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  1. #41
    RC Enthusiast
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    Those that have resolved overheating issues through modification have not mentioned modifying the flex drive (shortening being the exception), teflon tube or driveline per se; other than lubrication. While friction can be a factor, I don't believe it is in this case, given the experimentation by members here. Wouldn't the teflon tube show some torsional distortion/disfigurement caused by heat? I'm just saying.....

  2. #42
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    OK, before I start my post I want to be clear that I'm not looking for a fight, nor am I stepping on any toes. If I make any statement below that you find yourself in disagreement with, please feel free to discuss it openly and with consideration of general forum etiquette. The intent of this (and any of my posts) is to encourage discussion and to learn from the experience and expertise of others.

    I don't own a Spartan myself yet so I can't evaluate problems from a hands on perspective, so some of my comments will be of a general nature, based on my experience with other RC models, and may not be directly applicable to the specific design of the Spartan.

    To begin: The question of whether or not the drive line may be a source of additional drag/binding/friction causing additional strain on the motor, is, in my opinion, a valid question, and one that I asked here previously. We are brainstorming as a community to try and find solution(s) to a problem(s).

    Under normal circumstances a properly designed, properly lubricated, properly aligned, and undamaged drive line should not create any any appreciable amount of additional drag or friction not already taken into consideration in the design of the craft. (i.e. it should work).

    DESIGN: Is there a design problem with the drive cable/stuffing tube on the Spartan. Well, that is one of the questions we are trying to determine an answer to. I can't answer it because I don't have a Spartan to inspect that would allow me to form an opinion.

    Those who have a Spartan, and some previous experience to compare with, does there appear to be any obvious changes to the drive line design? I'm thinking in particular along the lines of perhaps a tighter fit between the drive cable and the liner.

    DAMAGE: This should not apply to the Spartan as a general problem affecting all of them, but I know one owner reported overheating with the stock nimh batteries, which seemed out of the ordinary. Inspect the stuffing tube for obvious signs of crushing, dents, kinks, etc. When inserting the drive cable make note of any "tight" spots.

    ALIGNMENT: Pretty simple, but for those who are new, When you insert the drive cable, does it line up pretty much center with the drive collet? In most cases it should slip into the collet with light pressure and a bit of a twist. You shouldn't have to "push" the end of the cable in any direction to get it to center with the collet. (note: sometimes a very minor physical alignment may be needed, but it shouldn't result in any pressure of the drive cable against the inside of the stuffing tube).

    I have two SV27's one of them came from factory with the stuffing tube out of alignment. it was an easy fix, but it can happen.

    LUBRICATION: OK let's start with Teflon. http://www.lenntech.com/teflon.htm

    There are several different formulations of Teflon, they share many common properties, but also each have unique physical, mechanical, and performance properties.

    Since there is no way to confirm the specific formulation used for the stuffing tube liner, I will summarize some of the general properties of Teflon.

    If anyone is bored this weekend, you can go to Dupont's website and read for hours on all the pro's, con's, properties, and applications of Teflon.

    - Resistant to many chemicals
    - Weather and UV resistant
    - Non - Stick
    - Outstanding Performance at Extreme Temperatures (Hot and Cold)
    - Low Coefficient of Friction

    This is not to say there can't be, or isn't an issue with the Teflon liner on the Spartan, but the probability is very low unless one of the other issues mentioned above is present. The Teflon liner puts the odds in favor of not having binding issues.

    Teflon is often referred to as "self lubricating". This is a bit of a misleading description, because it has no lubricant infused into the material. This simply refers to it's natural non-stick "slipperiness", that provides a low co-efficient of friction.

    Common advice among RC boaters is use drive line grease instead of oil, it is more viscous so adheres better to surfaces, doesn't wash off as easily, and helps form a seal inside the stuffing tube against water intrusion. This is the camp I currently belong to.

    However, the Spartan owners manual states that "the drive cable should be lubricated with the lightweight oil provided with your model".

    Now, we know some owners have run successfully using grease on the drive line (after modding the cooling system) so it would be fair to assume that grease isn't going to cause problems. But keeping an open mind to change, maybe there is a reason Traxxas recommends lightweight oil instead of grease. (going back to tolerances between the drive cable and stuffing tube liner).

    This would be easy to determine if someone has an AMP meter. Install the meter and run the Spartan up (no load) using the recommended oil on the drive line and check the AMP draw. Then grease the drive line, and run it up again to see if there is any significant change in AMP draw.

    To Close:

    If you feel that the drive line on your Spartan may be a source of additional drag on the motor, and possibly a contributing factor for overheating, check it for alignment, and damage to the drive cable, stuffing tube, and liner. If you have access to a temp gun, check the drive line temp while checking the motor and ESC temps after a run to see if anything looks out of the ordinary. (Sorry I have no idea what "ordinary" drive line temps might be, I have never checked them before)

    Kevin
    Last edited by dag-nabit; 02-04-2011 at 03:27 PM.

  3. #43
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    Now that is a well-informed, evenly-stated response. Thank you Kevin. We are all looking for answers. I don't disagree with anything you've said although I haven't seen "empirically" from those have modified and resolved heat issue also modified/altered the drive line. And you're right, we're all searching for answers...in our own way. We have all rushed to resolve the problem and have yet to isolate a singular problem. All input is good input. Some have found a solution that may not fit all conditions. The inconsistency suggests the same in quality control in production. Hey, its been fun though and a boost to the aftermarket industry!

  4. #44
    RC Turnbuckle Jr.
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    best way to solve the heat issues is open up the water pickup on the rudder and run bigger cooling lines
    the stock lines on my Spart are very very small.. not much water is able to flow though the stock cooling
    First MiniSlash
    HK6XL Revo 4s 60mph Amsoil dealer

  5. #45
    RC Qualifier
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    If u just do those mods as film described above, I read somewhere that the stock water jacket leaks from too much flow. Is that correct?

  6. #46
    RC Competitor
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    The problem is not the teflon liner nor the cable. on mine its alined perfectly from factory and there is no binding.I have inspected it after 6-7 runs and its like new.
    I did do some bench testing of the stock motor (no load) and I noticed it gets hot runing at any speed within a few seconds of running. Also its out of balance but at verry high rpms it stops vivrating and just makes a high pitched sound

  7. #47
    RC Racer
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    dag-nabit excellently said, I am of the same mindset and hope that none of my posts have offended anyone.
    I believe it to be in the best interests of the traxxas and boating community that this issue be solved easily and cheaply. The issue has many roots, I'm looking, as we all are, for the largest and easiest to solve.

    DESIGN: I believe that there is a design flaw in the spec'ing and mass production of the stuffing tube and liner. The brass stuffing tube has a high mirror like finish to the internal bore, most other boats I have dealt with have a natural finish. I also think that the ID&OD of the brass stuffing tube and liner were spec'ed incorrectly as the fit of the liner in the tube is not snug.

    DAMAGE: there is no apparent damage to the tube in my spartan, everything slides in freely.

    ALIGNMENT: There is no easy adjustment of the alignment of the stuffing tube and motor shaft, that being said there is no problem inserting the cable into the collet in my spartan. the only true way I see a miss alignment occurring is a warp in the power unit tray.

    LUBRICATION: I believe there is a problem with the lubrication method that traxxas has chosen, not to say that I don't understand why they choose it.
    my theory is that traxxas spec'ed a consumer safe food grade lightweight oil and I question it's water solubility.

    traxxas chose lightweight oil because of it's ease of use. grease can make a mess and if it is allowed to get where it shouldn't I could see it causing a problem. ex. the collet; I, and I'm sure traxxas, would question the standard individual's ability to properly clean the end of the flex cable to allow the collet to bite properly, without prior experience.
    Teflon has it's limits, I was thinking of when Proboat first released the miss geico. The first batch had a reverse rotation flex cable that caused the liner to attempt to extrude itself out the strut bearing. out of personal experience with the boat; overly lubricating it prevented the problem from occurring.

    PanamaJack: agreed the motor is horridly inefficient, but that's one big stump for traxxas to attack with all the setbacks they've already had. noise is usually a sign of a lack of lubrication.

    having said all this I betting on my dumb luck that my boat has no issues. radio has not lost it's mind as other recent ones, or Murphy's law will take affect and I'll have a flaming spartan 50 feet out. After everything thaws out, still no wet water for me

  8. #48
    RC Racer
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    one thing i have noticed is ware marks on the flex shaft in between the drive dog and strut bearing i have about a 10mm gap so that's telling me that the flex is binding up at least 10mm that's a fair bit. so if you don't have that decent gap in between the drive dog and strut you will defiantly going to have problems.
    Last edited by wilsta67; 02-05-2011 at 02:36 AM.

  9. #49
    RC Turnbuckle Jr.
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    Quote Originally Posted by Shaun78 View Post
    If u just do those mods as film described above, I read somewhere that the stock water jacket leaks from too much flow. Is that correct?
    oh wait, I think a decent water cooler is needed to?
    I'm going to try just spraying some WD40 on the stock water cooler and see if that gets it so seal up..
    but I do have an extra XL cooler lying around
    First MiniSlash
    HK6XL Revo 4s 60mph Amsoil dealer

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