Neptune SB-1 Adjustable Ballast

thingiverse

The ThunderTiger Neptune SB-1 is a great boat for modifying, but adjusting its fixed ballast in the keel section can be troublesome. To ease this hassle, you can install an adjustable ballast sled that allows front-back adjustment with a knob located behind the ON/OFF switches. However, I noticed that the knob occasionally comes loose and require a solution. To assemble this sled, remove the side panels and original rod, replace it with a 6mm threaded rod, print the provided .stl file, and glue or weld the terminal panels together. Insert a M6 nut and radial ball-bearing into one half of the terminal panel, screw in the M6 rod, add another M6 nut and tighten it, then attach the other half of the panel. Fasten the terminal to the sub's bulkhead with a wire strap, add the ballast by screwing on the panels and sliding it onto the M6 rod, and finally turn the knob to adjust the ballast position. Remember that this solution is still a work in progress, so pictures and updates may be posted after testing.