A K7NV Prop Pitch Rotator is a completely rebuilt aircraft Propeller Power Unit (as described in the "About Prop Pitch Units" pages).
This is true for both new and used units.
The scope of each rebuild will vary with the condition of the unit. Unused or virgin units are generally more straight forward. Units that have been converted by amateurs and been in service are often much more difficult to rebuild.

Every part in the gearbox and motor is disassembled down to the last part and then all parts are cleaned, inspected, and prepared for maximum corrosion resistance before being reassembled. The rebuild process used to convert a prop pitch into an antenna rotator is proprietary, taking about 50 hours, and is the result of 23 years experience and process development gained from rebuilding nearly 50 prop pitch units that included all four of the common prop pitch sizes.

All bearings that can be replaced are replaced with high quality sealed bearings.

The top end gearbox seal, if in good condition is reversed to be in the proper orientation to keep moisture out of the gearbox. If the seal is not useable, the case is machined to accept a modern seal.

A new seal is molded into the top case where the splined tube exits the gearbox. This seal is compressed when the bevel gear is installed on the splined tube.

An o-ring seal is installed in the adapter plate which seals against the bottom of the bevel gear to keep water out of the thrust bearing under the bevel gear.

The external parts are sandblasted and primed and painted with an industrial enamel coating.

All internal parts are bead blasted to obtain clean bare metal surfaces and then treated with a special corrosion prevention coating. After this is cured the gears and open bearings are packed with a waterproof “lube for life” rated grease.

The standard prop pitch fasteners are replaced with 18-8 stainless steel fasteners and heavy duty zinc coated fasteners are used for the mast clamp and mounting in the tower.

The rebuilt K7NV rotator is a “better than new” prop pitch that is ready for many years of trouble free service.  Rotators can be supplied from prop pitch units in my inventory or customer furnished units can be rebuilt.



The photo below shows a customer furnished small prop pitch that was sent in to be rebuilt. This customer had one in the tower that had died and this one was his spare (supposedly the good one).




This photo shows the 45 parts from the original ugly gear train after they had been cleaned up, bead blasted and treated with a corrosion prevention coating. And, the 10 new bearings all ready to be reassembled with new gaskets made to seal the case.


The Gearbox case halves and motor retaining ring have been cleaned, sandblasted, sealed, primed and painted. The lower ring gear has been reinstalled in the case.