High Performance MPX Foil/Self-righting Trimaran-The Test Model

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You're funny. You never contribute to the thread in any way-you make snarky remarks and then leave. Why in the world do you waste your time posting here?

 

Define contribute Doug. You post far more than I do in other threads and more often than not it's to divert to conversation towards your agenda. That's not how a conversation works. You do sometimes find wonderful videos to post, and I appreciate those, but it's a hefty tax for all your other "contributions" in threads I'm actually interested in. I don't contribute to this thread because I don't know ding about radio controlled boats or foils, and I certainly haven't learned anything here except for how to stay at the top of a forum with inane updates about overpainting a prototype. Prototypes don't need paint. I don't think you can appreciate how obnoxious that is.
Isn't this to some extent, a project about learning something? I'd like to see this thing work and wish you'd stop faffing around. At least stop posting until you have something to say. You don't say anything.

 

I would like se how some othe people complaing would get on working to the same restrictions as you are Doug. It cannot be easy to set up such a large model in a relitively small space. It also takes time to sort out the R/C gear. Would they try it and break some thing because the R/C gear was incorrectly installed.

 

MPX Test Model

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Thanks,Warwick! I'm convinced that the very few serious "complainers" do so because they simply don't know squat about what it takes to do a project like this. Finn admitted it-someone like that would have no clue about most of the stuff I've talked about in this thread and furthermore could care less.
Which brings up the same question: why do people, like that, bother to post in a thread they don't understand and don't want to understand. Seems downright silly and a waste of time-but each to his own.
Adds some dark humor along the way though.......

 

Good question Doug. That's another dissertation on it's own.

 

MPX Test Model

Riser is complete and works well. Has 5" of adjustment without bringing out the Automatic Carbon Tube Grinder, in which case it would have up to a couple more inches of adjustment.
Adjustment is done to keep the mainsheet pulling horizontally regardless of mast rake. As I mentioned before, rake will be between 3.75 degrees, 7 degrees with a maximum of 10 degrees.

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Pictures,L to R-- 1) Minimum riser position(for now) corresponding to about 10 degrees mast rake, 2) Maximum riser positon corresponding to about 4 degrees mast rake:

 

Cummon Guys.
Give Doug a break.
How many of you would be prepared to tackle the hard yards as Doug has done and for as long as Doug has.
No one has the right to castigate him for examining and acting on the advances in foil design in the dogged way he has.
If you found his posts boring then I think you must have little interest in the subject.

If so you should just keep your opinions to yourselves.

 

Oldsailor7

You say "that if you find the posts boring then I think you must have little interest in the subject" is entirely wrong, if that was the case then why would there be ongoing comments about when is it going to happen?

Even the most devoted of Dougs fans must be asking when the hell is this thing going to go in the water? We've seen what appears to be dozens of pictures of it on the lawn and maybe one in the water when the man with 50 years in the business discovered the hull didn't float correctly. I know I'm starting to sound like Chris O but there are many who are waiting to see the thing sail.

While on the subject of the hull floating stern down where has that left the float trim - now with main hull stern up - does that mean floats are now in bow down trim?

 

MPX Test Model

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Tony, this question was answered in some detail earlier and I guess the picture below answers it again. The reasoning behind the addition to the stern was also answered previously in much detail and is referenced under "mainhull" in the spec sheet above.

 

I was answering Doug's question about why I waste my time posting on this endless thread. He invited my opinion to be published here. My original snarky post was unnecessary, as are many here, but big deal. I'm sure he can handle it. Sticks and stones.

Any more info on the black wing boat above? That's a wicked looking toy.

 

MPX Test Model

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I appreciate your interest(?) in the boat but posting snarky remarks or personal attacks is frowned upon around here. So keep in mind what happened to the last two posters that "sounded like chris o"-they aren't members here anymore. If you(or anyone else) can't say anything relevant to the subject of the thread it might be better to say nothing. This is my thread and I've worked hard to provide as much detail as possible from a design and building standpoint. When I've screwed up I post that as well even though I know the "chris o wanabe's" will attempt to trash me for it. Just keep this in mind....Please.


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I'm aware of their absence Doug. I'm sure others have been warned, but I can't help but notice the common denominator in those cases.

Post AC 72, it seems like there is a movement away from the hydroptere style central rudder and constantly deployed foils, towards the leeward foils we see on the 72's, with the windward rudder constantly deployed. Is the Hydroptere style, seen in the black boat above, on it's way out as an approach to this type of sailing? I understand the AC version of foiling was aligned with a design rule, but it seemed to work damn well and is pretty convincing on the G32.

 

MPX Test Model

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The significant thing about the TNZ AC 72 foil and foil configuration(single main foil + 2 rudder foils) is that it is the first time in history that a single hydrofoil with no moving parts was used to support at least 80% of the load on a multihull*.
It is a breakthru in hydrofoil design. The cool ,revolutionary, thing about this new UptiP foil is that it includes altitude control and the refined versions have great heave stability which is a result of excellent altitude control. These foils work with leeway coupling that allows the foil to maintain a range of altitude with the breaching of the inboard tip a backup. Tom Speer says it is much faster to not breach the inboard tip, Dario Valenza says the foils can be sailed using breaching of the tip as a form of altitude control when leeway is low. But leeway coupling is the key most of the time. Go to the aero-hydro forum here to "Sailing Foilers" toward the end for Tom Speers concise explanation of leeway coupling. I think there is still a lot to learn with the UptiP foils("uptip" coined by Pete Melvin, co-inventor of the foil).
The rake of the foil may or may not have to be adjusted while sailing on the newer boats like the GC32 and Flying Phantom-any adjustment is far less than was required on some original incarnations of these foils.
Hydroptere is a surface piercing foiler and that means that lift is regulated by speed. It also requires two loaded main foils and I think the UptiP foil with the single main foil would probably be faster but surface piercing foils significantly reduce their area with speed so I don't know. I think the UptiP foil with a single main foil is probably significantly faster around a course.
* with the probable exception of the single main T-foil on "Happy Feet".
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The MPX Test Model may be the first trimaran of any kind to rely on UptiP ama foils*. When I first heard about these foils I had already had styro molds cut for circular "C" foils, but I trashed those when I realized the potential of the new foils. Going to be real interesting how well my UptiP foil design works-the hope is that, thru most of the speed range, it won't require any rake adjustment. The foil settings are detailed in the Spec sheet on the previous page. It's one of the fun things we'll learn about testing this model and we'll know something hour one of day one.
* with the potential exception of the 19' Exocet tri shown in a render with UptiP foils.

 

MPX Test Model

Installed main and jib sheet, loop fairleads on three booms, jib block and jib tube. Now, this tube is a neat little answer to a problem. The jib sheet runs forward from the continuous loop and moves half what the mainsheet does but as it is let out it would have the potential of snagging on the turnbuckle, the wand system or on other things I haven't thought of. The solution to make that impossible is pretty neat, if I do say so myself: it is a plastic tube that moves with the jibsheet totally preventing any snagging whatsoever. There is no load on the tube -it is just sort of a moving shield.
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There-- is-- only-- one-- job-- left-- to-- do-- and-- this-- boat-- is-- done. Just one plus a little tidying up........
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UPDATE: German Foiler tri post-- new picture-post 1284
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Pictures: The sheeting system and various components--click, if you feel like it:

 

87 pages! Come on Doug. Get it done already. You post links to boats (the black one back a few posts) that are sailing and haven't even one page. 87 pages and still nothing. Finish the build, stop fretting over the paint job and get some film of it preforming.