30" Scratch Built Cat

[Norman2]

Hi, Recieved my plans today from Jesse J and will start cutting forms this week.
Wil be posting photos of progress as it comes along. Hope this works.
Norman2

[Simon.O.]

Man that is just teasing !! You can't just tell us you are building a cat and leave us hanging.....that's cruel.

You are doing a twin drive right ??? Of course you are . Please tell us it's a twin.
What sort of power are you looking at throwing in there. Obviously lots, but just how much ??
I will be following this one closely as I want to get on with a twin drive 30+" cat as soon as the rigger is finished.

[Norman2]

30" Scratch built cat

Hi Simon, Just completed cutting bulkheads from 1/8" balsa and will glue
them together this week. I will take a photo and post. I do not think it
will be a twin but maybe. Just want to make sure I can complete hull and
if it looks OK I will then decide what power to use. Will post pictures and
photos.
Norman

[Jesse J]

Great! glad you got the plans and are having fun in the cutting process. The main struggle with this build is making dam sure the sponsons are true before sheeting. You will save yourself hours of bondo/sanding/bondo if you spend some quality time truing up the base of the bulkheads. I have even added strips of balsa just to ensure flat ride pad. My first one of these had a pretty lumpy base then my atrocious first fiberglassing really put it on the shelf.

Post pics, even of the bulkheads, I am always glad when I do, cuz you can't once you get to sheeting! Ahhh, the inocent phase of the build. ENJOY!

[Norman2]

30" Scratch Built Cat

Hi Jesse, Again thank you for the plans. I am going to follow all your tips in
building this cat. I have built several plank on frame kits with balsa sheeting
and have been able to have a very smooth finish. What I usually do is fiberglass
all the insides. Once I sheet I use two coats of fiberglass, sand the nibbles and
then use silkspan with thinned fiberglass resin. The only change I think I will
do is to square off the transom. I am attaching photos of my latest scratch built
52" Frigate. Hope you like. I am really determined to make a nice cat.
Regards,Norman
PS The frigate can be maybe considered fast FE as it is powered by Twin 700 BB
Graupners and it is very fast. Does not turn well but it does move
Norman

[Jesse J]

nice looking frigate, any vids?

I have changed the stern as well. first couple square. this micro i tapered and it looks way better, much more realistic. I can post pics if you want to see more specifically.

let me know if you have any more building questions, I am sure I have encountered the same ones.

[lomdel]

I managed to redesign the plans to 810mm length with a 150mm wide tunnel and modified it so that brace F becomes a slightly tilted plywood twin motor mount. The plans are available as JPG, PDF or DXF for those who want it... That is a CAD rendering below, not the real thing yet.
The single drive version is also available in the same format.

[Norman2]

nice looking frigate, any vids?

I have changed the stern as well. first couple square. this micro i tapered and it looks way better, much more realistic. I can post pics if you want to see more specifically.

let me know if you have any more building questions, I am sure I have encountered the same ones.

Hi Jesse, Was able to glue framework together. Unfortunately there is no one that
can laser cut within 200 miles from here so I cut it myself. During the week end
I will complete the cutouts on the bulkheads and add some bracing between each
one to make sheeting easier. Will use 1/16" balsa and then 1/64 ply. As you can
see, I indented the part of the transom to make up for the in-line hardware I am
going to use. Did not want it to be too far from the transom. However I will be
sheeting the top so it will not be seen from above. Will keep progress report.
Regards, Norman

[lomdel]

I changed the total proportion of this twin drive version of mine and shortened it to 770mm for a stiffer structure. Below is the drawings, I will again add a 3D rendering later today... (added )

[Jesse J]

Right on Norman! looking good! Glad to see progress. Is the indentation for the strut?

What hardware are you planning to use?

[lomdel]

Norman. I don't mean to hijack your build thread, but I would like to build mine parallel to yours. I believe we can use this thread of yours to pool information, tips and answers 'cause this would be my first scratch build as well. My balsa and ply cut-outs would be done this weekend and I should start assembling the frame next week some time. In the meantime I am following your build with interest.
How are you going to do the cut-outs in the bulkheads now that everything is assembled and glued?
Are you going to glass fibre it finally after sheeting? One tip; if you sheet the tunnel and deck with balsa, do it cross-grain not parallel. The cross-grain would add more lateral stifness to the frame (an old aircraft building technique).

[Norman2]

30" Scratch Built Cat

Hi, You can hijack this thread any time you wish. The more information out there
the better. The indentation in the transom is for the OSE In Line Hardware. Just did
not want it to be too far from the transom. I will cross grain the sheeting but I
will be using 1/16" balsa and cross grained with 1/64" ply. Then Thinned Fiberglass
coating over silkspan. I have found that this makes a pretty strong and light hull.
I am doing the cutouts today with my trusty mini-dremel. Let us see what we end up
with.
Norman

[Norman2]

30" Scratch Built cat

Right on Norman! looking good! Glad to see progress. Is the indentation for the strut?

What hardware are you planning to use?

Hi Jesse. Yes the indentation is for the OSE In Line Strut. Did not want the strut
and rudder to be too far from the transom. Photo attached. Regards
Norman

[Jesse J]

Wait a minute, where did you get that? I have been searching for that very gem for a long time now. I LOVE it! Could be the answer, do you have a link to a place I can get me one too?

Yes, I have cut out the bulkheads with my trusty dremmel too, much better to make a strong frame, then remove excess weight, good job Norman.

Next one of these I do, I may go straight to ply on the tunnel; cross grain and then 1/64th, I have found, needs reinforcing for the motor mount any way, otherwise some nice carbon fiber would do - I got me some of that 1/32" would be perfect.

Nice to have a parallel build to cheer eachother on! I will be following closely! good job guys. Are you gonna race them when finished?

[Norman2]

30" Scratch Built Cat

Hi Jesse, The in line strut/rudder is available at Offshore Electrics under
Hardware Systems. Steve can fix you up with one. Regards
Norman