Breaking Flex cable

[scotthend21]

I need some help!!!!! I have broken both .130 & .150 flex cables at the motor coupling. I just upgraded to 4S lipo from 4S A123. This is a cat with counter rotating 442 props and feigo 6L motors. Using the SV27 struts and bushings. Only the the clockwise turning prop has the drive cable break. I have already verified the correct cable is being used. Any ideas on this would be much appreciated. Everything was working great before the battery change.

[JimClark]

so you have both right and left cables?

[forescott]

Ok, I'll get the dumb questions out of the way first.... Using correct cables??(left and right hand lay cables) Proper gap between the drive dog and stinger?? Prop spins freely without binding??

[forescott]

Mr Clark beat me to it!

[marko500]

How long is the section of exposed cable between the end of the stuffing tube and coupler? Is the stuffing tube lined up with and supported at the end near the coupler? Any pictures?

Mark

[scotthend21]

First off there are no dumb questions. Yes, I have the correct cable for this side. it ran great about 1 year until I installed the 4S Lipo. It actually ran good for about 3 or 4 runs with the Lipos. distance between the stuffing tube and coupler .80 (3/32 in.) No support, excellent alignment props turn freely no binding. Spacing between the drive dog and stringer .50 (3/64in).

[Jeff Wohlt]

Heck I do not doubt it. 6L with 4S and 442 props....lucky it is the cables going.

[blackcat26]

Surely he's running 2s lipos in parallel and not in series. Series would be 69k on the unloaded rpm's.

[Jeff Wohlt]

Well we can hope but not how I understand it 4s is 4s. I am sure you are right.

[teach]

You did add an 1.6v. Maybe it's just a little to much for the cables?

[scotthend21]

Yes I am running 4S on each motor. I have the boca bearings installed and figured why not they should be good to 70k rpm correct. As long as I am not cavitating and the boat stays in the water there really should not be an issue. Yes, I will probably break something else and I will have to figure out how to design it stronger. The higher RPM still doesn't explain why the counter clockwise cable has not been damaged. As I said in my previous post it is only the left side clockwise rotating drive that the cable breaks on. I may be a fool but I enjoy taking it to the edge.

[Flying Scotsman]

Oh dear......that is your problem...end of story....2S max on that motor/props and I am really surprised that nothing else has gone

Douggie

[sailr]

No kidding! 4S is WAY too many volts on a 6L! You're lucky you haven't cooked the motors.

[scotthend21]

OK, thanks. I alwauys monitored the temps and the motors have never gone beyond 65 C. I was just over heating the A123 batteries and killing them so I went to 4S 5000mah Lipos.

[Jeepers]

I would back off on the voltage or get different motors thats way to hot of a set up. your living on borrowed time! for whats it worth I had a 6L that the magnet came off at a far lower rpm 30k, fried the esc and lipos. those are 2s lipo motors.