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

Doug - given that
a) you've not even got a working model yet
b) you've never actually built a successful full scale foiler
c) you've never sailed a trapeze boat

How do you know it can be single handed in up to 15 knots of wind?

Secondly while the weight calcs are somewhat similar the RM for the F18 is around 3350#

RM on yours is harder to cacluate because of the dynmaics of the center foil as the primary lift source, but you are probably looking at an effective RM of 1/2 of the F18 - assuming it ever gets built since the model has taken now some 4.5 years to get built.

 

Hmm if that makes sense to you, then perhaps you can explain where my analysis is wrong rather than engaging in a personal attack.

 

Why bother explain anything when you will dismiss any info before even considering if it is correct. How about giving Doug a break, you clearly are here to Troll any Doug Lord post, as you do on SA, grow up.

Oh and thanks for the negative rep, Im pretty sure I never actually said your name in any of my post, bit insecure there BB? Feel free to give me some more negative rep, Ive still got more than you

Sorry for the thread drift Doug, Im just sick of the trolling. Ill go now.

 

When have I dismissed things that have actually been logically explained? What am I trolling? Doug made a statement that in light of what I understand about mechanics, hydrodynamics, naval architecture and lift, just don't make any sense?

As for reputations - again isn't that what the are for? for pointing out when someone is trolling by engaging in off topic personal attacks?

 

MPX Foiler

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When it comes to me, my boat or the Flying Phantom, you really just don't know what you're talking about-you simply and maliciously make stuff up about me, and the MPX-and throw in inaccurate information about the Flying Phantom to boot*--I'm responding to help others understand the facts since I know, based on the numerous harrassing e-mails you sent me(and I saved), that your only purpose in this thread(and on boatdesign.net) is to harass me and try to wreck the thread or threads that I participate in or have started:
1) My 16 foot monofoiler was not successful in terms of what I wanted from it, however it was a great learning experience and successfully utilized manual foil control(twist grip tiller) for the main foil for the first time on any monofoiler. It foiled but was a bit difficult to control because unbeknownst to me the control rod was bent-but the control system worked. No crashes-not a single one. The bow design was poor for early take off in the intercoastal. Nevertheless, I call it a personal success because of what it taught me.
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2) I designed, built and produced 6 of the the worlds first rc sailing foiler 13 years ago-the F3.
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3) I crewed on a Flying Dutchman at the Pensacola Yacht Club in 1966 which was my first trapeze experience. I sailed a Hobie 16 on the trap for many hours during the 70's and 80s.
*as well as incredibly inaccurate and uninformed information about the planing ama in post 822. Anyone can check the well known FACTS in post 821.
==========================
Your "facts" on the Flying Phantom RM compared to the MPX full size boat are very incorrect:
1) Flying Phantom RM=
a-crew 350lb @ 11'= 3850ft.lb (crew CG on trapeze to center of lift of lee foil)
b- boat 363 @ 4' = 1452ft.lb
TOTAL Flying Phantom RM= = 5302ft.lb
===============
2) MPX 18' trimaran=
( Note: when MPX foiler is flying(with no mainfoil downforce) there is virtually NO LOAD on the mainfoil since the ama foil takes nearlly the whole weight of the boat. The main foil is designed to lift up to 80% of the total weight of the boat + crew= 600lb and is designed to create a maximum of 600lb of downforce(same "lift" up or down). The ama foil is designed to support up to 1200lb when the maximum downforce is used( normally only 200lb of downforce will be used except singlehanded where 440lb(or up to 600lb intermittently) of downforce would be used).Downforce is controlled by limiting wand movement(flap "up angle")or manually and can be increased by changing the preset main foil angle of incidence from +2.5 degrees down to zero degrees-adjustable under sail.)
a. crew 350lb @ 11'= 3850ft.lb(crew sitting on windward side of cockpit-measured to center of lift of ama foil)
b. boat 400lb @ 8'= 3200ft.lb
Subtotal = 7050ft.lb(1.33 times Phantom max)
c. mainfoil downforce-max 600lb @ 8'= 4800ft.lb-normally(except when single handed) downforce would be limited to about a third of this or 200lb @ 8'= 1600ft.lb
TOTAL MPX RM(normal config)=
a+b+c(normal)= 8650ft.lb or 1.6 times the RM of the Flying Phantom! And thats with the crew SITTING on the windward side of the cockpit-not all the way to windward-and NOT on trapezes.
==============
Single handed MPX-
a. crew 175 @ 11'= 1925ft.lb
b. boat 400lb @ 8'= 3200ft.lb
Subtotal = 5125ft.lb (almost equal to Flying Phantom with one crew!)
c. Downforce= 440.6lb@ 8'(from center of lift of lee foil)= 3524.8ft.lb
TOTAL MPX RM SINGLEHANDED=
a+b+ c= 8649.8ft.lb (so RM singlehanded can equal RM double handed by using only 73% of the available mainfoil downforce!)
Of course, one of the unique features of this design is that downforce can be turned off in the vast majority of conditions where it is not needed.
======================================
Ama foil details(based on 63412 foil) at max RM(max downforce plus 80% of all up weight-100% of all up weight) :
1) Nominal load =1200lb(can go up to 1350)
2) Nominal lifting area= 3sq.ft.( can go higher)
3) Running angle of incidence +1 degree( 20 knots +)-adjustable.
4) Lift Coeficient- about .4 (centered in low drag bucket of 63412-variable)
5) Foil Loading-400lb/sq.ft.-450lb/sq.ft.--(max on Rave close to 500,David Luggs small main foil on full flying Int. 14=800lb/sq.ft)
6) Max downforce range with this area and CL- 20 knots +. Max downforce range nominally 15 knots on up.
7) Every thing is adjustable to configure downforce and ama foil for lowest drag at maximum RM/maximum speed.
=======================================

SUMMARY- The 18' MPX foiler -fullsize version of the test model- has 1.6 times the righting moment of the Flying Phantom with two crew OR singlehanded! It has more power to carry sail than any current multihull under 20' as best I can tell. Movement of the crew side to side in a tack or gybe is limited to 3-4'. The idea is maximum comfort, ease of sailing with maximum performance.
It will have the capability of flying the main hull in a 5-6 knot breeze.

 

Doug your repeated personal attacks on me in this forum are not appropriate. I've asked the moderator to deal with this.... again - it would be nice if you followed the rules of this forum and did not attack personally and stayed on topic.

Now as to the substantive part:

I've looked at post 821. I don't see much in the way of "facts" there. You have made assertions about what your "planing ama" will do - but your assertions about the L'hydroptere ama are quite inaccurate. Firs off their ama is a "deep vee" hull shape that while capable of planing, is also designed to deal with penetrating though the tops of ocean waves and swell. And it has a fair shape.

the comparison to your ama shape could not be more different. You have a wide fat tail that no successful designer has ever made work. Its been tried on windsurfers and surfboards and it is slow in comparison to a "fair shape". So what is it that you are doing differently than what these other very talented designers missed?


Your RM calculations are questionable as well.

If your net beam is 22' then your Aka is at 11'. and you have about a 50/50 split between your amas and main hull in terms of weight - so assuming your build comes in at 363# - you have 90# x 22' = 1980 + 181 x 11 = 1996 ==> 3976# of RM from te boat. plus 2200 ft# from the crew (I suspect you are closer to 200# than 175#).

that means that your sails and your main foil will need to be lifting 6200 Ft lbs to fly.

WOW!!! your main foil has to generate almost three tons of vertical lift for the boat to remain in balance!!! L'Hydroptere clocks in at 15,500# so each of its foils has to generate roughly 7,000 ft Lbs of lift.

So according to you, your T-foil will be 80% as strong as the braced diagonal foils of L'Hydropere? I suspect that you must have something to teach to High On Carbon on how to manufacture Carbon 90 degree foil joints robustly!!!

 

Baltic, this is Doug's project and it is all part of the learning process to take an idea and turn it into something tangible. Whether it works or not will be determined in the field or on the water.
Consider that it is not what you say but rather how you say it. There is a level of snarkiness to your posts that seem bent on targeting the man personally.
жити і давати жити

 

Again, I came to this thread after being personally attacked by Doug. Other posters piled on.

I asked that those portions of the thread be moved so the conversation could continue WRT the design. I've done nothing but ask questions, offer help by making some of the content more readable, and point out confusing inconsistencies and inaccuracies in Doug's posts

for that I have again been attacked by posters and by Doug. I've asked the moderator to intervene in this but this seems to be of limited use.

I agree that this will be proved out on he water, but when I politely asked when we might see this I was again attacked personally.


Is it any wonder that I am less than patient? Particularly when I have been to the Paris Boat Show and seen the F18 Phantom and spoken to the designer. And Doug's statements are not consistent with what I have seen and heard .

and particularly when in another thread TSpeer basically told Doug that Doug did not understand how dihedral lifting foils worked to have heave stability?

 

Okay, we have all been told. Now let experience of field trials be our teacher. Just let it go.

 

So again, why the assymetric application of your rules? Doug has also basically posted the same content over and over without really answering any questions. All I've done is edit down his posts using Word's "Compare Changes" feature and ask the questions that are missing from the design.

Why the different rules? Particularly since I've been the target of the attacks?

Another question for you Hoyte - feel free to not answer it as it is more personal and hence somewhat off topic:

I believe Doug has said he is 64 years old. I suspect he would take offense if he was considered to be less capable than a full fledged adult. So why do you feel the need to attack and correct me in defense of an adult who should be perfectly able to represent himself in the best manner s/he chooses? where you acting that way on my behalf, I would feel insulted and belittled since it would come across to me as though you believed I was incapable of representing myself as a fully competent adult.

 

They are not my rules. Besides, disagreeing is not attacking. Unlike in some places, different opinions are respected if they are stated in a diplomatic way. If I failed in this regard, I apologise.

 

I'm curious as to what you are disagreeing with when you reiterate something as obvious that this is Doug's project and then instruct me to "just let it go"... or point out to me that I have "[already] told" my perspective.

too me that comes across as you having one set of rules for repeated commentary that you hold me to - and a different one that you hold Doug to. Which sure sounds like "your rules" and you "protecting" Doug..

At least that's how it comes across to me.


Again, frankly I'd prefer that everything from Post 824 onwards be once again, split from this thread and moved into a separate thread where those who wish to keep attacking me can be sequestered - Doug included.

 

MPX Test Model

As the thread starter, I don't want a single post removed. I want them all here for the record. Thanks.

 

Well you have already had posts removed for your blatant attacks on me. I'm asking that this attack be dealt with similarly.

Why do you believe as a thread starter you should be immune from the rules of conduct of this forum?

 

BB,
I did not instruct, command or order you to let it go. I did recommend or suggest that you do so for the sake of civility. If you are not interested in being civil I guess that would make you the aggressor not the victim.