Stuffing tube

[Kram]

I have two 3/16 flex cables that need brass tube. Should i go for no teflon liner or with teflon?

What size should i use with no teflon liner?

Please... i need help 😊

[martin]

Using K&S brass tube you need 1/4" o/d tube with no liner, using Octura liner you want 9/32" o/d brass tube.

[Kram]

Thanks

Should i go for with teflon liner or without?

[martin]

You will get 2 trains of thought on this, some say they don't use liners as its 1 less things to go wrong due to flex binding & melting the liner. Others use liners & have had no such problems.

[Kram]

The 1/4 tube feels a little to big for the 3/16 cable... but i will use it if its right!

Thanks

[martin]

If you go to OSE Parts Store @ the top of this page, then on the left hand side you will see flex cable parts. Go into that & you will see all the recommended sizes of K&S tube both with size needed for use with a liner & also no liner.

[CraigP]

Kram, I'm building a DF Vortex 34 Hydro and I installed a 1/4" Stainless Steel tube. This tube has a 0.028" wall thickness which leaves about 0.005" on all sides to the 3/16" flex cable. I use an anti-seize compound as a lubricant. There are all kinds of recommendations on this site for specific lubricants.

I too did not like the sloppy clearance of brass tubing. Also, brass has a much higher stiction factor, which is a measure of a complex friction. In plain words, it means the "stickiness" of the metal. Stainless Steel is much lower... It is much harder to bend. Don't even think about it unless you have a hand-help tube bender with 1/4" rolling wheels installed in the tool. I hope that helps...

[CraigP]

Oh, and I don't run a liner...

[Prodrvr]

I use an anti-seize compound as a lubricant

That's gotta be one of the last things you want to use as flex shaft lube.

[Fluid]

"Stiction" is not an issue as long as a good lube is used. Anti-seize is not one of those, it is designed for non-moving parts. Plus 0.005" is far too small a clearance between the cable and the tube. When it is spinning under load the cable winds up somewhat, and restricting that too much will add considerable drag. Whether one "likes" more clearance or not, it works well and has been used on hundreds of boats successfully. Most of my SAW records were set running cable in brass tubing, the fastest with 3/16" cable in 1/4" tube. I have never replaced a stuffing tube due to wear, even on boats which have been raced six heats a month of years.

Lubes which are designed for high speed rotation should be used. There is a plethora of marine greases and automotive oils available - use something which is designed for spinning parts. Hundreds of boaters are not wrong on this, and re-inventing the wheel is not required.


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[CraigP]

This is all great stuff... I did test the flex cable on the bench by winding it up manually, putting a 3/4 turn of windup on it. The cable actually gets smaller by 0.006" - 0.008", so it twists up tighter and smaller. So far, I'm having very good results with the SS tube, but I can swap it out if troubles appear. I misspoke about anti-seize compound... You are all very right about that. I was in a hurry and just typed that out. I'm using an engine Assembly Lube, a MoS2 compound meant to go on bearings, piston skirts and cam lobes while assembling the engine to provide break-in lubrication on initial startup and run in. It provides superior metal surface protection, where the two surfaces have to mate to each other. It's a U.S. Lubricants product. I add a 50wt racing engine oil to the stuffing tube/flex cable via the oiler port on the Shaft Tube Steel made by Aeromarine. A lot of people claim it doesn't work, but I feel they are not applying it correctly to their boat. I works great for me... The oil is important to properly disperse the MoS2 Assembly Lube, but that's all I have to do between runs. At the end of the day, just back out the flex cable, clean with acetone and the stuffing tube. I store it dry and re-lube before I run again.

Oh, something I found works great... I cut off the head of a Q-Tip, soak it in acetone and force it thru the stuffing tube with the flex cable. Two tips cleans it like new, gets any residue out of there.

[Kram]

Thanks guys!

I will try to run the boat with 3/16 and 1/4 brass tube with or without liner! Waiting on some teflon liners from OSE. But what should ido?? is it more things to go wrong when you dont use a liner? i really dont know... first boat im building...

Currently rebuilding the genesis with carbon fibre layers and new paint! Miss geico is the plan.. Quite excited to see the outcome :)

[CraigP]

Many folks run liners, many record holders... But, many don't. I don't, didn't want the possibility of the liner spinning in the tube, twisting then grabbing the shaft. But I think it really comes down to good, consistent maintenance and using the right lubes. Many good lube recommendations on the site. Seems most run liners, so if you don't have a clear vision for what you want your driveline to do, I'd go with the liner. Plenty of guidelines for running and maintenance on the site...

[Fluid]

Less to go wrong with no liner - 15+ years experience without Teflon, never broke a cable with no liner, never wore out a brass tube either. That's dozens of my race boats, not including many dozens more of fellow club members' boats.

The bottom line is that either will, and has, worked well if run properly. Anyone who claims otherwise either has not run them correctly, or only has limited experience.

.

[CraigP]

There you go! OSE is out of liners, so there's a sign too! Gotta go with the flow...