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[bbdave]

I will have two servos to operate my bow and stern planes do both these servos plug into the auto leveler or is a y lead used?. I don't have a leveler yet but i'm looking at the subtech leveler that pandan sell but any alternatives or advice greatly recieved. i assume they have to be mounted level or is this not the case?

Dave

[DavieTait]

They have to be mounted level and from the little I know working foreplanes ( unless they are large or WW2/WW1 design ) don't work at scale unless its a big model. The autolevelers i've seen all work the stern planes but how they work with the rx i'm not sure.

[Subculture]

Front working vanes work very well on a Type VII.

A leveller works on the rear vanes only, use the front vanes for depth control. A leveller isn't a luxury IMO, but an essential bit of kit unless you run your sub at a snails pace.

The Subtech leveller is a good unit, an alternative is the Engel LR2.

http://www.engel-modellbau.de/catalog/product_info.php?cPath=2_87&products_id=621&osCsid=096de9763277d6ff5aa8357361eafad6

The LR2 offers better manual control, the Subtech unit is a bit easier to set-up.

The units are connected in line between the receiver and the servo. The pulse from the receiver to the servo is modifed by a microcontroller depending on the attitude of the boat. The attitude of the boat is sensed by a small device called an accelerometer. These are micro devices developed originally for use in cruise missiles etc. and now handed down to more peaceful pursuits. the Subtech unit uses a small accelerometer that incorporates a micro machined beam and is referenced to gravity- effectively a small pendulum. The LR2 uses a different design of sensor, in this case the sensor has a small bubble of air, small elements heat up the air, and as hot air rises, further sensors in the chip detect which end is hottest, and bias the ouput of the chip accordingly.

The latter type of sensor is a more modern design, cheaper to produce and more rugged (can withstand very high shock loads). In practice either device is more than up to the job of keeping a submarine level, and they're a quantum leap over what was available just a few years ago.

Once you get one, set it up on a bench, and you'll soon get the gist of how they work.

Andy

[bbdave]

Thanks chaps. so only the forplanes are used for diving and the rear just for trim so they have a channel each is this correct?

Dave

[Subculture]

Sort of, but not quite. You can use both to create a crash dive. But if you rig your boat the way mentioned previously, then the rear vanes will react automatically as you operate the forward vanes. Effectively the boat will dive and surface on the level, with rear vanes only operational the boat dives in an arc.

Basically it works thus:-

1) You command the boat to dive by pushing the forward vanes down.
2) The down force from the forward hydrovanes pushes the bow down, as the boat rotates around the C.G (centre of gravity).
3) The auto leveller senses the boat is diving down i.e. not level and alters the rear hydrovanes to counter this in order to level the boat. The rear hydrovanes will command to go up, this has the effect of pushing the stern down. This cycle continues until the boat reaches the required depth.
4) Subtech also supply a depth controller. In the case of your boat, this would be fitted to the forward planes. They give an extra degree of automation to underwater control, as the boat is kept at a depth set from the transmitter, within a window of 4 feet. They're far from essential though, and most model submariners live quite happily without one of these gadgets.

Andy

[bbdave]

So the same as a gyro in a helicopter? i did wander what i needed 5 channels for now i know. cheers Andy

Dave

[Subculture]

Yes very similar, but don't fit a heli gyro to a sub- they don't work for our application.

Fortunately small, rugged and effective levellers are now inexpensive and readily available, that wasn't the case a few years ago.

Andy

[Subculture]

I should read your question more thoroughly.

To answer the last part of your question, they should be mounted reasonably level, but there is a small pot on either of the units that allows you to adjust the leveller so it is perfectly horizontal.

Ideally you should calibrate this adjustment with the aid of a spirit level. It only has to be done once, as these units don't drift.

Andy