The Black Pearl LSH Spec Hydro 2019

[InspGadgt]

How much angle was on the old version of the pearl?

[T.S.Davis]

Over the weekend I raced it. On start up I struggled to not nose dive half way to the bottom of the lake. I had to peg the throttle or it went down like a submarine. Then I blew off once. Jumped the fin once. Think I hit a buoy. Boat IS super fast but I couldn't finish a heat to save my life. I may have built it too light. It could be a learn to drive it thing. I need more time with it. It's just a different animal than a Stealth. We knew we were into uncharted territory with this design.

A number of us cold water guys struggled with first race gremlins down in Atlanta.

[Shooter]

Those are pretty 'safe' numbers Larry! Haha! Tried and true. :) I agree with them completely, but we were trying to do something different with this boat.

The full size Black Pearl has a 3.5deg kick-up angle which seems to work perfectly. Should have stuck with that, huh? :)

[Shooter]

Here is Terry's first and second run again. Disregard the fact that it's climbing the fin. The strut was very high, so the AOA was probably reasonable, but the bottom of the boat is not level (rear end is low). If you start lowering the strut to lift the rear, it is completely stuck to the water with bad behavior in the turns. Don't get me wrong, it could probably win races in this trim, but it's certainly not optimal. We'll keep working on them. I'm thinking we need to increase the AOA though.

https://www.youtube.com/watch?v=7tx_1fFGERc

https://www.youtube.com/watch?v=dwQ9ScqPd2U

[T.S.Davis]

Another thing I've been thinking about is less pitch with more diameter. Pull the rear end up without driving the nose down on start up.

[longballlumber]

Terry - I am assuming your running the new style ABC GameChangers (1816-17? guessing)? That is what you were running before.

Pete - I am assuming your running the H series ABC (H5 is what you usually ran)?

Those are COMPLETELY different animals. This explains the need for Pete to raise his strut and hopping he described. With Terry talking about lowering his strut and the suggestion that it's dragging the ass.

I hate to tell you this Pete, but if your expectation is to keep changing a boat design to meet a certain handling goal you will need to tell everyone what prop to put on the boat! Just my 2 pennies

[Shooter]

Yes, H5. H7 if I'm going for more than just podium.

[TRUCKPULL]

With the "H" series being a lifting prop and the ABC 17 series being a pushing prop with a lot less lift.

The 3 to 3,5 degree AOA leaves enough room for adjustment for both types of props.

Larry

[longballlumber]

With the "H" series being a lifting prop and the ABC 17 series being a pushing prop with a lot less lift.

The 3 to 3,5 degree AOA leaves enough room for adjustment for both types of props.

Larry

[Shooter]

I have to admit, I haven’t thought a whole lot about prop lift during design. I’ve concentrated mostly on keeping the afterplane level and letting the hardwired angles of the hull do the work.

So…I’m aware that the lifting props create a larger thrust cone. Do these new ABC props have a smaller thrust cone? They seem to have fairly high rakes. It would be nice to balance the boat such that ALL the thrust goes into speed instead of lift. I know a few people (that run really well BTW), that have boats balanced such that if you set it on a flat surface, the a$$ is in the air.

[T.S.Davis]

Pete, we're close. Call it a gut call but I think we're close. We've spent very little time with it. There are still guys that can't make the Stealth go. There are also guys that run H5 and the new style ABC on those without changing much of anything. That boat will take even more prop. So will this new boat. Need time though.

[Namba328]

Terry what motor are you running?

[T.S.Davis]

Just a Proboat 2000. We've tried all kinds of crazy things and kept coming back it. 10th scale we still run the 1500 but they are super scarce now.

[Namba328]

Just a Proboat 2000. We've tried all kinds of crazy things and kept coming back it. 10th scale we still run the 1500 but they are super scarce now.

That's my problem. I've been racing against Chris Emmard out here running the dam 1500s and mine blew up last race and I can't find another one. I'm running a PT stealth and now I'm stuck without any idea on what to put in it.

[InspGadgt]

There's a couple close in size around 2000KV at Hobby King that I've considered getting as backups for my AQ2030...but they are all 4 pole not 6 so I don't think they would have quite as much power.

[T.S.Davis]

Just get the Proboat 2000 (DYNM3831) and move on. They're solid enough and will turn 45mm props on most boats. Good starting point that is.

[InspGadgt]

I plan to...but I was hoping to find a less expensive alternative. Initially I was going through AQ2030 motors faster than I liked so was looking for something I could burn up without hurting the pocket book too much.

[Shooter]

I've been running the AQ2030's on my LSH since the first UL-1 with relatively no problems and my boat is no slouch:

https://www.youtube.com/watch?v=QdvK4ohe-Yc

Couple things I've found that help:

1. As much coolant flow as possible.
2. Water outlet on can should be on the TOP, otherwise you create a huge air bubble hotspot.
3. Water outlet at the highest point (back of the motor).
4. Motor radially mounted such that wires are at the bottom of can (heat rises, keep it away from them).
5. Heat soak fins like the ones on my post a few above. These work great for the end of the race.

[785boats]

That's my problem. I've been racing against Chris Emmard out here running the dam 1500s and mine blew up last race and I can't find another one. I'm running a PT stealth and now I'm stuck without any idea on what to put in it.

These guys seem to still have some of the original Proboat 1500's.
https://www.ebay.com/itm/223479932325?ul_noapp=true

[TRUCKPULL]

I've been running the AQ2030's on my LSH since the first UL-1 with relatively no problems and my boat is no slouch:

https://www.youtube.com/watch?v=QdvK4ohe-Yc

Couple things I've found that help:

1. As much coolant flow as possible.
2. Water outlet on can should be on the TOP, otherwise you create a huge air bubble hotspot.
3. Water outlet at the highest point (back of the motor).
4. Motor radially mounted such that wires are at the bottom of can (heat rises, keep it away from them).
5. Heat soak fins like the ones on my post a few above. These work great for the end of the race.

Pete
Where do you find those fins?

Larry

[InspGadgt]

I've been running the AQ2030's on my LSH since the first UL-1 with relatively no problems and my boat is no slouch:

https://www.youtube.com/watch?v=QdvK4ohe-Yc

Couple things I've found that help:

1. As much coolant flow as possible.
2. Water outlet on can should be on the TOP, otherwise you create a huge air bubble hotspot.
3. Water outlet at the highest point (back of the motor).
4. Motor radially mounted such that wires are at the bottom of can (heat rises, keep it away from them).
5. Heat soak fins like the ones on my post a few above. These work great for the end of the race.

Well that explains things then...When I swapped my ESC out for one that has an on/off switch I changed the way my water jacket was set up. First I figured I didn't want the inlet and outlet to be in-line with each other or else water would just flow right out without distributing around the can. So I placed them 90 degrees from each other...which had the side effect of having my outlet at the top rear of the motor. Since then I haven't burnt up a motor...that could be why. Another thing we tried on a friend's boat was to mostly block off between the inlet and the outlet to force the water to flow around the can...that seems to have worked as well though I would prefer something more along the lines of a spiral channel...but sealing that would be near impossible. I'm considering designing and 3d printing my own water jacket out of TPU. The whole thing would be a seal and I could print in the spiral channels. It would be similar to the old water cooling pipes that wound around the can but the water would still make direct contact with the can.

Question: Do you notice a difference in flow with the 90 degree inlet/outlets? I was wanting to put some on mine but a local mentioned it might adversely affect the water flow in and out of the jacket.

[bhorowitz]

Yeah, what Larry said. Where does that finned end cap come from? That's very cool. I think I made a pun.
Bob

[InspGadgt]

Still no word on that end bell heat sink?

[bozo586]

finned end cap was home made by pete (shooter)! i don't think they are available.

[rayzerdesigns]

Plus he can drive.. but the 1500s are still best motor out.. though that will change now that not available.. but I have been running mine now for 4 years

That's my problem. I've been racing against Chris Emmard out here running the dam 1500s and mine blew up last race and I can't find another one. I'm running a PT stealth and now I'm stuck without any idea on what to put in it.

[jaike5]

Post #139 gives a link to the pb1500kv

[Namba328]

Post #139 gives a link to the pb1500kv

Used to lol they sold out

[InspGadgt]

finned end cap was home made by pete (shooter)! i don't think they are available.

Well that does us no good to mention how much it helps when it isn't available to the public...lol

[785boats]

Used to lol they sold out

When I posted the link he still had some.
He sold two the next day, & the last one the day after.
I was hoping that you managed to score one.

Unlucky.

Aren't they replaced by the Dynamite 1500kv motors?
They are the motors that we use at our club here in Australia, now that the original Proboat motors are discontinued.

These ones.
https://www.amainhobbies.com/dynamit...nm3835/p234183

Not sure if they are as sturdy as the originals but mine are still going strong.

[Namba328]

When I posted the link he still had some.
He sold two the next day, & the last one the day after.
I was hoping that you managed to score one.

Unlucky.

Aren't they replaced by the Dynamite 1500kv motors?
They are the motors that we use at our club here in Australia, now that the original Proboat motors are discontinued.

These ones.
https://www.amainhobbies.com/dynamit...nm3835/p234183

Not sure if they are as sturdy as the originals but mine are still going strong.

The dynamite ones are better and stronger. But I just realized I have a older one in my box. I may have to try it one of these days.