design/ build Nightmare

How long before the multi is opened? Can we continue this topic here? Ernst: I would like the answers to my questions so I can build/ sail the tri’s against each other, then everyone will have a better idea of how to build. I just looked closer at Red. Does the pivot on the boom have to be offset to in front of the mast? Mine is directly under. Did he change it after having trouble tuning or was it always like that?


feel free to continue your conversation in the pub.

-Dan Sherman

Peter: I would like to know what you are using for keel/rudders in your area. Refer back to multi-hull same topic.

Dear Dansherman - THANK YOU! -

Dear William, dear Ian,
I have re-drawn the basic plans for Superslim and Mk VI in 1:20 Scale = 24.4cm long and wide! -

You can see the relations between Mk I, IV and VI. - Mk I has higher hulls than my Mk VI - but the mainhull is as narrow as the Superslim’s mainhull - with the widest cross section 4" more forward. -

I will store these drawings in
in High Resolution as well! -

If it is needed and wanted, I could draw each single cross section at 1:1 Scale as well! -
For every version. -

Centerboard trunk:
Just cut out the profile of it in Deck and hullbottom - center at 55cm from the stern - paint the outside of the trunk with epoxy resin, stick the trunk in and let the resin cure! - Fill the litte gaps which may remain, with clear epoxy resin as well! -
Resand the whole hull with finest sanding paper, wash the whole surface carefully with acetone to remove any fat, grease or sweat -and then apply one thin coat of clear varnish - acrylic paint recommended! -
Do the same procedure with the crossbars. -
The forward screw for the forward crossbar IS THE MAST PIVOTPOINT!

I had a problem, to upload the pics - they are at my homepage!

Professional shipwright - boatbuilder/-designer with 25 years of experience and a special interest in multhulls

Eveyone go back and see what never got finished before we got cut off and let’s continue here. Thank you!

Ernst: School starts in a week so I need to accomplish as much as possible in that time. Is the location of the trunk on the MKIII the same as MKI. How did you intend to install the trunk now that the hull halves are joined. Will the trunk support the mast oivot for the swing rig or is another post necessary before the truck is installed. Will have queastions for the deck mounted swing rig when i get these things done.

William, the mast doesn’t need additional support - the hull structure is stiff enough in any case! -
The hull halves are joined - right! - But that’s no problem! -
Just glue in the centerboard trunk as I told you! - Make a dry test before , if the trunkcut out is actually vertical and not jamming the trunk, by putting the trunk together with centerboard in place - and have a look from the bow of the hull to check if bow and centerboard are a straight line!- OK? -
I told Mark Baldacchino three years ago, to place the thickest point of the centerboard profile at 55cm from the stern - if he did, then the positions are identical on Mk I and III. On Mk III I glued in the centerboard trunk myself - at 55cm from stern! -

Professional shipwright - boatbuilder/-designer with 25 years of experience and a special interest in multhulls

Ernst: I am sorry. With the delay I was posting at 7:33AM and your 6:24AM post wasn’t there yet. Thank you! That was an earlier question of mine. The main hulls are different? They all look the same.

MKIII has no trunk in place. This is the one I am asking about and working on.

The forward screw for the forward crossbar IS THE MAST PIVOT POINT! Are you talking about the MKIV now. Then all I have to do is take the bolt out put in some all thread with a nut, tighten and leave enough out above the cross arm to be the pivot for your style swing rig. You sent no rig for this boat and I was going to use the Stingrig from Bob Sterne which is stepped on the bottom of the hull and is free standing. It is out of my 10 Rater and I bought and extra tube to mount it in the tri.

The MKIII and MKIV have vertical amas the MKI, FreightTrain, Ghost Train have them canted about 10 degrees, Pulse 3 degrees. Does this make a difference in performance and why, how much. Can we keep discussing boats. Mine are the only post about boats and no one replys. You seem to have time to keep on about things you can do nothing about. Doug is here. Many are gone. Nothing being said today about boats.

I have not canted any of my nightmares and they sail great. I had talked to Ernst about this along time ago. If I remember it correctly this is how he explained it to me…If it was possible to sail the boat even 40 percent of the time at that 10 degree canted angle then it would be beneficial…BUT… with these wild, and twitchy multihulls it is extremely difficult to sail them at a consistent angle therefore the canting of the hulls is more of a asthetic thing than a performance thing. Make sense?

I will have to look at the short movies a friend took and sent me. 10 degrees is about 8". I never paid much attention to the angle. Ernst hulls are circular so the angle matters less but the pulse are 25 degree angle V btm. but he only uses 3 degrees.

I looked at the movie and with 5-7 mph winds I am at 10 degrees about 8" out of the water flying on one hull. If anyone would like to see it send me your e-mail. 9 sec. movie?