Monos built strickly for SAW?

[Christian Lucas]

Hi,

some thought about monohull . First pic boat has a long arnesen drive stearable strut .

Second pic has twin counter rotating propeller mouted on the side not coming out at the transom . For electric motor i can use a motor with long shaft on both side of the motor running left and right hand flexcable . Extension is only a ruder suport and aerodynamic transom extension above watersurface.

 

[Andy Brown]

Hi,

some thought about monohull . First pic boat has a long arnesen drive stearable strut .

Second pic has twin counter rotating propeller mouted on the side not coming out at the transom . For electric motor i can use a motor with long shaft on both side of the motor running left and right hand flexcable . Extension is only a ruder suport and aerodynamic transom extension above watersurface.

Nice Christian! I have made similar drawings as your first one with the Arnesen drive.

BUT...according to John's comments about a transom overhang as in your first pics in this thread, it would not be IMPBA legal.

 

[Andy Brown]

Did you completely remove all the pre-installed plywood rails and bulkheads from your Northwind hull such that it can lay flat upside-down?

Yes... They were coming out anyhow from time and being in storage inside the box so long.

As you can tell, the hull needs some repair on the one corner, but if it's going to be a plug, that's easy.

Funny you should mention the 40 sized... I had a built one (rough, needed a lot of cleanup and repair) that I traded for this 20 kit... I wish I could get one of these that's in the .12 size... like 22" or so...

I have a Northwind 20. I might be good for a heavy electrics. Maybe 6S or 8S These boats have a lot of built in lift.. In the outer "wing" area.

Back in the 70's I knew a guy that cut about 2.5 inches off each side to reduce the lift. He ran a Super Tigre 29 with and OPS 29 pipe. It was wicked fast for the day. And super smooth running on rough water.

 

[David Bryant]

Did you completely remove all the pre-installed plywood rails and bulkheads from your Northwind hull such that it can lay flat upside-down?

Yes... They were coming out anyhow from time and being in storage inside the box so long.

As you can tell, the hull needs some repair on the one corner, but if it's going to be a plug, that's easy.

Funny you should mention the 40 sized... I had a built one (rough, needed a lot of cleanup and repair) that I traded for this 20 kit... I wish I could get one of these that's in the .12 size... like 22" or so...

I have a Northwind 20. I might be good for a heavy electrics. Maybe 6S or 8S These boats have a lot of built in lift.. In the outer "wing" area.

Back in the 70's I knew a guy that cut about 2.5 inches off each side to reduce the lift. He ran a Super Tigre 29 with and OPS 29 pipe. It was wicked fast for the day. And super smooth running on rough water.

The Northwind set-up instructions recommend off-setting engine mounting towards the left or port side (as opposed to the right or starboard side) to compensate for engine/prop torque. Also recommend applying 2 - 4 ounces of weight to the left-side rear wing outer-edge, and 4 - 6 ounces in the very front bulkhead cavity in bow (by drilling small hole in deck)

 

[Christian Lucas]

Hi Andy ,

Ok yes for the overhang that is a aeropart of the hull , but what about the propshaft and ruder ? How long can the propshaft be after the transom and how far away can a ruder be placed . A long arnesondrive is not much different to a solid propshaft . And where is writen where has the propeller to be ? After the transom or as my idee at the side of the hull ,best on both side with counter rotating propellers . If so i can easy have a counterrotating system without a gear only use of flexcable . The rules do not tell this .

 

[Christian Lucas]

Hi,

are historic raceboats like Babybootlegger not allowed ? As this overhang is no step , http://www.seqair.com/Other/Bootlegger/Bootlegger.html. .

 

[Andy Brown]

Hi Andy ,

Ok yes for the overhang that is a aeropart of the hull , but what about the propshaft and ruder ? How long can the propshaft be after the transom and how far away can a ruder be placed . A long arnesondrive is not much different to a solid propshaft . And where is writen where has the propeller to be ? After the transom or as my idee at the side of the hull ,best on both side with counter rotating propellers . If so i can easy have a counterrotating system without a gear only use of flexcable . The rules do not tell this .

Christian,

For IMPBA Mono rules there are many unwritten gray areas. If there is a questionable part in the boat design, John Finch decides if it is legal or not.

Classes with hull design rules will always have gray areas. That is why I have always preferred to design for the open hydro class where a maximum size and weight is the only hull restriction.

For mod mono designs you must only design for your pleasure and not be concerned with organized competition. Although I think a MOD VEE class could get some creative juices flowing.

 

[Christian Lucas]

Hi Andy,

Yea the grey areas are the spot for designer to look about ways to make them usefull .

I have looked for the streamlined transom and i think it's no problem to let the trasünsom end in a sharp knife . The rules want no step ,so the bottom can end with the round end or can styled rectangular like a normal monohull but the body obove end in a knife for better aerodynamic. The bottom that now is out of the centerbodyhull can be used as a trimtab . I have a article from Italien monohullraceboat designer that use this type of trimtab mounted at an 45 degree angle under the hull to stabilize the hull when it starts to roll from left to the right hand. Maybee John Finch say no to this type of trimtab ,than the bottom has to be stiff . I have made some fast drawing . My designes are moor the aerodart way ,but i know that Ralf Moser the king of monohull has a moore bumbelbee design and he told me that if nature likes moore this design he will prefere it.

 

[Mark Poole ModVP]

I have said for years that all of this illegal or questionable, experimental stuff would be right at home in Mod-VP. The boats we run in outboard Mod-VP are not legal in tunnel class or mono class but they sure do make fun and interesting racing.

As long as the keel remains the deepest part of the hull and no hydroplane style hulls are allowed, it goes.

Stepped hulls, monos with sponsons, tunnels with keels, bat wing, winger dingers, dinga lingers would all be welcome.

 

[dwilfong]

Here are a few pics of a Cal Craft that was modified for me by Rickard Andersson.

When I get the time I will set this up with my VAC 1.05 eng to see what it will do.

The boat was stretched from 39" to 42" and the top deck was changed some.

The top deck is made as a lifting surface with a completely covered canopy.

It maintained the 11" width to cut down on the frontal area..

The added length was added to help with stability at speed.

 

[Roger Hooks Jr.]

Not much of a SAW guy myself but I did run my Aeromarine Titan 33" hull in 60 Mono. My first time out I was within a mph of the 60 mono record. I was impressed how high up the boat could ride on top of the water. It was like it was running on the very edge of the vee. I thought this is why it worked so good. It's like it's possible for you to ride a knifes edge on top of the water. Can't get any less drag than that and still touch the water.

 

[vernon newson]

That's a nice boat Dave

 

[Christian Lucas]

Hi ,

news from the mono front . Ralf Moser new SAW boat " Corvus "

A very well designed Aero thingis , runing impresiv .

 

[David Bryant]

very cool design there

 

[Darin Jordan]

Love the Beer on the worktable! I need to travel to Germany next time!

 

[Christian Lucas]

Hi,

was great to have Tyler in Munich and i hope to wellcome you Darin next year . Bier is brew by the Bavarian Reinheitsgebot = purity law.

Ralf new boat hit near his topspeed of his last year boat by only halve powerconsumpion . And Ralf is allway cool .The boat is his totaly owen design .

Happy Amps Christian

 

[Christian Lucas]

Hi,

have upload a video of Ralfs monoboot runing 159 km/h topspeed in Munich .

https://youtu.be/xv5m9rkgNbU

Happy Amps Christian

 

[John Finch]

Wow! 98 mph! that is awesome Ralf!

John

 

[dwilfong]

has any mono hull broke 100MPH yet?

 

[John Finch]

Yes. Ralf did it at a namba event. 106 mph I believe.


Sent from my iPhone using Tapatalk