The 1515 is still killer but I'm not sure it can push Ty's boat. Built that one kinda fat like the old sled. We'll keep proping down until it will finish. Might have to modify something or maybe even swap out the motor for something more sane. Could have Neu wind something for it. Still think'n on it.
Noisy person
Holy mackerel! Ty's boat has to be pushing 70mph those first two laps. Too bad about the thermal, but the hull seemed to handle those speeds pretty well in race water. Fastest I've ever had mine is around 62/65mph. He's gonna blow my doors off.
So, are you still retrieving boats from that heat? What a disaster. A lot of testosterone in that class. I love it.
The one I built loved the neu 1415 and was significantly faster than the castle 1515 with an ABC 1717.
Wow. Ty, congrats. 2018 IMPBA National Champ! That boat looks good out there. When are you going to help me make mine run that good???
https://m.youtube.com/watch?v=b9HiioL8uP0
Some boat repair to my Pearl after the MI Cup, First heat I got a 2nd place finish. I had a boat flip right in front of me in the second heat, I did finish that heat with a 3rd place with the damage. I tried to tape it up for the third heat, but it opened up again and I got a DNF.
So when I got home I had some work do.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
Some more pictures.
Pete
Sorry for the last picture, my Nose Cone was damaged beyond repair.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
We raced last Sunday. Ty jumped the start in the last heat. Took second. That boat is reeeeediculous..
Noisy person
Hey all,
Been reading through the thread today...really interesting, especially the design aspect of the discussion. I recently got into boats (Coming from 25ish years racing on-road electric) and looking at the sport hydro design a question keeps rattling around in my head...Why not put the batteries low in the sponsons? I realize that would move the CG drastically but with the wider and lower CG it should reduce the risk of blow overs and help with cornering. Might have to move the motor back some to compensate though. Just a thought to toss around.
How would you get them in and out for charging?
Here are two 4S - 5000mAP packs as far forward as will fit in this kit.
To put the packs in the sponsons, -you would have no structure left to hold the weight.
Also with the weight on the two outsides, you would end up with a bad sponson walk, that would keep getting worse untill you slowed down.
Batteries in the sponsons may work in a larger hull.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
You would have to have hatch covers on the sponsons to get the batteries in and out. Some people with the UL-19s already shove their batteries up in the sponsons from what I hear though I haven't seen it done yet. The structure would have to be re-worked around a battery box but that isn't impossible...something more akin to a F1 monocoque chassis. What do you mean by sponson walk? Is that like chining? If anything I would think that would be reduced by a wider and lower CG.
There's way too much structure in a Pearl to do that. Besides that, these have no handling issues at all. I prefere to have that structure in truth.
A picture of why.FullSizeRender.jpg
Noisy person
I remember that day. Sorry.....again! I forget how it happened, but it was my fault.
Haha. No worries Pete. Forced my hand. Three of the fastest P sports I've ever seen on the pond together yesterday at the CanAm. All of them Pearls.
Noisy person
Larry - Nice job on the fix by the way!! Looks good.
I remember what happened now regarding the crash. The boat that pierced the bottom of Terry's was actually Jimmy's boat! We were all packed together coming out of turn 4. I switched lanes and darted across in front of Terry forcing him to blow off from my wake (penalty to me). Jimmy was following close behind and went right thru Terry's boat while it was showing bottom!
Regarding the batteries in the sponsons, I fully agree that you want the weight as low as possible, but as Terry alluded to, not sure it is all that practical with the structure in there. Randy Naylor did it with one of his Hydro's. I think it worked very well.
Been thinking about the cells in the sponson thing. Love to hear others thoughts too.
Moving weight out to tbe sponsons gives that weight more torque around the pivot point that is the turn fin. Think pendulum. Good bad idk?
Noisy person
Sponson walk. Large -- teter-toter. Once it starts, it would be the Never Ending Story.
There use to be a large 6S or 8S Sport hydro around that had the hatches on top of the sponsons.
There was one in FL. when I was there, - Sponson walk.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
Terry, got the length of my 4, 2s cells running 90 degrees to the length of the boat. One of the reasons I got the open hull DF34 hydro was for that purpose. This puts weight out and away from the CG point and the boat is extremely stable. Now if you tried to get them in the sponsons with the length of the batts running with the hull length, I would be worried about that weight being out too far from the CG as a front-rear weight skew. If I ever build a wood hull kit, I would be inclined to change the framing to accommodate the batt configuration I mentioned. I did the same thing on the dual motor hydro build as well. Here’s pics on what the batts look like...
Think high wire balance bar...high wire acts use very long balance bars for the very reason that the further out the weight is, the more it will resist rotation. Same thing with figure skaters who pull their arms in to spin faster and fling their arms out to slow down and stop. However noted that even though it will resist rotation a good deal more...once it does start rotating it will have more momentum and be harder to stop.
Burton, that’s correct. Except that it’s not rotating thru in one direction, where the weight can gain inertia. It’s rocking to one side, stopping, then being forced to turn directions, where it has to gain inertia again. By the time it does that, the offending water is past the boat. So I think the proper term is Inertial Damping. If there is no weight out there, then there is very little inertial damping and it can get to rocking back and forth very fast.
It’s important that the weight goes out sideways at the CG, or you introduce other problems and create a complex teeter totter.
Fun mental exercise aint it?
There is a difference. The wire walker isn't trying to turn a corner at 4+ G's. If he did he would want to hold the bar a little different.
I know with mono hulls we fare better with the weight centered in the boat.
Noisy person
Agreed, on mono hulls. But cats and hydros seem to like weight dispersed sideways.
Cool. I remember having this discussion years back when the UL1 came out. The further the batts were out, the slower the rotational response (lower frequency side to side motion). The concern was always the recovery. If it DID rotate, could it recover quick enough.......like what inspgadget said. Maybe since the sponson is limited by the water surface, it DOES recover. It sounds like Craig proved that.
Are the black pearl kits still being sold if so how can I get one thanks
Send a private message to the person who wrote the post above yours (SHOOTER)
He is the person that designed and cuts the kits.
Larry
Past NAMBA- P Mono -1 Mile Race Record holder
Past NAMBA- P Sport -1 Mile Race Record holder
Bump & Grind Racing Props -We Like Em Smooth & Wet
Did these kits come with sticks, the v5.7 I have? Can’t remember and I’m packing mine up to ship to this gentleman. Sadly I will not be building this one, too many irons in the fire for me.
Nortavlag Bulc
Hi Ray. No, I've never shipped them with sticks.
Thanks. I gave him what I had.
Nortavlag Bulc
Bookmarks