head of the river cat hull thread

[ozzie-crawl]

it seem to me there is a lot of people setting up these boats or others who have already done so. but they seem to be all over the place so i thought i would try and start a thread to help people out and keep it all in the one place.
i will start with my setup:
motor, 7xl(2384kv)
esc 200 amp himodel
batt 4s 2p 3700s
prop pranther 215
on this setup my cat runs a constant 90 klmh (56mph)
iam also in the process of building a twin motor hull as well.
i will add video and pictures later

[Fluid]

This thread is a great idea, I have wondered a lot about these hulls. Even more, detailed information would help more folks out. Things like:

- Did you have to stiffen the tunnel floor with carbon fiber?
- Is your motor/ESC watercooled?
- How deep are you running the prop?
- What hardware are you using?
- How does the hull handle with your setup?
- Does it turn well at full throttle or do you need to back off in the turns?

If we want to really be helpful we include information like run times and temperatures. For an example, I have set up one of my 34" cats to run near 85 mph - but the run time, handling and temperatures are not what most sport runners would tolerate.

Too, it makes sense that the setups are "all over the place" since different builders have different goals. Your setup is pretty hot and woould not be good for someone wanting 5-10 minutes of run time. OTOH it is not fast enough for some types of competition. But it is perfect for you and might be so for others. I encourage you to continue this great thread, just add more information.






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[Viking]

Great Idea.
But back up a step or two.
I don't know anything about "cats", so this is a great idea, but ,after some searching the internet I haven't found a cat called "head of the river cat".
Perhaps you should start off with what hull you are building, length, width, design.
Where it is available.
Then what set up you are going to run in it, and for what, sport, racing, bashing????
Continue Please;
Viking

[rockwerks]

Great Idea.
But back up a step or two.
I don't know anything about "cats", so this is a great idea, but ,after some searching the internet I haven't found a cat called "head of the river cat".
Perhaps you should start off with what hull you are building, length, width, design.
Where it is available.
Then what set up you are going to run in it, and for what, sport, racing, bashing????
Continue Please;
Viking

Head of the river-RC specialist sells on ebay. 32" cat for dual or single motor setup 10" beam

[Viking]

Thanks Rockwerks;
I just searched ebay about 8 ways to sunday and got 0 results for Head of the river cat RC specialist, all and each part of that .
Post a link to something, Please.
Looks like a nice boat, nice size.
Viking

[Viking]

search for RC catamaran and look through the 90 items.
Try the search for "Head of the River-RC specialist" and you get 0. Go figure?

[rockwerks]

Thanks Rockwerks;
I just searched ebay about 8 ways to sunday and got 0 results for Head of the river cat RC specialist, all and each part of that .
Post a link to something, Please.
Looks like a nice boat, nice size.
Viking

Link:

http://cgi.ebay.com/32-fibreglass-ca...1%7C240%3A1318

[Spot Me 2]

I have a build going with one of those hulls. Here a link.

https://forums.offshoreelectrics.com/...ead.php?t=5398

[ozzie-crawl]

hi everyone thanks for your replies. i did not mean for this to be the only thread if people want to do there own please do. my aim in this is for people to have a place to go and find answers and hopfully others will put there setups. if anyone thinks i should change the thread title let me know what would be more applicable.and if you have your own thread please give a description and a link
thanks scott

[ozzie-crawl]

hope these photos come out as it is the first time i have uploaded to o.s.e and they were taken of my phone.
first picture is the single motor hull at the front with the twin motor project behind.
second picture is inside the hull sorry about the mess as iam adding a new servo bracket
third picture is front on shot

[ozzie-crawl]

datan this setup 7xl 4s2p pranther 215
max amp draw is 70 amps
esc temps run at 40 deg c (104f)
motor temps 45 deg c (113f)
max rpm 30,000 @ 90klmh
max watts 1200
this data was taken with the eagle tree logger . as a note the tempratures are after 2-3 minutes, i have not run this steup for more than 4 minutes but they stay at this tempreture up to the 4min mark and only rise when the boat stops due to heat soak were they can rise 5-10deg c
i will run this hull in 5 lap oval racing but i am not a serious racer (closest racing is 90 minutes away) so it will be more for fun. i could push this hull further but that would take away the reliability
cheers scott

[focused]

My setup is :

Motor, Feigao 540XL9
Esc , ETTI 125amp
Lipo , 2 x Zippy H 5000Mah 3s
Speed , 58mhp with 42mm K prop hope to reach 60+ with a 42mm metal prop
Time of fun . 6 to 7 min.

I think its best to put all the head of the river cats in one place so i`m in and if you need help just ask.

grtz

Michiel.

[ozzie-crawl]

michiel: looks good and thanks for your setup. i take it you are running 2x3s in series for 6s ?. interested as my mate is doing one that will run 6s.
my first hull was brought as a near ready to run so i didnt add extra cloth or carbon fibre. although most of it has been changed now.
my twin hull was brought bare so i can make it how i want. i should add a extra layer in the bottom but my glassing skills suck
scott

[focused]

Scott,

I will run the 2 x 3s = 6s in series yes , i believe in high voltage and low revs/voltage so the amp stays low and you can use larger props 42mm to 45mm.


I also made a window decal you can find it here LINK


grtz

Michiel.

[ozzie-crawl]

yes high voltage is the way to go unless you are class racing. i run 4s as i have a few boats and find it easier/cheaper to run the same voltage other wise i would change to higher voltage
the setup i have now is only drawing 70 amps max so some prop testing will happen this weekend
thanks for the decal i and others will find it very usefull.
cheers scott

[Spot Me 2]

My setup is :

Motor, Feigao 540XL9
Esc , ETTI 125amp
Lipo , 2 x Zippy H 5000Mah 3s
Speed , 58mhp with 42mm K prop hope to reach 60+ with a 42mm metal prop
Time of fun . 6 to 7 min.

I think its best to put all the head of the river cats in one place so i`m in and if you need help just ask.

grtz

Michiel.

Your boat looks great!!! I think you are on barrowed time though. Accourding to FEcalc, that setup is pushing 150+ amps.

[focused]

Your boat looks great!!! I think you are on barrowed time though. Accourding to FEcalc, that setup is pushing 150+ amps.

Thanx,

The ETTI can handle a lot more 150 burst is no problem so i`m not worried about my setup , i have a smaller boat with a 540S7 on 8 cell Nimh and 37m prop on the same esc and also no problem .

I also do not calculate with FEcalc but trust my experience and do al ot of trying with almost no errors and never pussing the limits the first time.


I did a quick calculation with FEcalc and ended at 114 amp so no overheating the Esc.

grtz

Michiel.

[rockwerks]

just curious what is the running weight of these boats?

what does the hull weigh empty

[Fluid]

Accourding to FEcalc, that setup is pushing 150+ amps.

Don't put much faith into FECalc. It was designed at a time when BL motors were just starting and LiPos were not on the horizon. Then it worked pretty well, but today it is only a very rough guide. From personal experience, if the boat is set up well it will draw considerably less than 150 amps. One dead giveaway is the run time: if he runs his packs down to 25% capacity - considered a safe stopping point - his average amp draw is about 40 amps. Peak draws would obvioulsy be higher.



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[Spot Me 2]

Good to know. I am building one currenty and have the same motor. I guess I will be running 6s.

[Fluid]

Keep to the smaller diamter props and you'll be alright, I'd start with an x637. A 9XL will work great on 4S too, in fact you can use a bigger high pitch prop for more efficiency. In my Mean Machine I ran a 9XL on 4S with an m645 prop and if I aired the boat out enough it would almost hit 50. Actually with today's power a narrow 32" boat is a better 4S boat than a 6S boat anyway (and cheaper too). I hit the mid-80s on 6S in my wider 34" SprintCat at the SAWs, and an even longer boat would have been better.


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[rockwerks]

I have that custom hull of Lonewolfs that I plan on putting in a lehner 6xl, 4s or 12 cells 4600, 200a himodel and start out with a 440/3 33" hull and 10.5" beam balsa hull about the same weight as this FG hull. Im very interested in the setups

[Fluid]

Lehner doesn't make a 6XL (their Basic XLs use a different nomenclature), perhaps you mean Hacker? If so, a Hacker or Feigao 6XL is too much for 4S and that prop - you will be buying new ESCs often. That is really a SAW setup, you won't get much run time while you overheat everything. If you insist on doing it - not recommended - use an x438 or y536 prop.

Really, so many others have tried the 6XL and met with disappointment - why bother? Get a more appropriate motor - an 8XL or 9XL makes a lot more sense.

If you did mean an LMT Basic XL, what Kv do you have?



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[rockwerks]

Lehner doesn't make a 6XL (their Basic XLs use a different nomenclature), perhaps you mean Hacker? If so, a Hacker or Feigao 6XL is too much for 4S and that prop - you will be buying new ESCs often. That is really a SAW setup, you won't get much run time while you overheat everything. If you insist on doing it - not recommended - use an x438 or y536 prop.

Really, so many others have tried the 6XL and met with disappointment - why bother? Get a more appropriate motor - an 8XL or 9XL makes a lot more sense.

If you did mean an LMT Basic XL, what Kv do you have?



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one glass of red too many I guess, you are right hacker b50 6 xl, which I would need to run on 6s correct? and I did just buy a lehner basic 3100xl to play with also. going to be an 8 cell stepped mono motor. I do have a nemesis 7xl also. Im new to the boat thing so its all learning to me. I have props from 438 up to 645...about 10 now so I have lots of room to play, and any info is always welcome.

[focused]

you are right hacker b50 6 xl, which I would need to run on 6s correct?

NOOOOOO , dont a B50 XL6 on6s is way too much you`ll end up in 60.000 revs , you`ll need only between 32.000 38.000 for a 32" cat .


grtz

Michiel.

[Tunda]

How does this hull handle in the turns? can you hold it wideopen in the turns?..........

[focused]

How does this hull handle in the turns? can you hold it wideopen in the turns?..........

No not possible , its a cat it will slide away, break out and flip over on full throttle .

grtz

Michiel

[Fluid]

No not possible , its a cat it will slide away, break out and flip over on full throttle...

How much experience do you have racing catmarans? While this particular hull may not like WOT turns (I don't know), all of my current cats thrive on it. A catamaran's forte is excellent turning, I have raced against hydros and won by cutting inside them in the corners. Most - not all - decent cat designs can be made to run fast through the turns without flipping over......if you know what to do.



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[focused]

How much experience do you have racing catmarans? While this particular hull may not like WOT turns (I don't know), all of my current cats thrive on it. A catamaran's forte is excellent turning, I have raced against hydros and won by cutting inside them in the corners. Most - not all - decent cat designs can be made to run fast through the turns without flipping over......if you know what to do.



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I`m just answering his question with my experience witn this particular hull ,

How does this hull handle in the turns? can you hold it wideopen in the turns?..........

You just cant go 50 to 60 mph and make a turn at that speed, if so i like to see that on video , you have to step of the throttle and slow down .
Maybe a twin-drive handles it better then a single drive i dont know but believe me i smashed my cat arround the corner and it didnt like it .



Michiel,

[rockwerks]

NOOOOOO , dont a B50 XL6 on6s is way too much you`ll end up in 60.000 revs , you`ll need only between 32.000 38.000 for a 32" cat .




grtz

Michiel.

LOL I guess I needed to use this