Pursuit ala HK

[puttekula]

Thx for the pictures. I can see that you are squezing in some 6s 4000 packs. And they are big. But if we are going to compare , those are "equal" to 4s 6000mah packs. (power wise) . 4s 3600 must be compared to 6s 2400mah.

Is that welcro tape holding the packs in a good way?

thx, P

[wparsons]

Keep in mind that you need a certain amount of amperage, and most smaller packs can't supply that much current.

On a 30c 2400mah pack you're only looking at 72a continuous, if it were mine I would want a bit more buffer, even in a 2p setup. If there's room for a 6s4000mah pack on each side, I would run them. You'll appreciate the extra weight in choppy water too.

[Diesel6401]

Thx for the pictures. I can see that you are squezing in some 6s 4000 packs. And they are big. But if we are going to compare , those are "equal" to 4s 6000mah packs. (power wise) . 4s 3600 must be compared to 6s 2400mah.

Is that welcro tape holding the packs in a good way?

thx, P

It's not logical to run 2 6s 2400mah packs. That's alot of extra weight for only4800mah, yea it's a 2p setup, but a un-needed 2p setup IMO. It would make more sense to just 6s1p with 2x 3s 6000mah packs for all that.

The packs that I added in the pic the 6s 4000mah packs where ONLY so you can see how they fit. Not any reason/logic behind it and no needed to compare any "power" specs, only to guage the size of packs in that hull. Velcro works GREAT for me.

[puttekula]

Keep in mind that you need a certain amount of amperage, and most smaller packs can't supply that much current.

On a 30c 2400mah pack you're only looking at 72a continuous, if it were mine I would want a bit more buffer, even in a 2p setup. If there's room for a 6s4000mah pack on each side, I would run them. You'll appreciate the extra weight in choppy water too.

Thx for your input. I will take the weight in to the planning...
You say only 72A. 72A can easily make a train go forward with the right amount of Volts. And what is making it go forward? The Watts. Watt is the more popular word of effect/horsepower etc. And combining the two ingredienses A and V gives Watt. And I really miss Sailrs input in the discussion. Yes, those who are removed now. And believe me, I honestly will be teached in this matter. But then in a real sience and a pure practical way. No bla bla bla because it has always been....
Why is there dangerous "high voltage" cables going here and there from "power plants etc " around the country? Why using dangerous high voltage if pure Amp is the solution?
Yep, u can guess. the pure power must be transported. But if the word Amp. is the bible, the lines would be 1 meter thick....or such... So my friends, where is the sweet spot? Time for diskussion....

[puttekula]

It's not logical to run 2 6s 2400mah packs. That's alot of extra weight for only4800mah, yea it's a 2p setup, but a un-needed 2p setup IMO. It would make more sense to just 6s1p with 2x 3s 6000mah packs for all that.

The packs that I added in the pic the 6s 4000mah packs where ONLY so you can see how they fit. Not any reason/logic behind it and no needed to compare any "power" specs, only to guage the size of packs in that hull. Velcro works GREAT for me.

Yes, I guessed there were no thought/plans/suggestions about the 6s example. But that gave me a mark of whats possible. And Im thankful for that.

But Im still into the thinking of that the final effect of the system will be with the same size/weight of the source. The amount of cells give more weight, so do the higher Amp rating and C rating. But in the end there will be no, or not much, difference.
Remember, what are those C ratings for? Yep, the ability to transport huge amount of Amps. So are the cells. And high C ratings creates bigger/heavier cells.
And that also gives an interesting thought about size and weight comparison between packs.
Can anybody confirm my thoughts about this. Or disagree as well...
I think there will be less demand for high C rating for a higher voltage system with the same power output as a high Amp system?!

Im not into a war against people who have their thoughts etc just because of my curiosity. I just want to have an open diskussion in this matter. A serious one though..

[wparsons]

Thx for your input. I will take the weight in to the planning...
You say only 72A. 72A can easily make a train go forward with the right amount of Volts. And what is making it go forward? The Watts. Watt is the more popular word of effect/horsepower etc. And combining the two ingredienses A and V gives Watt. And I really miss Sailrs input in the discussion. Yes, those who are removed now. And believe me, I honestly will be teached in this matter. But then in a real sience and a pure practical way. No bla bla bla because it has always been....
Why is there dangerous "high voltage" cables going here and there from "power plants etc " around the country? Why using dangerous high voltage if pure Amp is the solution?
Yep, u can guess. the pure power must be transported. But if the word Amp. is the bible, the lines would be 1 meter thick....or such... So my friends, where is the sweet spot? Time for diskussion....

Not disagreeing, but we're talking about a very specific example, not in general.

You can't really compare high power lines since they're AC, not DC. They aren't just higher voltage for line size, they're also higher voltage because voltage drop over long distances at higher voltages is less than at lower volts.

[puttekula]

So. at last everything is up and running. Waiting for a GPS to meassure speed. Tested with a X442, 445 and 645. An 4082/1450 with 4500 6s setup gives a quite short ride. Havent meassured the time. The system is warm, but not that hot really. Havent meassured that either...
How many out there have reached 60mph+ with this boat? And whats their setup? A big + for the hull. It goes quite stable in the water.

[Lasse Baardseth]

I have powered my Pursuit with a NEU1521 (1050kv)10s setup. (2x 5s 4000mAh, Nano 45-90c)

I love this HV system. Lot of power and no heating problems.

I don`t see why 4s is the "standard" in this boats?

[puttekula]

Ahhh, quite interesting. What ESC and prop are you using? Meassured speed?

[Lasse Baardseth]

It`s an Etti 200 HV. I have tried different props, X642, X645 and Prather 230.
Of the props, the Prather 230 was the fastest. Recorded with GPS at 60mph (97km/h)

But for the fun of it i tested my Prather 250 prop! The boat flipped at an insane speed, hatch came off and my GPS and my 6s battery was gone So the speed was never recorded, but alot faster than 60mph.

See this thread:
http://forums.offshoreelectrics.com/...23-10S-Pursuit

[puttekula]

So, there was the maiden run with GPS. I tested my wifes Garmin 305 runner. You know, looks like a watch to wear on the arm.

But I don know what to say. The speed was so dissapointing. Or is it possible the gps does not show the right numbers?
Max speed was 60km/h.... (37,5mph) This sucks....

What speed can I expect from my setup?


Leopard 4082 1450kv
Seaking 180
Turnigy Nano 4500 6s 45/90C
X645

The motor is warm, not hot after 1 minute. The esc and batterys less warm. The cables even less warm.
The boat goes really well in the water. Not much touching the water at full speed. I think the motor rpm is guite high.

Here is a film with an x442 propp. The rpm is slightly less with the 645 prop. ANd yes, my wife hold the Iphone in the
wrong direction while filming....

http://youtu.be/dpSKDiOYKDo

[Lasse Baardseth]

Its hard to tell from the video, but it seems to me that the boat is running wet.

I run my boat with the strut in line with the boat, and the flaps in a positiv angle. You have to test in different angles.

The differens in speed is huge, but you loose the "train" like handeling.

This boat should push 90 km/h easily (55 mph)

Good luck:)

[puttekula]

Thx for the answer.
Yes, in the video the boats seems to go a bit wet. But in real life and with the 645 there is not much of the boat in the water. ANd the strut is slightly bent
upwards when meassuring it. But the next time I will bring my temp meter and video camera with me....

And yes, 60km/h is way to low. It must be the GPS.....I hope.....

There must be a ton of Pursuit runners out there. Where are you...help.... ,o)

[puttekula]

Update:

Swapped to x445 and put an Garmin car GPS above the floatation and under the front deck. By the looks there were appr. the same speed. Maybe a bit slower than
the x645. The 645 maybe is a bit to much. Temp reading after 1 minute 50c degree for the motor . The boat has appr 20centimeters (appr 8") in the water. Is that to much?
The COG is very near 10" from stern. How to best get the boat going higher in the water? The "strut" is pointing slightly upwards.

And now its all cleared out, there is missreadings when putting an GPS (Garmin 305) in the engine compartment. The new reading is 79km/h. So perhaps with a little
adjustments I can push it further.....