Twisted drive line

[scotthend21]

I just had the drive lines turn in to a knot today. I finally got the set up I am looking for. I have about 5/8" spacing between the stuffing tube and the collet. do I need to replace the stuffing tube to shorten the distance? Any suggestions?
I am running a head of river cat.
Feigao 6L
ETTI 150 ESC
A123 4S1P
Counter rotating X442 AL props.

[teach]

Ouch. Did the drive dog and strut maybe contact each other?
Sorry I'm still very much a rookie so I don't have anything solid for you.

[scotthend21]

No. I use a o-ring spacer between the drive dog and the stinger.
Note; this happened on both sides.

[paulwilliams]

do I need to replace the stuffing tube to shorten the distance? Any suggestions?


I take it the flexis failed in the 5/8ths" gap?

Twisting a flexi in half like that is the usual result of running it unsupported, so you've answered your own question: yes, you need to close that gap. If the stuffing tube is a regular size of brass tube, make an extension piece with an outer collar (ie., a larger diameter brass sleeve over the join) which you can simply glue in place with Loctite - this will save you the trouble of removing the original stuffing tube. If the flexis are running in teflon tubes, you would need to extend these as well with longer replacements.

Another suggestion would be to remove the original flexis and replace with wiredrives - take a look at Jeff Wohlt's website, or here on OSE. Wires will take a lot more power than a flexi.

Paul

[DISAR]

As above and:
a) Check alignment motor-flex. The flex must slide into the coupler easily
b) Are you running with teflon or without. Make sure you use the right size stuffing tube for your flex. If the stuffing tube is too big this can happen. This will help http://www.offshoreelectrics.com/products.php?cat=70
c) Do your shafts rotate easily by hand or bind somewhere?
d) Which flex is this one? Is it soldered to the prop.shaft?

[Jeff Wohlt]

And you wonder why a cable has so much more resistance in a stuffing tube than a wire. This is what a cable tries to do while running even though a tube keeps it in check. They rub the stuffing tube all the time trying to tie a knot while under power.