0.150" vs. 0.187" flex

[Insaniac]

At what point should you switch from 0.150" to 0.187" flex drive? I'm running 0.150" flex with Teflon liner for P-spec motor but plan to go to something more potent in a hydro.
Does everyone run Teflon liners? Why or why not?
Has anyone broken a 0.150" flex?

[steveo]

i think with out is alttle more free to me at least i am using a .187 with about a 16" cable with minimal bend in a cat and it feels smooth

[Fluid]

The 0.150" is fine for spec power, but for anything more potent I use the 0.187" (or 0.25" for 10S). The friction/drag difference is small while the strength difference is large - the 0.187" is 55% stronger.

I haven't used a Teflon liner in many years, even swapped it out in my UL-1 for straight brass. If a good lube is used there is less friction with a bare brass stuffing tube than there is with a Teflon liner - tests prove it. This is because the Teflon deforms and has a much greater contact area with the cable than the hard brass does. Too, the Teflon wears out, shreds, grabs the cable and breaks it. This has never happened with brass IME.

I have yet to wear out a brass stuffing tube either, even though some boats have been raced three heats a day, twice a month for over several years. The trick is to use a good quality EP (Extreme Pressure) lube, this cuts friction immensely. With a brass sleeve bushing in the strut and the good lube I have yet to wear out a sleeve either. More drag, shorter life, and you still have to lube the Teflon liner - so where is the advantage?



.

[steveo]

fluid can you tell me what lube you use and where to get it

[Fluid]

Pennzoil Synthetic Gear Lubricant (SAE75W90 GL-5)
There is no magic in that particular brand; I bought a quart five years ago at WalMart for $4 and it's still half-full. Other brands may work just as well, the important component is the extreme pressure additive (check the label carefully).

Part of my core business is spinning one loose-fitting steel pipe inside another. The pair often make 90 degree changes in direction, and lubricants are important. The lube listed above works well in high load friction testing, and even when emulsified with water it still provides excellent metal-on-metal lubricity.

Are there better cable lubes? Maybe, I've only tested a few. But I also know a few which are popular yet don't work particularly well at reducing cable friction.....



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[LuckyDuc]

I run a 3/16 cable in my P limited, P Sport, and P mono with no Teflon liner as well. I have broken a .150 cable when the Teflon liner wrapped itself around the cable. I stopped using liners after that.

[Jeff Wohlt]

Dollar General Motor honey for oil burning motors. Like STP but $1. I use this crap for threading couplers, drilling stubs and love it.

Another good option is Chain Saw bar lube....extreme heat and rpm and sticks. One gallon is good for 57 years running everyday...LOL.

[steveo]

alittle of topic but were taking lube can someone give what type to use in motor bearing, is there a high speed something i should use

[Jeff Wohlt]

I use Trinity bearing lube in a needle dropper that comes on it. Seems to be good stuff. One drop is all you need.

Boca makes some good stuff but not sure what it is.

[Gary]

What do you guys run with a .187 cable a 7/32 tube or larger for no stuffing tube liner.

[Jeepers]

I run the 1/4 tube with no liner with the .187 cable seems to work fine. I tried the 7/32 with the .187 cable stuffing tube got really hot after a run.

[BakedMopar]

I run the 1/4 tube with no liner with the .187 cable seems to work fine. I tried the 7/32 with the .187 cable stuffing tube got really hot after a run.

My hydro was like that with a 7/32" and it got hot enough to smoke the lube. I use 3/16" in 1/4" no teflon in all my boats except my spec rigger which is .150" with no liner.

[LuckyDuc]

I fiber glass a piece of 5/16" tube in the hull and then slide 1/4" tube through that for the stuffing box. This allows you to replace the stuffing box without cutting it out of the boat.

[Fluid]

I've done the same thing on all my boats.....except that I have never had to replace a brass tube. It is also handy for pulling out the stuffing tube and making careful bends in it to adjust the strut.


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[Insaniac]

Thanks for the great input. I was ready to pull the 1/4" stuffing tube in my hydro and replace it with 7/32", but it sounds like I am better off using the 1/4" with the 0.187" flex.

[Flying Scotsman]

How does this lube compare with the usual Prather, Grim, BluGoo cable greases a lot of us use?

I think you have your answer as stated by Fluid and it is a lubricant.

Douggie

[Insaniac]

Here are some detailed tests of various gear oils including the Pennzoil Synthetic 75W90...

[Fluid]

Thanks for the test paper ranking various lubes for use on hypoid automatic gears. Sadly, none of the tests have much at all to do with what we want out of a cable lube and the 'top rated' lube is probably not the best for our use. We have no need for viscosity indexes, 20-hour shear tests, oxidation tests, weld points, foaming....the bulk of the testing. The most useful test was probably the industry standard Falex pin/block test, but even it had far more loading than what we will ever see in a model boat.

What is not given - but would probably be the most important measurement - is the lubricity provided when emulsified with water, which happens with all cable lubes used in model boats.

I tested two of the lubes in the study and there was little difference between them as far as Falex testing and results on a 3' length of loaded 3/16" flex cable. Several lubes not in the study did not do so well, but none were failures. I know from on-the-water SAW testing that the gear oils give slightly higher speeds than some 'special blends' that racers like to use, and slightly better than the cable greases tested (only two were tested though).

What do you take from all this? I think all it highlights is the fact that any lube is better than no lube. The conclusion from all my personal testing?

I think that we spend too much time trying to find a magic cable lube and not enough time on boat setup.



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[helpeconomic]

Many years ago, I replaced my UL-1's Teflon liner with plain brass. Testing shows that there is less friction between the brass stuffing tube and the Teflon liner when a decent lubrication is applied. To put it another way, the Teflon deforms and has a larger contact area with the cable than the solid brass does. As the Teflon ages, it becomes frayed and brittle, allowing the cable to snap. Brass IME has never had an issue like this before.




quordle

[jamesevans336]

I believe you already know the answer because Fluid has already told you that it is a lubricant.

duotrigordle