Levi drives

[ted655]

For those who don't have this link
http://www.fastmail.fm/mail/Choongs%...l=MR-GetAtt**2

[Jeff]

Bad link.

[xrudi]

Hi,

I will attach some information to the e-mail. I hope it works.

Best Regards
Rudi

[Frosty]

How far is the prop from the transom? What criteria do you use to achieve this distance? Why is it not as far back as that of an Arneson? Do you use a 'water break' on the trailing edge of the transom? What is your speed prediction on that of an outboard motor of the same HP rating?

[xrudi]

Dear Jack Frost,

The shaft angle of our commercial units are 8 degree. Our racing drives have lower shaft angle. This would natually make the propeller holder longer.
This hull is a normal fishing boat hull. With a 60 hp outboat our fisherman get about 21 - 22 knots.

Best Regards

Rudi

[Frosty]

Thank you Rudy but That was not the question. How far back from the transom is the prop and from what criteria do you use to get this measurement. I ask because your shafts seem much shorter than that of an Arneson. Surely this distance is not guess work and the hull shape will vary this distance?

Im sorry but what do you mean the prop 'holders' longer?

[xrudi]

I think, I did (cosin. The distance is about 600 -800 mm.

Sonny will have a laugh when he hears your question about the distance criteria. I think his answer would be "30 years of surface drive construction experience".
The "propeller holder" is the piece of metal or plastic which holds the propeller and rudder in place. Our sales people call it "Drive Unit"

Best Regards

Rudolf Scholz
Naval Architect

[Frosty]

Thank you for yor reply--600 to 800mm So plus or minus 200mm????? Why is it not critical then? Why are the Sony drives so much shorter than Arneson that now make an extended shaft modification?

Surely the criteria would be for maximum utilization of wake fraction? This will vary from boat to boat? Or is it not?

If its not critical then why do you think that your competitors are moving it further from the transom. This will be going on toward twice your distance.

Is Sony right or is Arneson right?

[Frosty]

I have just been to the web site and there are no real measurements available. However it does say that the shafts are standard 800mm. This I take it is shaft length so we still dont know or you dont know ----How far is the prop from the transom?

If this is making Sony Laugh then I am glad he finds it amusing.

[Willallison]

Jack - 1st up - it's Sonny, not Sony, as in Renato "Sonny" Levi. Rather acclaimed in the powerboat world...
2nd - I think what Mr. Scholtz was trying to say is that how they arrive at this would be regarded as proprietry information....

[xrudi]

Thanks!! I'm sometimes not so diplomatic.

The surface propulsion art is in the propeller. We have already too many propeller holders on the market which all do the same thing : " holding the propeller in place". What is needed are improved propeller designs.

We have some development in this direction but it requires a lot of money to produce and test new propellers.

Best Regards

Rudi

[Frosty]

Shall I give up --is this a difficult question, shall I try one more time.

I shall make this reall easy. I want to buy a Sonny drive, I want to fit it to my fishing boat, I have a short parking space, Ok heres the tricky bit, how far does the propeller stick out from the transom?

I really want to know, plus I an trying to give Mr scholtz an opportunity to tell us about his product and talk about it. Discuss the pro's and cons of his drives against others. Can he see this ???? Im sure most of you could. Well almost most of you. Oh well!!! 600 to 800mm shaft length--OK

[xrudi]

Dear Jack Frost,

The propeller is covered by the tunnel rudder to protect the propeller and people from the propeller. You need about 1.2 m aft of the transom for our LD170-150. Other model need more space.

I will send you a quotation direct to your e-mail address. We will have an agent in Thailand soon.

Best Regards

Rudolf Scholz

Naval Architect

[Frosty]

You dont have my e mail address. Can you post the quotation on the forum?

[xrudi]

Thanks, but I think the general forum rules don't allow such direct action. Please contact me by e- mail. We will send you our price list.

Best Regards

Rudolf Scholz
Naval Architect