Titan 33" with twin screws???

[mschaffer66]

So I've got this Titan hull kicking around and right now I'm contemplating doing twins in it. My thought is:

Turnigy 180A ESCs
Leopard 4074 2000kv motors
4S2P
Speedmaster stinger, rudder, turn fins, etc...
No clue on prop size yet, but something counter rotating for sure.

What does that sound like to you guys? Not enough? Too much KV?

I figured 2000kv at 4S gives me like 29600 rpms and I've heard that 30000 is the magic number.

I figured I would run 2 4S 40C 5000mah packs in parallel then to each esc to ensure each esc sees the same voltage at all times and each back gets the same draw.

What other suggestions would you guys have for this setup?

[mschaffer66]

Hmm..no input...

This idea is either incredibly stupid, incredibly boring, or so damn groundbreaking no one dare touch it :) I'm thinking a combo of stupid and boring lol

[Chilli]

I have no experience with twin screws. Every once in a while someone throws out the idea of a twin mono. Most dont think it will work, but a few have said otherwise. My gut feeling is the Titan 33 is a deep vee hull with allot of lift and I think you'll have a hard time keeping the props in the water once you get her up to speed. The good news is its a great sport hull that handles well and is allot of fun to drive. More than a few of us race them also.

[D. Newland]

The above post is correct...it will mostly blow out the outside prop in the turns.

But, I've been bitten by the twin bug before, too, and the only cure is to actually build one.

[mschaffer66]

Ahhh....so I should just be looking into a solid single motor setup and run with it.

I had figured twins counter rotating would make it more stable at higher speeds

[Steven Vaccaro]

One idea that was floated out there was a single motor running two drives. If both props spun from a common source, there would be no blowout. It sounded feasible.

[D. Newland]

The Titan 33 is a nationally competitive hull in P mono and P Offshore. Just build a single drive and focus on a quality motor and ESC. You won't regret it.

[04DarkShadowGT]

Hmm..no input...

This idea is either incredibly stupid, incredibly boring, or so damn groundbreaking no one dare touch it :) I'm thinking a combo of stupid and boring lol

Stupid and boring pretty much sums it up :)

[mschaffer66]

Motor selection is still kinda up in the air so I can work on that. ESC will be the Turnigy 180A because I have an extra one sitting on the bench.

What motor should I be running in this thing? and what kind of speeds would I expect on 4S?

Keep in mind I'm not racing it and have no desire to race it. I've beat up my share of cars racing, the last thing I need is to crush a little fiberglass box containing hundreds of dollars of electronics :) I'm just a guy screwin around at the lake :)

[Brushless55]

Hmm..no input...

This idea is either incredibly stupid, incredibly boring, or so damn groundbreaking no one dare touch it :) I'm thinking a combo of stupid and boring lol

no way man
someone on here has done a twin mono with great results

[obrien008]

Newland "The above post is correct...it will mostly blow out the outside prop in the turns."

You know that for a fact???

My Twin DF 33 runs perfect, twin 540Ls 2000KV on 5s1p at almost 40k rpms, no blow out at all. Turns better then my single monos and watt meters show almost identical draw from each side regardless of the run.

Check my thread,
https://forums.offshoreelectrics.com/...a+force&page=2

Funnest boat to drive that I have especially on some chop. Got a few more videos that ill put up for you to check out.

Good looking out brushless

[Chris Harris]

It can work but you need to run the drives as close together as possible so running smaller props would help, not the 45mm-47mm that seems to be
the norm on this size boat. This would mean maybe a little higher Kv motors.

I have seen an FE mono setup with twins where the outside drive would rev up higher in the turns but not completely blow out. It wasn't real effecient in the turns but honked down the straights. The drives on this boat were placed a little too far apart but it was cool.

Chris

[Rumdog]

It will still run better with the proper single drive.

[TotalPackage]

Its gonna all depend on where the struts are in relation to the strakes if there are any it seems the struts need to be a least the level or just slightly above the keel.And go with low to medium lift props. RUMMY when am I gonna get to see the elam?Oh i almost forgot different hulls react diferently. Does the boat have strakes tha come all the way back to the transom?When you set up a twin you really need to know what you are doing.Too much lift? Remove some strake. Most new hulls have very little strake thas why they run so good an stable under high power.

[Brushless55]

Newland "The above post is correct...it will mostly blow out the outside prop in the turns."

You know that for a fact???

My Twin DF 33 runs perfect, twin 540Ls 2000KV on 5s1p at almost 40k rpms, no blow out at all. Turns better then my single monos and watt meters show almost identical draw from each side regardless of the run.

Check my thread,
https://forums.offshoreelectrics.com/...a+force&page=2

Funnest boat to drive that I have especially on some chop. Got a few more videos that ill put up for you to check out.

Good looking out brushless

I would love to see more vids of your twin man

[D. Newland]

I built a 40" dual mono with twin 10XL's and 14 NiMH's a side. It blew out in the turns.

But, I saw your video and your boat runs well...just get some straight away vid!

Newland "The above post is correct...it will mostly blow out the outside prop in the turns."

You know that for a fact???

My Twin DF 33 runs perfect, twin 540Ls 2000KV on 5s1p at almost 40k rpms, no blow out at all. Turns better then my single monos and watt meters show almost identical draw from each side regardless of the run.

Check my thread,
https://forums.offshoreelectrics.com/...a+force&page=2

Funnest boat to drive that I have especially on some chop. Got a few more videos that ill put up for you to check out.

Good looking out brushless

[obrien008]

Heres some vid, just got back from the lake and had about 8 or nine runs in the last 2 days with only about 5 videos cause noone wanted to work the camera haha, i only got two up so far and they arent speed passes but ill try to get those tomorow

http://www.youtube.com/watch?v=lO9HE...eature=channel

And how do you like the self recovery feature?????

[Brushless55]

Love the self recovery!

[obrien008]

Haha my mans still hating on the dual mono

It will still run better with the proper single drive.

In what sense? More efficiency per motor maybe in a single if it stays cool.

In a dual you have no prop walk, no torque roll, better acceleration, better stability, higher top speed, better handling, less heat, less stress on the system, and more reliability.

In a mono the prop walk and torque roll seem to always be a bit of an issue especially when you try to run a single mono in some waves. So by getting rid of them id say you would have a better running boat.

The offshore driving is the main reason I wanted to build a dual in the first place, personally I think its more fun then driving on flat water cause its more about driving and steering then just full throttle the whole time, plus you cant beat jumping waves esp with the extra acceleration and stability of a dual.

[obrien008]

Love the self recovery!

Thanks it comes in handy when I take it out in the chop, and no I usually dont let a huge wave smash it onto shore before grabbing it like in the video aha

[Rumdog]

i didnt realize this thread was about obrien's twin df. Sorry. You have my blessing. Better now. All i was trying to say is that the single is easier to setup, and will generally be much more tunable. Also, you can make the single faster than your twin. 2 540l's wont be as fast as a single 1521 running 2p. Nor will a 1p setup be as reliable, especially running 2 motors. Yes, your boat runs pretty well obrien. Although it is VERY limited to a specific setup. Esp. Prop size, cog, and the fact that the rudder being set back so far that it makes the hull run really wet.

[mschaffer66]

My goal is to build something that I can have fun with when the lake isn't glass. I have the cat, hydro, mini boats, but they all need very smooth water to run good.

I want something that I can run when there are 1-2' waves and stuff like that. Speed is cool, but in this case stability>speed...within reason :)

[photohoward1]

Thanks it comes in handy when I take it out in the chop, and no I usually dont let a huge wave smash it onto shore before grabbing it like in the video aha

Where are you located in Ohio?

Howard

[obrien008]

I wasn't trying to offend you RD i'm just saying that no one thought mine would work when I was proposing it. Yes it did run wet and the COG was too far forward and made it run wet but that was in May on my first few runs. I have made major changes since then and it runs much better, and actually it is surprisingly adjustable, struts, cog, and I can even get 45's on it. And try getting a boat ready to run with a neu motor and the required ESC for the $700 I spent on all the parts that I needed for this thing. And fiegos obviously arent comparable to neu motors but imagine a 45" mono with twin neus and castle ESCs on say 8s.....

But your right this isnt my thread so ill take it back to to mine, ill get the new pics and videos up finally. Sorry for grabbing your thread but I am interested in your build and will be happy to help.
And ya I got my cat for the smooth water too, but you'd be surprised how nice the mono does on the smooth water now too. If you do decide to build it I would recommend a 45", I really wish I would done a 45" with 540XLs

From Youngstown area, How about you?

[mschaffer66]

obrien sounds like we need to do a little talking as our boats and goals sound similar.

I guess I would rather try something different and maybe fail, maybe not instead of just doing the same cookie cutter thing everyone else does :)

For me the fun of these boats is in the acquiring, building, and tuning...running is just something that kills time during the week :)

[obrien008]

obrien sounds like we need to do a little talking as our boats and goals sound similar.

I guess I would rather try something different and maybe fail, maybe not instead of just doing the same cookie cutter thing everyone else does :)

For me the fun of these boats is in the acquiring, building, and tuning...running is just something that kills time during the week :)

Haha my thoughts exactly

I feel the same way about building the same boat that everyone else already has. I thought about building a single mono but after seeing peters zircha's 45" sniper I saw no point as you really cant get any better then that.

And the funnest part is forsure the ideas and building that go into it, but I actually have alot more fun driving now too, only when I got it out on the chop anyway, and with the CF reinforcement mine can really take a beating. I get about 15 mins of runtime out on the chop at about the speed Im going in the video which sounds ridiculous but but id say its only at about half throttle 80% of the time plus I spend about 5 of the minutes bringing it in.