Mailing List flyrotary@lancaironline.net Message #66920
From: Le Roux Breytenbach breytenbachleroux@gmail.com <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Ross Redrive Dimensions
Date: Mon, 19 Jul 2021 09:45:14 +0200
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Neil here is a calculator to calculate the proposed tip speed of a prop.


The Ross Redrive is a 2.17:1
at 6500 turning 2995 rpm on flange
68 inch diameter prop tip speed 0.790  Mach   (Maximum performance between 0.8-0.92 Mach.)

I don't no - as you say it is trial and error all the time.

With my set up i walk in the shadow of Ed Anderson as i also has turned the 13B   90*

Just completing the engine mounts (the ears that fit to the steel housings) must still drill the mounting holes.


Fitting the intake manifold and brackets to hold in place


Have find some Barry type rubber isolator that fits in the 40 mm holes

https://drive.google.com/file/d/1gavn548KN1LEamoEMPIsOSJPm3sIrbT3/view?usp=sharing

Le Roux

On Mon, Jul 19, 2021 at 9:12 AM Le Roux Breytenbach breytenbachleroux@gmail.com <flyrotary@lancaironline.net> wrote:

Neil :


Yes, the ring gear is threaded and locked.

I did not loosen it, as it was not necessary for me to do so.

Obviously, it must have right hand thread to tighten at propeller thrust, with the anti-clockwise propeller (pilot side view)

The needle bearings are pressed into a sleeve and the sleeve in the aluminium-housing and the shaft slipped tight fit into it.

The propeller flange locked everything in place, and then there is just enough end play on the shaft.

The shaft must be put into refrigerator and the prop flange into oven to press fit into place.

It must be line-up precisely for the lock pins to match the holes first time. After press fit there will be no chance to rotate the prop flange as it is very tight fit.

 

Included is a couple of photos and video clips for clarity as a photo is worth a thousand words.

 

Here is the steel 12 lug 6 planetary. As always a arm and leg in price

 https://www.ctpowertrain.com/c6-e4od-4r100-new-6-pinion-12-lug-steel-rear-low-reverse-planet-66-on/

Photos 

https://drive.google.com/file/d/1tDiLL85_Q8IzKrTne1vfyVB67y4x4JA-/view?usp=sharing

https://drive.google.com/file/d/1NVoGiYLYWB6VrJKaKEuKqcMrtDIa54s-/view?usp=sharing

https://drive.google.com/file/d/1lf7WUnpI2UUTtgAMaQjH8oSTQFe_70oP/view?usp=sharing

https://drive.google.com/file/d/1zKQwAbq2IXrFb9uGZHNxYdwbnbt1jp4C/view?usp=sharing



Video Clip:


Sent from my iPhone
Le Roux Breytenbach 

On 19 Jul 2021, at 01:24, 12348ung@gmail.com <flyrotary@lancaironline.net> wrote:

Le roux,
                 First Lou Ross was an excellent machinist so tolerances are tight.  I suspect that the ring gear may be threaded and then loctited??  I am guessing in the dark without being unable to sight  "in person" Then in order to get bearings over the shaft, one of the ends must be able to be removed.  I can understand the oil holes to allow movement of oil for lubrication and possibly cooling.  So it appears that Lou assembled the bearings on the shaft and then the final assembly was the prop shaft to hold all together, hence the 3 pins.  Are thrust bearings behind the prop flange or in front of  the ring gear.  How did Lou allow for thrust both ways?
   Without a fixed ring gear the rotation will be less in RPM and counter clockwise.  
You say Ford g/box bits available?  Can you tell me where, as to date no one in the US will answer emails let alone sell me bits?  What is the prop tip speed at 2900 rpm?  Seems high, so must be smaller dia than normal?    Nothing like a guess to be verified in practice.   My experience with P ports is that they do give a little extra HP, but not as much as Paul Lamar often quoted.  However just get flying and then fiddle, or you may never leave the ground -- we all fiddle too much and go by hearsay far too much.
Regards,  Neil.  

-----Original Message-----
From: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thursday, March 18, 2021 9:23 PM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Ross Redrive Dimensions

Neil: I got it wrong the propellor flange and ringgear flange is not the same.
Can’t figure it out ? how the ringgear side flange is stuck to the hollow shaft.Seems to me it has thread that screw in. Somehow it must be locked. I did not removed the pilot bearing as there is no need to do so as it is still brandnew never been used.
The propellor flange has 3 pins that holds it in place after the pressfit.
The hollow shafts needle bearings ,run over the oil holes in the shaft, and there is some holes between them too.


This psru is counter rotating and a 2,17 : 1 ratio.Therefor needs an anti - clockwise prop pilotside view. I am planning to put in just a 6 pinion planet steel casing planetary No other modifications to be done.There is a  6 pin planetary with 12 lug available to drop into the housing.
I believe with the 2  - 44 mm p ports @ 6500 rpm will have sufficient Hp for take off and climb turning the prop at 2900 rpm.
The at “top of climb “ level out and cruise at 2300 prop rpm.


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