30" Scratch Built Cat

[rcboatfan]

looks great!!! i cant wait to see this boat run!!

[lomdel]

...PS I started with 2S1P 20C 5000 MAH lipos so I do not start frying everything. When I learn about lipos I will start asking again if I should
use more powerfull batteries.

She looks good Norm! Mine is progressing very slowly...

Using too weak batts will fry stuff. If the lipos can't deliver what the motor and ESC is asking, they will overheat and the ESC will suffer! Stronger lipos have the ability to deliver what the system requires. A 30C rating lipo will not deliver all its power, only what is needed and would therefore run cooler and easier on the system.

[Norman2]

Hi Lomodel, will get some 30 C rated lipos. Thanks
Norman

[lomdel]

There is a slight misalignment of my cat's sponsons! When placed on a flat surface the one sponson's running surface is flat on the table and the other one is not by about 2-3mm. This means at the transom where the stingers will be mounted the one stinger is going to be about 2-3mm higher than the other one... Is this is major problem or can I compensate for it with the stinger trim angles? Is it worth it to continue this build? I don't want to spend all this time and money on a cat that is going to have handling issues...

[Simon.O.]

All builds are worth continuing with Lombard.

Cat you elaborate on this missalignment ?

First of all is your table FLAT ! I ask as I have run across problems like this.
Are you saying that when the boat is placed "flat" one transom is off the table by 2-3 mm.
Which side is off the table ?
A photo may help but a good description may do the job.

[lomdel]

The surface was flat Simon. The boat "rocks" a little like a table with one leg shorter than the other. That rocking motion is about 2-3mm.

[Simon.O.]

The surface was flat Simon. The boat "rocks" a little like a table with one leg shorter than the other. That rocking motion is about 2-3mm.

I have had a cat like that ( and a table too )
Given your description it must rock upon an axis, which is it ??

Is it left rear- front right or right rear- left front ? It is important to see which way the cat rocks.

How far from the transom is the frontal point that contacts the table ?

The amount of "rock" in your 30"cat may not be as bad as the rock that I had in my 24"Cat

[lomdel]

I'll check over the weekend...

[Norman2]

Hi Lomodel, I really do not think this will be a problem. You can probably compensate when
you install the stingers. I am positive that in a cat this size with twin drives you will not have
a handling issue. Mine rocks like yours and the sponsons are not perfect and up to now there
are no handling issues. It would be a pity if you did not complete such a beautiful build.
Regards, Norman

[Simon.O.]

Hi Lomodel, I really do not think this will be a problem. You can probably compensate when
you install the stingers. I am positive that in a cat this size with twin drives you will not have
a handling issue. Mine rocks like yours and the sponsons are not perfect and up to now there
are no handling issues. It would be a pity if you did not complete such a beautiful build.
Regards, Norman

There you go Lombard, Norman says his rocks too, on and off the water.
With my smaller cat even though it is a single drive I place it on the table and press down on the rear to set the two transoms on the table. All adjustments are made from here.
Finish it and get it wet. PM me if you have any worries.

[Jesse J]

WELL put Simon. Get it wet man (oh and vids would be good too)

[lomdel]

Thanx for the encouragement guys, I WILL finish her, but not soon. The finishing/painting work will take time (which I don't have a lot of) and the electronics still need to be ordered and that will take money (which I now don't have a lot of). Bear with me, I'll keep you posted on progress...

[rawsonreyes]

hi norm, jesse,lomdel. i am still awaiting for the quote from the laser man hope i can join you guys with some pic soon.put up some videos of the cats in action,i already have 2x 90amps bl esc and 1 442mod prop wish you guys could of send me a complete build but that is not the fun part i guess.awaiting laser man

[ice_spy]

I have built one out of balsa. it does around 65klm. here is the link on youtube.

http://www.youtube.com/watch?v=adVifB3iF_I

Funny i could only build it 30cm long as i could only print the plans on my A4 copier !!! lol.
But yeah, i thought why not try to build this cat the smallest you can! It runs a single 2s 900 mah pack but i plan to place two upfront still 7.4 engine is a china 4200kv outrunner and 30amp esc. prop is also small china clever weapon.
Hardware curtosy of Head of the river, Mr J Cheung.
Dam thing is WAY overpowered!!. cant apply full throttle or it rolls over even @ 70-75% throttle. However tests in vid with were a lager prop from the EP1 aquacraft outboard with 1/8th drive. Temps were good. run time estimate @ 10-15 mins! I will also run a low volt buzzer with led that will change the canopy glass from green to red to avoid over-discharge.

[Norman2]

30" Scratch built Cat

WELL put Simon. Get it wet man (oh and vids would be good too)

Hi Jesse, Lomodel and all. Well I am finally done. Ran it today using X640 prop
that I got from Steve and with the 2S 1P 30C 4900 MAH lipos and can not be
happier. No problems with heat and my friends GPS clocked it at 44.6 MPH. I think
I may be able to go to a X642 so I can get my goal of 45MPH. For now I am not
touching it as it runs super. Attaching photos of the installation of the UL-1 Power
system in case anyone wants to see how it will look. Now have to think of what
else to build and maybe a Neu for my Titan 29. Regards
Norman