Bennett Driven Wake Plate

[CJD]

Here's a technical issue for those who are into solving problems.

I designed a hydraulic wake plate system that is powered by Bennett A1200S actuators. I designed the system before I understood how the actuator position sensors work. It seems the sensors are a coil that senses the position of an iron rod inside the piston. The problem is that the rod is not restrained, but is held at the bottom of the piston by gravity...nothing else. The piston pushes the rod up into the sensor as the cylinder retracts, and gravity pulls it back down out of the sensor as the piston extends.

My design uses 2 actuators that are mounted horizontally, so gravity no longer holds the iron rod in the piston. That means the rod no longer moves with the piston, but rather just sits there. No motion of the rod, no motion sensing. And that's the problem I have to solve.

I have a spare A1200S cylinder on order to play with. I have to find a way to lock the rod into the piston. The obvious solution is to epoxy the rod to the piston, but the issue there is the rod is in the "wet" part of the cylinder, submerged in automatic transmission fluid. I am not sure of any adhesives that are stable in ATF. In the mean time, has anyone else run across this problem before?

[CJD]

It figures...crickets.

Well, is anyone interested when I find a fix or should I just let this thread die a graceful death?

[MJHKnox]

I have read posts about the tabs, but they have been mainly about the pump or trim tab cylinder not working. Usually people are just replacing with factory specified parts. Your going in uncharted waters on this one.

Plus, this forum does not get that much attention anymore.

[CJD]

I live in uncharted territory. But, I'll take that as a "no", nobody is interested.

[MJHKnox]

If you lived in charted, what fun would that be?

Sent from my P00I using Tapatalk

[Jetlink]

I live in uncharted territory. But, I'll take that as a "no", nobody is interested.

While I have zero experience nor a need for what you are embarking upon, I am always curious how others solve various problems. If anything, think of this thread or any thread in general as a way to highlight your work and show it off.

[h2wow]

I'm terrible at technical and mechanical stuff, so I can't offer advice, but I enjoy reading the posts. If you post the fix I'll read it, for whatever that is worth.

[CJD]

Will do...as soon as we get past this winter storm!

[CJD]

https://i.imgur.com/CPNKs8j.jpg

https://i.imgur.com/oaUPGTE.jpg

So this is what the Bennett 1200 cylinder looks like when you take it apart. Not very complicated, but in the basic form here there is no feedback to tell you how far out your trim tab...or in my case the wake plate...is extended. You have to buy a Sensor to replace the end with the mount, which they call the hinge plate. There is no real hinge, the plastic just bends!?!

https://i.imgur.com/7qRIVt3.jpg

https://i.imgur.com/FwFnLl3.jpg

This is what you get in the sensor kit, a new "hinge" with a coil in it and a wire that goes back to the control module, and a steel rod, which is slipped inside the hollow piston.

[CJD]

The problem is that the steel rod must slide within the coil for the sensor to work. There is nothing to hold the rod inside the piston, so the entire system depends on gravity to work. The rod stays bottomed in the piston, and as the piston pushes the rod upward, it follows. Gravity must pull the rod back downward as the piston returns. My problem is that I have 2 cylinders mounted sideways, so gravity will not pull the rod back down.

https://i.imgur.com/ode7RZc.jpg

https://i.imgur.com/EgORgpQ.jpg

https://i.imgur.com/OiHMzTa.jpg

[CJD]

My solution was to machine a sleeve that could be slid into the piston until it bottoms. Then, when the rod is tapped into the center of the sleeve, it expands, locking the rod and sleeve into the piston. Now the rod will move with the piston and the sensor will work.

https://i.imgur.com/AKrDPrZ.jpg

https://i.imgur.com/OR8KCOC.jpg

https://i.imgur.com/x80yMRK.jpg

This is the dashboard plate the mounts the controls for the plates. There are LED's that tell you how far the plates are extended (not lit for this pic). I had to install the switches inverted, so that the direction you move the switch is the direction the plates move. They were designed for trim plates, so the "up and Down" are actually boat nose direction, which is opposite the plate direction. They are designed to auto retract when the ignition is turned off.

https://i.imgur.com/n8OWdGG.jpg

Not as fancy as the new programable systems, but I've spent a total of only $2k for the 4 plates with sensors, new teak swim platform, and a swim ladder that auto-stowes if you forget to bring it in. So all of it for the normal cost of a teak platform alone. Now I have to go back to the reversible ballast pump upgrade on the other thread...

[CJD]

To close out this thread...here is a link to the final wake plate project:

https://forum.supraboats.com/showthread.php?21363-New-Swim-Platform-Winter-Project

Cheers