A "Liner-less" Drive Line

[10gauge]

What are peoples thoughts and experiences on installing a drive line consisting of flex cable and brass stuffing tube without a teflon liner?

I know it's the "metal to metal contact" friction argument, but one can also argue that internal combustion engines have metal to metal contact as well. I tried sanding the flex cable with 200, 400, and 600 grit sandpaper and tried spinning it in a KS brass tube. Wow! It spins effortlessly compared to the higher friction teflon liner set up. I would think the tolerances are good enough that very little water can leak through the stuffing tube. Since both the cable and the tube are brass, it would seem that they may wear evenly over the long term. Even with cable grease, I wonder how long such a set up can last?

I guess I could design a bench top mounted BL motor, curved drive line, mounted strut, with a large flywheel at the end to test it all out. But, I'd rather take your word if you've had any experience with a liner-less system...

I am curious:

How long can such a setup last?...
Any longterm effects of wear?...
Can it withstand high rpm?...
Would it be better to use a stuffing tube made of a harder material than brass to avoid having the stuffing tube wear out faster?...

[SJFE]

I have seen this question posed & resulting debate before. There are just as many guys that don't as do from what I remember. I am a liner user. Always have been. I use it more to keep out water than anything else. I also think it will prolong the life of the drive system. In a perfect world all my boats would have wire drives. But I'm not good enough to set them up like that yet. I'm sure you will get alot more feed back as guy happen across this post.

[raptor347]

To be honest, I run both (all three). It really depends on the application and what fits. I run wire drives in my N2 monos, .150 cable with liner in the N2 sports/riggers and linerless .187 cable in my P up stuff. It's mostly a case of working with available hardware.

For sport running in most cases the linered .150 cable is easiest. You don't need the .187 cable until you go to big motors and props in the P classes and above. UNfortunately I've found wire drives to be pretty much limited to N2 use at this point. Initially I put an 1/8" wire drive in my DF33 P mono with a 1521/1.5d and an X452/3 on the back, I turned 3 shafts into cork screws.

At this point I've had boats over 100mph with all three drive line types. I will say you need to use a good lube with the linerless system, regrease every run. In small quantities the Grimracer grease is great, if you need bulk go with quicksilver marine outboard grease.

[ReddyWatts]

I do not use flex tube liners in any of my boats. I add a short piece of water cooling tube between the drive dog/strut and also use heat shrink over the strut/brass tubing connection. This will make a good water seal to keep your boat completely dry. This is not a conventional method, but great works for me. Use the lubrication of your preference, does not have to be heavy grease.

[steveo]

two of my monos run with out linear, there is no indication of wear on anything, and its a super smooth feel to it and i dont have problems with water coming in from the tube

[Raydee]

I have been running Liner-less gas boats for many years without a problem. Most of my smaller FE boats have liners just because it helps keep the water out of the hull in my opinion. I just built a Sport 20 Whiplash with a .150 cable that uses a liner but the Sport 40 hull I also built using .187 cable will have no liner. I think its all personal preference.

[txboatpilot]

I have been running Liner-less gas boats for many years without a problem. Most of my smaller FE boats have liners just because it helps keep the water out of the hull in my opinion. I just built a Sport 20 Whiplash with a .150 cable that uses a liner but the Sport 40 hull I also built using .187 cable will have no liner. I think its all personal preference.

Raydee, when you run no liner, do you get a smaller dia tube than you would run with a liner? For instance, a .150 cable with liner takes a 1/4od k&s tube, if you run it liner-less do you still use the same 1/4od tube??

[10gauge]

I am surprised that so many of you are running liner-less drives predictably well. Thanks for sharing your experiences and great info.

SJFE, I am intrigued as you are about wire drives...

ReddyWatts, To stop water, I've tried the fuel tubing on the stuffing tube/flex cable at the motor end, but never between the dog/strut - Very clever!

Txboatpilot, when I was experimenting, I was spinning a 0.150 flex cable in a 5/32" KS tube I think, or whatever is the next size up. I think the 1/4" tube is too loose. That's why I need to decide NOW whether to implement a liner-less system or not because once you epoxy a 1/4" tube it's a pain to change it later.

Raptor347, how do you like the Neu 1521/1.5d in a 33" mono? How's your setup? I am curious because just last week, I got a Titan 33 to finally use the 1521/1Y I've had lying around. My setup will be a 0.187 drive line with a Neu 1521/1Y, Neu 6S1P/5000/30C LiPos, Hydra240, and will experiment with various props.

Thanks again guys!

[steveo]

Raydee, when you run no liner, do you get a smaller dia tube than you would run with a liner? For instance, a .150 cable with liner takes a 1/4od k&s tube, if you run it liner-less do you still use the same 1/4od tube??

if you use a .150 cable use the .130 tube with the least amount of bend

[txboatpilot]

My setup will be a 0.187 drive line with a Neu 1521/1Y, Neu 6S1P/5000/30C LiPos, Hydra240, and will experiment with various props

Food for thought,,,Jay Turner says not to run any Hydra120 or 240 on 6S lipo..... I would find a higher Voltage esc for that 6S set-up...JMO

[10gauge]

Thanks for the heads up txboatpilot.
I am a fan of using higher voltages and lower current to give the same power output of a 4S to avoid burning out an ESC. Last year, I burned out a Hydra120 with a 4S2P/8100/15C, Feigao 8-XL, X445 on a Mean Machine... Don't want that happening again!
With all the FETs in the Hydra240 and a 240amp rating, you would think that the Hydra240 should handle 6S LiPo as advertised?... Then again, I remember somewhere in the fine print that the warranty covers up to 4S. Well, I do have the OEMRC 2-12S 100Amp ESC lying around, do you think that may suffice?...

[txboatpilot]

Thanks for the heads up txboatpilot.
I am a fan of using higher voltages and lower current to give the same power output of a 4S to avoid burning out an ESC. Last year, I burned out a Hydra120 with a 4S2P/8100/15C, Feigao 8-XL, X445 on a Mean Machine... Don't want that happening again!
With all the FETs in the Hydra240 and a 240amp rating, you would think that the Hydra240 should handle 6S LiPo as advertised?... Then again, I remember somewhere in the fine print that the warranty covers up to 4S. Well, I do have the OEMRC 2-12S 100Amp ESC lying around, do you think that may suffice?...

Yes, the OEMRC 100HV is what I use on a 6S Cat.. I have watercooled and waterproofed mine, and installed a fan! It runs smooth, cool, and has seen over 120amps cont.. without a problem! I run the OEMRC 100HV in a 34" Drifter L Cat, it has a KB45 8XL, M442 prop and does 52-54mph on the gps...It is running 2/ 3S1P 5000mAh 30C lipos in series, for the 6S total....Attached ia a picture of the 100HV...

The reason you toasted the 120, is due to the prop being too big.. That caused the 8XL to pull too many amps and Poof!! I run my M/M on 8XL with M440 prop and hydra 120A... It is at its Amp limits with the M440.... If I ran a x445, I would see some SMOKE for sure!! That is with a 4S lipo set-up.... Here is video of the M/M...http://s246.photobucket.com/albums/g...t=47e37116.pbr

[10gauge]

"Poof?"... It was more like a salvo being fired from the U.S.S. Missouri when the ESC caught on fire last year... I've run out of Spring Breeze Air Fresheners, it still has the burn smell inside the hull. I was told that

OK then, it's time to order more 5.5mm connectors from Steve to wire up this OEMRC 100A ESC with the PisTix and put it to use. Good job with the innovative cooling system!

Very impressive runs on the video by the way. Ah, that's what I need is a dog for good luck too! :) I've also got an M-1 SuperCat on deck and I am thinking of running the KB-9XL or -10XL with 6S1P or even swap it with the Neu 1521/1Y. I am curious how that EGSRA-21 HW is working out for you? I am a little worried that it doesn't have a bushing inside the strut, and I am not sure if the entire Strut/Rudder has to be replaced if it does wear out?

Thanks again for the info!

[txboatpilot]

Very impressive runs on the video by the way. Ah, that's what I need is a dog for good luck too! :) I've also got an M-1 SuperCat on deck and I am thinking of running the KB-9XL or -10XL with 6S1P or even swap it with the Neu 1521/1Y. I am curious how that EGSRA-21 HW is working out for you? I am a little worried that it doesn't have a bushing inside the strut, and I am not sure if the entire Strut/Rudder has to be replaced if it does wear out?

Thanks again for the info!

The Neu 1521/2D (1425KV) is the 6S motor for the 32-36" Cats!! It will be a whole different animal than the KB!! NO COMPARISON!!

The strut does have a bushing, mine uses the octura lead teflon bushing,, OSE sells them....The hardware is fine, I have ran it for almost a year. No slop, you can order any of the parts individualy.. You just have to call them up and ask....

OH, and please take your Dog with you to run your boats!! My boats always run faster when the Hound is cheering me on!!

[raptor347]

Raptor347, how do you like the Neu 1521/1.5d in a 33" mono? How's your setup? I am curious because just last week, I got a Titan 33 to finally use the 1521/1Y I've had lying around. My setup will be a 0.187 drive line with a Neu 1521/1Y, Neu 6S1P/5000/30C LiPos, Hydra240, and will experiment with various props.

It's an animal. Just a fantastic combination. Brutal power and very little heat. It spins the x452/3 like it wasn't there. There are faster motors in the straits, but nothing pulls through the corners like it. It'sa tough boat to beat.

I'm actually going to put a 1527/1y in my Phil Thomas Sport 40 hull on 6S. With a kV of 1250 it should have the same loaded rpm as the 1521/1.5d on 4S. I'm expecting to start with an X455.

On the hydra 240, I'll back Jay T on this one. Nothing above 5S if you want it reliable, honestly I consider it a 4S max ESC in stock form. I add a third cooling plate and another 4 470uf 25V capacitors for extra buffer.

[Fluid]

In recent discussions with Castle about the Hydra 240, they stated that an "inadequate battery" will cause high ripple currents which take out caps and FETs. They recommend using at least 4500 mAh packs and a 20C minimum discharge rating. They also recommend using 1P where possible. This inferrs that those boaters who use the less expensive, smaller capacity packs should be careful about pulling high amperages, even if the draw is within the "C" rating for the pack.

BTW, when I recently upgraded a Barracuda 180 to a Hydra 240, the invoice listed the Hydra 240 as a 6-16 cell ESC......



.

[10gauge]

txboatpilot and raptor347 the 1521 and 1527 motors sound like nitrous oxide for FE. I'll let you guys know how the Neu 1521/1Y will work out in the Titan33 and M-1 SuperCat. It would seem the rpm @35,000 is a little on the high side for sport running, but I hope to use it only for fast runs on a larger pond. I just ordered (2) Neu 3S1P/5000/30C-60C LiPos for 6S1P operation. I heard they're good LiPos.

raptor347, I'll have to look at the Hydra240 tomorrow and see how the electrolytic caps are arranged. Maybe, even a capacitor upgrade to 1000uF @35VDC could be incorporated somehow?...

Jay, it's sad that the Hydra240 is listed as only a 16cell ESC. You'd think that higher voltage FETs could have been implemented for additional headroom to cover the advertised 6S ceiling. I don't know what I am going to do with my unused Hydro240 ESC since it's not reliable for 6S and I am trying to get away from high current 4S setups?... An Aside: Too bad they don't design modular ESCs for plug-in power where you could substitute various output power stages to suit one's voltage and current needs. That way even if the ESC burns, you just replace the output FET power stage and leave the PWM and programming circuits intact, and it would be cheaper in the long run.

Thanks for all the input guys!! My next project, it's time to get a nice dog and train it for rescue operation... :)