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kurz wrote:well - when I remember correctly - they ask you during installation procedure how long it takes to get the max position to get the tiller to the max position. As a standard the say 4sec I guess.
And also the say you can aproximately. So they dont say it has to be very accoryte. It is just that the tiller does not go to far out if your rudder cannot go so much.

But in our installation the tiller ev 100 is the limit - not the rudder.

Correct - the value was less than 2.8 seconds on 'boat' but I think an X boat has a better turning radius than an M boat so the value would be higher on some boats. The X turns better too because of the flat bottom.

A traditional keel boat takes forever to make a turn - their hulls are designed to go in a straight line.

seems to be a misunderstanding:
I think they dont mean how long it takes to turn the boat but how long it takes that the tiller-motor has to reach the max of the rudder.
When I remember right raymarine says you have to measure it the boat fixed in the harbour.

Right - it's how long it takes to go rudder lock from left to right - and as I recall it's divided by half in the unit to find zero rudder. How fast does the piston find rudder stop when it's extended or retracted at it's fastest speed.

The turning time is also part of it. There is a mode selection - SLOW TURN sailboat - SAILBOAT - and POWER BOAT

When the AP goes into full rudder lock:

1. The AP it trying to get the boat back on course but nothing is happening - this makes the "brain" start to do things:

2. The "brain" will use the GPS to see if there is any forward movement first - if there is forward movement it will hold rudder lock until certain conditions prevail:
a-the boat returns to course
b-the preset mode time is reached for turning from the mode selections SLOW TURN sailboat - standard sailboat - or power boat
c-the feedback from the piston returns an over current

There are few times the piston will remain in rudder lock if the boat is moving but it needs rules for NOT holding a rudder lock because the AP - being a tiller pilot, does not know when it's disconnected from the rudder. It can be in full rudder lock, yet still be ON COURSE AND MOVING FORWARD! That condition is called "being disconnected from the rudders!" And the pilot has no way of know that - so you need to program the presets for it.

It's a simple thing for the pilot to just go into rudder lock and wait for a change in heading and if nothing happens it will stop sending power to the drive and call out a course alarm. What more can it do?

Wheel pilots get REALLY mad when they run into a rudder lock with no change in course - wheel pilots are even harder to program.

Thanks for the Dremel tips guys, I've got one in the shed with loads of tools so I'll give it a try.

Regarding ram travel limiting, I think I better have a go at a mod to add this. The two simplest ones I've seen are:

1. https://m.youtube.com/watch?v=cNod0wDNf ... e=youtu.be , and

2. http://www.cruisingonstrider.us/ST1000mods.htm

I like the use of the diodes in 2. and the simplicity of the switches in 1. so I may try a hybrid version.


I've made my tiller extension arm and coupling ball addition to the ram end. Just started working on the hardwood shelf to go on the engine well liner; getting excited!

Thanks again for all the help and encouragement.

MikeFloutier wrote:I like the use of the diodes in 2. and the simplicity of the switches in 1. so I may try a hybrid version.

Both versions require the use of limit switches (which don't have to be on the actuator itself, by the way), but the use of diodes in the second version seems the simplest to me. It directly interrupts the output to the motor in the direction of travel, at or near the end of travel (set it back a bit if you don't want the nut to bottom out), but allows it to travel away from that end. Can't be any simpler, and shouldn't void any warranties as long as the limit switches are put outside the actuator rather than inside. Like on the arm it's driving. Or on a simple structure clamped to the actuator.

I'm not real clear on what the first one is doing, but it looks like it's interfacing the control board, presumably at the signal/control end rather than the power output. I'm not sure I'd want to be poking around in there.

We use limit switches as belt-and-suspenders [braces, for the UK] on things like crane boom max up and down travel, to back up the control system, which 'knows' where the boom is all the time, as the risk of catastrophic failure of the crane is very high in the event of a control failure or tampering by well-meaning but ham-fisted parts changers who shouldn't be in there in the first place. So we interrupt the actual valve driver signal directly, using mechanical limit switches with positive drive (will push right through and break welded contacts, if necessary, like real E-Stop switches).

Tom is one of the smartest people i know. I'm sure glad he understands all that stuff in that video.

I don't know why any tiller pilot would go into rudder lock and stay there for no reason at all - there must be something here that I am missing - I know that the EV-100 will shut itself down if it "feels" that there is a chance it's in a rudder lock - but in all my use I have never had the unit in rudder lock when it's connected to the tiller. Why would a unit be in rudder lock if it's connected to the tiller?

You probably need to get out more, BOAT.

I agree - I don't know why the controllers wouldn't do something as simple as either limit the current to a safe level, or trigger a fault or other preemptive measure once current exceeds a software set current limit, or current times time limit (the way the typical inverse-time AC circuit breaker in your house works - the higher the overload, the faster it trips). It's a simple bit of programming, assuming the control knows how much current it's delivering, or assumes how much based on some algorithm using PWM output and a known design input voltage.

Tom, could you please suggest a suitable diode to use in this mod. It's a 12v circuit, the normal current is 3A rising to 9 or 10A if the ram runs to either end and overloads the motor.

You could probably just use these, which are marketed (on Amazon, at least) for solar panels.

https://www.amazon.com/Akak-Quality-Sch ... =20a+diode

15A and 45V. There's a rule-of-thumb for diode current, but I don't recall what it is. Something like best to not exceed 1/2 rated current for continuous operation, or something like that. The 15A is probably fine alone, but you could always put two in parallel, which will double the current capacity with each one taking half of the current, and it will lower the forward resistance (two resistors in parallel of equal value will have a total of half the resistance). They're cheap at 35 cents each, so no big deal to use two for each direction.

But those actuators are not continuous-duty anyway, with the motor usually bumping the rod in and out in steps when making fine adjustments to the rudder position (at least, my wheel pilot on another boat was that way), so I would think just a single diode in parallel with each limit switch would be fine and last forever. Heat is the enemy, but burping a motor along means current flow only part of the time. And the limit switches are there to prevent running the motor against the hard stops, so they should never see the stalled current.

Many thanks Tom!

Just been chatting with Roger Long, the author of the "diode" ram travel limit mod. Very nice helpful gentleman.

He installed his "drop-in" mod originally in 2008 and subsequently transferred it to another unit when the original unit died for other reasons.

Apparently the mod is still functioning well after 20,000 miles!

I've ordered the diodes and micro-switches. It seems ridiculously simple; the only finesse appears to be in the positioning/fixing of the switches.


One issue this whole thing highlights is one's ability to balance the CE/CLR in order to reduce the rudder angle/pressure when holding a course.

Is there a simple way of monitoring this, whilst under AP control, or is it just a matter of knowing what it's likely to be under all combinations of wind, sail and daggerboard.

I suppose marking the "dead-ahead" point on the wheel (to facilitate Ram ball/tiller extension capture) will also provide a point of reference indicating the amount of lee/weather helm.

What's a diode?

MikeFloutier wrote:I've ordered the diodes and micro-switches. It seems ridiculously simple; the only finesse appears to be in the positioning/fixing of the switches.

Just be sure that if the actuator over-travels for any reason, the switch(es) won't be damaged. Limit switches with plungers, for instance, can get wrecked if the mechanism doesn't stop and jams into it beyond it's normal range of travel, so techniques like using a ramp with a flat to actuate it (usually with a roller on the end) will prevent overtravel and damage. Same with the long spring levers on many small ones - push too far, and it simply deflects (elastically) without causing damage.

The actuator, of course, only has a limited travel range with a hard stop at each end, so a little careful layout and adjustment should work well for cutting power just before it hits the ends. Using some element with a large range of motion, like the end of an actuator arm, or the actuator itself, rather than using the same arm but close to the pivot axis, is generally the best way to get fine resolution without having to have micro-adjustment capability where a small misadjustment and/or poor repeatability of the switch (relatively) causes a large over or under range of travel.

It's something to be aware of at least.

BOAT wrote:What's a diode?

A check valve for electric current.

Tomfoolery wrote:

BOAT wrote:What's a diode?

A check valve for electric current.

Well, there's that too.
I was gonna say it's a lyrical poem sung twice. For relevance, I'd suggest a nautical diode!