TFL Ariane CF and FG hulls

[kenrid]

IRON-PAWW: The 3 blade we tried last week was in fact an Octura X646/3. I have since spent more time sharpening and balancing it. I was quite happy with my first sail, also note I am using the stock rudder with single water pick up whereas the RCBB is much wider. Given we are running a two 3S @5800mAh configuration, obviously we need to experiment with more props. An excellent hull, with great turning characteristics, congratulations to TFL. I am sure we can push over 105 km/hr (65mph) out of this one.

Paul: - X446/3 does not appear to be an Octura? Have I missed something?

[785boats]

No, the 4614 I was using was a CNC prop

http://www.offshoreelectrics.com/pro...od=cnc-4614350

But this is the 646/3 I have on it now.

http://www.offshoreelectrics.com/pro...d=oct-x646%2F3

Steve has them already sharpened & balanced in the "Sharpened & Balanced" section on his props pace if you want to save yourself some work.

[IRON-PAWW]

Paul,

Thanks for your reply. I think you pretty much summed up all I could read about torque roll - and torque roll-related issues, which was ace man. Cheers.

First comment I think is that the M445 is a Dasboata S+B prop I happened to have in my toolbox. Got a M545 in there too but I'm really just testing with those at the moment. I do actually have a CnC 4614 (2 blade) though I just noticed. Have a S+B Octura 646/3 coming from OSE though too, along with the 3 blade CNC 4614350. So - plenty to test with there. I actually got the same-ish torque roll issues with Kenrid's 646/3.

Another thought. I seem to remember someone mentioning torque roll issues possibly related to thrust bearings?? I do have a thrust bearing fitted - a possible issue?

Another factor - The hull is definitely hooked on both sides, from the transom to about 10-15cm back. Very noticeable when I place a straight edge there. As long as the hook is more or less the same on both sides this shouldn't be an issue right?

Could there be something going on with that bigger RCBB rudder? Sits tight with only a shade of slop.


In any case - took some pics of what I've got.


So yeah - I'm pretty sure the rudder isn't exactly square. No matter how I look at it - or what rudder I fit, I think the rudder mount is slightly off. Surely though this wouldn't make the roll get worse with speed would it? Like the roll caused by the woof in the rudder would be constant wouldn't it?




This is pretty much what you mean by the rudders' leading edge is level with the front of the prop? However, add the gap for flex wind up.

[785boats]

With the hooks, if the nose is being forced down onto the water by them you may need to move your packs back a bit to get it off the water.

If the rudder is leaning to the side, you should straighten it up. It looks as if the bottom is over to the left a bit? but that could be the perspective of the photo.
The effects of water on all surfaces is a cube of the speed. So, as the speed increases the drag is cubed in relation to the speed. So yes, the faster you go the worse the effects.
The size of the rudder is fine. You need a bit of depth for authority in choppy conditions.

I would either raise the left trim tab or lower the right trim tab if that doesn't fix it. But move the weight (batteries/ESC) to the left a bit first.

I've never heard that a thrust washer would induce torque roll before. Bit if it did, it would be in the other direction anyway. To the left, as a product of friction from the direction that the shaft is spinning.

In the pics, there doesn't seem to be any gap at all between the drive dog & strut. Is that a two part square drive shaft in there? It looks too tight even for that. Could just be the photo.
If it is a welded flex, then there needs to be at least a 3 - 4mm gap there.

All the best.
Paul.

[IRON-PAWW]

That is a 1 piece welded flex cable. I just shoved it back in to take the pics. I do leave a gap when running the boat.

There really isn't much in it at all but yes - the rudder is misaligned slightly to the left. Removed the whole assembly last night and cleaned off the glue - and was able to make it better but still a shade off. Looks like a slight manufacturing fault where the mounting screws go through at an odd angle, making the end result different to how you lined things up. Needs re-drilling to correct it I think. Unless someone has a method of bending rudder assembly's slightly to correct such issues?

Hopefully another test in the next few days.

Could the old silicone tube over the end of the stuffing tube to prevent water ingress affect torque roll? Not that it seems to on my other boats. Just.... this one seems very sensitive to it. Anyway...will test with some changes as suggested.

[IRON-PAWW]

Small update. Torque roll issues solved. Fairly certain it was a bad drive collet. When I spun the prop by hand with everything connected there was a noticeable wobble on the flex before it disappeared into the stuffing tube. Not good. Replacing the collet fixed this, and the boat now runs without a single hint of torque roll. WOT is super stable and I could finally see how nice this hull is to run.

[785boats]

Well there ya go.
All those tuning tips & it came down to that.
Well done. I'll store that one in the memory banks.
But did you change anything else too?

[flraptor07]

That's awsome, I knew it would probably be something simple. As nice as mine and Paul's Ariane run, I couldn't see how your's could be that bad. I'm glad you got it figured out!

[IRON-PAWW]

Cheers lads! It did seem a little odd - particularly since another member at my club had a very similar setup. Soon as I noticed the issue I had a suspicion it was the cause of the torque roll.

I was able to straighten the rudder somewhat by re-seating it, then just adjusted the trim tabs and strut to as neutral a position as possible. Hardly changed anything there though, so pretty sure the collet was the culprit.

[msundsd5]

After a year of struggling to get this boat to ride and only topping out at 55mph several times with the most unstable attitude, I finally have her dialed in riding smooth and increased mph by 10 up to 65.1 mph yesterday!!! This is a SEXY Hull and it looks even sexier when she rides nice, I'm so stoked!!!

http://www.youtube.com/watch?v=0hMHvMBrAHM

[785boats]

Well done.
I've never set a boat up for "point & shoot" runs on smooth water. Only ever ovals in choppy water.
I'll have to give it a try some time.

[ADxRC]

Hello everyone, new here. I know this thread was started a few years ago, but I was wondering where you guys purchased your 3/16 one piece flex shaft. Also how long is the flex shaft of the Ariane? Maybe I'll look for flex shafts at OSE, or RCBB.

Thanks, Ant