warfile

Hi, after reading this post i dicided to build my own rig(1st).
I already have the plans printed in 1/1 scale.
Will THIS strut be ok for it?

Thanks in advance
Rui

warfile

And THIS rudder, will it work?

Thx
Rui

toyotatruckin

stick with american stuff that takes a 4mm shaft my octura stubs are 4.73mm hughey stubs are close to the same and if its a 4mm flex that comes with it its to bigproblem i see you having is getting replacements for it.. .125/130 flex and 3/16 stub drop down to 1/8 is what i recommend for any power at all and stubs and shafts are easily available in the USA

rudder will most likley work

And now looking i see your not from the USA (woops) stick with what ever you can get in your area

warfile

Here in Portugal is very, very difficult to get this stuff, so...

What brands of strut should i look in to it?

j.m.

make your own.

Like these:
http://image2-6.rcuniverse.com/e1/fo...19/Av69126.jpg
http://pagesperso-orange.fr/pleindetrucs/
This one's not too clear, but it is homemade.
http://static.rcgroups.com/forums/at...172-strut1.jpg

warfile

Right, i thought of that but what about the measurements for it?

ISIRC10

well, I'm glad others are building more predators... I must admit, it is a very fun build, and doesn't take too much time or past building experience (I think... )

as for me, I am having some fun tuning and running the boat, which seems to run fairly well IMO. It provides a great distraction from school and sports which are taking over my life.

aside from that, I mowed a few lawns, and now I've got a barracuda 80a ESC and a feigao 8s coming in the mail [sm=angel_smile.gif][sm=lol.gif]
in two or three days, my rigger might just be the fastest thing on the lake... then again, there are only sailboats and paddleboats, but you get the idea!
I just have a question... how the heck do I cool my esc? It doesn't come with a heatsink, so is there a way to cool it, and if so, where should I attach the heatsink?

and I still haven't solved my water cooling issues... the water comes up to the motor coil and doesn't reach the ESC during normal running, but if I stick it under a faucet, everything flows nicely (although it is more like a trickle)
BTW, I did get a thrust bearing and a few props, so I can see which ones runs best.

j.m.

i've got my tub assembled and sealed. I need to put the top sheeting on, then i'm going to start on the sponsons.

How do most people assemble the sponsons?

toyotatruckin

the way I do it is epoxy the inside sponson 1/8 first, drill my foam for the booms after that has set-up, top skin,back skin,bottom skin, shape the outside, then outside skin

test fit without any glue before each skin is put on to make sure things are going to be right!!

pompebled

There are a number of ways to skin that cat:

Adapt the design attached to fit over the powerfets of the ESC, the size in the sketch is for my 50A ESC.
After it's machined into shape, I solder a piece of 0,8mm brass over it and add 4mm brass tubing to the inlet and outlet.

As my machineshop takes their time to make me two, I've made a supersimple version from two aluminum sheets, 2mm thick in my case, overlapping the circuitboard of the ESC by 5mm on each side, to have room for four (in your case probably six) M3 bolts to hold them together.

I made the waterchannel out of closed cell selfadhesive foam, by drawing the pattern on the backing paper and used a sharp scissle (did I write that correctly/) to punch it out of the foam, cutting didn't work as the foam deformed under the pressure, maybe with a scalpel...
I omitted the in- and outlet in the foam at first.

I took the backing off and glued it onto one of the aluminum sheets, which had been drilled and tapped with M3 thread earlier.

I used a Dremel and a 2mm drillbit to carefully make two holes for in and outlet an inserted two 4mm tubes.

Screwed the two halves together and the narrow holes in the foam sealed of the tubes, tested it, no leaks.

Added heatconducting paste on the Fets and re-shrunk the esc with new shrinking tube (take the old one off).

Regards, Jan.

ISIRC10

pompebled: boaters ARE nice people! Thanks for the help with the water cooling... I visited the link in the post a bit further up the page and see that the person had a similar heatsink as the one you described. I have a bit of aluminum left, so I will try my hand once the ESC gets here.

j.m.

the way toyotatruckin did his sponsons is the way I did mine, and I found that the plans weren't exactly perfect on the panels, so I just did the outside sheeting by hand. when you are doing it, use the wood grain to your advantage, see which way it bends easier. that way you will be fighting it less when you glue the curved surfaces.

ISIRC10

Well, there have been a few changes done to the boat, paritially due to the fact that soccer has ended. homework and projects are still a time issue, so I can only get an hour or two to work on the boat each week. I ordered the Barracuda 80A ESC but it came to me deffective, so I used Castle's awesome customer support and they sent me a replacement, the Hydra 120 [sm=thumbs_up.gif] [sm=shades_smile.gif]
That thing is a monster (and the 10guage wire was the thivckest I have seen on any ESC)
I installed the feigao, and changed the watercooling in order to better accomodate my setup. now I need to make a new hatch cover and then its time for some fun (although it's getting a bit chilly!)
One thing I must say is that Castle Creations has a great customer support line and they have understanding and helpful people. thumbs up for them replacing my ESC with another at no charge.

ryan_t888

Which motor and cells are you using?

Ryan

ISIRC10

I am using 7.2v 6 cell orion pack, 3000mAh
the motor is A Feigao 540 8s
I am waiting for a lipo for christmas! or maybe a 8-cell IB pack...
as of now, the power it generates is insanely greater than my previous setup.

ryan_t888

Cool! Go LiPo not NiMh.

Ryan

j.m.

Definitely.

As soon as I get LiPo's for my planes, I'm going with a BIG 3s pack for mine...

ISIRC10

yeah, but then I would have to get a new charger and when combined, that would probably end up to be my christmas and birthday present... are they really worth all of that money?

can a 3s fit in the outrigger?
will it be able to power a 30" catamaran?
(thinking of making a "shockerman cat")

ryan_t888

Yes, it's worth the money. I would not even think about using NiMh.

3s LiPo on a 540 8s is way too hot.

3s LiPo in a 30" cat would work well.

I'd try and stick to 2/4 cell packs. 3s packs are really odd ball. I have a couple 3s packs for my planes and that's pretty much all i can use them for. Just a one off application. I will eventually convert the planes to use 4s LiPo so all my packs are universal in the stuff I run them in.

Ryan

j.m.

3s will be too much with your motor.

Do you already have a 30" cat?

What are you running in it?

2s would be great in your rigger.

4s could be good in a 30" cat, but 6s would be better.

try these:
http://www.hobbycity.com/hobbycity/s...0C_Lipoly_Pack
(3 of 'em)

and a charger:
http://www.hobbycity.com/hobbycity/s...r_&_discharger

ISIRC10

well, I probably would not have gotten a 3s pack any way, as I want to use these lipos in my car also (if possible)
with a Mamba Max 5700 kV setup, a 2s would be plenty of speed, a 3s is slightly edging towards the insane side... (60 mph anyone?)

I do not have a cat yet, but I do have the plans to build one, so I will probably end up putting the 540 8s and a 2s lipo in it. I would probably scale it down to a 24" boat.... Ive got all year to think about this... its going to e a summer project. As of the rigger, I am in the process of making the canopy - this time it's not going to be so big!

CadillacDTS2001

3s on a 8S... i dont know i would do it!

but then again i could careless if my motor blew apart.

j.m.

Anything smaller than an XL won't move a 30" cat.

If you are going to stick with small motors, stay with small boats.

But these might change your mind:
http://www.hobbycity.com/hobbycity/s...hless_Inrunner

http://www.hobbycity.com/hobbycity/s...eed_Controller

http://www.hobbycity.com/hobbycity/s...imple_100A_ESC

j.m.

And this one for even bigger boats:
http://www.himodel.com/electric/HiMo...00A-OPTO.html#

ISIRC10

I allready have a pretty solid ESC, so I probably will not be getting any in the near future... unless...
The cat will probably end up in the 22-24" range, so I guess the motor from the rigger should suffice - right?

back to the out rigger...
I finished the cover today, it still looks weird, but it has a better seal. I guess that covers aren't really my type of thing.
Tested the water cooling in the tub today, everything worked, so maybe I can get out tomorrow and have some fun at the lake.
hopefully all of this rain stops too... I ran my airboat in my back yard today, whats how much water there is!

If I get out, I will try to get some videos - there should be a marginal increase in speed!

j.m.

I would go with an L can in a cat.

And you could rotate your water jacket to the left and use a flat hatch, right?