36 inch rigger slow

[RC boat addict]

Hey fluid, what puzzles me about this rigger is MOST of the weight is forward of the rear of the sponsons like the 800 gram battery and the 350 gram esc and the 400 gram sponsons and boom tubes etc only the 350 gram motor and the rudder and strut and receiver that are very light are behind the COG yet the COG is at the rear of the sponsons, just looking at the position of all the weight you would think it?s too heavy at the front yet the balance point doesn?t show it.

[HTVboats]

It is really hard to help when you can't watch the boat run or just borrow someone a prop out of your box to try. That said RC boat points out what I was thinking in front loaded weight. Hard to change without major reconstruction.
The only options to change cornering you have in my opinion is working with turn fin placement and fin angles of attack. You might also try some sponson offset to the left. As you move the right sponson closer to the tub you take cornering leverage away from it. Also the boat tracks more left allowing less rudder preload to go straight.
Mic

[RC boat addict]

Thanks mic, I never considered the offset. Also I have tried the balance with a split LIPO pack And it only moves the COG back to the motor but if I move the fin back as well I may be able to still achieve the fin being 1 inch in front of the cog but more importantly it gets the weight back a few inches for a try.
For the moment the offset is difficult as I epoxied the booms in place.

[RC boat addict]

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I have moved the battery behind the motor and moved the motor forward a bit, the ESC is at the front now.
This moved the cog to the back of the sponsons, I put the fin back to the original rear boom tube incorporated position.my question is, is the turn fin supposed to be in line with the COG or forward or rearward.This thing is still burying the sponson on a turn
I have the lower rear edge about 2 inches forward of the COG at the moment, it still will turn in its own length and spin out I am only using 3mm of rudder angle.

[RC boat addict]

Ok I ran the rigger and its still digging in on the turns but not flipping at least, I moved the fin back to the back of the sponsons as far as it would go and its still digging in and turning in its own length. At full speed it doesn't seam to do it but if I slow down a little to dodge a mooring bouy it spins out I still only have 1/8 inch travel either way on the rudder.Its running 4.8 Degrees AOT now STILL DIGGING IN.

[Moonie]

Ok I ran the rigger and its still digging in on the turns but not flipping at least, I moved the fin back to the back of the sponsons as far as it would go and its still digging in and turning in its own length. At full speed it doesn't seam to do it but if I slow down a little to dodge a mooring bouy it spins out I still only have 1/8 inch travel either way on the rudder.Its running 4.8 Degrees AOT now STILL DIGGING IN.

How many skid fins have you tried out? Looks like you have a zip kit fin I never had the best of luck with those. I had a few keps riggers. Here is a video of one I was testing a prop new on.http://youtu.be/fi-QexOoqRE

[RC boat addict]

Hey Moonie, the fin is home made but it still does the same thing even with the fin removed.
I like the look of the sponsons I made on this larger rigger they are more buoyant than the Taipan we spoke of on the other post and this is good as this boat has a big heavy 455 gram TP 4060 motor but looking at my TFL arrow That goes so well all the weight of it?s battery ESC and motor etc is behind the back of the sponson ride plates and it handles like it?s on rails, so I may have to move the back edge of the ride plates forward by cutting the sponsons and taking about 2 inches out of the ride plate length so this moving the back edge of the ride plate forward putting the weight behind the rear edge of the ride plate. I can?t just move the whole sponson without serious modification. I hate to give up on this thing but it has a great motor and esc that could just go into a ML esc 380 once I try a few more things if I fail.
James