the stupid question and a major bonehead moment.  I remember that you must “ clock “ the rear rotor to the front rotor when installing them.  However, when I installed the rear rotor the other day I placed it where I though it needed to go base on when I removed it, however, I can’t remember now if I actually got it back in the right position in relation to the front rotor.  I was thinking it is only gonna fit one way based on the position of the e-shaft to the chamber walls.  Is this so, or could I have it out of position?  I am having visions of me getting it to start with the rear rotor out of position, thus only running on the front rotor while banging the hell out of the rear rotor.   Would it even start if this were so?

 

If I gotta tear it down to check, I will and as mentioned, cracking open is not all that big a deal anymore.  Other than this obvious brain fart, I am understanding the process much better….rote practice does this.

 

Thanks guys/gals.

 

Chris Barberfly

 

 

 

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