New Bi-Rig Performance Cruiser

[ldrhawke]

Originally Posted by Nordic cat

Thanks 44C,

It is exactly this complexity I want to avoid. The anti-feedback valves can be done as NC(Normally Closed) solenoids, so they only consume power when hand steering. My idea is to have a pushbutton at each helm, that lets me take control at that station. By pushing the button at that helm, the other valves close...

But all this is more stuff to go wrong.

I have a tiebar across the back, so alignment is no problem.

Once the schematics are done, it will be much easier to make a decision.

Alan

With all three of the wheels fairly close to the same fore/aft center line, has any thought been given to use a chain linkage off of all three wheels to a single shaft run under the floor back to aft section and then use a double right angle drive at the rear of the shaft off to each each rudder? Another right angle gear box or a universal joint directly to the rudder shaft. It could be a fairly simple, very positive feed back, and less complicated system than a hydraulic system. Each will could have a separate mechanical engagement clutch at the wheel so it didn't turn when not in use and the turn down ratio could be made directly on the chain/ sprocket linkage at the wheels.

[Nordic cat]

Originally Posted by ldrhawke

With all three of the wheels fairly close to the same fore/aft center line, has any thought been given to use a chain linkage off of all three wheels to a single shaft run under the floor back to aft section and then use a double right angle drive at the rear of the shaft off to each each rudder? Another right angle gear box or a universal joint directly to the rudder shaft. It could be a fairly simple, very positive feed back, and less complicated system than a hydraulic system. Each will could have a separate mechanical engagement clutch at the wheel so it didn't turn when not in use and the turn down ratio could be made directly on the chain/ sprocket linkage at the wheels.

Hi Idrhawke,

my initial idea was to do something like that using carbon tubes, I got a proposal from Jefa. It turned out to be very expensive, and did not adress the redundancy issue. 4 gearboxes , with the one connecting to the rudder/crossbar being critical. I guess caryying a spare of each type could be a solution.

Before looking at this, I wanted to go with Vectran, but everyone I asked said it was a bad idea with those long runs. I tried an Edson wire system on a 47 footer, but it was really difficult to setup so that you got feedback without too much play at the wheel. My impression was that the friction was really loading up the autopilot.

Anyone tried something like this before?

Regards

Alan

[44'cruisingcat]

Originally Posted by Nordic cat

Thanks 44C,

It is exactly this complexity I want to avoid. The anti-feedback valves can be done as NC(Normally Closed) solenoids, so they only consume power when hand steering. My idea is to have a pushbutton at each helm, that lets me take control at that station. By pushing the button at that helm, the other valves close...

But all this is more stuff to go wrong.

I have a tiebar across the back, so alignment is no problem.

Once the schematics are done, it will be much easier to make a decision.

Alan

TBH I would just get helm pumps with anti-feedback valves built in. (In fact I AM doing this). I wouldn't be messing around with solenoid valves just for the sake of having a little "feel"

Ive sailed cats with mechanical and spectra steering systems, and frankly you don't get a huge amount of "feel" from them anyway. It never struck me as something I would dearly miss.

[freetime]

Hi Alan, any news about your new catamaran? Homepage, pics, info....

Regards

joakim

[lurocat]

I've got some info on a guy renting mold for this boat somewhere close to you i guess Oslo. Do you have any info on this boat?The hulls look similar to your design?
Thanks

[beiland]

Not exactly seeking a 'performance' vessel, but here is another gentleman wishing to experiment with a Bi-Rig catamaran with a sqaure rig variation. I cross-referenced the two discussions.

Square rig variation - Boat Design Forums