Cat build advice

[Nomad]

New to RC boats, looking to build new boat but so many catamaran hull choices not sure what to go with? Some of the older guys say stay away from carbon fiber because of radio interferance...but like the looks and being in the aerospace industry know it is tough stuff. I have a Spartan with VXL-6S ESC and a 540XL 1800kv motor ...thought about decking it out with bunch of upgrades to run a pair of 3S 5000mah 45C batteries I just got but not sure if it is worth putting money into? or if I can take the guts out and throw it in a new hull. Looked at some of the Zonda ARTR boats.....got me thinking.
Any help welcome

[TheShaddix]

You might find it surprising but the carbon fiber hulls that you're referring to aren't as tough as you'd think. Most, if not all, use very thin single layer of carbon and you can see right through the weave. They are ok till your first decent crash, then you realize just because something is made of carbon fiber doesn't mean it's tough. For example, I bought an HPR boat a while back as my first nice boat. It was a used boat, cost me a small fortune, and was made of carbon, so I thought it was incredibly strong since that's what you're led to believe when you hear carbon fiber! The first time I took the boat to an event and did a 70ish mph pass against the wind, the boat flew into the air, then hit the water pretty hard. The hatch broke in half and flew off and the boat nearly sank due to lack of flotation. A lot of lessons were learned that day, that's for sure. Since then I've put 2 layers of carbon on the hatch and hull and it's been through countless crashes at much higher speeds, and not a thing happened to it. In most cases you're better off with a fiberglass hull since they are much cheaper and you can just reinforce it yourself. The only time it makes sense to get carbon fiber hulls is if you either like the look of unpainted carbon, or just want it for bragging rights.

I would recommend not wasting any money into the spartan unless you really like that boat for whatever reason. Try something new and you'll see why most don't like that boat. Besides the crappy hatch design and flimsy plastic, you're limited with your choices of hardware unless you're willing to really go all out and butcher it up. The back section where all the hardware mounts is a nightmare to work with.

Look into wider cats such as the zonda as you mentioned. However, I personally think the ARTR zonda is a waste of money as you can get the fantasm hull which is the exact same boat, but totally bare, costs much less, and doesn't have the hideous decals. Here is a good place you can find them at: http://fightercatracing.com/index.ph...d=13&Itemid=97

The next best choices are the rivercat and the shocker. There is also a genesis/daytona (same thing but one is painted). But they are narrow hulls and not as much fun in turns, and get a lot of torque roll with higher power setups unless you go twins. If I were you, I'd start off with a fiberglass rivercat, for around 100 shipped that's a bargain. I know someone who's built one and the boat runs great, looks nice, and it's a good learning platform. Then you can step up to something bigger and more expensive (carbon fiber, etc). If you get an expensive hull now and mess up building it, you'll just get frustrated and wish you didn't touch it. It's always best to learn and get comfortable with every step of the build like reinforcing your boat, installing the hardware, painting, etc. before you go up in size and value.

[Nomad]

ThanksTheShaddix
Can I use the motor, servo, esc and radio out of the spartan to build a single?

[TheShaddix]

Yes, you can! In fact, if you put all that into a medium sized cat, your boat will be faster and more reliable since there is much less drag on a cat than on your spartan. At full speed those boats hardly even touch the water.

[Nomad]

How would the shocker do with these guts?

[TheShaddix]

The shocker is a nice hull that is wide and is of good length. It would do great with this power setup. The spartan has much more footprint in the water and a lot of drag.

[Nomad]

Wonder stinger and drive would work?......what prop?

[kfxguy]

You might find it surprising but the carbon fiber hulls that you're referring to aren't as tough as you'd think. Most, if not all, use very thin single layer of carbon and you can see right through the weave. They are ok till your first decent crash, then you realize just because something is made of carbon fiber doesn't mean it's tough. For example, I bought an HPR boat a while back as my first nice boat. It was a used boat, cost me a small fortune, and was made of carbon, so I thought it was incredibly strong since that's what you're led to believe when you hear carbon fiber! The first time I took the boat to an event and did a 70ish mph pass against the wind, the boat flew into the air, then hit the water pretty hard. The hatch broke in half and flew off and the boat nearly sank due to lack of flotation. A lot of lessons were learned that day, that's for sure. Since then I've put 2 layers of carbon on the hatch and hull and it's been through countless crashes at much higher speeds, and not a thing happened to it. In most cases you're better off with a fiberglass hull since they are much cheaper and you can just reinforce it yourself. The only time it makes sense to get carbon fiber hulls is if you either like the look of unpainted carbon, or just want it for bragging rights.

I would recommend not wasting any money into the spartan unless you really like that boat for whatever reason. Try something new and you'll see why most don't like that boat. Besides the crappy hatch design and flimsy plastic, you're limited with your choices of hardware unless you're willing to really go all out and butcher it up. The back section where all the hardware mounts is a nightmare to work with.

Look into wider cats such as the zonda as you mentioned. However, I personally think the ARTR zonda is a waste of money as you can get the fantasm hull which is the exact same boat, but totally bare, costs much less, and doesn't have the hideous decals. Here is a good place you can find them at: http://fightercatracing.com/index.ph...d=13&Itemid=97

The next best choices are the rivercat and the shocker. There is also a genesis/daytona (same thing but one is painted). But they are narrow hulls and not as much fun in turns, and get a lot of torque roll with higher power setups unless you go twins. If I were you, I'd start off with a fiberglass rivercat, for around 100 shipped that's a bargain. I know someone who's built one and the boat runs great, looks nice, and it's a good learning platform. Then you can step up to something bigger and more expensive (carbon fiber, etc). If you get an expensive hull now and mess up building it, you'll just get frustrated and wish you didn't touch it. It's always best to learn and get comfortable with every step of the build like reinforcing your boat, installing the hardware, painting, etc. before you go up in size and value.

This concerns me. How did you break your hatch? Was it taped on or bolted on? I've crashed multiple times at 70, 80 and 90+ mph and I don't have a crack on anything carbon. I can't say the same about the Fiberglass hatches tho. I'm a firm believer that a carbon hull is much stronger even tho you can see through it in some spots. Not trying to start an argument here but I know what I know from experience with many crashes. I don't have a crack or any damage in any carbon boat I owned/have owned. I'd never run one straight out the box without proper reinforcing in the areas that need it of course. Not trying to under mine your post, but I feel certain the Carbon is noticeably stronger than the same comparable hull. Every fiberglass hull I've seen that's been run fast has stress crack in it. Carbon fiber does not do this.

Op, the shocker or Rivercat would be a great choice depending on the water roughness you plan on running in. I have both of them. I would not worry about radio interference unless you plan on not having the antenna run out the hull....if you don't run it out the hull, it's not going to communicate.

I would highly recommend against using that power setup in just about anything. That esc is known to run hot and fail. Personally I don't care much for that setup. The motor is a decent motor but not for anything your looking at using it for. My buddy has a stock Spartan on 6s and it would puff his lipos and still only did 45mph.

[Spartanator]

Stay away from the Spartan unless your planning on running at slow speeds. That hull is not 6s, just too narrow of a deep of a ride pad.

[TheShaddix]

I agree that the CF hulls are stronger if you compare stock to stock. What I meant to say was that once you fully reinforce both carbon and fiberglass, there is little to no difference in strength between the two, but a huge difference in initial cost. For example, a rivercat in fg costs around 80 whereas the same hull in cf goes for 200! With just a single layer of 6k or 12k carbon that fiberglass hull becomes as solid as you'd ever need, and it looks cf on the inside, and it'll be painted on the outside... So then what's the difference for those who build it up? If money is not an object and you want the best, by all means one should always go CF! But I assume the OP has a budget and should not start out with a nice CF hull for his first build. I'm a huge fan of carbon fiber no doubt, I just find, from my experience, that fiberglass isn't so bad when strengthened.

My hatch on the hpr was bolted on 4 corners. I know if it had 6 bolts, it would have survived. It was fairly stiff but with some flex. I knew very little about carbon fiber at the time so I assumed it was really strong. Since then I realized that just because something is made of carbon fiber, there are a lot of variables to that, and the point i was making is that one should not automatically assume that carbon = bulletproof. When you run it unreinforced, you are taking chances. I like knowing that it's indestructible because I've lost too many boats due to this very problem before I realized it was time to rethink my methods.

I personally think every hull needs to be reinforced. I got two mhz's in kevlar, 114 and 138, and both have some give/flex everywhere which I'm not a fan of. A lot of people build those out just as they come, some say the hull needs to flex to absorb the shock in a crash, but I personally disagree with that and prefer when it feels like a solid brick (while being reasonably light) to the point where you can stand on the hull and it doesn't even flex. If you look at the HPR bulletproof hulls, that's pretty much how they feel. I remember seeing a picture of someone standing on top of one of those hulls, that was what got me thinking. That's just my preference and I'm not saying it's necessary, but some strengthening should be done nevertheless, especially at the joining seam along the hull and the transom where the hardware is mounted.

As far as the spartan, for sure, not the best hull out there! But it's a damn good looking boat when it's riding flat and fast and not hopping and chining. I'd still like to see how mine does once I'm done with it. Never really saw a spartan that was fast, stable, and reliable. It's usually only one of those!

[ls1fst98]

My hpr hatch on my 135 hit land upside down and not a single mark on it, and it has suffered a serious crash before at 90+. You can not achieve the same strength in a fg boat. A fully cf boat if done properly will be stronger by a long shot versus an fg hull with a cf inlay, and if done properly will be lighter as well. To achieve the true strength using cf or a mix of cf and fg, the inlay should be done wet in wet, while it is being layer up in the mold, And should have minimal resin. Vacuum bagging will yield the strongest, lightest part by removing all of the resin that is not necessary, but from a cost standpoint on the economy hulls, a cf inlay jn most will do fine. We have learned a lot about the weak points of these hulls. But here again, we are adding weight.