Hello all,
The Ballast tank system that I have been using of late is what has been called the "Sheerline system". It is the 12v car wind screen washer pump forcing water into a sealed pvc pipe tank, using the simply but effective servo pinch on a nitro tube. It is a system that is slow to dive and surface, but very reliable. I like the fact that you expend the energy to dive and surfacing is just the release of the built up energy. The pressurized air inside the tank pushes the water out to surface.
I build my tanks of PVC pipe and it is forward of the cylinder. If there is a leak or other problem with the tank it will not affect the cylinder. I have cut a 70mm PVC pipe and found two thick 70mm end caps. I then took a flat section of PVC sheet from a down pipe funnel and cut a semi-circular slosh baffle out of it to fit in the middle of the tank. I drilled a hole in one end cap in a corner that would act as the outlet for the
Silicon pipe coming from the cylinder. I took a length of nylon plastic pipe to use as the internal pipe leading to the pickup at the bottom of the tank. This was bent at about a 45 degree angle and just touches the bottom of the inside of the tank near the middle next to the baffle.
All this has been glued in using green Plumbers pressure glue. This stuff is designed to seal PVC pipe under pressure. The internal plastic pipe connects to a 4mm barbed off take.This is glued and allow the silicon pipe from the cylinder to connect. I then cut out some strip of PVC and bent it to make two brackets that are glued to the ends of the tank. In the flat section I drilled a 4mm hole to take a stainless steel bolt.
I then cut some strip fibre glass sheet and glued it to the sides with some resin and cloth. Once glued down I drilled a hole in the middle and then bolted down the tank.
It has taken a bit of time to make dozens of fine little adjustments to aligning the shafts to the outputs from the cylinder. Aligning up the magnetic couplings for the pushrods is also something that
has taken a bit of time. I placed lead in positions that are similar to their corresponding locations on Borei (Project 955). As these two boats are about the same size the positioning of the lead should equate to
similar trim.
Maiden voyage details later...
David H
The Ballast tank system that I have been using of late is what has been called the "Sheerline system". It is the 12v car wind screen washer pump forcing water into a sealed pvc pipe tank, using the simply but effective servo pinch on a nitro tube. It is a system that is slow to dive and surface, but very reliable. I like the fact that you expend the energy to dive and surfacing is just the release of the built up energy. The pressurized air inside the tank pushes the water out to surface.
I build my tanks of PVC pipe and it is forward of the cylinder. If there is a leak or other problem with the tank it will not affect the cylinder. I have cut a 70mm PVC pipe and found two thick 70mm end caps. I then took a flat section of PVC sheet from a down pipe funnel and cut a semi-circular slosh baffle out of it to fit in the middle of the tank. I drilled a hole in one end cap in a corner that would act as the outlet for the
Silicon pipe coming from the cylinder. I took a length of nylon plastic pipe to use as the internal pipe leading to the pickup at the bottom of the tank. This was bent at about a 45 degree angle and just touches the bottom of the inside of the tank near the middle next to the baffle.
All this has been glued in using green Plumbers pressure glue. This stuff is designed to seal PVC pipe under pressure. The internal plastic pipe connects to a 4mm barbed off take.This is glued and allow the silicon pipe from the cylinder to connect. I then cut out some strip of PVC and bent it to make two brackets that are glued to the ends of the tank. In the flat section I drilled a 4mm hole to take a stainless steel bolt.
I then cut some strip fibre glass sheet and glued it to the sides with some resin and cloth. Once glued down I drilled a hole in the middle and then bolted down the tank.
It has taken a bit of time to make dozens of fine little adjustments to aligning the shafts to the outputs from the cylinder. Aligning up the magnetic couplings for the pushrods is also something that
has taken a bit of time. I placed lead in positions that are similar to their corresponding locations on Borei (Project 955). As these two boats are about the same size the positioning of the lead should equate to
similar trim.
Maiden voyage details later...
David H
Comment