[Graeme Smith]

Here is the assembly sectioned of the attach cone and the tail rotor gearbox.
The idea is that the builder will cut back the boom skin to the last bulk head then the attach cione will slide over the boom skin and the last bulkhead once in place (at a canted angle TBD) the cone will be tightened firm then the existing 3/16" holes (that fix the vertical fin bracket to the boom) will be drilled through to attach the cone, other holes can then be drilled from the outside in, The existing proud pop rivets will need to be removed and the holes countersunk to then be replaced with countersunk rivets.
Once the cone is attached the gearbox can be bolted to it via the opening on the bottom of the cone that gives ample, (although a little tight) space to install the lock wire to the attach bolts. The access hole also allows access to fit the flex coupling that fits on the last TR shaft to the Gearbox.

[Graeme Smith]

---

UPDATE ... we have finished the design, now getting machine quotes here are some snapshots FYI Just for general information, The shaft RPM at 100% RRPM will be 2519rpm, the tail rotor will be 2897rpm

[Graeme Smith]

Here is the latest updated drawings, we are working on getting some quotes for machining so to maximise my buying power the more I can order the cheaper it gets, so far I have 3 orders.

[Jared Hartzell]

Looking good @Graeme Smith ! What's the estimated cost per order and estimated time to install/convert for the average mechanic currently?

[Graeme Smith]

Hi Jarad, thanks for the interest,

I am obtaining costs now for the machining that will probably be available in the next 3-5 weeks.

From some initial costs I put the gearbox upgrade around the USD 6750 plus freight etc but I know if I can order more at the one time that price is reduced. 

That said the only way the TR upgrade works is by deleting the belt driven fan its shroud and the belt driven water pump (replaced with the Stewarts EWP) as that is where the secondary gearbox fits. 

There is a cost there with fiberglass work etc, I have made moulds for my latest conversion and have an experienced fiberglasser who does car racing fiberglass work ready to make the parts, that price would be somewhere near USD 1000 for the outside scoops, (2 off) the upper radiator shroud (1) and the lower radiator shroud (1off) (all 3 USD 1000) plus the electric fan that comes from the USA around USD 100. The fiberglass work can be done by anyone who has a little experience if desired ,as those parts will be bulky thus freight costs will be higher. (the outside scoops are a seperate item from the lower rear panels so the builder needs to cut out the shape to fit the outside scoops to his/her panels, these scoops have an inside protrusion such that they slide into the top shroud of the radiator with a rubber seal, so once the alignment is dine the builder fiberglasses them to his/her existing panels.

Also another electric fan is mounted to the top rear angled tubes of the frame above the final drive area with some aluminium supports (.025" 6061 T6) bent to suit) this fan draws out the hot rising air from above the engine and exits that hot air out via cut outs in the dog box access flap (in forward flight this fan remains off due to the NACA scoops in the forward section of the tub). I will supply photos and templates or make them for the buyer for a little extra.

That all said the end result means, gaining back the fan's running HP (approx 10hp) to fly with and keeping the engine within its operating parameters, with a faster warm up as the electric fan would be off when cold, (no thermostat or bypass needed) then cycle as required with sensors in the output side of the radiator and in flight the fans usually stay off as the forward flight feeds air into the exterior scoops thus through the top of the radiator and out the bottom

So no money needs to be spent on turbo's, or superchargers or higher HP (which brings with them all a higher need for cooling)