Cutting a flex shaft?

[Rumpelhardt]

What's the best way to cut my flex shaft and what if anything should I do to the end once it's cut?

[Johnc]

Tell what I have done and haven't had a problem so far, heat the area that needs to be cut to red hot, while it's still hot solder near the area that needs to be cut and the solder penetrates, cut with dremal cutoff tool at length, then after it cools down chamfer the end a bit so that it slips in collet easy, I check solder on the ends after chamfering just to make sure its a good soldering joint (if not re-solder the end)

[fweasel]

I wrap the area that needs to be cut with masking tape and mark the cut with a sharpie. I cut the cable with a thin dremel cutoff wheel, remove the tape, then put a light bevel on the blunt end with my bench grinder. I do not solder my cut ends and it has never been an issue on my boats.

[Fluid]

I haven’t soldered a cut flex cable in almost two decades....never had one unravel either. But, I do use collets exclusively, no set screw couplers for me. I use a cut off wheel to shorten cables, and also bevel the cut edges slightly. I never leave a cable in the stuffing tube after a day of running; I wipe it off and place it inside the hull for storage.

Some downsides of soldering flex cables:

- most folks can’t solder well, so it’s a bad job
- overheating the cable when trying to solder will damage the cable, shortening its life
- the flux required for a good solder job must be removed or it will corrode the cable inner strands, shortening its life
- excess solder may make the cable too large to fit in a collet

YMMV

.

[Rumpelhardt]

Thanks tons guys.

[Old School]

Bringing up an old thread. I have cut quite a few flexshafts. My preferred method is to cut the shaft using a Dremel thin cutoff wheel. Using a portable gas flame (used by chefs/cooks) in the kitchen for browning broule, etc. I then solder the cut end and chamfer the edge. Ensure flux used is thoroughly rinsed off.

[HTVboats]

Bringing up an old thread. I have cut quite a few flexshafts. My preferred method is to cut the shaft using a Dremel thin cutoff wheel. Using a portable gas flame (used by chefs/cooks) in the kitchen for browning broule, etc. I then solder the cut end and chamfer the edge. Ensure flux used is thoroughly rinsed off.

+1 I like a little bit of solder on the end not so much for unwinding but helps with a compression collet and or set screw.
Mic

[jfrabat]

The day after tomorrow I have my first cut (tomorrow I epoxy in the motor and stuffing tube). Seems there are two school of thoughts; to solder or not to solder... THAT is THE question! Considering folks have not had problems with flex cables unwraping and that I will use a collet, I think I am going with the no solder school of thought. Besides, I can always solder later!

[martin]

If you find the flex is a bit tight when fitting or removing the flex from the coupling i always rotate the flex clockwise. This stops the flex wind catching & unwinding.

[jfrabat]

Well, flex cable is cut and set (and stuffing tube is bent and glued in)! Everything lined up VERY nicely! No binding or extraordinary friction or anything. Did a dry test with the motor (lowest possible speed and just for a second or 2, as I have not lubed the tube yet!), and runs just fine. Could have cut the flex shaft maybe 1/8 to 1/16 longer, but I think it will work just fine as it is. But I wanted to post some pics in case you (more experienced) guys see something I don't.

1587662424568893932604310277950.jpg

Top part of stuffing tube.

15876691884756030689037104835527.jpg

Bottom side

15876693003334974877687926152904.jpg

And here you can see the angle of the shaft/prop.

EDIT: Ignore the tubing, as I am waiting for more to arrive to run it through all the right places. Only the ones with tie wraps are final.

[fweasel]

I prefer to leave more room between the end of the stuffing tube and motor collet. Gives you more room to wipe the grease off the flex cable before it goes in the collet. Nothing much you can do about that now unless your collet can move further up on the motor shaft. I'd also eliminate the motor mount from your cooling route. It's an unnecessary restriction and doesn't really do anything for motor cooling.

[jfrabat]

I figured as much with the collet spacing, but I kind of painted myself into a corner there. I cannot move the motor forward because of balance, and I cannot make the angle shallower because of clearance with the canopy and hull... but I completely understand your point here!

As for the motor mount cooling, will do so. Wish I knew that before I bought the fancy mount with cooling!

[fweasel]

I have at least one of those mounts in a boat I own. I unscrewed the hose barbs and threaded in stainless grub screws to fill the holes just so I didn't have to look at the unused connections.

[dasboata]

I haven?t soldered a cut flex cable in almost two decades....never had one unravel either. But, I do use collets exclusively, no set screw couplers for me. I use a cut off wheel to shorten cables, and also bevel the cut edges slightly. I never leave a cable in the stuffing tube after a day of running; I wipe it off and place it inside the hull for storage.

Some downsides of soldering flex cables:

- most folks can?t solder well, so it?s a bad job
- overheating the cable when trying to solder will damage the cable, shortening its life
- the flux required for a good solder job must be removed or it will corrode the cable inner strands, shortening its life
- excess solder may make the cable too large to fit in a collet

YMMV

.

what he said and I might add don't heat your shaft up until its cherry red and use past flux not acid flux !

[dasboata]

Well, flex cable is cut and set (and stuffing tube is bent and glued in)! Everything lined up VERY nicely! No binding or extraordinary friction or anything. Did a dry test with the motor (lowest possible speed and just for a second or 2, as I have not lubed the tube yet!), and runs just fine. Could have cut the flex shaft maybe 1/8 to 1/16 longer, but I think it will work just fine as it is. But I wanted to post some pics in case you (more experienced) guys see something I don't.

[ATTACH=CONFIG]168755[/ATTACH]

Top part of stuffing tube.

[ATTACH=CONFIG]168756[/ATTACH]

Bottom side

[ATTACH=CONFIG]168757[/ATTACH]

And here you can see the angle of the shaft/prop.

EDIT: Ignore the tubing, as I am waiting for more to arrive to run it through all the right places. Only the ones with tie wraps are final.

On the water cooling jacket water exit should be on the hi side and directly on top