I copied this over from R/C Groups. For anyone that's interested.

As you know HK (as well as some other vendors) released a few new boats from TFL.
I'd never set up a stepped hull before & I liked the look of this one as soon as it was posted up on their site.
[link]http://www.hobbyking.com/hobbyking/store/__30530__OuterLimits_Fiberglass_Offshore_Brushless _Racing_Boat_w_Motor_870mm_.html[/link]

Well, I needed another boat like a fish needs a bicycle. But I bought one anyway.
It arrived Thursday & I ran it yesterday. I thought I'd share my thoughts on it.

Firstly, I'd like to say that I think it's possibly the best ARR hull I've seen. Beautifully finished, solid glass work and well set up inside.
The steps obviously strengthen the bottom of the hull.

The finish is first class with the clear coat over the graphics & decals.

Unfortunately the battery tray had broken loose in transit which shows that they still use that hot glue type stuff without prepping the inside of the hull before they stick things in. The waxy film is still on the resin. So before the motor mount has a chance to break loose I scuffed the surface beside the mounts & tray, wiped it with some Acetone & epoxied in some 1/4 carbon rod.

A nice feature is the adjustable T bar mount at the end of the stuffing tube. I played with that & the motor mount adjustments to produce the most freely spinning drive shaft, and guess what. I ended up at the same points as they started. Shows they are paying attention to the set up.

It has a good solid true running coupler. A big plus. Still a two part square drive though. But I don't mind that any more.

The transom has a piece of ply added & then a layer of glass has been laid over that to seal. Another plus.

The motor is one of the TFL black motors as sold by HOR Racing as the 'SSS series. I've got a couple of those motors & they are efficient powerhouses.
On this motor (3660 2075kv) I even worked up to an m445 prop & the motor was still coming in just tepid, with long run time. Stock prop is a TFL 440. Nice finish
& almost balanced. All I really did was sharpen it a little bit. Drove the boat pretty well.
But as usual with this sort of KV & this size boat, the old 440/3 performed the best

The Stinger is of good quality with nice tight fitting bushes with a 3/16 shaft to suit all your 3/16 props. The prop cone nut is held on with a set screw to a flat spot on the shaft. I have that system on a couple of boats & don't mind that.

So this one will be easy to change the flex to a welded stub flex drive. Just pull out the teflon liner & its ready.
Possibly aimed more at the European & Chinese/Asian racers, where they can race stepped hulls, but a great sport boat for me.

The Smash Shark is a no step hull & is set up pretty much the same way, & if it is built like this one, will be a good option.
[link]http://www.hobbyking.com/hobbyking/store/__30568__Smash_Shark_Fiberglass_Offshore_Brushless _Racing_Boat_w_Motor_840mm_.html[/link]

As usual, Check the tightness of all the mounting bolts,
strengthen the motor mount & battery tray to hull join, mount your gear & go.

I honestly think that TFL have been listening to the suggestions & comments about their boats. These are a far cry from the offerings a few years ago.

The V is very flat & as such turning at full speed is a bit tricky. Wide turns are ok bit tight turns sets up a lot of skipping & spin outs.
Perhaps our European friends can offer some set up advice from their racing experience. Please.

I've got a few motors to try out in this thing, but the one that comes with it is certainly a good one.

Here's some pics & a bit of a video.

[link]http://www.youtube.com/watch?v=etd8EgIaIqo[/link]

Thanks for the nice review they do look nice I just wish they would stop putting the same decals on them all,id much prefer to see them come in bare gelcoat colours.The main problem I see with the boat is where the turn fin is positioned it should be right on the corner on the transom but due to the overhang that looks as if its not possible,that could explain the poor turning .
I would think the smash shark would turn much better as you can put the turn fin where it should be.If it were me id remove the part of the overhang that's in the way so you can get the turn fin on the outer edge,its a poor design in that respect.
Mart

Thanks Martin.
But you must remember that this boat is a semi scale model of the full size Outer Limits, Lucas Oil sponsored racing boat. Hence the same colour schemes & Graphics.

I'm still not sure about the turn fin yet. My biggest concern is that it is mounted so that it is at 90 degrees to the water (when the boat is level) not 90 degrees to the bottom of the hull. But I've seen this on European Naviga Mono1 & Mono2 stepped hulls before, & figured that is the way it works best.
I have every intention of trying it the way we usually fit them. But I had to try it as it was first. From all the videos I've seen, these shallow V, stepped hulls, can be very twitchy in the corners at the best of times.

We also have a guy in our club that used to race these types of boats in Hong Kong with the great Mr Etti himself. So I will be discussing all this with him for sure the next time I see him.
Cheers.
Paul.

I've run a number of stepped monos. The turn fin is too small for tight turns, that's why the bounding and spinning. It's size is more suited to gentle, scale-like turns. As far as the angle it is mounted - yes, many/most NAVIGA boats run the fin parallel to the rudder, but that has seldom worked for me. It depends on the hull and the speed, but I mount mine on the extreme outside of the chine with at least double the area of the fin shown. Bigger is usually better...



.

Thanks man.
That's the sort of info I'm after. I'll sort something out there.
Any other setup tips for stepped hulls would be greatly appreciated. Is the optimum cog still around the 30% mark or is it a bit different?
I want to try & get the 6 minute runs out of it eventually.
Cheers.
Paul.

Oops! double post.
Deleted.

The CG depends more on step placement. All my stepped boats like the CG ahead of the front step by one to three cm depending on the hull and speed.



.

RPMYou typed to have turn fin parallel to rudder. Ok, does this also mean the length of turn below strut will be the same, so they will work together completely in unison. Also will the turn fin be vertical or 90 degrees to transom. Now if vertical, my guess that it would work the best. Also the turn fin should be the same width as rudder. Correct me if i'm wrong!

Thanks for that.
I'll throw some numbers at you to see if it makes any sense.
The hull is actually 800mm from transom to point. There is a 75mm overhang.at the rear. In the attached pics the transom is level with the rear hatch line.
The first photo is where I was running the battery which gave me a balance point where the black lines are on the side hatch lines. That is 32%
The second photo is where the pack needs to be to have the balance point 2cm in front of the step on the keel. That's the forward black line on the side hatch lines. That works out to be 37%.
I'll make a bigger fin, angle it & play with the balance point this weekend.
The stinger is level at the moment. Should it have negative angle on it like the straight/solid shaft setups I see in Europe? Or is that not necessary with the balance point being further forward?
Isn't it interesting learning about a new aspect in the hobby. Well, new to me that is.
Cheers.
Paul.
[img][/img]

I think you need to do your research on how turn fins work,a turn fin should not even touch the water when the boats running straight this is why most of us mount them parallel to the bottom so when the boat leans into a turn it enters the water to help hold the transom in the turn but in straights the fin or fins are completely out of the water.
Mart

Stinger needs to be parallel to start with,negative will push bow down positive will bring it up,you will need to adjust the stinger to suit the conditions of the water at the time.As for cog there is no magic number each and every boat is different,power output will also come into effect also ,you will need to test and test until you find what works best.
Mart

Trust me Mart, I know about testing. I just don't know about Stepped Hulls. The mechanics are different to the no step hulls that I usually race. Even though I can't race this one under our rules her in Oz, I'm just after some basic starting points for a fast(ish) sport boat.
I don't suppose you could post a pic of the rear end of one of your stepped hulls could you. Just for comparison.
Cheers.
Paul.

I don't have stepped boats. I set mine up like you typed, line except my turn fins are on the side, like chine line and bent to a 90 degree. Same angle as the transom and work great. I have a 29" mono ( BBY ) setup this way and turns on a dime. I'd send a picture but I don't own a camera, I have no need for a camera.

Is this the type of fin you are talking about Mike? The Bargeboard set up?
I've tried that too om a different boat & it is very effective for sharp turns.

Paul785- yes but where chine line is, mine are bent more out. I take a 6" ruler and lay it up next to side fin to make sure it is 90 degrees. I do this on both sides. I see you keep fin above keel line too. Suggestion on turn fin; try on a boat that is not to great in quality. LOL, you might have a hard time finding such a boat. Your's are always great from videos. The picture you had with the slant of fin is how I do mine.

Thanks Mike.
But that's not one of mine. I just grabbed the pic from the web whilst looking for info on stepped hulls.
But yes I do generally keep the tips just above the keel line. Just dropping them down a bit for windy weather & rough water is sometimes all you need to settle the bow down a bit.
Here's one of my favorite pics of my Arowana with the tips just barely cutting the water.
I did find some info that corroborates what GotRPM said. COG just ahead of the first step. But also with the stinger set parallel with a line from the front step to the transom. At the moment it's parallel with the last step. Something to play with now.

In my experience just setup your stepped hull as you would a normal mono hull,the main difference is the extra lift a stepped hull creates but in my experience it isn't much on such small hulls.The main drawback of a stepped hull is turns can be quite tricky but then again that depends on the boat.Also many so called stepped hulls are not really stepped hulls as the steps or not really steps lol.As I said turn fins should be parallel to the bottom not the keel line or when you lean into a turn the fin will act like a planning surface causing the transom to lift and the boat to spin out,its common sense just think about it.
Mart

Well I love this Outer Limits stepped hull mono.

I bought this of Mr 785boats and is one seriously fast boat on 4s. Mine is propped up and still running all stock components .

I'm so impressed with it I purchased the Smash Shark to race in 4s next year since stepped hulls aren't race legal in Oz. . These boats offer excellent bang for buck.

Glad you are having fun with it Mark.
You were driving it well with the other guys on Saturday. She was holding her own against them.