Monos built strickly for SAW?

[Andy Greene]

N-1 OR 2 ??

 

[BobLondress]

N super stock

 

[BobLondress]

Yes Andy

with all that Horsepower, I did not want it to move !

 

[John Finch]

Speaking of the strut...........I am thinking the prop might bury the bow being that it is so far away from the transom. If it does, shorten the tube a little at a time until the bow comes up. Just a suggestion. I had a similar setup many years ago and used two rods to form a three point stance and it worked great.

John

 

[BobLondress]

John,

Thanks for the input on the length, I will keep that in mind.

I thought about a 3 point deal also. The power is so low, I don't think it is necessary. But we will see.

 

[Amp Eater]

Nice build!

Vid vid vid the crowd chants.

 

[BobLondress]

Thanks, now lets see if it runs !

 

[David Bryant]

My new mono designed and built for SAW trials. Testing begins next week.

What overall length?

Transom width?

 

[BobLondress]

23" length

11.5" beam at transom

3# ready to run

 

[John Finch]

Get that puppy wet!

 

[BobLondress]

John

I have been busy and not had a chance to even put it in the water. I just got back from the NO race and am planning on running it before the Huntsville record trials in a few weeks. We will know soon !

 

[Jeff Lutz]

Here is Don Pinckerts flat bottom mono. He modified his sundance many years ago. His Sundance was fast, this boat here is basically his straightaway version. Jeff Lutz

 

[BobLondress]

The angles on those stakes look to be more than allowed. 15 degrees is maximum.

 

[Jeff Lutz]

The angles on those stakes look to be more than allowed. 15 degrees is maximum.

. I have not read that about the strakes, but I do know Don's boat is legal, and held some impba records years ago.

 

[BobLondress]

Its in the rule book, I think it has been for many years. Its hard to say from a picture if they are more than 15 deg, but if they are, its not a legal mono.

 

[Andy Brown]

Its in the rule book, I think it has been for many years. Its hard to say from a picture if they are more than 15 deg, but if they are, its not a legal mono.

1. 1. Mono Hull Definitions and Restrictions

“Mono” is a hull that has a continuous wetted surface when operating at racing
speed.
Mono must incorporate the following design characteristics and not exceed any of the dimensional restrictions.

a. A hull that has no discontinuities between or steps in the wetted surface running at
more than a 15- degree angle with keel, in plane view (bottom view).

Bob,
The key word is "plane view".
This means the strake must basically run parallel to the keel, but can angle inward or outward up to15 degrees.

Many hulls have strakes that angle inward at the bow. This does not really cause a discontinuity, even if they angled in more than 15 degrees.
If the strakes angled outward as they move toward the bow, they can effectively become a step. Even 15 degrees would be a mild step. 45 degrees more so. And 90 degrees would be a complete breaking step.

I hope this clears things up.

 

[John Finch]

Good explanation Andy.

John

 

[Ralf Moser]

Hello,

back after a break with monos the question with the strakes fits my question i had last year.

In the picture the strake is parallel to the keel from bottom view, but the "running surface" of the strake itself is angled downwards relative to waterlevel.

in detail this strake is forming a tunnel.

Does this fit the rules?

Also the chines are angeled downwards significantly.

Regards

Ralf

 

[guy leveque]

draw views...

Guy,Pretty close, but your drawing would be illegal in IMPBA with the step just before the flat spot. My boat did not have a flat ride surface. I actually had two hulls. The first was a true deep vee all the way to the keel. The second one had a 10 degree vee at the keel. I used flat pads on my sightler boats and on some twincrafts but the flat pad is sort of like skipping a rock across the water with no control. I prefer a bit of vee to the keel for control. The distance of the prop to the transom is key in getting the boat to air out as is the rudder location for both ride angle and roll stability. Tune the boat with those two elements and you are on the way to getting to SAW record speeds. No tricks on the hull, just weight vs lift.

hi John! how are you?

Finally, after a health problem period of 2 years...

...

I was happy to start the project of my .21 saw mono record hull one month ago!!!

as I have the benefit of cad and prototyping supports, I generate the mold of my hull, and now have produced one unit to build...

the hull is delta shape and very small , I follow your experience.. my target is to pass up to 65mph next month...

engine will be to start RB.21 reworked (mac21 in the pic)

please, could you provide me some informations for starting initial location of prop and rudder, in order to have the best configuration the day of first test run?

I also read that some people suggest to place engine, drive and prop strictly in the center line (symetric plane) of the hull

because as I understand, at high speed, the hull will fly out of water, ans so design dissymetry would not allow best performance

can you confirm?

thanks so much for help

guy

 

[Mark Poole ModVP]

The one thing that needs to be cleared up in the mono rules is weather or not a mono can have a "pad" that drops off the deadrise of the hull. I was told that was not legal. But, if you were to put strakes real close to the keel that go all the way to the transom, that does the same thing.