Need Help Mini Hydro

[Jesse J]

How much hook on the fin you got? On these micros, I have noticed that it is a balance between torque roll and enough weight on the inside (starboard) to keep from flipping. It looked like something caught and flipped you over; thus need to see the angle of your turn fin - please post a pic of the underneath so we can see just what angle your turn fin is set.

[BakedMopar]

In that video there was no turn fin. The rudder has about 30 degrees of throw.

[Jesse J]

How many times has it flipped like that? and agree tight turns can do this to you. A turn fin will definitely help this, especially with some hook in it.

[BakedMopar]

It flips a lot. Almost every other turn. I will try to get you some pics of the turn fin.

[Rumdog]

Agreed, less rudder throw, longer sweeping turns and the turn fin is a must!!

[JimClark]

Before I would mess with the turn fin I would add weight to the nose to drastically change the CG seems like the CG is way back too far

[BakedMopar]

Here are some better shots of the fin mounted and trimmed. I turned down the rudder throw to about 20 degrees. I am going down to run it now I will get back and let you know how it did.


Thanks for the help guys!

[BakedMopar]

I'll take some weight with me. Where should cog be?

[RandyatBBY]

Have you ran it sence you put the fin on? I run that type of fin in that location with a little more curl to hold in the cornor, turn right only at full speed and let off power to turn left. Turn fin should be stright up and down.

[RandyatBBY]

I'll take some weight with me. Where should cog be?

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If you put the CG foward you will need to move the turn fin foward.

[BakedMopar]

Okay after a whole buch of swimming er testing, I think it runs much better. I had changed the layout of the electronics. I put the speed control back to the starboard side. I added 3 oz of weight to the port sponson and 2 1/2 oz in the middle. This was the last and best setup so far. It lost a some speed but was much more stable. I didn't have a camera person so I will try to get some later. I did not play with the fin at all with the exception of moving it's center in line with cog. All my testing today was with weight.


Thanks,
George

[Jesse J]

I would think on one that size COG shouldn't be more than 1" back from trailing edge of sponson. Where is it now?

Did it flip any this time?

[BakedMopar]

Okay here is a detailed breakdown of my testing. Plaese note that everything happens fast and my eyes aren't the best so this is what I observed.

1st run: Turn fin added only. Still flipped.

2nd run: Added 3oz. to starboard side. Same thing.

3rd run: Added 1 1/2oz plus the 3oz. from run #2. Seamed to bury the nose hard. I say that because I tend to see a lot of prop from the back.

4th run: Took everything out and remounted the electronics. Put the ESC on the starboard side and the receiver on the port side. I also took out all of the weights. Port side was really light and had bad sponson hop. Now it seemed that the fin was digging in and throwing the boat over.

5th run: Added 3oz weight to the port sponson. Calmed the hop down a little but turn much better. Flipped only once but I think it was from a cross wake.

6th run: Added 2 1/2 oz to the center (in the nose). Ran flat and turned even better. I did not flip it on this run. I still ease off the throttle a little but not much. I'd say about 85-90% on the throttle. This was the best it ever ran overall.


It lost a little speed with the fin but it's probably due to the extra drag. I did not play with any other settings other than those that are listed. The center of gravity is still way behind of what is recomended. When you say trailing edge is that where I am measuring from? This is a scale of the whole boat.




Thanks for all the help,
George

[JimClark]

What motor and batteries?

[BakedMopar]

Motor is a Feiigao 380 8L. Batteries are Turnigy 3s 2200 30c. Prop that was run today was a Octura X632.