flyrotary@lancaironline.net Mailing List Archive

It could be a ground problem but of course don't neglect the +12 distribution either. If you have electrical glitches big enough to shut down all the avionics you mentioned it could be affecting the EC2 as well causing the violent hiccup. And if it is affecting all these devices it is not a coincidence -- Something Is Wrong and must be fixed.

I got the first clean compile on the new EC2 code but havent completed bench tests in the hardware yet.

The sun gear slip I experienced many years ago was with the old welded gear setup (not pinned) and it did feel very much like an engine miss but not as violent as you describe. The clue that it was the gear was that it only happened at WOT and never at lower throttle settings. I know of no other way to verify it than pulling the drive off the adapter plate and putting eyeballs on it. I've done this many times over the years. Takes me less than an hour if I leave the prop mounted. Having two people helps when doing this.

Tracy

On Sat, Dec 8, 2012 at 3:40 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

I currently have a separate ground from each of the batteries to a Nuckolls “forest of tabs” ground point. Everything inside the cockpit grounds here. Also the fuel pumps and injectors ground here. The coils ground on the center iron. There are separate grounds from each battery to the PSRU plate on each side of the starter. I have considered bringing two separate grounds from the center iron to the batteries just in case there is resistance getting from the center iron to the PSRU plate.

I am also taking all my grounds apart to check for corrosion or anything that seems that it might not be properly bonded.

I am doing this for two reasons. One, I am still getting that occasional “hiccup” that is violent enough to shake the plane when it happens. It is bad enough that I am concerned that it might be bad for the pin in the PSRU. I am also wondering if it could be the PSRU that has sheared the pin and is slipping? Someone on here had that happen and I would really appreciate a description of what that sounded and felt like and also how I could make certain that is not the problem. No, I don’t want to dismantle the PSRU to check it unless that seems to be the only way to check it.

Also, Tracy, how are you progressing on getting the upgrade for the EC-2 that might fix this hiccup if that is what it is? I think you had it done for the EC-3 and were working on the EC-2 implementation??

The second reason for going thru the grounds is that I am having an intermittent problem with my GTX327 transponder, MFD150 moving map, and TruTrak autopilot shutting down. This seems to happen more often when I key the mike on my GNS430W radio, but keying the mike is not required. It sometimes happens just out of the blue. Also most of the time, only the transponder shuts off. Only sometimes does the moving map and autopilot join in the fun.

Everybody tells me that it sounds like a ground issue, hence I am going thru the ground system.

I welcome all opinions and input!

Bill B

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy
Sent: Saturday, December 08, 2012 10:56 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Aeroquip hose

Tying the engine parts together should not be necessary but you still need a separate ground from battery to airframe ground (if metal) and your avionics ground point. Also separate feeds from +12 battery to starter/alternator and avionics. You can Use the starter/alternator feed for coils, injectors & fuel pumps to keep noise down on the avionics bus.

Tracy

On Sat, Dec 8, 2012 at 12:23 AM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Several months ago, after a discussion with Tracy, I ran grounding straps from each battery to the PSRU plate on both sides of the starter mount. I had previously had the grounding strap running between the center iron and the “forest of tabs” grounding block on the firewall. Tracy suggested I move it so the starter amps would not get into the grounding block.

Now I have the igniters grounded on the center iron and I am considering running a ground strap from the center iron to the batteries or trying to tie each section of the engine “sandwich” together by running a wire between them. This would to be certain that the ground is good on the igniters.

Any opinions on this??

Bill B

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Andrew Martin
Sent: Friday, December 07, 2012 8:29 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Aeroquip hose

Bill

As Mark says + make sure you have a ground cable/strap connected battery direct to your starter. Do not expect starter to ground through your engine without problems.
I remember Tracy posting on this issue years ago just a bit hard to find in the archives now.

Andrew

On Sat, Dec 8, 2012 at 7:26 AM, Mark Steitle <msteitle@gmail.com> wrote:

Bill,

You may want to check your engine ground. Starter current may be causing this.

Mark S.

On Fri, Dec 7, 2012 at 5:12 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

I am working on cleaning up my ground system and I noticed that I have
several, 3 or 4, places on my SS braided fuel hose that appears to be burnt
like it had an electrical spark exit from it. I have not found anything in
the vicinity of these places that look like where the spark? would have
jumped??

Has anyone seen something like this and what should I do about it? Do I
have a ground problem in the engine compartment or is this maybe static?
The hoses are covered by SS and are connected on one end to a filter that
has a ground strap on it and on the other end to the fuel rail which is
grounded to the engine.

Bill B

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