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Home made H16 anti-pitchpole bow planes

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(@waiex191)
Posts: 359
Mate
Topic starter
 

I know, I shouldn't need these. But I wanted to try it so we would have some more margin as we were learning.

I made it out of .090" 6061-T6 aluminum. To make the sharp bends I annealed the material locally.

Hope to get a chance to try them and report back.

 
Posted : October 18, 2021 3:50 pm
(@jack108136)
Posts: 160
Mate
 

They work good until they don't.

If it gets too far down it goes the equal and opposite reaction happens.

A trip around the bow from the trapeze turns that thing into a machete.

 
Posted : October 18, 2021 11:25 pm
Andres Chianale
(@Andinista)
Posts: 880
Chief
 

A trip around the bow from the trapeze turns that thing into a machete.

Yes, that’s dangerous! Perhaps the edges could be covered with rubber seals.

 
Posted : October 19, 2021 12:59 am
(@wxguy)
Posts: 56
Lubber
 

If these worked, every H16 would have them on the bows. Learn to sail the boat without those meat slicers. Adding more aft mast rake helps in this department.

 
Posted : October 19, 2021 1:43 am
(@jack108136)
Posts: 160
Mate
 

wxguy & I setup next to each other at the Hobie Midwinters East, St Augustine, 1984. I've still got the rudders from his buddy.

 
Posted : October 19, 2021 1:12 pm
MN3
 MN3
(@MN3)
Posts: 7090
One Star Admiral
 

Yes, that’s dangerous! Perhaps the edges could be covered with rubber seals.

death race 2021!!!!

Add a fire throwing bow sprit!

MN3

 
Posted : October 21, 2021 12:12 pm
(@waiex191)
Posts: 359
Mate
Topic starter
 

MN3 wrote:
death race 2021!!!!
Add a fire throwing bow sprit!

Could be the solution to the kayak problem!

 
Posted : October 21, 2021 2:58 pm
MN3
 MN3
(@MN3)
Posts: 7090
One Star Admiral
 

haha

MN3

 
Posted : October 22, 2021 2:36 am
(@jack108136)
Posts: 160
Mate
 

Someone needs to post up the Cat vs jet ski video that's hidden here.

 
Posted : October 22, 2021 5:36 am
MN3
 MN3
(@MN3)
Posts: 7090
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jack108136 wrote: wxguy & I setup next to each other at the Hobie Midwinters East, St Augustine, 1984. I've still got the rudders from his buddy.

If you mean you watched him sail away into the horizon, so have most that raced him. 😆

Fortunately I was in a different class when we were in the same race (Mini MachoMan).

This was a distance race. We were in first (beating a Nacra20 flat out) when we capsized with a spinnaker at the last jibe about .5 miles from the finish

MN3

 
Posted : October 22, 2021 7:04 am
(@waiex191)
Posts: 359
Mate
Topic starter
 

So we tried them out yesterday. We were not even on a reach, we were just tacking upwind. The wind and boat were pretty stable, and the bow dipped.
https://youtu.be/WQXUIY0gJz8

I'm a believer.

 
Posted : November 25, 2021 4:52 am
Andres Chianale
(@Andinista)
Posts: 880
Chief
 

 
Posted : November 26, 2021 5:58 am
Andres Chianale
(@Andinista)
Posts: 880
Chief
 

please...

 
Posted : November 26, 2021 5:58 am
Mike Krantz
(@mikekrantz)
Posts: 99
Mate
 

Rudder winglets would be more effective and less dangerous.

 
Posted : November 26, 2021 1:06 pm
(@waiex191)
Posts: 359
Mate
Topic starter
 

mikekrantz wrote: Rudder winglets would be more effective and less dangerous.

What are those? I have a hard time getting my rudders down and locked as they are.

 
Posted : November 26, 2021 2:08 pm
(@charlescarlis)
Posts: 599
Chief
 

More like an elevator trim tab; trim down to keep nose up I'm guessing so would actually help to keep rudders down maybe. Those bow tabs look like they work, but also look like razors, especially handling the boat by the bows on land or if in water around swimmers. That's why people are a little itchy about the idea. Could also mod the bow planes with a thicker, less slicey edge, perhaps welding a rod on the edge or sticking the above referenced trim stock on it. If trim stock, I'd glue it with 3M something, because I doubt the PSA will hold up.

 
Posted : November 26, 2021 4:19 pm
(@waiex191)
Posts: 359
Mate
Topic starter
 

It is actually pretty thick metal, not very slicey. I rounded/deburred all the edges to an aviation standard. To bend the material tight enough I had to anneal it.
In my limited experience, the bows are buried in the water during the pitch pole when I go rushing by.
I definitely don't see any concern with handling the boat on land or in the shallows.

 
Posted : November 26, 2021 6:38 pm
(@revintage)
Posts: 281
Mate
 

Sorry to say, but they will not help much against pitchpoling, only added volume will. What will happen when you nose dive and the angle of the metall gets below horizontal, is that you get a quicker somersault.

Edited by revintage on Nov 27, 2021 - 08:31 AM.

 
Posted : November 27, 2021 2:25 am
Mike Krantz
(@mikekrantz)
Posts: 99
Mate
 

you set the winglets at zero angle of attack. When the bow goes down, it creates negative lift on the stern, pulling the stern down - leveling the boat. It also has the added benefit of reducing pitching/hobby horsing in chop - works as a dampener on the motion.

 
Posted : November 27, 2021 3:46 am
(@revintage)
Posts: 281
Mate
 

Hi Mikekrantz, I suppose you are talking about adding aerofoil shaped winglets to the rudderblades, which is the sensible thing to do 😉 ?

Edited by revintage on Nov 27, 2021 - 11:06 AM.

 
Posted : November 27, 2021 4:40 am
MN3
 MN3
(@MN3)
Posts: 7090
One Star Admiral
 

Sorry to say, but they will not help much against pitchpoling, only added volume will. What will happen when you nose dive and the angle of the metall gets below horizontal, is that you get a quicker somersault.

I agree with this
they may add a small bit resistance to pitching but the second you get them underwater they will increase the velocity in which you fly through the air

what is the airspeed velocity of an unladen sailor?

plus the added risk of injury to anyone on land or water that get in the way

as mentioned above, if these really worked - they would be on every h16

better off learning how to avoid and recover from an near pitch - but easier said than done for sure

after a few seasons (or pitchpoles) you may want to up your volume with a different boat -

BUT if these work for you, and you don't slice anyone or anything in 1/2 - enjoy!!

MN3

 
Posted : November 27, 2021 5:11 am
(@waiex191)
Posts: 359
Mate
Topic starter
 

MN3 wrote:

Sorry to say, but they will not help much against pitchpoling, only added volume will. What will happen when you nose dive and the angle of the metall gets below horizontal, is that you get a quicker somersault.

I agree with this
they may add a small bit resistance to pitching but the second you get them underwater they will increase the velocity in which you fly through the air

I think any increase in velocity from our first two pitchpoles would require the bows to be pulled backwards.

I am curious as to the root cause of our tendency to pitchpole. I am sure a lot of it is lack of skill. I also wonder if we are too heavy for the boat. We have an all-up crew weight of 400 lbs, and we have a heavy boat with a 101lb port hull and 85 lbs to starboard. More flotation would be good, but I would think less weight would have a similar effect. Once we are confident enough to solo it will be interesting to see if we do a better job of keeping the bows out of the water.

revintage wrote: Sorry to say, but they will not help much against pitchpoling, only added volume will.

They surely helped on that last trip! Definitely kept the bows from submerging all the way.

wxguy wrote: If these worked, every H16 would have them on the bows.

mikekrantz wrote: Rudder winglets would be more effective and less dangerous.

I'd assume wxguy's statement would apply to rudder winglets as well.

MN3 wrote: after a few seasons (or pitchpoles) you may want to up your volume with a different boat

I just asked Tom Haberman for a quote to replace my standing rigging on the SC17. It's time.

 
Posted : November 27, 2021 7:39 am
(@revintage)
Posts: 281
Mate
 

What about moving the weight back of the H16, might solve the pitchpole-problem 😎 ?

Edited by revintage on Nov 27, 2021 - 05:06 PM.

 
Posted : November 27, 2021 10:40 am
(@waiex191)
Posts: 359
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Topic starter
 

revintage wrote: What about moving the weight back of the H16, might solve the pitchpole-problem 😎 ?Edited by revintage on Nov 27, 2021 - 05:06 PM.

Excellent point, and you may have noticed in the latest video I posted that I was helming from inside the rail. That would let my son on the trapeze move all the way to the back easily. I had also put some neoprene on the aft hull so in theory you could step down there and get your weight further back. But for going upwind, my understanding is we need weight more forward for the hulls to act as the daggerboard. Early on we were super far back and were sinking the sterns. I assume this is no good either.

 
Posted : November 27, 2021 11:20 am
(@revintage)
Posts: 281
Mate
 

Good point, Bryan!

Edited by revintage on Nov 27, 2021 - 05:32 PM.

 
Posted : November 27, 2021 11:31 am
(@shortyfox)
Posts: 369
Mate
 

But for going upwind, my understanding is we need weight more forward for the hulls to act as the daggerboard.

You are exactly right. Especially true with board less cats, the more the leeward hull is buried the more resistance to leeway. In lighter airs it's still more efficient to induce heeling and only have drag from one hull. Monohulls can always point higher, ever notice how when your windward hull starts to leave the water you can point higher? Another thing about the Hobie16, it has asymmetrical hulls which pull towards each other when the boat is sailed flat, you always want the windward hull just "kissing" the water.

 
Posted : November 28, 2021 1:18 am
(@waiex191)
Posts: 359
Mate
Topic starter
 

shortyfox wrote: Monohulls can always point higher, ever notice how when your windward hull starts to leave the water you can point higher?

I've never done that, but thanks for pointing it out in advance.
The only thing I've noticed about the monohulls on the lake is they seem to be under impulse power while we achieve warp factor 1.

 
Posted : November 28, 2021 4:23 am
Jerome Vaughan
(@rattlenhum)
Posts: 438
Mate
 

waiex191 wrote: So we tried them out yesterday. We were not even on a reach, we were just tacking upwind. The wind and boat were pretty stable, and the bow dipped.
https://youtu.be/WQXUIY0gJz8

I'm a believer.

Sorry, but that vid isn't convincing at all. Going upwind there is more pressure on the stern and little tendency to pitch regardless of those foils. The bows will easily pearl though smaller waves like that going upwind...not necessarily so when sailing off the wind with more pressure on the bows. If you pitch while truly going upwind, you're really doing something wrong.

In general, you do want weight forward, primarily to get the transoms out of the water to reduce drag. However, if you start pearling/punching too much in heavier air/bigger waves, you need to get your weight back further. Otherwise, it slows you down and can throw you off balance on the trap.

A heavy boat/crew and old/blown sails make it difficult to sail very high, so one tends to foot more toward a close reach. Doing that in heavier air with heavy/boat crew depressing the leeward hull and those blown sails all powered up opens the gateway to the pitchpole zone.

Similarly, if you can't flatten your sails enough or get all that weight back far enough when sailing off the wind in heavier air/bigger waves, you are launched into the pitchpole zone. I expect then those shoehorn foils will provide a substantial fulcrum. That said, you really haven't pitched until you pitch hard in shallow water and come out of it with a shovel full of mud on each bow tip.

Jerome Vaughan
Hobie 16
Clinton, Mississippi

 
Posted : November 30, 2021 2:13 am
(@dirtybanana)
Posts: 24
Lubber
 

Jerome- what you have posted makes sense. I would think they would be standard equipment if they did more good than harm. I haven't had my boat in the pitchpole zone yet but your tips above about how weight distribution and hull submersion affect the boat dynamics seem to bear out.

 
Posted : November 30, 2021 3:27 am
(@shortyfox)
Posts: 369
Mate
 

I would think they would be standard equipment if they did more good than harm.

Don't know for sure, but I suspect they are not class legal. In some racing situations they may be an advantage.

 
Posted : November 30, 2021 9:23 am