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View Full Version : Having problems...NEED INPUT



gibbies_03
04-28-2011, 12:31 AM
so...the strut keeps pushing into the hull(damaging fiberglass) and blowing out the driveshaft. Is this from the Thrust of the big motor on 6s? Or should I be worried about something else. I am going to tap another hole in there so that the strut is held by two bolts, but this is kinda throwing me off...Im down 2 driveshafts in 2 days...

any opinions would be awesome

JPriami
04-28-2011, 12:41 AM
whats your setup?

gibbies_03
04-28-2011, 02:00 AM
Neu Castle 1515 2200kv...180A ESC....6s...offset rudder

Diesel6401
04-28-2011, 10:31 AM
Neu Castle 1515 2200kv...180A ESC....6s...offset rudder

WAAAAAY to much voltage my friend. That motor is much better suited as 4s2p. Your spinning close to 55,000 unloaded rpms which is out of the range must FE run at especially for sport boating. Running at that rpm is why you are having some issues. You also should change out the bearing in that motor. Depending on how many times you have ran it at that rpm, you may have shot the motor bearing as well. The strut bushing could be destroyed as well. I would change the bearing, bushing and check out the whole boat and not ever run at that voltage again. It also sounds like you are not running enough of a gap between the strut and drive dog and when the cable goes unloaded load and contracts its pushing into the strut then blows the cable out because it pushing against the strut. Check the strut for damage and wear marks... JMO

http://forums.offshoreelectrics.com/showthread.php?t=23729

jac4412
04-28-2011, 01:40 PM
Way diesel awesome table... I'll have to save that... I've been recalculating that crap everytime... I should just start making tables with the forumlas! Awesome thanks!


Gibbles... sport running is typically at 20,000 rpm (low end) to juuuustt around 40,000 rpm (thats the high end). You really want to run your boat at like 28,000-34,000 rpms for an optimal setup. Obviously like Diesel said... what you've got there is like a SAW setup... that thing must be a rocket... but way to many rpms for that boat with what you've got. You've got a problem with that... maybe the strut, and also maybe the prop. If you got a big prop going at that rpm... actually maybe any size prop... the force in acceleration must be nasty on the boat. That motor would be on the high end in even a 5s setup....

gibbies_03
04-28-2011, 02:47 PM
i appreciate your input guys....we went into this set-up knowing that it was waaaay too hot of a set-up. never do i just punch it, as I always roll into the throttle. Basically we are going to hit 60 and then run 6s in series to enjoy longer run times. we have been in the sport for years and I def dont want to dump a whole bunch of cash into it...although with anything RC it always turns out that way. It has been a blast sooo far and we have already gotten a lot more locals interested in sport boating.

I run the x642 prop, but was curious if there is another prop out there that can get me a little more top end...maybe the 42/55??? we are going to true the hull as well...

jac4412
04-28-2011, 02:55 PM
Gibs what are your temps looking like? I'm suprised that t180 hasnt popped yet

JimClark
04-28-2011, 02:59 PM
It would help if you showed pictures of the strut

TheShaughnessy
04-28-2011, 03:00 PM
that is a 4s motor, 4s that motor and an m445 or an x642 and you should be moving pretty good and reliable.
g
you should be able to start closing in on 60 on 4s. Why 60 in a MG?

gibbies_03
04-28-2011, 03:14 PM
Gibs what are your temps looking like? I'm suprised that t180 hasnt popped yet

temps are very good...esc is about 95 and motor is maybe 110...we are only running it for about 2 minutes at a time

gibbies_03
04-28-2011, 03:15 PM
that is a 4s motor, 4s that motor and an m445 or an x642 and you should be moving pretty good and reliable.
g
you should be able to start closing in on 60 on 4s. Why 60 in a MG?

just want to do it once because it seems like very few have...then she will get tuned back down to a sport boat

Diesel6401
04-28-2011, 04:59 PM
You don't need tons of voltage to reach you goal with that motor. It's all about the prop/setup. That motor can swing a decent size prop and your not hardly propping it at all. Try a m645 or prather s225 on 4s2p. I bet you get close to your goal without destroying your bearing, bushing and possible motor and esc running at the insane rpm.... It's all about setup and prop... Adding more voltage on a bad setup ususally ends with bad results... JMHO

gibbies_03
04-28-2011, 08:37 PM
You don't need tons of voltage to reach you goal with that motor. It's all about the prop/setup. That motor can swing a decent size prop and your not hardly propping it at all. Try a m645 or prather s225 on 4s2p. I bet you get close to your goal without destroying your bearing, bushing and possible motor and esc running at the insane rpm.... It's all about setup and prop... Adding more voltage on a bad setup ususally ends with bad results... JMHO

I def know it is all about set-up...My pops and I have taken a boat that did 35mph and had it going 46mph with just a few set-up changes...Thanks for the input...

Should I even waste me time getting another x642 or grim 42/55 or octura 445?

Thanks

jac4412
04-28-2011, 08:44 PM
FOr speed? No x642.... It's similar to the stock plastic prop I believe. The m445 will give you the most speed when properly worked up.

TheShaughnessy
04-28-2011, 10:37 PM
FOr speed? No x642.... It's similar to the stock plastic prop I believe. The m445 will give you the most speed when properly worked up.

i have a m445 and an x645, the m445 gave me another 4-5 mph over the 645 with the stock motor on 5s. Thinking I'm gonna detounge the crap out of the x645 and that should help me get some more rpm under load im thinking. Boat is being blueprinted right now though. Hope to have it finished painted by tonight or mid afternoon tomorrow.