Morspeed

For near on two years I have been thinking/ planning on building a multi hull, as a cat enthusiast I was dedicated to the cause of building 1.2mt cat, howeverbefore I could start building I was commissioned todeliver a cat 2/3rd's the way around the world. Home now after 18 months on the water, I am ready and have started building.
However, I have been keenly following the advice and input on this site from the likes of "Dick L" and Idealist, I would like to thank everyone who has contributed to this forum. I have learned many valuable things before even picking up a tool and this assists me greatly.

I also thank TBK and Siri for inspiration, it is fantastic to seeboats being actually built after two years of people just talking about it.

I have been swayed by by these forums to build a tri first, before attempting a cat.

My plan is to build a set of female moulds as I will build several boats to compete against each other and trial various rudder, keel fin, foil, rig ideas.

This is my first scratch built RC yacht and there are certainly things I will need some advice on as I proceed so I hope to get a little help with input. This will not be a super fast build, although I would like to have a boat sailing by October, I prefer to take my time and get a high quality finish without to many design regrets.

I will build components with Epoxy vacuum infused carbon and am planning on experimenting with elevated post cure temperatures.

So...a very long time ago Ernst kindly supplied me with Nightmare VII plans, about six weeks ago I cut the frames and mounted them on my building boards, then stopped and took a long hard look at what I was putting together ...I did not like it...nothing wrong with the plans..I think Ernst has done a fantastic job....So I asked Ernst for the VIII plans, This was closer to what I was looking for but I knew I could not build this design, I understand why Ernst designed his boats this way and I could not fault them...the problem was the finished product would lack the style and shapeI wanted.

The picture attached shows the VII frames cut and mounted, I have no use for these now so if someone out there would like to make use of them just drop me a line, they are free to a genuine home.

The other pics attached show what I really wanted to see in my boat...I love the Banque Popular look...I wanted a nice curve / shear line on my hull deck join that would compliment the shape I am putting in the deck and I wanted some shape in my topsides. There is strength gains in shape that flat panels cannot offer and since I am looking for very thin composites with minimal internal structure I had no choice but to spend considerable time redesigning Ernst's fine work.

Ihope Ernst,that you do not take this badly, we knowyour design works , your hydronamics seem to be effective, I figured that a little deviation in design efforts could only be good for growing this class.

So let the build begin.

Gary

TBK

Gary

I would like to see what your new design looks like. I also like the look of the Banque Popular boat (It's my screen saver on my desktop). Just a caution. The performance of a scaled down model is not the same as a purpose designed model. There will be necessary tradeoffs required in the esthetics/overall look to optimize performance. Ernst's design has been shown to have most of the key attributes needed for a robust racing platform, especially when built to optimize the overall weight. As Sirit has pointed out you could spend a lot of time and money developing a new design and then find out it does not provide you with the performance you were expecting. His approach is to build a "rough" prototype version using glass over foam, with minimal finishing simply to test the design/shape. He only invested about 16 hrs in the little mini 65G tri. Once he is happy that the boat will perform he plans to take the design and then build a quality set of moulds. Like you I have had many years racing full-size catamarans and I used some of that knowledge when building my models. Initially I was expecting that the MKVII would not look as esthetically pleasing as my previous Snapdragon design, especially since I decided (on purpose) to build the "square bottom" version. But when it was all finished and painted it turned out to be quite a "looker". Good luck with your build and keep the pictures coming.

TBK

Idealist

Dear Dreamwakes,
there is no reason for me to take this badly in any way!

It´s actually the other way round.
After nine years of correspondence with about 250 persons,who only wanted to know/find outwhat I know - instead of being able to share their knowledge with me,
I felt very disappointed and also exhausted, because I seemed to be unable to find persons to discuss designconcepts which could lead to a promising future.

Most of them where even too lazy or simply had too little knowledge to understand why I designed my boats the way I did.
For example, I only sold TWO "Nightmare Mk.I" to the USA - and there where almost NO intentions to reproduce them there.

My conclusion was, my designs where still toosophisticated and too complicated to be reproduced.
Therefore I looked for design- and build-simplifications, while keeping up big safetyfactors to reduce capsizing danger.
The Mk.VII was the result!

Now - after giving out 107 plans of this boat for free - and approximately 13 free plans of the Mk.VIII,
Plus about 20 via the german Mini40 forum: http://www.rc-network.de/forum/forumdisplay.php?f=166
This group there had the ability to pick up some of my ideas and develop them a bit further,
but where unwilling/unable to share their knowledge on a worldwide basis.
So I did it myself in this forum!
And now I finally found someone who has the guts, to use my designconclusions as a BASIS, to develop a completely NEW hightech boat!

Please do understand this -
neither "Nighmare Mk.VII", nor "Nightmare Mk.VIII" - or Siris little "RT65 Race Trimaran" should be considered as "the end of the line",
but only as a stable and functioning basis TOSTARTFROM!

(Proverb: "This isn´t the beginning of the end, it is only the end of the beginning!")

Please also note - from now on I can only be reached at: [email protected], instead of: [email protected] - as my old PC broke down.
This also fits for the free selfbuildingplans!

Morspeed

TBK , agree on the aethetics of the VII, it does look good, I was impressed with your result.

I have faith in Ernst's design and have infact leaned heavily on his below waterline measurements. Above waterline I have not moved the volume forward or aft (much)but havechanged the shape. With this I have confidence that what I build will work, it may or may not bethe best/fastest tri and I am very comfortable with that. Given the methodology behind by build methods , I will be able to produce modifiedfemale moulds easily and quickly once the first set is made.

I was quite concerned about the overkill in volume in VIII design, but now I have a planked float it actually looks perfect and I can only imagine making very smallchanges to the shape, should it require future modifications.

Inmy experience, by far the most amount of work in building a set of production moulds (around 95% of total build time) is in the building of a set of plugs, (or it should be cause your finished plug will reproduce every detail good and bad). With all this in mind I cannot see the sense in building a rough version first, my free time is limited so want to put it to the best use...and at the end of the day if it don't workat all then I will still have a fine looking boat to add to the collection.

And Ernst, Thankyou...I am pleased I can move forward and have you on my side.

A bit of explanation behind the building board method I am using.....

I wanted a board that was very rigid, easily and safelytransportable (without plug distortion) between workshops, cheap,reusable and big enoughfor future projects planned. I am using16mm thick MDF (medium density fibreboard)with a plastic veneer laminate finish.Beneath eachside I have through bolted a very straight and true length of 25mm x 25mm 1.6mm thin wall steel box section. MDF has a tendency to sag / warp and swell over time and does not have a lot of rigidity /strength, the steel box section should keep my plugs true.

Morspeed

Next step was to cut and mount the frames for float hulls, but first a little insight into the changes I made to theVIII float hull design.

Below waterline I have only changed the radius's by a few degrees and only where neccessary to get the overall shape I wanted. I did however flatten off the three aft frames tocreate a planing surface. My thoughts are when the boat is on a close reach and higher, then the leeward float forward section is doing all the work, however when on a beam reachthe aft sections will come into play...this small planing area should prevent the aft hull section digging in by adding a little lift..

Below waterline I have also lifted up thefirst three bow frames a little, somewhere between the VII and VIII profile.

Above waterline I have put a radius around 280 degrees between the waterlineand hull deck join , this gives a very pleasing curveand results in a look very close to Banque popular. I have changed the aft fourframes so the transom begins witha flared hull that tapers into the forward sections.

It was surprising how little I had to change the fundamental measurements of the VIII design in order to get a satisfying result, it did however require a complete redraw to obtain a hull deck join that looked right and would still provide correct mould release angles.

Next was the making of the aluminium frame mountsdesigned to give maximum flexibility to bulkhead/frame alignment.

I fabricated these aluminium mounts from a length of 20mm x 20mm x 1.6 mm angle section. In the face that bolts to the board I drilled two holes in each peice and then tapped M4 thread.

In the face that screws to the frames I drilled two oversize holes (approx 1.5mm oversize) for M3 pan head screws to fix through into the frames.These oversize holesallow for very small adjustment to alignment and height of frames.

Usingthin wall aluminium angle gives enough rigidity to hold frames strong but also allows for easy slight bending / tweaking when ensuring the frames are square with the building boardonce mounted.

I then placed each aluminium frame in position on the building board and marked the hole positionsfor through fixing.

Drilling the build board frame mount holes over size (approx 3mm oversize) allowed for very small adjustments toframe position to ensure perfect alignmentand centreing of frames.

By fixing the aluminium frame mounts onto thebuilding board from underneath (M4 bolts with washers) I can now remove the hull plug from building board easily when ready for that step.

Once frames were mounted, I fixed (Ca glued) balsa rectangular sections between each frame and just alittle below the gunnel line, this stiffens up the frames, aprecaution against the plugs twisting/ movingwhen removing from the building board. Next I added a 7mm block of balsa to the bow frame (15) front and back.This just gives alarger glue surface for the fairly stiff planks I will be laying. I should also point out I actually moved the bow bulkhead back 5mm from its correct position (and therefore cut this frame to suit this position). This gave me the space to put a balsa block up front.

I choose 5mm mdf for making my frames as it is very easy to work, cheap and 5mm gives enough rigidity to withstand the pressure of the vacuumI will use.

TBK

Gary

Nice job on the building board. I used the coated MDF base board and the 1/4" mdf for the templates as well and it makes for a nice rigid platform for planking the hull. Like you I only have a limited amount of time so I did a quality build, assuming I would get a good desired result. The only decision I was unsure of atthe start was if I was going to use theplanked hulls as male plugs or as a one-off glass over balsa boat. I kept my options open by only covering the sanded hull with 2oz glass. After making a couple of hull shells in a range of different cloth weight combinations, including carbon fiber and then comparing the overall strength vs weight to the coated balsa hull, I decided to use the all glass shells instead of the balsa glassed shell. In hindsight had I made this decision before glassing the balsa plug, I would have used a heavier weight of cloth or at least another layer for more strength. I would have spent a little more time in final finishing of the plug as well, which would have saved time and effort later incompleting the finished shells. Since you are going the next step to make female plugs, finishing of the male blank is critical. As you have said every little imperfection will show up in the final product. Good luck and keep the pictures coming.

TBK

[email protected]

i would like to bild a verry simpel bote to start with.  wont to bild bote use moter and servos from a helicopter should be powerful enuf to push it  have any simpel planes. thanks.  

Morspeed

Hey David..not sure where you will find a basic set of plans to suit your needs but would suggest someone in the nitro or elctric power boat forums should be able to point you in the right direction.

TBK...Yep that custom wood is good stuff for plug building. But if there is only one lesson I have learned in the art of plastic composite boatbuilding it is this....absolutely and always avoid sanding fibreglass.....always!!.... cause it is horrible stuff in dust form.

For this reason I choose to build plugs a little differently than most. At this point it is also worth noting that although it takes alot more effort ( read time ) to build a quality set of female moulds...you save a lot of time at the other end when you have a gelcoat finish out of the moulds and fairing / painting the end result is not neccessary .

My method involves the removing of the plug from the building board once frames are planked and before I sand back/ fair up hull.

I will lay a epoxy mat into the hull interior , butting the mat up to each frame. This will provide all the strength needed to hold plug true and allow me to sand the balsa as thin as required

I was fortunate to have Brian at Airsail mill me a pile of hard grade balsa planks 1.22 long 100mm wide and 3.2mm thick. With a balsa stripping tool I was able to strip planks down as required. I needed to strip planks as thin as 6mm to cope with the compound curves below waterline.

Using a hard grade of balsa provides for a stiff strong curve on the frames and can take the pressure of strong clamps without creating pressure dents in surface. This will also aid in giving a tough plug surface which as always will help give the plug an extended / resuable life.

It is also fantastic to sand /shape, easy to fair but not so easy you gouge through it in 5 swipes of your sanding block.

It was a little tough getting the stiff balsa layed but Ca glue worked out well and only had to cut my finger tip off the hull twice during the glueing process.

So here is a bunch of pics of the float hull planked...I am very pleased with the result and will start framing up the main hull tommorrow.

Idealist

Looks good, dreamwakes - just keep the pics coming!

I´m nervously waiting to see your final hullshapes.
And I hope you don´t mess it up for some reason.

Morspeed

No need to be nervous Ernst, as you can see the fundamental underlying VIII profile  is still there, I have  primarily changed the above water shape to create the Banque Popular look.

Idealist

As stated before, I also like the look of the big "Bank Pop" a lot.

It´s inspiring me to go back to my drawing board and fumble around with some new linedrawings myself.
You know - a little bit less there - and a little bit more here - just asusual! - *ggg*

Let´s see, how much similarities we will have in the end. - The race is on!

Morspeed

yep...that and the Brossard are my favourites...but maybe its the colour scheme that attracts me to the Brossard..it does look good. Speaking of races...one day..some how...  I would like to show you my wake ..just to throw out a challenge for further inspiration.

Idealist

Haha! - Just sent me a flight ticket to New Zealand!
I might never return to Vienna. *ggg*

Morspeed

Ernst, was thinking a trip to Vienna sometime...the missus wants to go to Italy (something to do with shoes and old buildings)...you are just up the road from there aren't you??...

So I thought I would start building rudder and keel fins this week and would like your thoughts on the optimum size...(length, width and thickness) of these..

Cheers  Gary

[email protected]

thanks ill try trhat

TBK

Good progress. Your hulls look good. I did follow the same process, using harder grade balsa stripped to suit and thin CA glue. It does fair very well without any high/low spots. Only got my fingers stuck to the frame once, but I got them stuck together twice. That hurts even more. Keep the pictures coming. The shape looks very pleasing.

TBK

Idealist

Dreamwakes

In the beginning (2000-2001) I used Helicopter blades 50mm wide, whichhad about 15% thickness, but moved to selfbuilt HQ profiles 60mm wide and only 8% thickness.
One reason for wider profiles is the reynoldsnumber, because the waterflow is allways overcritical otherwise.
Length to width should be 5:1 at least.

But as Phanchita showed with the RT65, also profiles with only 45mm wideness work.

Idealist

Morspeed

Thankyou Erns't,  good info...I wil get onto building these soon...Have the mainhull frames mounted and began planking..looking good so far....will post some pics tommorrow.

Idealist

Cool! - I´m looking forward to see them.

Morspeed

A brief interlude, check out the pics of Alinghis newest Multi getting a lift to the pond...there's gotta be a witty caption in these pics...a landlocked country holding the AC...how does that work??..

Morspeed

Back to business, as promised here is picture update of main hull construction...almost nothing changed in this hull, as per Nightmare VIII main hull design . Big changes are in the redrawn gunnel lines, hull deck join will now feature a little shear as with the float hulls.
Built in exactly same method as float hulls..so far ...so good.

TBK

Looking good so far. I'd like to see the hull template when it's planked, to see waht you've done. Keep the pictures flowing, especially when you start with the female mouding process, as that is something I've not tried yet, but I have looked into many ways to get it done. Are you planning on using the latex moulding material or are you going to make fiberglas casts, using casting resins?

TBK

Morspeed

TBK, not sure what you mean by "seeing hull templates when planked"??...please expand...will likely use tooling gelcoat,epoxy resin and plenty of glass cloth for building female moulds, from the qualtiy of work I have seen you produce I think you would have no problem going down that road yourself.

TBK

Gary

I guess what I meant to say was I'd really like to see the hull profile once it's planked. I like what you've done to the hulls so far. Keep up the good work andI look forward to following your progress. Have you given any thought yet to the design of the xbeams that you will use? This might impact the design of the deck profiles to build in gussets etc. In my build I added some small gussets under the xbeams and then faired them into the hull. They look kind of ugly when the boat is disassembled but they really make the lines flow when the boat is together, as they tend to blend the xbeam joint to the hulls. I could have added these to the male mould before I cast off the second set of shells and it would have avoided a lot of extra custom fit up etc. Unfortunately I had already made the carbon shells long before I decided to add these pieces in. A similar situation exists with the shaped transom. This was all custom made prior tobonding the two shellpieces together. You could make a mould for this piece as well and then have athree piece assembly on the main hull. The German fellow who has a build log on RCForum seemed to use this approach. Again a little more time spent upfront would save many hours later, especially if you plan on making a number of boats from the moulds. I'm sure that this would also allow you to reduce the overall weight as well. I've finally finished all the "building" on the my second all carbon Nightmare MKVII and I am into the final finishing and painting. I'll be posting some photos on my build log once I get some color on the boat.

TBK

Morspeed

TBK, nearly there with planking...maybe a few more days yet.

From the out set I had been considering a female mould split at the transom to accomodate the angle I would prefer..but there are several ways to do this...will make a call soon...normally would not go down this road but vacuum bagging will enable me to get the sharp angles without air pockets in laminate..
Will definately incorporate sections into deck mould to receive the X members..I want curved foils for these..loads of work in that department..  Thinking about a set of split moulds for these as well.

I would really like to see a vid of  your carbon version in full flight!!.

Gary