----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----
This message was automatically forwarded
on behalf of Bill Bayne. Please address any responses to the mail list or
directly to Bill at: [EMAIL PROTECTED]
From: William R. Bayne [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 08, 2006 4:44 PM
To: Ed Burkhead
Subject: Re: [COUPERS-TECH] C75-12 vs. C75-12F
rlytech
Dear John,
As you already knew from the following sentence of my email, I was referring to the crankshaft. Sorry if anyone was truly mislead by the typo.
You can't clarify points not thoroughly researched by reading ESM 28 (as I suggested).
On Feb 8, 2006, at 09:54, John Cooper wrote:
Just for clarification...
At 12:23 AM 2/8/2006, WRB wrote:
The later "flanged-shaft" design incorporated the rearI suspect a typo here. Crankshaft is undoubtedly what was intended.
propeller mounting flange as part of the crankcase.
interesting choice of words, "front face." (In our case, the "face" of the prop is the "back" side facing the pilot. The "back" if a prop [blade] is the cambered side.)
If prop "forward face" (per Erco) and "front face" are synonymous in restating 2.2. of ESM 28, my words merely restate those Erco chose, presumably in the interest(s) of clarity. Erco was writing for owners (and their mechanics) in the field, and not prop manufacturers ;-)
"casing?"
Well, to pick nits, a crankcase COULD be referred to accurately as a "(crank) casing", but most likely a dropped "T" in "(engine) "casting". Sorry.
It's not clear here which engine has the larger dimension. The flanged crank version has the prop mounting face moved 27/32" forward relative to the face of the hub on a tapered crank.
Is it not absolutely clear that if you move the prop forward such distance as to require a longer spinner, per ESM 28, then the flange shaft engine increases the length of the then-necessary spinner (and the length of the plane)?
The current spinner is the same for both. The backing plate differs between the two cranks.
The backing plate differs because the rear hub mount differs. Aluminum props are manufactured to accept the flange shaft crank hub bosses, and spacers adapt these props to fit taper shaft installations. The "current" spinner is a flange shaft spinner (or its successor with an additional front mounting bulkhead), which must be trimmed to fit taper shaft installations.
Regards,
William R. Bayne
<____|-(o)-|____>
(Copyright 2004)
--
John Cooper, A&P
Skyport Services
============================================================================== To leave this forum go to: http://ercoupers.com/lists.htm
