Flex shaft breaking

Ok I set up my impulse v1 to run 6s, normally run 5s but I had two new 3s batterys and wanted to get some more use out of them so anyway reprogramed the t180 for 6s and to the water I went, made a half a lap and then it stoped, got it back only to find my prop,stub shaft and half of my flex shaft gone.
after takeing it apart is when I found out that the flex shaft broke in half, ok I said to myself it happens but why?
so after putting in a new teflon tube new shaft and another prop Here I go again to the water, and a half a lap into running, again it stoped with the same results, the gps read 47.9mph but I don't feel it really got up to speed just yet. pulled it apart again and again shaft broke in the middle. whats up, to much torque?
1500kv motor, t180ecs 6s.
it handled the 5s set up fine, any clues to whats causing this?
there is no binding in the stuffing tube and motor is aligned just fine, I just don't get it, any help would be apprecaited.
flex shaft is a .150

Pics would help,, but to much of a bend can cause that to happen !

Thy as a lot of power for a 6s setup. Your adding 1 more battery at 3,5 volts. That's more than 5000 more RPM. Everything better be free and aligned very well for that much total RPM. Everything has a limit.


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6S is really not too much for a 1500 Kv motor. The problem is the flex shaft - 0.150" is NOT enough for a potent 6S setup, period. If you want to stop losing shafts and props, go to 0.187" shafts.



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I've been trying to post for the past 30 minutes and it wouldn't let me. You can run that setup on 6s but the flex will not hold it. I found that out in short order with my impulse 31. Run 4s...just fine. Put in 6s and I even had the upgraded ose small flex...shredded it in short order. Pull the Teflon liner out, get a 3/16 shaft and collet and let it rip!

Thanks every one, thats what I thought also.
everything is lined up nicely and no binding, will upgrade the shaft and collet.
again, thank you all.

Well I went to my LHS to find a .187 flex shaft, they did have one but it had a square end on it, no biggie i could cut that off, the problum was I could not find a prop shaft for it, they were all solid, also the collet was huge and it was for a 5mm motor shaft and a .187 cable.
I can see why it would not break.
well anyway I thing i'll stick with the.150 flex and drop my battery volts back down to 5s untill i can find the the right .187 stuff.

Having the same problem with my Impulse 31 on 6s lost a shaft and broke one.G-UNIT what are your speeds mine was running 51.1-53.5.Anybody else have any ideas or is 6s to much the hull is capable of more speed its running flat.

My flex shaft broke at 47.9 mph and I don't think it was even up to speed yet.
your speeds sound good.
I feel the boat will handle alittle higher speeds though if tuned right.

Quote:

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Originally Posted by G-UNIT

My flex shaft broke at 47.9 mph and I don't think it was even up to speed yet.
your speeds sound good.
I feel the boat will handle alittle higher speeds though if tuned right.

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Yes for sure had mine running 50-51 and it was okay.When it got it up to 53.5 it broke going to try an upgraded flex shaft and see what happens.Yes I am sure the boat will go faster it was running flat at 53.5.

Has anyone tried the upgraded flex shaft form OSE ?
oduct ID: ose-cable-impulse31
OSE Upgraded ProBoat Impulse 31 Cable

In Stock: 8
OSE Upgraded ProBoat Impulse 31 Cable
(Enlarge)
OSE Flex Cable Assembly for the ProBoat Impulse 31. Upgraded .150" Cable with 3/16" prop shaft. This is cut and ready to install in your boat. This upgraded cable is a higher quality with thicker wire strands and better aligned to the prop shaft then the stock unit. The prop shaft is only 2 1/4" long which reduces resistance and allows more strut adjustment. Which will help vibrations which will help reduce strut bearing wear. Just install it and go!

No soldering or cutting required!

This can also be used in any other boat requiring a .150 cable that measures approx 8 3/8" (212.7mm) from tip to tip.

Includes: Teflon Liner, .150 cable with 3/16" prop shaft and attached drive dog and streamlined bullet nut.

You could always prop down, it may be no faster than it is on 5s, but it would give you more run time and let you use that second pack without snapping your flexies.

Or follow Fluids advice which is bang on about a .150 flex and 6s setups.......

I have .187 in all my 6s set-ups , 8s and 10s get .250 cables .

Mine made it up to 58.2mph before the OSE upgraded flex shaft gave up! I will say it didn't break! The strands started to loosen up and spun on the collet...so now I got the .187 cable and hope to see 60!