norbique

Hi!

I've already promised to some of you that I'll post a thread showing my 1.1m balsa cat scratch build.
Not long ago I built a balsa cat per Shockerman's plans at 80% size of the original plans. I liked the boat so much that I decided to build it agan, but this time enlarged.
I very slightly modded the plans and enlarged them to 166%. Most of the pics speak for themselves, some I will comment.
All comments suggestions are welcome!

n.

SV27dayton

Love that boat.  I gotta finish mine.

Stokes

looking good buddy....and the small one - that's quality that is.....excellent stuff - keep it up!!!! Is the hull bottom also balsa? if you want it to be stronger maybe modelling ply (1mm) would suit you better, and just as easy to cut with a Stanley knife...my only doubt is the strength of balsa for a boat this big (and this powerful). ok you'll glass over it, but still, I think ply might be better.

keep the pics coming!

Dayton - you still not finished ?

norbique

SV27dayton, Stokes,

Thanks for the kind words! I'm always trying to be as precise as possible when I work.
The small boat's shell is made of 1.5mm balsa laminated with 0.4mm 3 layer ply. It's very strong. The ply does wonders.
The light blue coating is actually a 2 component base coat. It is sprayed over and it fills the grains very nicely. When it dries it feels like it's some kind of a plastic, still it's easy to sand. I still haven't decided on the color. Maybe light blue metallic.

The big cat will have 3mm balsa on the bottom and the sides, 2mm balsa on the top, and everything will be laminated with either 0.8mm or 1mm ply. Plus I'm thinking of adding 2 or 4 carbon pipes going through the hull lengthwise and woven glass fiber reinforcement from the inside of the hull.

Simon.O.

Norbert.
I will watch and help where I can.
My next build of a Cat will be a twin drive, no surprise there. It will however be small, about 20 inch long with Mystery style heli motors. This is to keep the cost low and fun high.
Balsa build all the way with a bit of hardwood here and there for strength.
Varnish, sand, varnish sand etc............then water time.

SV27dayton

Not sure if the ply is the same.  I think I used Birch.  Looks like there are 3 or 4 layers - very thin, but I think way more impact resistant.  That paint sounds really cool.  Mine will maintain it's natural finish but I'll remember that for later.  If I do an F1 I'll paint it.

Stokes - My life must be too full of good things!  (one of them isn't money)[:@]  (and another isn't spare time)[&:]

norbique

Some new pictures.

norbique

Picture update agian.

I was working on the rudder holder (sorry, I don't know the name) of the boat. I looked at some (many) cat pics and took the shape from there. Then I designed something similar. It turned out quite well. I bough some SS lock nuts and bolts, M4. Those will hold the rudder mechanism in place.
I also added the carbon pipes, 5mm outside diameter. I had to do it in two pieces because of the shape of the hull. I will reinforce the joints at bulk "C" where the two pipes meet with ply on boths sides just to make sure. I was wondering should I sand the carbon a little bit where the epoxy will be added, since the surface of the pipe is so smooth.

justintime2w8

My Feedback: (1)

Wow your work is incredible, I am now roasting marshmallow's in the backyard over the three I built :-)

norbique

Hi,

Thanks justintime!

I did some work today. I epoxied the rear segments of the carbon reinforcements, the last bulkhead, and began planking the underside of the tunnel with 3mm balsa.

Stokes

keep going.....definitely an inspiration to us all!!!!

norbique

I glued the front segments of the carbon pipes in place. These carbon pipes make a huge difference. The hull is already very rigid thanks to them, although it still has a little torsion play of about 2-3mm. But considering the hull is more than a meter long, it's quite good I think. I cut and glued reinforcing ply pieces to the front of the sponsons, see pics. Then I worked on the rudder holder. I carefuly drilled the 4 holes for the bolts through the ply. I wanted to make them nice and parallel to each other. Then glued the M4 self-locking SS nuts to the indside of the rudder holder with a tiny drop of CA, just to hold them in place. Then I surrounded the nuts with clear epoxy. Not much work but it took quite some time....

Jackedman

My Feedback: (2)

norbique you are one fast worker and do very nice work i might add. You said you were going to paint it an light blue metallic may i add to say add some silver metal flake to it or even an darker blue i use it in a lot of my trucks and it looks crazy , But really nice work cant wait to see more pics

norbique

Thanks for the compliments and suggestions Jackedman!

Can you post a pic of your truck here just to show us how it really looks? A daylight pic would be best, as artificial light screws up the metallic paint color, or the camera white balance or somethin, but it doesn't look the same as in natural light.
Another quesiton, where can one find those silver metal flakes you mentioned? It's kinda hard to find these kind of exotic stuff on this side of the pond you know.
More pics will come later today. I was repairing an office desk in the morning. Didn't touch the cat at all.

Jackedman

My Feedback: (2)

I will take some pictures for you and post them I have a few trucks i have done this too and all the metal flake that i use is just the fine glitter ( craft glitter ) and some clear coat mixed together but try it out on a scrap peice first .

Jackedman

My Feedback: (2)

Hope this helps but if needed i can take some more pics

norbique

Thank for the pictures Jackedman, it looks really nice.
How do you apply this glitter? You can't spray it on, right?! The flakes are too big to go through the nozle of the spraying gun.
I didn't make any new pics, since I only varnished certain parts of the inside of the hull, which will not be accessible once I plank those parts. I'm gonna give two layers of varnish, then I can continue with the planking.

norbique

I coated the parts I refered to earlier with two coats of varnish, and continued planking the bottom of the tunnel. I also worked on the rudder holder.
Now it's beginning to look something like a boat, not just a skeleton Current weight as shown in the pictures is 652g.

Stokes

did you epoxy in the transom bolts? useful trick that...in some boats I own it's a bloody nightmare to get an allen-key/screw driver in there. The only downside is that you can't use some of the tasty hardware hopf make, as you screw that in from the inside of the transom, but what the hell, plenty of manufacturers to choose from.

norbique

Yes I epoxied the nuts in their place. The hardware I have (Marine Specialties) is made to be mounted like that. The bolts holding the rudder mechanism are screwed in from the outside.

Jackedman

My Feedback: (2)

norbique
the glitter you can put it threw a air brush but just put the bigger neddle in and make sure you mix it with clear coat and that should work for you

norbique

Thanks Jackedman, I'll keep that in mind when I get to painting the boat.
I began planking the sponsons of the boat today, but I could only make a single picture, before the batteries in my camera died

Jackedman

My Feedback: (2)

no when your done that you round all the edges and do the other side right or do you do all your sanding later??

norbique

After such a long time, here's a new pic.
I added two 3x4mm cross section wood pieces to help shape the edge of the sponson and did some more planking. And I ran out of 3mm balsa...

norbique

I found some more 3mm balsa, so I could finish the planking of the underside of the sponsons.