I have had a lot of Captains ask me about this system and I hope Ill see more applications of the system on subs.
Here is how it works
The pump pictured is a gear pump ,connected to 2 syringes ,one is the actuating cylinder the other is the reacting cylinder.
The size of the syringe is important for the distance of travel and the volume of fluid,if a small one is used like a 1 cc it will not move at all. Medium to large syringes work the best.They can be cut to fit and attached in any place wet or dry.
Even pnematic cylinders work as well! Longer extentions but cost more,just let one end open to the air or watter so there is no lockup.
The reason to use 2 syringes is to make the hydraulics sealed and always free of air.It can be done with just one syringe but there is the high chance that air will enter the pump and cavitate.
By simply gluing the 2 brass rods of the dive planes retracting mechanism to the plunger of the syringe in the retracted position ,let it dry,then attache the other syringe to the pump with water and some anty freeze ,fill it to the same rough amount as the other one takes to extend the planes ,since there graduated its a breeze and does not have to be accurate just get the fluid in the system.
Operate the pump,be sure its going in the right direction to fill the other syringe,no biggie if not it just wont extend,once you have achieved full extension of the dive planes with no air in the system reverse the pump and it will retract and when it stops at the point that you like bleed down the reacting cylinder to the stop lock point or where the plunger bottoms out at by removing the supply line at the syringe,that is very important for both the retract as well as the extending points of the dive planes,that way there are mechanical stops to the hydraulic piston travel,no need for pressure switches ext. and very simple and cheap.
The pump will just work a bit harder for a few seconds by the time it takes for the pump to be turned off and wont cause any damage.
Be very careful that the syringes and the mechanism that they are moving does not bind as this system is very strong at 12 volts.
Another point is that I use a blue brushed speed controller from Pro Boats any will do to run the pump at the desired pressure that is scale like and can be adjusted via the radio,very handy!
It is fine to install a stop at the planes retracted position so that the exact point of stop is reached since there is some flexing in the Robbe retract setup,by the time the syringe reaches this point the pressure is gone by the other piston bottomed out and by installing a stop just before the end point will insure that the planes stay at that point.
The planes wont move at all unless the pump is activated.
On the radio I suggest the 3 position switch or a variable or even one of the left stick channels as the center provides the all stop or off position.
Hydraulic lines are a combination of 3/16th aluminum Versa tube available from Aircraft Spruce.com and large RC air craft glow fuel silicone tubbeing, no special fittings at all.
There are several pumps that are suitable but the one I use works well in the wet and is inexpensive and high quality available on Ebay motors for around 28.00$ new.
I have also found 2 micro gear pumps that perform very well and will be used in both the hydraulic system as well as my pump dive system.
This picture shows the reacting syrige installed in the bow area with the pump below it.
This simple system can be applied to a huge host of applications from doors to masts and arms and landing gear as in real vessels.
Please feel free to ask questions Dave
http://s82.photobucket.com/albums/j278/ ... 0001-2.flv