Twin Mini Cat, version 2

[ace028]

Well, if you followed my thread on "yes, another catamaran build" you will know I built a 16" cat with 2 400 size outrunners, its nearing compleation of paint work, and will get the wiring sorted out along with 3 cell batteries instead of 2 cell like in the vid of it, well since the boat is about 2850 miles away at dads house (i'm in the Army on the other side of the USA) awating paint work. I decided to start another twin cat, learning from my mistakes from my first one, this one I plan to be better, and fuel my twin power cat cravings!!!


Projected parts:
3s 2p batteries
Etti stand off rudder
Etti stinger 1/8 struts
Wire drives
Counter rotating x430's
380-400 size motor (still deciding between outrunner or inrunner)
El cheapo escs (prob mystery or turnigy or something)
possible water cooling

I plan to style it similar to my other cat, keeping the offshore racing look,

welcome to suggestions and comments good or bad, especially power system, I can go a stepup from cheapo esc and motor, just point me in the right direction, I see that many people have had great luck with cheapo esc's and motors in their mini boats.

Stay tuned, I will be purchasing parts next week, and I will take lots of pics and updates for those wanting to build a mini twin cat out of wood.

[ace028]

Thinking of 2 of these LMK, from what I can tell scorpion is one of the best outrunners. Need input (short circuit lol)

http://www.scorpionsystem.com/catalog/motors/hk22/HK-2221-8/

[Jeff Wohlt]

Yes, that wil be a rocket alright!!

[wakeboardfusion]

what mistakes will you be fixing with this one? I am going to have to start a mini cat build soon.

Oh and what are the advantages to running twins in such a small boat? Just to buy double stuff and have it just for looks, or does it serve a functional purpose in a boat this small? Also if you were to compare twins with a single would the twins be 50% better overall in speed/handling? or just slightly better.

[ace028]

Mostly the mistakes I am talking about is motor placement, in my last one I installed the motor mounts before I had the drive hardware which in the end resulted in my flex cable being at a undesirable angle. And my hull bottom steps weren't what they were suppose to be like, even though they are still functional. This new build is just going to be better planned out.


Twin drive does have a pourpose. I don't know that it is nessicarily faster, I'm sure you have seen video clips of single motor boats that are wicked fast, but I have seen twin setups wicked fast too. I think the advantage you get with twins are since there are two motors, they don't have to work as hard, so less amp draw, and with counter rotating props the boat handles sooooooo nicely (in my opinion 100% better, but that is my opinion, with limited expirence to other boats), no prop walk. My thought is a ideal rc boat thats for fun and not racing will turn well left and right, and with my last twin cat, it turned equally well to either side. I'm not an expert on the pros and cons of single vs. twin, but I know that I loved how my last twin cat build drive, and twin motors also sound sweet too!!!!

[bonewar]

TWIN CAT'S RULE BROTHER.

BONEWAR

[ace028]

Stuff I ordered so far:

two etti stingers
two wire drives
two motor couplers
(thanks Jeff Wholt for above stuff)

some custom decals ordered (thanks eyekandy)

Will take pics once I get the above items.

[ace028]

Well, these are some of the custom decals for my build, some of them I won't use for the build, but here they are.

I am still waiting for the drive hardware, and I just got the plans lazercut so waiting for that stuff to come in the mail, hope to start building in the next 2 weeks.

[Eodman]

Twins are the way to go!

Toysport Twin Jolly, Twin Intruder, and a Twin Mean Machine Outboard (waiting to upgrade to the graupner GTX820 brushless outboards) in our fleet!

Oh the sound!!!!

[ace028]

Received some building supplies today in the mail

12"x16" 2x2 twill weave carbon fiber 5.7oz, only 10 bucks from Kinetc Racing. Bought some mixing cups and brushes. Finially bought me a balancer, also from kinetic racing, under 19 bucks and comes with all those shafts as well as 4mm threaded adapter.

[HYDROJERRY]

Dude you got the hookup, i need to get some of that carbonfiber to,,,

[ace028]

http://kintecracing.com/Building_Supplies.html

[wakeboardfusion]

I just put in an order for some CF from there too

[ace028]

Here are some pics my dad sent me to tease me, my lazer cut kit is at his house awaiting shipment to me, fresh from the lazercutter! These are just mocked up for the picture, they will be getting a building board and some blocks for a jig to assure proper alignment and avoid being tweeked while being built.

[peells]

I get to fondle them all yo get to do is look,

Ok as far as the single vs twins goes here is my thoughts on the subject! I built the yellow BobKat (very similar to the Lynx) they share the same stringers and size steps ect. my Bobkat was a single and very sensitive to operate, it was very critical in turning and it only liked to turn well one direction, this could have been due to some trimming issues but I doubt it as it had a definate pull to one side and did I say it was really touchy (Opps I did)
next the available space with a single for your equipment is smaller as the motor is right there in the center of everything along with the batteries servo and anything else you can think of, Look at both builds BobKat(save those scraps) and my Lynx build pay attention to the layout of the gear, the single took a lot of care in the placement of the motor and battery it was really tight in there an there was like 1/8" of extra space between the motor and the battery I can increase that now with a larger hatch and cutting the bulkheads out for more clearance to slide the battery more forward and that is one thing I needed to do during the build it is too late for that boat as I konked it with a rock trying to recover it at the local pond
smashing off the corner of the boat.