Gyroscopic Roll Stabilizer

[justin]

I own a 2008 R-21 and am an engineer. I am considering building a gyroscopic roll stabilizer similar to the seakeeper, but much smaller. The design objective would be to reduce roll amplitude by 30-40%. The box would be approximately 12" x 12" x 8" and consume about 100 watts and activated with a on/off switch, with about a 5-10 minute start-up time. I would mount it to the hull in the front v-berth under the cushions. I am thinking about $1000 final cost. Please let me know if there is any interest.

Regards,

- Justin (Maryland)

 

[Connerkip]

Wow, that sounds extremely interesting. I have a Cutwater 30. Let us know how it turns out.

 

[bevis]

yes i would be very interested let me know how it comes out

 

[jroyle]

Interesting that you bring this subject up!. About two months ago we were at Catalina on a mooring. There were southeast winds a blowing which means a bit of rolling in the harbor. I started my generator up to make some morning coffee and I noticed the boat stopped rolling a significant bit. I stopped the generator and the rolling started up again. Mind you I had not even had Baileys in my coffee yet so sober as a judge. My little mind started to wonder if the spinning axis of the mass in the generator (whatever it is called) was somewhat offsetting (gyroscopically) the boat roll. I know that is the general principle for the SeaKeeper etc. Which leads to the question if a gimbaled generator has ever been designed for a two fold purpose. 1). Generate Electricity, and 2). Function as a stabilizer?

 

[Spinner]

Sounds great! My only question would be have you thought about how to mount it ? The hull might not be designed to react the kind of loads that the gyroscope would create.... I am guessing here, but I think it would be something to think about.

 

[Irish Mist]

I would be interested as well an in a larger one. My question is the location to mount. I would think closer to mid ship is prime ?

 

[paulspbe]

All ears ..!

 

[dialtone]

Generator idea is brilliant. Especially since it utilizes existing motor mounts (may need reinforcement but still).

On my CW30 I do however think it would be very painful to remove the generator and would require pulling the d6 🙁

Next boat : I will for sure be looking into this.

 

[assignment]

I have some ideas, buy a bigger boat, use flopper stoppers on the hook, mount outriggers like a PROA. Seriously, the gyro idea for stabilization works well with SeaKeepers...I've seen them in action. Great product, expensive, requires a lot of power and as an "engineer" you can imagine the forces required to be effective. A unit so small would require a lot of work but I would recommend proceeding with the dream because if you're successful, you will be able to use your 21 as one of the dingies on your much larger boat. Best of luck and keep us in the loop.

Maybe I could attach a bike track-stand on the roof and get a workout while stabilizing my boat.

 

[nzfisher]

Don't do it. It will cause a flood of people using their boats in the ocean that is now reserved for a handful of people that don't get sick. Seriously, if it enabled my bride to go out with me more often a couple of grand would be easy to spend.

 

[justin]

Just now checking the replies... The generator idea is interesting. I'll see if I can find time put one together over the summer. I'll report back with results, thanks for the feedback.

 

[andrew]

The stabilizer idea sounds interesting. Has anybody tried adding ballast in the bilge midships on an E21, say about 250 pounds of lead. I am wondering if this would be enough to make a difference in the roll. I don't believe an extra 250 lbs low down would make much difference to fuel consumption

 

[harry ames]

I've never spent hours on the open ocean being beat by wind and waves, but I've been in some pretty heavy weather for a couple of hours and I don't get seasick nor does my first mate. In fact, I like the feel of the waves and water moving my boat up and down and rolling to some degree. I'm thinking as a rocket scientist, (yes, I am one), that the real mass and spin needed to substantively reduce the degree of roll that would be unpleasant to people susceptible to rolling motion would be a bigger and more difficult engineering task than it might appear. (Sorry for the long sentence). In short, playing around with the idea isn't a bad idea, it is just that the resulting actual working control system is, I predict, going to be a waste of money and time except for the fun you will have trying. I know, I'm still working on perpetual motion and cold fusion.

Another idea that has been used for 150 years has been the use of a steadying sail. A small sail that the wind blows on that does in fact substantively reduce roll on small boats. I've seen a pix of a R21 with such a steadying sail.

 

[andrew]

As a long time sailor, the roll of my 21Ec always bothered me a bit, so I thought I would try this solution to see if it would help. Because of the small space, it was not necessary to actually fasten anything to the boat.
There is a space in the bilge, between the engine pan and the cabin bulkhead,which is 14" long and goes to the bottom of the keel. I was able to place 150 lbs of lead ingots,securely strapped together, and wedged in so there is no possibility of movement. This location is very near the 21EC's centre of gravity, and as low down as you can get.
Although it is difficult to quantify, I believe the role the boat is significantly reduced and is now a lot more comfortable in a beam sea. The speed of the boat has only not been significantly reduced.