Flex Shaft, end of stuffing tube to collet distance, to much exposed shaft?

[Checkmateguy01]

Never even thought about it when i built the boat and epoxied in the the stuffing tube, but i was reading another post that said there should never be more than a 1/2 inch of flex shaft exposed between the collet and end of tube? Is this true? I have about a full 1 inch of seperation between the two. I'm running a .187 (3/16) shaft thru a non-teflon lined tube. I didn't go with a teflon liner, and it probably was not a good idea, but all the nitro racing i did we never had liners so that's where my thinking came from. I have noticed some guy's with some type of sheething or nipples over the stuffing tube ends, what are they and would it work form my set-up? Here's a picture of my delema, will it be OK and just go ahead and run it, or do i need to come up with some kinda fix before it hits the water? If so, what? Thanks!!

IMG_0490.jpg

[LarrysDrifter]

Id pull the stuffing tube amd install a longer one. That is too much flex exposed. I personally use an 1/8" gap on my boats between the tube and collet. Also, is that the water outlet sticking out the side of the boat?

[Checkmateguy01]

Id pull the stuffing tube amd install a longer one. That is too much flex exposed. I personally use an 1/8" gap on my boats between the tube and collet. Also, is that the water outlet sticking out the side of the boat?

Yeah, that's the water outlet but the nut was not yet on the back side to hold it in, it sits nice and flush when all tighten up! Unfortionatly there's no way that tube is coming out, i epoxied it in real good, i mean i might be able to dremal it out but that's gonna be a rough job. I'm goin back to RTR's...

[LarrysDrifter]

Dont get discouraged. Its very easy to remove it. Heat the epoxy with a heat gun until it gets soft when you poke at it with a hobby knife or flat blade screw driver. Scrape it out in small chunks and before you know it, its out. Only use the Dremel if you have to.

[dana]

what about extending the tube?

[dana]

or get a longer coupler?

[m4a1usr]

Or you could solder an extension piece to the current stuffing tube. Just cut the right length/ filler piece of the same size id/od tube, deburr it. Then get shorter piece of the next size up tubing and solder it over the stuffing tube, creating a joint splice. Its worked for me over the years I have been doing it. If your worried about exact alignment, slide a drill bit into the stuffing tube. It will hold it in place enough to get the soldering done. I like to seal the end of the stuffing tube to the flex with a small section of silicone tubing.

John

[dana]

or you could go down to .150 cable and put the liner back in

[Checkmateguy01]

Or you could solder an extension piece to the current stuffing tube. Just cut the right length/ filler piece of the same size id/od tube, deburr it. Then get shorter piece of the next size up tubing and solder it over the stuffing tube, creating a joint splice. If your worried about exact alignment, slide a drill bit into the stuffing tube. It will hold it in place enough to get the soldering done. I like to seal the end of the stuffing tube to the flex with a small section of silicone tubing.

John

OK, i was just coming back to ask this very question!!! I was in my shop looking it all over and wondered about simply extending the current tube exactly as you described!!! Although, i wondered about using epoxy instead of solder? Either way i think that's what i'm gonna do!!

[LarrysDrifter]

You can use Loktite 648 also.

[JIM MARCUM]

1" of flex shaft exposed will cause the shaft to twist & fail. Nothing wrong not running teflon liners. The stuffing tubes that come with a teflon liner are usually thinner than a regular hobby store tube & will wear too soon. But, you can extend your existing stuffing tube by adding 3/4" of tube of the same OD, and sliding a 1/2" long piece of tubing the next size larger over the butt joint. Clean all tubing to tubing surfaces, then solder, epoxy or red Locktite the tubes together.

I replaced all of my brass stuffing tubes with seamless Stainless Steel tubes. They are thicker, don't require teflon liners, and will likely outlast your boat. SS brake line tubing works for some applications. Seamless SS tubing is usually sold in 20" lengths. If you can't find any near you I can sell you whats left of my 20" long SS tubes. I'll send you 3/8" OD X .270" ID SS tubing for $8 per foot, 1/4" OD X .178" ID for $5 per foot + shipping. JIM (Yeah Steven, I know:)

[Checkmateguy01]

1" of flex shaft exposed will cause the shaft to twist & fail. Nothing wrong not running teflon liners. The stuffing tubes that come with a teflon liner are usually thinner than a regular hobby store tube & will wear too soon. But, you can extend your existing stuffing tube by adding 3/4" of tube of the same OD, and sliding a 1/2" long piece of tubing the next size larger over the butt joint. Clean all tubing to tubing surfaces, then solder, epoxy or red Locktite the tubes together.

I replaced all of my brass stuffing tubes with seamless Stainless Steel tubes. They are thicker, don't require teflon liners, and will likely outlast your boat. SS brake line tubing works for some applications. Seamless SS tubing is usually sold in 20" lengths. If you can't find any near you I can sell you whats left of my 20" long SS tubes. I'll send you 3/8" OD X .270" ID SS tubing for $8 per foot, 1/4" OD X .178" ID for $5 per foot + shipping. JIM (Yeah Steven, I know:)

I thought it could cause some type of "whip" and create failure, that confirms my suspicions. I have a 1/4 stuffing tube, K&S, so i'm gonna take a ride up to the LHS in the next couple of day's and get the next size up to make a sleeve for it. I will probably solder the collet end, and either epoxy or loctite the other end. I think this is a good fix, i don't see why it wouldn't work. Thanks for all the info fellas, i knew i would have a few more tweaks and adjustments to make before it's first trop to the pond, no big deal!

[Checkmateguy01]

Does this look a little bit better? Now there is only a 1/4" gap instead of an 1+". I have not perminatly put the sleeve in yet, i've been debating the use of Loctite, or good epoxy? Definatly don't want any seperation from vibration, what do you all think?

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[LarrysDrifter]

Dont use epoxy. It softens with heat. Loktite retaining compound will do the job perfectly. Sand the stuffing tube and the extention where the coupling goes and use a degreaser such as brake clean and allow to air dry. All the mating surfaces must be absolutey clean. Do this, and the extention job will be done right.

[LarrysDrifter]

Also your gap will work, although I still prefer the gap closer, though im over cautious.