gonggongboy

Hi im getting ready to start my Maxcat build im bumping the size up to 6ft.

Im going to be using a Blata fully modded and ported motor to a gearbox and counter rotating props.

What is a good size prop to use to get started at.

Im a huge KU Jayhawk fan so im gunna make like the Bud Light Cat but silver will be red and the right front corner will be yellow and some other decals im hoping it will look pretty sweet.
Im having my hardware custom made. Ill start building this weekend i have to get the plans printed and get the wood.

Im going to use 7/32 lauan for the skeleton and im planing on using 1/8 balsa to plank it.

Im wondering whats the best way to cut the wood out. I dont have a woodshop so it'll be more complicated.
And whats the best adhesive to use on the skeleton.

Ill use some what thick fiberglass on the outside and thin on the inside. Im gunna put a couple of naca ducts infront of the canapy and two big scoops in the back.

Ive got this build planned out pretty well im just gunna need a little nudge from you guys here and there and tips will be a big help also. I have only built one other boat and it was a Predator rigger.

FlogginHarvey

Rock Chalk...baby! Beak 'Em Hawks!!!

take pix and keep us posted.

mkharv3

GO WILDCATS!!!!!!!!!!!!!!!!!!!!


Sorry I had to do that when I saw that you were a Jayhawks fan.....

Good luck to you!

Mark

gonggongboy

Ill keep you guys post everystep of the way.

dicko

I personally wouldn't bother glassing the outside of the hull, just the inside of the hull. If built properly you shouldn't need glass on the outside.

gonggongboy

Im going to glass the outside to protect against objects puncturing the hull.

Ron Olson

My Feedback: (1)

Why balsa to skin it with? Just use lite ply then seal it with thinned epoxy. Balsa ain't cheap either.

gonggongboy

Lite ply is a little to stiff and balsa not that much. I looked into it.
It would only cost $4 for long 8"x 36" balsa

Also im not really trying to be stubern i've just got this planned real well.

What kind of GLUE OR OTHER should I use and also whats the best way to cut the wood out. Just a regular Jigsaw or some thing else.

Ron Olson

My Feedback: (1)

OK, it's your boat! Some people might call me stubborn too! I don't know where they get that idea!
The trick with laying lite ply on curved parts like the bow is to start from the front and work your way back.
I hope that you've got LOTS of clamps of various sizes and types as they come in real handy.
You can tack pieces with thick CA glue then use a slow setting epoxy. As far as cutting, balsa is easy compared to most other woods so if you're cheap like me, a razor saw and/or an X-acto knife will work. You can invest in a cheap saber-saw (jigsaw) to roughly cut parts to size. Sand when you get close.

gonggongboy

Alright thanks thats what ive been thinkin of doing.

BlueWave

Dont think I seen a balsa max cat build....

I'm using balsa ply combo on an own designed cat, just in stages of glassing the outside (builds over on jims/projects). Interesting your not going to glass the inside. Get going and post some pics of the build....
Interesting to follow.

Glassing the inside was a pain in the butt.. if your turns out well with just the outside, then may follow suit in a v2 one day...

My reason for choosing balsa was I though it would be easy for contouring, ha. still made a bit of a pig out of it.

good luck adam...

thevirginian

Hey, gonggongboy;
If you have seen my building thread of a 48" Maxcat that would have given you an idea of how to build this cat. If you try to save weight by using balsa instead of ply wood I guess you are thinking wrongw. When using balsa you need to glass the outside pretty heavily to prodect the skin and give it some strength. Believe me, I know from my own experiene. All the weight saving is gone by doing that. You most likely end up even heavier. If you use 1/16" ply instead it is strong already and requires very little epoxy on the outside. Ply wood provides the necessary strength for the sceleton of the hull, which is very important to guarantee a boat to be straight and run true at high speed. It's your boat and you project, but you asked for some building advice and here you have it. My Maxcat came out on the light side and I had to add lead to the lfront of the left sponson to correct prop walking in turns. At 60 she was getting really light and blew over easily.

Dreamin Hemi

OK, I'll throw in a few cents on the balsa thing....

Using balsa as a skin on your hull and glassing the inside AND outside may not be so bad. Balsa itself is not at all strong. However used as a core and laminated on BOTH sides with at least a 6oz fabric/resin will produce a very stiff and stong laminate. Not sure about any weight savings, however strength would definately be there. There are a few full scale boats I've worked on with a laminated balsa core. Heck, even some have only foam as the core! Balsa is also used as a core to beef up full scale molds. Adds thickness and rigidity. Perhaps that's what you're thinking?

gonggongboy

I was planning on using 1/8 balsa to skin then heavy fiberglass to add strength but not as much weight as ply.

Is 1/16 ply better to fiberglass our just epoxy it. Im wanting a sturdy boat that wont break under the stress of waves but i still want it light enough to glide through the water.

thevirginian

See, here is where you are wrong. You don't glide through the water. Your boat skids over the water surface at high speed that is harder than concrete. You also need some weight, otherwise your boat will bounce off every small ripple. Theoretically 1/16 ply is strong enough to provide a stiff hull without the need of extra fiber glass. A buddy of mine build a wooden "Whiplash" that has a skin of 1/16" ply wood. No extra fiberglass on outside! Only one coat of thin epoxy on both sides for water protection - that's it. This boat is doing over 70!. No problem with his hull. I protected the hull of my cat with a thin layer of glass on the oputside only. I used 1.5oz. glass for that and one coat of epoxy on the inside. No glass here. I saved weight and my hull is super strong. What Dreamin Hemi is referring to is correct, but there is a big differnence between a full scale boat and our RC race boats. In order to protect the balsa skin of your boat sufficently you would need to glass it just as thick as a commercially built fiberglass hull is thick. Now you still need to coat the inside to protect it from water. So, you will definitely end up heavier, believe me. Or your hull is too weak. You need the rigidity of the ply wood to give the sceleton its needed stiffness. Balsa is not strong enough. We just discussed only the outside. Now let's go to the inside of the hull. As you probalbly know, you need some motor stringers. I hope you haven't planned to use balsa for those, too. If your hull is made of balsa, the stringers wouldn't have enough strength in their connection areas with the hull. At last there is the transom, which normally made of 1/4' five layer ply wood, for good reasons. Unless you add even more fiberglass to the transom, it would be too weak to hold the rudder bracket sturdy enough. Again, think about it what you want to achieve with your balsa boat. I would heed the advice of all who have scratch built boats before and know what they are takling about. I have build many full scale fiberglass boats, fiberglass and wooden kayaks, and RC boats from scratch. One thing I would never, ever do is to build a boat with a blasa core. Especially if it is a racing hull. But it is up to you. Good luck.

gonggongboy

Yea i guess thats true ill probaly end up getting 1/16 ply since its cheaper and i wont need to buy as much. Will regular fiberglass epoxy resin work as the epoxy to seal it.

Ron Olson

My Feedback: (1)

That will almost take care of your cutting issue also as I've cut 1/16" lite ply with a good pair of scissors.

DJLaPalme

Gonggongboy, i bought a scroll saw at a local home improvement store for under one hundred dollars. It will cut everything(wood) that you are using for your boat and do pretty precise cutting. Dennis

gonggongboy

Im so excited to get going i have till I wake till I sleep to work on this boat. About 12 hours a day.

gonggongboy

I know this may sound crazy. I have thought of away to make units like

http://206.206.85.209/xtdoc/Details....k&store=mhzusa

that a guys making me, adjustable from the remote.

So they will startup and as i increase the throttle they start lowering to plane it out. =)

Sounds crazy but if it works that would be awsome. Correct me if im wrong.

BlueWave

Like to see what he comes up with..

MHZ (I think its them) do a remote controlled version....

To be honest I had remote trim tabs on a boat, really bit of a gimmick and more to go wrong, you will be blasting across the lake with the leg in up or down position!.

If its only a fun boat keep it simple, would be my advice....

In a mono hull arrangement the drive angle raises after plane-out to lift the bow... more speed opposite to what your doing.....

may be reverse in cat, but you may want to check that out...

thevirginian

I used only polyester resin for my full scale boats. I use only epoxy resin for my small RC boats and especially over wood. The working time is much longer. Get some good quality resin from www.raka.com (they are very reasonable) along with the proper cloth. I 'd go with 1.5oz. since it goes on smooth and conforms better to sharp corners and edges. I f you feel like you need more strength you could double a layer in certain places like the bottom. Get the ply wood from Bals Usa. They have top notch quality for low prices.

gonggongboy

I got my plans today and started tracing the patterns. Ill have some pics going up soon.

Dreamin Hemi

Why trace? Take your full size plan and cut it up. Spray a light application of spray adhesive (usually like a rubber cement) on the paper and like a sticker, place it on your wood. Instant perfect cutting lines.

gonggongboy

Yea i guess i could of done that but to late now. =(