Counter rotating props on twin Jolly cat.

[Eyekandyboats]

i'm not sure but i think hes talking about prop slippage
But what that has to do with this conversation i have no idea

[G Doggett]

Hi Eyekandy
When you have a spare minute ( or maybe an hour) to spare I would love to learn the theory or explanation of how the prop rotation can lift the stern or bow.
Graham.

[Eyekandyboats]

Yep. I'm really busy now. some time.

[G Doggett]

Well - I tried the props rotating outwards today and it didn't make a scrap of difference.
Even with the batteries as far forward as possible and two cans of Coke jammed up in the sponsons to give at least 40 % c/g it still porpoises like crazy.
Next move will be to angle the drives down the maximum ( about 2 degrees) and try some lifting props to try and lift the stern.
Graham.

[SJFE]

Why not cut your drive tubes flush @ the stern and order a couple scale ajustable drives from MHZ? There is plenty of room above the step in the hull for servos. That would give you the ajustability you need to get those bows down. The drives are just over 100$US. Another option would be a set of aquacraft stingers. The have a fair amout of downward ajustment also.The last thing I'd try would be a conventional strut and bracket. That setup really gives the most movment. If I where in your position with what you have invested these are the options I would start to consider.

[avery]

counter rotate or not counter rotate twin drive

hi all i am new to forum and couldnt fine out how to post a question not to computer savy so question is just talked to guy at gizmotors in florida to order counter rotation motors he said dont do it to keep same rotation i asked him wouldnt that afect handling he said no that boat would turn better and run faster with both engines normal rotation now im totaly confused i have a hpr ct04 im trying to put together and need motors i like the rmck cause where the exhaust face rear well im rambling on. counter rotate or not to counter rotate that is the question thanks

[Simon.O.]

hi all i am new to forum and couldnt fine out how to post a question not to computer savy so question is just talked to guy at gizmotors in florida to order counter rotation motors he said dont do it to keep same rotation i asked him wouldnt that afect handling he said no that boat would turn better and run faster with both engines normal rotation now im totaly confused i have a hpr ct04 im trying to put together and need motors i like the rmck cause where the exhaust face rear well im rambling on. counter rotate or not to counter rotate that is the question thanks

Have a read here and if you have more questions then please ask.
http://forums.offshoreelectrics.com/...ead.php?t=6663

[Gerwin Brommer]

G. Dogget

Porspoising. When ? At high speed ?
Does your Jolly already have the modified last part of the tunnel ?
No ? Start with extending the tunnel.
Yes : Okay !

[G Doggett]

Hi Gerwin

I solved the porpoising by fitting a tunnel flap the same dimensions as the wedge recommended by Joseph Toth.
I made this adjustable by tightening or slackening the rear screws on the plate.
The plastic tubing acts as a spring to force the plate against the screw head.
This simple mod completely transformed the handling.
Graham.

[Gerwin Brommer]

Yeah baby ! That's what I wanted to see ! Well done !

[rude5150]

Great!

[SJFE]

Holy thread necro... You know it's old when I've posted in it.