I'm realtively new to RC boating (mostly been doing RC planes).

When tightening the collet on the square drive shaft, how tight is tight enough? Should the square end of the flex shaft loosely ride in the collet to allow for shaft compression at speed or should it be tight in the collet? I've seen someone mention to leave a 1/4" gap between the strut and the drive dog. How about between the ferrule and the strut? should the ferrule butt up against the thrust washer and the strut? I hope that these aren't too simplistic questions as I'm new to this arena.

I have a 5 year old Shockwave 55" (deep V) I bought from Horizon Hobby quite a while back. I had trouble starting the engine and keeping it running at the time and as a result I shelved it till now. I ran the boat the other day, tweaked the engine and she ran like a charm till the flex shaft snapped. I had taken the shaft out to lube it before the recent run and after about 7-8 minutes we heard a pop and the boat came to a standstill with the engine purring comfortably at idle. My drive dog was up against the rear of the strut and the ferrule was up against the front of the strut. The collet was fairly tight with the square end snug in the socket. I suspect that there wasn't enough play somewhere (probably at the drive dog-strut region for flex shaft compression at speed). HELP!!!

I hope someone can help me with the basics of the drive setup (collet, ferrule and drive shaft)

My son also noted that on turns, the boat wouldn't turn very easily with letting up the throttle or with speed into the turn. The turn would lag and then the boat would snap into a turn. A smaller deep V nitro boat that I have doesn't have this tendency and responds well to a little throttle in the turn. Your help is appreciated.

If you have the round collet you shouldnt be doing it up on to a square flex.
You can get a square insert for your collet in which case the square flex just slides in and out allowing movement for cable windup.
If it is the round collet insert it is meant to be tightened onto the round part of the flex shaft, so you will have to cut the square end off before you set it up.
It also helps to solder the end of the flex before putting it together to prevent the cable from shrinking and spinning loose under load!
As for the strut drive dog etc. that also depends on the motor end, you will have to leave a gap between the ferrul/strut/drive dog.
If you are running the square adapter less gap is needed as there is no cable windup.

Hope this helps somewhat!
Chad.

i have a shockwave 55 (well kinda its in pieces now)the collect (square drive)should be tight (about as tight as a spark plug) so that it done spin in the collect.when i set mine up i left a little bit of room for every thing to spin free.as for soddering i never did have much luck doing it i could only get about 2hrs of run time on mine but a friend did tell me to drill 2 small holes in the farrel to let the sodder go in the holes.my segestion would be to get another strut so you can use a 1/4 shaft with the stub shaft welded on it and go to a round collect.i belive you have a 3/16 stub shaft now.your turnning is probley the rudder (it is behind the prop)what i did to help was i bent the rudder bracket to the port side so the rudder is about 1 1/2in away from the prop. if you can find a used set up (strut & rudder)you will be ahead of the game for it will handle a lot better.o and you may want to replace the stuffing tube and go with a 5/16 tube.you can do away with the liner. there r some changes you can do to help this boat but remember its not a race boat,its a fun boat.hope this helps ya (boatking)

Those are all good except one response. I wouldn't suggest removing the liner, 1st it helps with the smooth operation of the shaft. 2nd With the shaft rattling around in the tube it could very easily cause radio interference(NOT A GOOD THING) and lose control of your boat. Take the time and do some research on this site, (and others) there is a ton of good info scattered throughout this site!!! ENJOY!!

i dont think you read all of it i did say go with a 5/16 tube and you can then get rid of the liner.and yes you r right dont get rid of the liner now the shart will woble inside the tube.the stuffing tube on the shockwave is steel the 5/16 tube is brass and that is what most of the race guys use 5/16 stuffing tube

I understand that, but the way you put it, made it sound like you were saying remove the liner. The man said he was new to boats so I just wanted to clarify that. Nothing would have turned me off from boats when I first started more than watching one speed out sight or SMASHING up against a pile of rocks. The rest of info you give him was excellent!!! To Doc.... I built one not so long ago with the same problem (shockwave digging in on turns...HELP) and the thread I opened was offered alot of good help. I was able to melow it down some, but could never get it to go away completely. Like boatking said, this is a sport boat to play around with and have fun, it's not a racer!!!

Ozpulse wrote:
Thanks for the response Chad,

The Shockwave has a square collett insert and the drive shaft has a square end in the collett and a ferrule that is soldered onto the flex shaft so that's not an issue. I've read quite a bit about cable windup so that's wehre my concern was with how if at all to tighten the square ended flex cable in the square collett.

Thanks to all who've responded to my thread. I understand that this isn't a race boat. I never intended it to be as I'm very non-competitive. My son, son-in-law and I just want to have some fun. I was just concerned that after about 45 minutes engine run time that the flex shaft bit the dust at mid shaft. Not a big deal as I already have a couple of replacements in hand, but I hope I'm not spending more time fixing than using. That's one reason it was shelved for around 5 years.

In any case, the engine part was straightened out, it purrs like a kitten. I just wanted advice on the tightening of the flex shaft and the gaps near the strut. As far as a Teflon liner goes, I'm not sure there is one as I've taken the shaft out several times and none ever poked out? I'll check that this evening as I want to get this boat in the water one last time before the winter weather sets in here in the northeast.

Regards,
Mark (Doc)

Boatking,

Are you saying that an offset rudder is preferable to one in direct line with the propwash? I've seen this on some boats on RC Universe but I always thought that was odd. I've never seen full scale boats with this setup, but I suppose our smaller boats are subject to somewhat different physics?

Radio interference is virtually a non-issue since I switched over to 2.4 GHz (Spektrum). I've been using the Spektrum radio on all of my planes since the 2.4GHz was introduced and I would never go back to 72 MHz or 27 MHz. I've had two airplanes shot down by dizzy colleagues who didn't pay attention and turned on their radios while I was flying. Needless to say, aircraft aren't as forgiving as boats when it comes to conflicitng radio signals.

this is if you have the old boat (the yellow one)the rudder is a thin one and it is right behind the prop every time i went to turn it would turn on a dime.i fix that by bending the rudder bracket to the right side of the boat bending about 1 1/2 away from the prop and now i could make a slow turn and a wide turn.the shaft , make shur you have the liner there and it is not broke replace it if nessery.the stuffing tube on that boat is 3/8 steel tube and it is a sub surface drive(prop below the bottom of the boat)i also found out that the boat is a bit faster with a 265 prop and that boat comes stock with a 270 prop.if you do get a 265 prop you will need a sleve for the prop for the hole is 3/16in dia. and the 270 prop is 1/4dia.if you would like more help just let me know (i dont know much but i do know a little about a shockwave)