Lotus
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Posts posted by Lotus
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Would love to hear about some performance specs. Hope you have a great time with this beauty !!
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Great work , nice boat Lenm
Congratulations
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2 hours ago, lenm said:
Thanks Lotus!
Re HP, the Australian way is to overpower everything
I have ordered the smallest engine which has digital speed control (DEC) being the 150hp Yamaha.
There is a shortage of new motors over here at the moment (have been waiting since August for it to arrive from Japan).
I'm not too hopeful it will be arrive/be installed before xmas, so probably a mid January launch.
I hope your boat has been good?
Good HP choice , I'm pretty sure it hit 40 knots + , and will be very economical at cruising speeds . ( the bigger the better
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We are having great time with our boat
good luck !
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Nice looking boat Lenm !
Almost time for rigging .
Have you decided about what HP ?
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Welcome onboard Keven and congratulations !
Riggs’ build is a great looking boat and those Suz 200ap are awesome motors with great performance !!
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On 5/10/2020 at 4:30 PM, Designer said:
Thanks for all or your posts, you do not realize how important it is get good feedback so that we can continue to create, especially someone with your level of craftmanship and to see you add your own interpretation to our designs.
Thanks a lot Graham, really appreciate your comments.
This was all possible thanks to your hull designs and your technical help and support .
Would also like to take the opportunity to thank all members in this forum that showed their interest in this build !
Thanks every one and happy building
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My 'Ocracoke 20 modified' officially ready and congratulations to the new happy owner of 'Marissa'
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Working on a shading top attached to the radar arc, that can be easily folded down. It is fabricated with 40mm x 2.5mm wall thickness aluminium tubes and should weight less than 8kg when covered with upholstery.
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Some more updates !
Decided to uninstall and remove completely the Bennett auto trim tabs setup and moved to zipwake interceptors.
These new fully automatic interceptors are very fast acting and I am 100% satisfied with their performance , although the main reason for switching was that the trim plate itself made it very difficult to maneuver the boat in reverse gear . Some times but not often they also interfere with the fishing line , risking to loose the catch !
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Nice work Lenm! That console is very interesting !
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2 hours ago, Hirilonde said:
Just for clarification, a knot = a nautical mile per hour, it is not also a measure of distance. When you say a total trip of 36kts. I think you mean 36 nautical miles?
statute mile = 5280 feet nautical mile = 6023 feet and some fraction that we can ignore
I find it interesting that in spite of most of the world switching to the metric system sailors every where still use the knot and nautical mile. It used to matter a lot because of celestial navigation. 1 nautical mile = 1 minute of latitude. With the advent of GPS it no longer has any real need, but it is still fun that many still use it anyway, and kind of binds us together. I sailed with an Italian friend in the Adriatic for 3 weeks on his boat. His speed gauge and wind gauge measured in knots, and his depth gauge measured in meters.
Totally agree with you, and yes I meant 36 nautical miles .
I don't know what measurements use in the rest of the word but in Europe we us Knots for speed on water and meters for depth and that's the way most of us sett their instruments
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Thanks Riggs.
Today another test run !. Think we matched the perfect prop for this boat . 3 x 16 x 21.5"
Cruising speed of 23Kn (26miles) at 3650 rpm and burns 17 liters of fuel per hour
Top speed (WOT) 45Kn (51.8 miles) at 6150 rpm
A total trip of 36Kn (41miles) in 2 hours burned 28 liters of fuel .
Think that these motors and this boat are super efficient !
Now the boat rides very stable at all speeds. Very happy and satisfied with all the results and thanks again to Graham !
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As promised here are some photos.
We have tested the 4 blade prop 20" pitch. It performed very similar to the 3 blade 20" but also generated lots of lift . WOT was 6050 rpm and 38 knots . Still think that best prop will be 3 blade 21.5" pitch. That will be her 4th and last test
Best cruising speed was at 3600 rpm 22 knots and 0.8 liters per knot mile .
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20 hours ago, lenm said:
Sounds like you are getting closer to optimum setup..
Look forward to some pics.
Is your self draining deck working better now?
Thanks Lenm,
Yes the self draining deck is working perfectly. Well not exactly a self draining deck as I connected all drain pipes into a sump with an automatic bilge pump inside . I could have made it self draining but my boat surveyor told me that the drain outlet should be at least 4" above water line , and that was impossible .
I had raised the whole sole by 2" from the original plans to compensate for the additional weight so it can be easily self draining by just adding 2 scupper valves.
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Hi Hirilonde, my first test was with a 3 blade 20" prop the boat was stable even at 40+ knots !
4 blades generate more lift and torque than 3 blade same pitch
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Now that the weight is shifted she floats perfectly , parallel with the original plans water line, but just a little deeper because of the overall added weight. ( sorry for no photos as we were in a hurry because of a bad weather ).
We have tested a 4 blade propeller 22" . It noticed that the response was immediately and with just a little acceleration the boat was on plane. The bad side of this prop is that it generates a lot of lift and the boat was very unstable at 30 knots and over .
This 4 blade prop also produced a lot of prop torque and the boat roll was very noticeable to the left side at acceleration.
I think that these 4 blade prop are at their best on heavy load boats with planing problems.
Fuel consumption also increased , but with a 22" prop the boat was over propped, as wot was just 5400 and 36 knots.
At 3500 rpm she hit 18 knots and 19 liters per hour , way too worst than the 3 blade 20"
Next time I will test the 4 blade 20", just for curiosity but think the perfect prop for this boat will be the 3 blade 21.5" prop.
Will promise you some photos next time tested !
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Hi Graham , I managed to shift some weight backwards , batteries fuel tank and have installed the auxiliary motor. I have to see how she trim next time I put her in water . Waiting for some good weather.
About the prop I was thinking of going to 4 blade prop instead of changing the pitch. At the moment I am running a 3x 16x 20" and goes over 6300 at wot. So either go for 3 bladed 16 x 21.5" or 16 x 23" or the 4 bladed 15.25 x 20" or even 15.25 x 22" . These are the original suzuki props available .
I dont mind if I loose a couple of knots at the high end ( this is not a speed boat ) , I am looking for the very best cursing speed and fuel economy at around 3500rpm,
An other question is , dose it make sens to go for a counter rotation prop, because the auxiliary motor is installed at port side and the boat leans slightly that side when no one on board . The ap series motor have the selective rotation control function so it is very easy to switch between , just change the prop and a plug in the harness.
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On 1/10/2020 at 8:28 PM, Designer said:
The cockpit sole is pitched aft 1 degree. That means that you are trimmed down by the bow a fraction over 1 degree.
1 degree in a waterline length of 15 feet is about 3" in height . Think I have to shift a lot of weight to transom to level !!
A 110 pounds auxiliary motor at transom and shifting 80 pounds batteries from under console to transom area would not be enough ?
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4 hours ago, lenm said:
Congrats Lotus - she looks amazing! Elusive is a very fitting name..
You went to town with the 200hp
- nice!
Thanks Lenm.
You are doing a great job too ! Hard work pays off
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5 hours ago, Designer said:
Emvrin,
Congratulations!!! You outdid yourself this time. You put the rest of us to shame with the quality of your work. She looks beautiful. You do need a larger prop with 6300 rpm at wot. Have you weighed the boat?
Because the keel is straight and level as designed, if you can put a mark on the bow and maybe on the forward edge of the leg at the water line next time that you are in the water. You can measure down to a keel line extension back on land and we can calculate her weight and trim.
Thanks a lot Graham, really appreciate !
I haven't weighed it but I know for sure that the floor ,sole ,is almost parallel with the sea water . I doped some water on the sole when no body was in the boat including me . The water remained stationary and after a while it moved slightly forward ( instead of backwards ) Therefor the self draining sole is not working ! At transom the water level is as the water line indicated on the plans.
Again I still need to put the auxiliary motor and move the 2 battery to transom . Hope this will solve the problem . If not I can relocate one of the fuel tanks that are easily accessible .
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Finally the great day has arrived . The highly modified Ocracoke 20 named Elusive 20 hit the water for the very first time !
My first impression is that she is a little bit bow heavy , by the way she sits on the water . All the rest is superb !!
If I shift the 2 battery backward and put the auxiliary motor of about 50kg ( that is still unavailable ) at transom she might be leveled correctly. At the moment the batteries are located inside the cabin under the 2 steps to step inside.
Some performances data are as following in choppy water of about 1 to 1.5 " waves.
800 rpm ( idling) 2-3 knots
2000 rpm 7 knots and 6 liters per hour
3500 rpm 20 kts and 17 l/hr
4000 rpm 24 kts and 21 l/hr
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6300 rpm 41 kts and 70 l/hr in very calm water (47 miles !!
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I liked the best cruising speed of 21-22 knots ( 25 miles ) at around 3600 rpm . She cuts trough bigger chops like knife into butter with no splashes and slamming sounds and a very dry ride all thanks to Graham and his hull designs !
The boat rides much more stable with the trim tabs slightly trimmed down at speeds of 18 kts and over. This may be because of a heavier bow that can be addressed with a better weight distribution .
The propeller is a 16" diameter by 20"pitch attached to a Suzuki df200ap and think it is under propped as the engine is revving up to 6300rpm that is its limit. May be a 21 or 22" will be much better all over the rpm range . But don't know how this will effect the fuel efficiency !!
Over all I am very happy and satisfied with the results and the whole project !
Would like to say a big THANKS to Graham for all his help and patience answering my questions ( a lot of questions !!
) and also all members in this forum that contributed with their comments !
THANKS again !
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Great work Lenm and nice looking console !
Karnic 1851 boats have a center console that can easily accommodate a person under it when opened from the front side . Maybe you can do some google search about it. The front seat of the console can be opened forward with part of the flooring with it
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14 hours ago, Riggs said:
Looking very good Lotus. I do like that radar arch in the fact that it comes down nice and simple like.
Thanks Riggs. now complete with anchor and navigation lights !
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On 11/6/2019 at 11:59 AM, lenm said:
Looking good lotus!
The sides of your cabin look to be at least 2 inches thick. May I ask how you achieve thickness?
Hollow on inside with a backing plate/washers for radar arch?
Hi Lenm,
only the outer part is boxed to give that 2" thickness. All the rest is 1/2" plywood as you can see in this photo
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OC 256
in B & B Yachts Forum
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Is this another one Riggs?
Nice work as usual