Old Fashioned Pendulum Sub Levellers.

[Kim Sleep]

Any info anyone has would be greatly appreciated, along with pictures and schematics.. I have some bits of a elderly unit that I would like to play with. I understand that they were not as good as the modern solid-state units, but Id like to play with this one.
Im not even certain that what I have is even complete.

What was the theory of operation ?..
a pendulum with a magnetic end that swung between 2 hall-effect switches (or reed switches) that controlled the adding /subtracting of pumped water to fore and aft tanks??????????

n advance
Kim

[He Who Shall Not Be Named]

An angle-keeper almost always operates a set (or sets) of hydroplanes or a gimbaled propeller. Response curve is too long to be useful changing a boats center of mass with an angle-keeper in the control loop.

Yes, HAL effect pick-off, liquid displacement (dialectic), sometimes IR -- all back when the earth was still warm and we didn't know any better. Nowadays sensing is by an air-bag/IPhone accelerometer.

[Subculture]

Here in the UK, the first commercial leveller I know of was the SALCON. This uses a photo interrupter set-up, so is optical based.

[He Who Shall Not Be Named]

Yes, Ron Perrott's SALCON. A pendulum device that was liquid damped, right, Andy? A much coveted device, even today.

Here in the States, the guy who recognized the need, and started using modified rate-gyro units in this capacity (see the pictures I previously posted) as r/c submarine pitch-controllers is Skip Asay. This one invention made the hobby, as we now practice it, possible!

Everything since Ron and Skip's work has only been improvements on a theme.

Before these guys (to the best of my knowledge) angle sensing and control devices were purely mechanical in function and did not have the sensitivity (drag forces on the pendulum), nor produced the force required to effect meaning control surface response to detected angular displacement. There exists the need for force-multiplication in such systems, hence the detection-amplification-response nature of the modern angle-keeper system pioneered by Skip Asay and Ron Perrott.

M

[Subculture]

That's it. Some of the devices also ran dry apparently, although I only ever saw the oil bath versions.

[Kim Sleep]

Yes, this one looks very much like it (thanks to "he who shall...."). Is it practical to get this thing going...or is it just folly???


The other question would be, if it is feasible does anyone have schematics to the circuitry??

[He Who Shall Not Be Named]

Why spend more money to bread-board your own circuit when you can buy one that is cheaper, smaller, and will work better?

What you show there is my version of what Skip initially talked about: converting a rate-gyro unit to sense the gravity line, not acceleration in space about one (typically yaw) axis.

The old style (real) rate-gyro removed, the magnet pulled from the gyro gimbal arm and glued to the bottom of the pendulum weight, and the HAL pick-up and associated H-bridge glued atop the units 'amplifier'. Big, heavy, ugly, a chore to convert .... but worked like a charm.

(Today's 'rate-gyros' actually use acellerometers, not a spinning mass ... showing my age here).

M

[redboat219]

Try getting in touch with Manfred aka MFR here. He might be able to help you. He converted an old heli rate gyro to an angle keeper for his Type XVIIb uboat.
Here's the link. Scroll down to the bottom.http://forum.sub-driver.com/showthre...highlight=gyro

[Subculture]

Ron swears that his SALCON's are better than todays miniature marvels.

Well I know what is in a SALCON, and if there's any advantage I think being an analogue controller, the parameters like gain have a very wide adjustment range. Most of the levellers today are based on micro controllers with firmware that give three or four discrete settings, usually one of those is sufficient for most practical purposes, however an analogue controller can be precisely dialled in for the proportional/differential loop. That could be done with a microcontroller too, for instance Norbert Bruggens LR3 has a pot with a wide adjustment range for gain, but my guess is that most modellers would moan about a leveller being difficult to set-up if you went much beyond this.

[MFR1964]

Like Romel mentioned i did convert a heli gyro to be a angle keeper, have the same inside my type VIIC, works like a charm, less responsive to vibration, for me it's just a matter of choice, inside my dry hull boat i've got room enough inside.
For using those inside a SD, i would go for the ADF, a neat little package with excellent respons, like Andy mentioned the adjustment range is less, but it does the job for us, me as a maniac like to play around with the gain control, with my type VII i dailed her in on a difference of 1 cm running straight.

If your old leveler doesn't work, scrap it !!!!!, not worth the effort to repair it, or try to get hold on a working example, still have one as a spare for both the type VII or type XVIIb.


Manfred.