3/16 or 1/4 cable drive Which One

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And the FACT the is absolutely NO more drag turning a 1/4" cable than a 3/16", contrary to popular belief

Don, I'm just not sure about this. Let me try to use some logic or a hypothethical situation.

Imagine our 1/4" shaft and it is solid and is riding in a bearing. Now imagine another solid shaft that is now 1 foot in diameter riding in a bearing. (For this example, lets imagine that the shafts are made of some alien material from Roswell that has no weight!) The 1/4" shaft has a circumference of 2 X pi X r or 2(22/7) .125=.786" and the larger shaft is 2(22/7)6=37.71". Now with this exagerated example, the small shaft would only have to "ride" through .786" of rotational distance and resultant friction within the bearing for each revolution. The larger shaft would move through 37.71" of distance with resultant friction per revolution.

We could apply this to 3/16" vs 1/4" shafts as well but obviously, the differences won't be as dramatic. Its probably negligable but I still say its there!

Not only that, but our flex shafts run inside much larger OD brass tubes than what I have in my simple hypothetical example so my thoughts may not really hold water :lol: . The friction characteristics are way different and probably unpredictable :unsure: .

In any case, if its a larger engine, use a 1/4" cable and be done with it !

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Man you have too much time on your hands..... :lol: :lol: :lol:

 

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Look at the set up on this 1/8 scale on ebay....looks like a thin piano wire for a cable.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...5942777312&rd=1

 

[Don Ferrette]

Don, I'm just not sure about this.  Let me try to use some logic or a hypothethical situation.

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Danny-

This was extensively tested by Rod Geraghty, no logic or a hypothethical situations, just real world numbers. This was the same test series that showed how an "S" bend in the stuffing tube had the least drag because it controlled cable whip better. B)

 

[Jerry Wyss]

Hey , you guys could do me a mini-huge favor,,,give me a good decimal measure

ment of the 1/4 cable with the teflon around it. :huh:

 

 

OR NOT!!

 

[Jerry Wyss]

"Beavers-n- Ducks"!!

 

[dannyual767]

This was the same test series that showed how an "S" bend in the stuffing tube had the least drag because it controlled cable whip better. : cool:

I do remember hearing about the S bend being better after local guys said that it wasn't . I'll be keeping my S bends!

Man you have too much time on your hands..... :laugh: :laugh: :laugh:

If I'd spend more time working on my boats than I do coming to this and a couple of other sites, my one and a half year projects would already be done! Heck, someone could probably grow their own trees for wood and be done quicker than me !

 

[Jerry Wyss]

OK,,One final question on this: Duz anyone Know what diameter of Teflon is used

Around a 1/4 Drive Cable Shaft? :huh:

 

[P THOMAS]

OK,,One final question on this: Duz anyone Know what diameter of Teflon is usedAround a 1/4 Drive Cable Shaft? :huh:

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The teflon tube is .270 ID .305 OD

1/4 cable, used in teflon tube, in 11/32 brass shaft tube, a 3/8 brass tube over that can be glued into the hull.

 

[Jerry Wyss]

Thanks for that info Phil, Thats exactly what I was lookin' for. I'm a plumber but

theres no tube that we use thats close enough without "sleeving" it with another

tube,,,,But in "refridgeration" I think there's a one tube solution. I'll let ya know.

Jerry

For your infomation: In that boat that I'm holding, before with 3/16 cable, I used

1/2 in OD "Soft Copper" tube for "stuffing" tube and inside that I slid a simple

"plastic" 3/8 OD water supply tube, like for hooking water up to a "bathroom

basin" or kitchen sink faucet,,Perfect fit for 3/16ths.

 

[Don Ferrette]

OK,,One final question on this: Duz anyone Know what diameter of Teflon is usedAround a 1/4 Drive Cable Shaft? :huh:

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I stopped using teflon years ago after the teflon "liner" wrapped itself around a cable & cost me what would have been my first 1st place overall for a weekend's racing. :angry:

 

[Jerry Wyss]

OK Dono, I give , what do ya use now?? :huh:

 

[Don Ferrette]

OK Dono, I give , what do ya use now?? :huh:

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See the brass tube in pic with holes in it, that's what I use.

 

[Jerry Wyss]

Whats the purpose of the holes? :huh:

 

[Don Ferrette]

Whats the purpose of the holes? :huh:

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To hold grease.

 

[Jerry Wyss]

Whats the purpose of the holes? :huh:

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To hold grease.

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AHH BAHH SO

 

[P THOMAS]

I stopped using teflon years ago after the teflon "liner" wrapped itself around a cable & cost me what would have been my first 1st place overall for a weekend's racing. :angry:

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Yea been there done that one too, stuck so hard you cant pull the cable out.

You can just run those brass bushings in the strut tube, just grease the bushing and cable before the run, usually lasts for days running 3-4 tanks of fuel.

the bushing is made from 9/32 tube it runs in the 5/16 shaft tube that goes all the way from the engine thru the strut.

here is a picture of the bushing i use it is flared on the end to eliminate the soldered on retainer ring, and the oil holes are cut with a cut off disk which doesnt leave burrs to clean up.

 

[Jerry Wyss]

h34r: I'm Lost

 

[dannyual767]

Phil, thats a good picture. These bearings are real simple and from what I understand, they work real well. How do you keep them from spinning in the strut?

 

[missbudpilot55]

Jerry,

Bill @ Speedmaster Products has them or they are very easy to make.

 

http://www.rossisales.com/strutbushing.html

 

Check them out.

 

Danny, it's OK if they spin as they only retain the grease like a bearing does in the tube at the strut end.

 

When I was @ Hydro Sport we silver soldered a stop on the shaft to keep them from creeping up, until we started to bell the end slightly as Phil has done.

As long as you leave enough space in front of the drive-dog they won't bind either.

 

[dannyual767]

Thanks Bill for the clarification on spinning. I was thinking that maybe I needed to CA them in or use that high tech locktite that some use with their wiredrives.

Question: With the bearing able to spin, won't it tend to wear out the soft aluminum strut bore :unsure: ?