flyrotary@lancaironline.net Mailing List Archive

Bobby,

I hear you and agree............Unfortunatly in Dave's and Mark's case they both are grounded

until a fix is in place...........For the average NA 13B or Renesis the RX7 flexplate will probably

give good service as long as it has no prior damage before flight.............But in the case of the

20B (NA or Boosted) and Boosted 13B or Renesis it looks like a fix is in order.............You are

correct that Tracy will address the problem I am sure and a standardized fix blessed by Tracy

will be forthcoming...........

Dave besides wanting to get back in the air is under a time constraint to get in the air and tested

before the middle of September to race in the "Sportsman" class at Reno.............

Kelly Troyer
"DYKE DELTA JD2" (Eventually)

"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold

"TURBONETICS"_TO4E50 Turbo

From: Bobby J. Hughes <bhughes@qnsi.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Saturday, August 6, 2011 10:51 AM
Subject: [FlyRotary] Re: Fwd: Flex plate cracks

The modified aftermarket part my work but I would prefer a "standardized" solution be adopted. In my opinion the gearbox is one item in our unique aircraft that should not be modified. The more hours we accumulate as a group the faster any weak links will surface and be corrected. Three items have been identified within the last two years.

1. Pin size increase. I think Tracy has made a change for new gearboxes. Since I'm running a supercharger I will be sending mine back for an upgrade.

2. Harder rivets in the drive plate. I think Tracy has made the change for new gearboxes. I'll replace mine if /when I see any wear. I painted the area white so any smoke trail (or oil) is easy to see.

3. Flex plate. I'm sure Tracy will identify a solution for existing and new gearbox customers. Until that happens I'll keep inspecting mine every few hours. If the change is a custom RWS part and a few hundred dollars that's ok.

It also appears these items are showing up first / only on higher horsepower installations. Boosted and 20b's. I think we have a good gearbox and as a group we're identifying and correcting the weak areas and making our installations more reliable. In the near term Dave may need a one-off for Reno. Buying, individually machining and balancing an aftermarket part, that will likely be discontinued within a few years doesn't sound like a longterm repeatable solution. Safety in numbers?

Bobby

( no Hushpower II mufflers or overly tight water pump belts either)

Sent from my iPad

On Aug 6, 2011, at 1:03 AM, "Chad Robinson" <crobinson@medialantern.com> wrote:

Cost, availability?

On Aug 6, 2011 12:44 AM, "David Leonard" <wdleonard@gmail.com> wrote:
> And here is a good view showing the thickness.
>
> On Fri, Aug 5, 2011 at 9:41 PM, David Leonard <wdleonard@gmail.com> wrote:
>
>> Well, I'd say that pretty well seals the fate of using flex plates. You
>> guys all owe me a beer for finding the issue :-)
>>
>> Here are some pictures of the machined flywheel that Kelly turned us on to
>> (ACT prolite). Weight is now under 9 lbs. I think it is a good balance
>> between weight and beefyness. Someone with better access to a CNC could
>> make the mods quick and easy, and the mods to that start/addapter plate are
>> pretty easy.
>>
>> Here is the front side.
>>
>> --
>> David Leonard
>>
>> Turbo Rotary RV-6 N4VY
>> http://N4VY.RotaryRoster.net
>> http://RotaryRoster.net
>>
>> On Fri, Aug 5, 2011 at 6:08 PM, Charlie England <ceengland@bellsouth.net>wrote:
>>
>>>
>>>
>>> I was moving stuff around in the hangar today& picked up my salvage yard
>>> flex
>>> plate. Found two 3/4" cracks: down from 9 o'clock& up from 3 o'clock
>>> holes in
>>> the pic. Plate has never flown AFAIK.
>>>
>>> Charlie
>>>
>>>
>>>
>>>
>>> --
>>> Homepage: http://www.flyrotary.com/
>>> Archive and UnSub:
>>> http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>>
>>>
>>
>>
>>
>
>
> --
> David Leonard
>
> Turbo Rotary RV-6 N4VY
> http://N4VY.RotaryRoster.net
> http://RotaryRoster.net