Convert a Graupner Systems Catamaran to nitro!

[override]

Hello all,

This is a project that I would like to get started eventually down the road...More or less sooner than later.

I have a Graupner Systems Catamaran electric boat that I would like to convert to nitro. Now to me this seems like it would be an easy project to plan out but actually converting it is probably going to be more of a challenge than I have knowledge for.

I know off the bat I'm going to be dropping in Traxxas TQ reciever. I would also like to drop in the original motor that came with the nitro package which was an O.S. Max .15 marine engine. OS doesn't make this motor anymore though and I believe the replacement for it is the .18 CV-RMX.

I will most likely be changing out the prop, shaft, gears and rudder. Adding a clutch, and outer trim tabs.

The biggest thing that stumps me so far is how to mount the motor and figuring the center of gravity on the placement of components. The hull is plastic, so I'm thinking fiberglassing the motor mount down. Ofcourse I dont know how fiberglass will react to the hull.

These are just my beginning thoughts on everything. Any advice or websites that anyone can recommend for ideas or anything of the such feel free to post.

I will throw pictures of the boat and guts up sometime this week, I know one thing, I dont want to start ordering parts until I know this CAN be done and wont cost me an arm and a leg.

 

[Rolex]

Not a good project to do. A catamaran has twin hulls and needs twin props. Doing it with one engine won't work out.
Either stay with twin electric motors or go to a V-hull for the nitro drive.

 

[override]

Thanks for the advice guys....

Rolex, would it not be possible to mount the engine so that it drives both props? I can't remember the way it is setup but I believe its one motor in the middle with a spur gear attached to the two gears on the prop shaft or its two motors attached to one drive. Originally the boat could be bought as either electric or nitro powered.

If I were to throw two brushless motors in it would there be a maximum size that I could go on the motors and I'm assuming Lipos would be the best choice of battery?

Thanks guys,
override

 

[Rolex]

You can run 2 props with one engine, but you'll need to run a double spur on one prop. If both props turn the same way, you'll have a real fight getting it trimmed. The props need to have reverse pitch on one, turning in the opposite direction.
There's no limit to what you can run brushless as long as there's room in the hull. You'll also have to upgrade all the prop drives to handle that much power.
If you're mechanically inclined, you can do whatever you dream.

 

[override]

I did a little bit of googling and found some information on this boat.

This is the boat I have (electric version ofcourse).

This is the nitro version of my boat.

Tomorrow I will post up some pictures of my actual boat...What do you think about this nitro setup rolex?

As for being mechanically inclined...Yes I am, very much so. It's just been a long, long time since I have been in the RC scene. There have been many advancements since I used to play with my electric toys. I'm still kinda learning whats new out there and what can be done.

Thanks for the input so far guys.

 

[override]

Easy guys, easy! I appreciate all of your guys opinions! I love both of those Cats that were posted up. Especially the Maroon/White one. How much does a setup like that boat cost?

Well as said here are pictures of my Cat after sitting on the shelf for about 8+ years...

Here is my other boat aswell, I'd like to drop all new electronics in this boat sometime down the road. I imagine this sucker would scream with all new components in it! Heck as it is with brushed motors and 6 Cell NiCd batteries it has some very impressive speed.

 

[Rolex]

41" hull

 

[Rolex]

A certain douche who did not play well with others, has taken his toys and gone home. I'll be cleaning house here.
Override, you can have this thread back.

 

[w bill]

I would just be concerened about the material the hulls are made of if its plastic the nitro may eat it.Do a little homework first you may want to pickup a different hull for nitro power.Also strentgh may be a factor!Good luck get em runnin.Just remember if you up grade to a new radio 2.4ghz you can't use your old servos they need to be digital.

 

[JessF]

I would just be concerened about the material the hulls are made of if its plastic the nitro may eat it.Do a little homework first you may want to pickup a different hull for nitro power.Also strentgh may be a factor!Good luck get em runnin.Just remember if you up grade to a new radio 2.4ghz you can't use your old servos they need to be digital.

you don't need to run digi servos when using a 2.4ghz system. You only need digi if you're running HRS mode on your transmitter.

if you brace the hull and provide a solid motor mount, I bet a nitro conversion is within your grasp. Consider, though, that you'll have 2 servos instead of one, a receiver battery, a full tank and the engine itself. You'll need solid mounting surfaces for all these items. Weight distribution will be important so organizing the engine bay area will be vital.

i say go for it.

 

[override]

I have put alot of thought and have been weighing the cost to rebuild this boat to nitro. I have considered the structural integrety of the boat since it has been sitting in a storage unit for the last several years. I don't think it will be worth the money I would spend when I could go out and buy a fiberglass hull that will hold up over the years and actually be worth putting the money into it.

I believe I'm going to cancel my nitro conversion Idea and put this boat back on the shelf and focus on something new. I may end up putting both of these boats up for sale to help fund that project. More on that at a later date, sadly for now I'm gonna focus on my T-Maxx upgrades and put off my love of R/C boating.....AGAIN.

 

[Rolex]

You could always do a brushless conversion on the boats you have now. It's all about the speed.

 

[alpinehyperlite]

+1 on a BL setup.

 

[override]

Brushless has entered my mind but I don't know poop about any of the new technology of motors, batteries and speed control units. Everything I have seen thats new has to be cooled and have heatsinks and looks all fancy and complicated. I'll have to study up and learn the new stuff before I try to tackle either of those boats for a BL setup.

 

[alpinehyperlite]

Brushless has entered my mind but I don't know poop about any of the new technology of motors, batteries and speed control units. Everything I have seen thats new has to be cooled and have heatsinks and looks all fancy and complicated. I'll have to study up and learn the new stuff before I try to tackle either of those boats for a BL setup.

You will get SOOOOO much more power out of a brushless setup than a nitro setup. Way more RPM's as well.

 

[override]

I think its so weird that an electric motor would outrun a nitro in the top end. Thats pretty crazy if you ask me...

Ok so given I did do this kinda of upgrade I know how the Stinger will be setup but the Cat I'm not sure what would be the best setup. A single motor on the shaft, using two motors on the gearbox (I dont want to do this), or putting two motors in a series on a single shaft. Decisions, decisions.....Since I have never actually seen a brushless motor in action, nor any of the newer style batteries beyond NiCd I have no clue what kind of power and different setups can be had.

 

[alpinehyperlite]

Yea, but it's true.

 

[Rolex]

You could start with the single motored boat and go with a Traxxas Valenium system. Motor and speed controller are matched, you'd know what batteries to get, and it would be a cheap and easy introduction to brushless systems.
It looks like that boat has a 'toy grade' 3 speed sweep controller, so the ESC would be a really good upgrade.