30" Scratch Built Cat

[Heath M]

I'm thinking twin super Vee motors on 4s would make this hull rip :)

Heath

[lomdel]

The guy who did my laser-cutting is very keen to help anyone worldwide out with similiar jobs on balsa and plywood. PM me for the contact details.

[Norman2]

30" Scrath Built Cat

Hi, How do you guys secure the hatch. I am thinking of a base of ply around the
outline of the hatch opening and High density weather stripping. Any help will be
apreciated. Thanks
Norman

[Heath M]

Must guys just use hockey tape to hold it in place, this also keeps the water out..

Heath

[Jesse J]

yep, I make a piece of balsa with my custom canopy and just tape her shut. If you wanna get fancy, you could make a little shelf, so the hatch doesn't fall in - they are WAY too cool looking when sitting nice and flush and the hockey tape is pretty clear so clean sailin!

[Norman2]

30" Scratch Built Cat

lomodel Hi, Could you PM me the contact for laser cutting. I won' go through this
again. Thanks
Norman

[Norman2]

30" Scratch built Cat

Yo Norman, how's progress? I know you are doing single drive, but this size cat is entering into the twin realm. What size motor/esc are you thinking? Batteries? Updates please

Hi Jesse and all in this thread. Attached photos of latest progress. Have completed
sheeting and first coat of white polyurethane sealer and primer. Use white so I
can see any ding or imperfection. Once sealed will primer and fiberglass over
silkspan. Still a lot of sanding and finishing before it is smooth. Now for the hardware
from OSE. Regards
Norman
PS. Will work on hatch while waiting for sealer drying

[Jesse J]

Great job Norman! I've been busy and you snuck this update in on me. I like the staggerd strakes, I think I noticed that on the plans but forgot when I was adding them... Sorry if I talked you into hours of bandsaw torture, I kinda like cuttin stuff on my bandsaw (one of my good friends). The trick to the lasercutting is to make sure you know how wide your slots will be compared to the thickness of wood you will be slotting. I have never done laser cutting, but definitely like the ease factor!

How ya gonna do the hatch?

[Norman2]

30"Scratch built cat

Hi Jesse.It was hard work on the bandsaw but well worth it. I am using 1/32
basswood for the hatch. Will post pictures soon. I am building a shelf all around
the outline of the hatch opening 1/8 x 1/2" ply. It will sit on high density weather
stripping and will self lock in front and two screws will hold the back. Pretty neat
and my titan 29 never leaks. I will keep you posted. Regards
Norman
PS:I put the strakes in that position because I used to own and drive a 32' Champion Offshore cat and that is where it had the strakes.
the rear ones act as a mini turn fin and keeps the transom from sliding during turns. Hope it works. regards
Norman

[lomdel]

I have a few 3S lipos that I want to run my twin version on. Will 2x 540 6XL motors with X442 props have enough oomph?

[lomdel]

Hi Jesse and all in this thread. Attached photos of latest progress. Have completed
sheeting and first coat of white polyurethane sealer and primer. Use white so I
can see any ding or imperfection. Once sealed will primer and fiberglass over
silkspan. Still a lot of sanding and finishing before it is smooth. Now for the hardware
from OSE. Regards
Norman
PS. Will work on hatch while waiting for sealer drying

Norman. What sealer did you use and what is silkspan? I am a bit worried about the added weight of fibreglassing. Can't the hull run without it?

[Simon.O.]

I have a few 3S lipos that I want to run my twin version on. Will 2x 540 6XL motors with X442 props have enough oomph?

I have played with FE calc a bit and for Twin cats use the Hydro settings which should reflect the fact that 2 motors are in there.
This is still a guess. !!
6XL on 4S over 442 props will show.
101 amps 931W out of the motor 26.900 rpm 48 mph.

The question now is do you have the 6XL cans yet ??
If not, given that you have a bunch of 3S packs then you could go 6S on a higher wind motor and drop your amp draw for the same power output.

[Norman2]

Norman. What sealer did you use and what is silkspan? I am a bit worried about the added weight of fibreglassing. Can't the hull run without it?

lomodel Hi, I used a polyurethane sandable wood sealer by Valspar. Got it in Lowes.
Silkspan a very light material used to cover R/C Aircraft wings. The fiberglassing
is only a very light and thinned coat of resin just to impregnate the silkspan. It is
very light but very strong. It could do without it but I need strength and a perfect
finish. Regards
Norman

[lomdel]

I have played with FE calc a bit and for Twin cats use the Hydro settings which should reflect the fact that 2 motors are in there.
This is still a guess. !!
6XL on 4S over 442 props will show.
101 amps 931W out of the motor 26.900 rpm 48 mph.

The question now is do you have the 6XL cans yet ??
If not, given that you have a bunch of 3S packs then you could go 6S on a higher wind motor and drop your amp draw for the same power output.

I do not have the 6XL cans yet, still counting pennies... It would be twin 6XL on 3S through X442 props. 101A or above is not my concern, the ESC will handle it. Going 6S would mean 4x 3S packs in the boat - too heavy!

[lomdel]

lomodel Hi, I used a polyurethane sandable wood sealer by Valspar. Got it in Lowes.
Silkspan a very light material used to cover R/C Aircraft wings. The fiberglassing
is only a very light and thinned coat of resin just to impregnate the silkspan. It is
very light but very strong. It could do without it but I need strength and a perfect
finish. Regards
Norman

So you'll be applying resin over the silkspan without actually laying fibreglass cloth?