About time..........................

[Terry Keeley]

Good for you guys. Outside the box, I like it!

All else being the same, how do you think a flat bottomed rear section acts vs a rockered bottom rear section?

ps: I have my thoughts but just wanna put it out there...

 

[dwilfong]

OK here is the next setup for testing...........Can't raise the strut any more slammed up on the tub now.

Will try and swing the 6.5 LE pitch prop from hell this week end...........................................

Terry I'm no expert by any means on what the rocker dose compared to a flat bottom tub.

I can explain what Andy told me but better off to here it from the source first hand.

 

[dwilfong]

Well got on the glass again and when taking it apart to open the holes for the boom tubes.

Found a cracked tube at the hole on the turn fin mounting side. Guess you cant side swipe a gas mono coming out of the turn full bore and throw it in the air and not hurt some thing................LOL

Reset the AOA from 2.5 to 4.5 with the tops at .4 tips up.

That should help with the stabbing and gain some speed............

 

[dwilfong]

Time to take it to the outer limits and see what happens...............

66mm dia 6.5 LE and 9.2 TE at 70% mark on the prop. only 30 deg of blade rotation at this point to check.

now I assume this is a big prop.................................

Amazing what drops out of Jerry's prop box after a few beers.....................

 

[Terry Keeley]

Yup!

6.5" x 24,000 rpm / 1057 = 147 x 80% = 118 mph!

How much of that LE are you measuring to get 6.5"?

 

[dwilfong]

.181 rise at 10deg from LE. Total travel is a little less than 30 deg at this point. TE is checked at 5deg

I will make a map if it can pull it and may be some adjustment.

Don't think it will hold shape to long in this raw state.

The blade dose have a hefty back bone running down the middle of the blade.

Had do grind the crap out of the TE. It had the typical ABC woop on the TE.

If it pans out will send it to Norm to get the treatment............................

Looking more at 26000+ RPM I hope.................................If it pulls it like the V967....................

 

[dwilfong]

Here are a few pics of the next setup ready to try. 4 deg strut angle and prop set at 70% mark on the glass. drive tube is slammed as high as it can go.

The cut down rears are set level with the tub now. same attachment angle as if thy where full height on the table.

This should help planning on launch and help with hard drops in the rear. At this height thy will not come in to play much at all when running in the rough water. The prop will still be in control.

Forgot to mention but the boat just pins my 12lb max scale ready to run with no fuel in it.....................

 

[Terry Keeley]

.181 rise at 10deg from LE. Total travel is a little less than 30 deg at this point. TE is checked at 5deg

I will make a map if it can pull it and may be some adjustment.

Don't think it will hold shape to long in this raw state.

The blade dose have a hefty back bone running down the middle of the blade.

Had do grind the crap out of the TE. It had the typical ABC woop on the TE.

If it pans out will send it to Norm to get the treatment............................

Looking more at 26000+ RPM I hope.................................If it pulls it like the V967....................

Cool.

Lots of pitch but not a bunch of blade area, will be interesting to see what happens.

Wish we were still running up here, water's gettin' hard again.

 

[dwilfong]

Terry you where asking about the CG of the boat.

I checked it and it is right at the tip of the turn fin................

 

[Terry Keeley]

Terry you where asking about the CG of the boat.

I checked it and it is right at the tip of the turn fin................

Was curious because sport & scale boats with no rears like to balance close to the sponson TE.

 

[dwilfong]

some thing to ponder about.....................

props all marked at the same spot %70 of the blade.

First on is a AB 6545 CNC prop cast in SS, second one is a Jerry Crowther ? ABC casting, last one is a V967.

Starting to look at things a little different now.....................................

 

[ALLAN YUEN]

David Will you try use four blades?

Good luck!

 

[dwilfong]

Not right now Allen.........have enough to try and figure out with what I have on my plate.

 

[Terry Keeley]

Shows you how little is in the water with those "Ninja" blades!

 

[Brad Christy]

David,

Is that 70% line just a reference point for where to measure pitch, or have you determined that to be the waterline when the boat is up on step?

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

Model Machine And Precision LLC

 

[Ray Sametz]

Dave, have you coated the blades with blue layout fluid, old MD trick to show whats in the water.

 

[dwilfong]

Well was a good day for testing. calm in the early morning buy my self. Then all the gas boats showed up..............................and the wind with them 15mph 4-6" swells and gas supper boats to deal with in the chop.

The setup with the small short sponsons totally changed the way the props worked. The V props that only hoped some times now hop all the time. The small sponsons most definite changed the aero on the back of the boat.

Even funnier was it started to take plugs. Had to richen it up a few clicks.

Pulled the prop from hell no problem but could not control the hop. Same with the V prop and the AB SS prop.

Good news is all my other props are runnable now with only a few adjustments to the cups.

The tall AOA did not pan out in the rough water. The boat teeder tooderd with all that angle.

Pulled some shims and readjusted the strut a few times and hit the sweet spot........................................

Flying on top of 4-6"......throttling perfect and running laps around the Super boats passing them at will any where I wanted with a 1475.

Will check where I am at and go at it again tomorrow.

The V style props will take a very special setup to work. Is it worth all the testing????????????

Don't know will go back to it later.......................................BUT DAM THY ARE FAST>>>>>>>>>>>>>>>>

 

[dwilfong]

Well had some time to check where I am at. sponsons tops .1 deg tips down and AOA right at 4 deg.

Checked the prop height and the water line is right at the 50% mark on the blade.

There is definitely a sucking affect with the rocker in the hull. Also and disturbance in this area seams to release the sucking action.

This testing has given me some answers to question I had.

Will store them away till I have time to make a better plan in the future.

Have some ideas bouncing around in my head that is for sure.

Surface drive rigger is one of them.......................................also X2 adjustable wings............

Time to get back to the Vector here soon..................have lots of new stuff on this hull bottom to try next.

I don't care what any one says toy boats are a great test bead for ideas...........................

The biggest hurtle to over come is the prop designs that are available.

A boat has to be designed around them instead of the prop being designed around the boat.

 

[shoboat]

David,

I think the propeller designs are already here at ABC propeller in Columbus, Ohio.

Some of the newest blade designs will be able to help you in your quest.

How big of diameter was the 1475 on the boat?

Thanks For Sharing,

Mark Sholund

 

[Terry Keeley]

Good for you!

Never had any luck either with the "Ninja" wheels...