Seafox Retrofit Thrusters

The biggest improvement on the Seafox retrofit is the conversion of the Rule 1100 Bilge Pumps to use a boat propeller. Converting the pumps also cuts down the number of pumps need to 4 while still allowing the 4 degrees of fredom I achived with the 6 Stock Pumps. The propellers I went with are 3 Blade Plastic Propellers made by Robbe and are 50mm with a 42 Pitch. The stock pumps pushed a little over a 1/2 pound of thrust and the converted pumps put out an average of 2 Lbs.

Conversion of the actual pumps can be see in Here in the How To's Section.


The mounts I made for the Horizontal Thrusters are machined from PVC Pipe and Delrin.

The Pump simply slides into the Mount and is held in place with 4 stainless steel set screws.

The mounts are held to the base plate with two 4/40 Screws.

I used counter rotating props to help cancel out the torque of the motors and to keep the Rov tracking straight. The torque really isn't a problem on something such as this but counter rotating props couldn't hurt so I did it anyway.

This is the Lateral Thruster and Mount which again is made from PCV Pipe and Fittings.

The T fitting of the Mount clips onto one of the vertical Frame supports and is screwed in place.

The Prop Shaft on the Lateral Thruster had to be extended to fit through the Frame.

This Pump is also held in place with 4 set screws. The extra holes are to let air out of the mount so there are no buoyancy issues.

Overall I'm really not happy with this thruster because the prop sticks outside of the frame but being a retrofit I really didn't have the room to fit all 4 Thrusters inside the Frame and still keep the props in the location they need to be. This Thruster along with the Vertical Thruster has to be exactly in the center of the Frame so I really didn't have too many options without changing the entire Frame. If I moved this Thruster off center either forward or backwards the Rov would have a tendency to turn rather than just move laterally. I will probably have to put a shroud over the prop for safety sake.

The Vertical Thruster is just press fit into this PCV fitting.

This Mount is screwed to the Base plate with two 2/56 screws.

Here you can see both thruster on the Center Line of the Rov.

The Horizontal Thrusters can also be angled inward to achieve a better turn radius if need be.

All Information, Pictures, and Material is copyright © 1998-2009 by Stephen Thone and may not be used for any personal or commercial purposes without the consent of the author. All rights reserved. The Author makes no guarantees or warranties as to the accuracy or completeness of, or results to be obtained from accessing and using the Information herein.