head of the river cat hull thread

[ozzie-crawl]

this is what i run in mine and batteries have never gotten hot https://www.hobbycity.com/hobbycity/...idProduct=7296

[CircusCircus]

Thanks ozzie, I think Im starting to understand things a little better

I have been reading all I can on here about batteries and charging etc.

Can you tell me the difference in run-time between a 2350mah pack and a 4000mah pack, just a rough guess.

[785boats]

Hi Circus Circus.
It's good to see that you are researching & reading about Lipos before investing your dollars.
To add to the confusion I run a pair of Hi Model 2s 5350mah 25c packs in series in mine & they barely get warm. They fit easily into the sponsons held in with velcro. I also have a pair of 4600mah packs too. Just scroll down this page & you'll find them http://www.himodel.com/sort.php?sub2=G2&page=3
A point to remember. If you are considering joining a club to do some racing there may be some rules on battery setups for different classes, like no parrallel packs, maximum mah rating, or maximum total battery pack weight. This may govern your final decision. Of course it won't be an issue if you're just running for fun.
On the subject of clubs, I would urge all boaters to join a club if there's one nearby.
It's a lot more fun than running on your own & you can learn so much more in a short space of time. And you meet some great people too.
All the best.
Paul.

[DISAR]

It is better to run two 4s bats in parallel than two 2s in series. Higher amps capacity and run time but also more weight which might be good if your boat is too fast. For example
a) The two 4s rhinos 3700mah 20c in parallel. Discharge capacity: 2x2x37= 148 amps
b) The two 2s himodel 5350 25c in series. Discharge capacity: 53.5x2.5= 134 amps

I have many 2s packs but I wish i had bought 4s ones. Eventhough the himodel packs are not that expensive. Also check that one:

https://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8584&Product_Name=ZIPPY_Flightmax_5000mAh_4S1P_25C_

I will run now mine Apparition with 9xl, 6s1p, himodel 200a, m440. Let's see...

[CircusCircus]

Thanks for the help guys, about ten years ago I raced 1/10 electric touring cars, and I considered myself knowlegable in battery and motors. Back then it was all Ni-cads and Nimh and the motors were all brushed. It was alot of fun cutting comms and playing with different brush set-ups. I slowly moved on to racing Nitro-boats and never looked back. Now I find myself wanting to go electric, because its cleaner, faster, and less noise.

I just find it funny how much things have changed in the world of electric RC, everything is brushless with lipo power. Oh well this is what makes the hobby so fun

[785boats]

DISAR
You're right about the higher capacity for 2 x 4s packs in parallel but the weight saving is a plus in this boat I think. Unless that's the reason I cant go around the corners at top speed without spinning the thing. At least it doesn't crocodile roll in the process. That's a plus.
Does yours corner fast or do you have the spinout problem too.
The setup you intend to instsall should be pretty damn quick. We await the results.

Circus Circus.
Yep. Battery & motor technology have certainly changed over the last ten years.
And who knows these Lipos & brushless motors will probably be a thing of the past in 10 years time.
It may be Tesla electro-magnetic wireless generators & Harmonic motors. He! He!.
Cheers.
Paul.

[DISAR]

785boats
The turning issue that you have may be due to the big prop 645. I think that this is the max.diameter propeller that will fit in the RTR version. Maybe the the turbulent flow coming from the prop does not provide any adequate lift force to the rudder at high speed. Just guessing. I also strengthened the steering rod by placing it inside this:

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7326&Product_Name=Sullivan_Gold-N-Rod_36in/91cm__SemiFlexible__2sets

I put the rod inside the yellow tube (fits perfect) and glue the blue tube to the hull. I use this method in all my boats and works nicely.

[DISAR]

Is it turning ok with the 642?

[Jeff Wohlt]

Just finishing one myself. 8Xl. Inline rudder and .078 wire drive.

Just need to put my water cooling in and Electronics. A buddy of mine does the car wraps and says he can make me whatever I want on it....might be easier than painting.

[785boats]

Disar.
I've used that type of linkage on a few boats, both scale & F/E. The only difference being that I use the braided cable type.
I think that because the linkage is on the right hand side of the rudder & pulling to turn it, strength or flexing is not an issue. Although I have glued a guide block under the deck just behind the hatch to stop any flexing or bending in corrective left hand turns. I prefer to have a linkage each side wherever possible but there is not enough room to stand the servo up in this one.
It has the same turning issues with the X642.
I've also tried the following props with the same result X637, K440, K442, Grim Racer 40 x 52 - 3 blade.

Jeff
That system can produce some amazing graphics & artwork.
Of course I will be very interested in how yours handles. Please let us know.

Thanks guys.
Paul.

[Jeff Wohlt]

I layed my servo down and run a 1/16" wire for the linkage...I have never had one flex even in much heavier larger rigs. I used the double wire on each side as that would be the strongest but just not enough room to stand up a servo...unless you use a mini which would not be good.

I also use the clevis that I solder to the wire for the servo end and then use the brass connector for 1/16" wire at the end of the rudder.

The Traxxas boots are sweet and fit great just by pulling them thru the hull where the lip is after drilling a hole.

I will gets ome pics soon. I made my own strut/rudder brackets and that kind of stuff. Should run well....handling is another story.

[johnnyoverkill]

Mine is finished Jeff! You are still playing catch up!

Was I being smug after you did such a beeeeeeaaaautiful job on my wire drive?

[Jeff Wohlt]

LOL...very funny. I am slow but is built like a tank.

[ozzie-crawl]

tried mine out on the weekend with some fast cornering and yes it didnt like it iam running a 7xl does anyone else have trouble with what seems like torque roll in a straight line.
cheers scott

[785boats]

Hi Ozzie.
Did yours hook & spin in the turns, or did it flip?
I've got no torque roll problems with mine that I can see, Seems to ride flat & straight with a slight nose up attitude. It does roll a bit out of the hole for a short distance but not after that.
Just thought I'd show you a pic of the wedge I added some time ago. I've convinced myself that it helps the hull run a bit drier but who knows?
Cheers.
Paul.