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  1. #1
    RC Turnbuckle Jr.
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    Gear pitch, Mod?

    Can someone chime in on this. What is the benefit of running 32 pitch gears instead of 48. Also what is Mod 1 or .8. What does all this mean. Does it add to strength, more options?



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  2. #2
    Marshal ksb51rl's Avatar
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    Gear pitch, Mod?

    Quote Originally Posted by Gripdog7205 View Post
    Can someone chime in on this. What is the benefit of running 32 pitch gears instead of 48. Also what is Mod 1 or .8. What does all this mean. Does it add to strength, more options?
    Not much, so long as you know how to set your gear mesh and are certain that it will remain as you set it.
    Simplified, 48P, 32P, 0.8 mod, and 1.0 mod are measures of gear tooth size and are referenced to one inch or 25.4mm of pitch diameter. They express a ratio, with the P numbers being the numerator (top number) of the fraction and 25.4 being the denominator (bottom number) OR the mod values being the denominator and 25.4 being the numerator. So:
    48P/25.4 = 0.5288m
    32P/25.4 = 0.7938m
    25.4/0.8m = 31.7653P
    25.4/1.0m = 25.4P

    I have listed them in order of ascending tooth size. Having larger teeth does lend more strength and a certain amount of mesh forgiveness, but it also reduces efficiency. On a severely overpowered Rustler or Bandit, switching to 32P/0.8 mod or even 1.0 mod may be necessary for spur gear longevity, but you'll likely have to upgrade all other driveline parts before you must make the change.
    I KNOW others will disagree. (And that's O-KAY.)
    Last edited by ksb51rl; 01-19-2017 at 07:44 PM.
    Alt-248 on the number pad =

  3. #3
    RC Turnbuckle Jr. Petertje60's Avatar
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    Nice explanation. Fully agreed
    Nobody is born with experience

  4. #4
    RC Turnbuckle Jr. JerrysMaxx's Avatar
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    To add to KSB's excellent explanation......

    "Pitch" is the standard/imperial term. "Module" is the metric term and is calculated slightly differently. Module is the millimetres-of-diameter per tooth, rather than teeth-per-diameter used with Pitch.

    0.8-module (sometimes abbreviated to mod-0.8, Module 0.8, or 0.8M) means the tooth is 0.8mm in diameter for each tooth, so a 100-tooth gear would be 80mm in diameter.

    With Module, lower numbers (0.6, 0.4) means lower diameter for a given tooth count (finer teeth) and higher numbers (0.8, 1.0) mean larger diameter for a given tooth count (coarser teeth).

    Bigger teeth (lower pitch or higher module) are stronger, but noisier and since you have to move in 1-tooth increments when changing gear ratio, the available ratios can't be tuned as finely. Finer teeth are quieter and more finely-adjustable, but aren't as strong.

    0.8M and 32P are practically identical in tooth size, and these are the only compatible sizes between metric and standard (in common use with RCs). All other modules/pitches commonly used in RC are not compatible with any other. If you come across a "metric 48P" then it is NOT compatible with a true standard 48P.

    Common pitch per vehicle type:
    - 1/8th electric and nitro: 1.0M
    - 1/10 nitro: 1.0Module or 32P/0.8M
    - 1/10 electric 2WD offroad: Usually 48P. High-power brushless conversions often convert to 0.8M/32P to handle the extra torque
    - 1/10 electric 4WD offroad: Often 0.8M/32P
    - 1/10 electric onroad: Often 48P, but 0.6M for many Tamiya and some others. Sometimes 0.4M or 64P for higher-end cars.
    - 1/16 and 1/18: 48P or 0.4M. I'm not so sure about these smaller cars, though.
    T/SportMax/Slayer Pro/Bandit
    Stampede/Rustler

  5. #5
    Marshal ksb51rl's Avatar
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    That's an addition?!? You burned down my nice little house and built Versailles on the ashes! Great job.
    FWIW, Robinson Racing Products makes pinions in both 32P and 0.8m. I don't know if they're actually different or if they just claim to be. I've used both successfully with Traxxas spurs.
    Alt-248 on the number pad =

  6. #6
    RC Turnbuckle Jr.
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    Thank you that does explain the Mod gearing. I am now informed. Thank you both


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  7. #7
    RC Turnbuckle Jr. Petertje60's Avatar
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    The difference between 32P and 0.8M is less than 1%. I wonder if you will ever notice that.
    Nice Versailles addition, Jerry
    Nobody is born with experience

  8. #8
    RC Turnbuckle Jr. JerrysMaxx's Avatar
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    Thanks but the only credit I can take is the extensive research I have done since I have been in the hobby. This was one I found years ago and saved. I'll take credit that I am an info junkie

    KSB you are far more advanced than me and I have learned a lot from you. Got lucky I guess.
    T/SportMax/Slayer Pro/Bandit
    Stampede/Rustler

  9. #9
    RC Turnbuckle Jr. Petertje60's Avatar
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    Lol. The info junkies are often the ones that can help out other people.

    I have always had this link in between my RC links: http://www.metrication.com/engineering/gears.html
    Nobody is born with experience

  10. #10
    RC Turnbuckle Jr. JerrysMaxx's Avatar
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    Quote Originally Posted by Petertje60 View Post
    Lol. The info junkies are often the ones that can help out other people.

    I have always had this link in between my RC links: http://www.metrication.com/engineering/gears.html
    WOW that link is way out of my league. Math was never one of my strong points
    T/SportMax/Slayer Pro/Bandit
    Stampede/Rustler

  11. #11
    RC Turnbuckle Jr. Petertje60's Avatar
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    Quote Originally Posted by JerrysMaxx View Post
    WOW that link is way out of my league. Math was never one of my strong points
    Lol. Just multiply or divide
    Nobody is born with experience

  12. #12
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    Can anyone tell me if my 1.0 Metric Pitch 20 Pressure Angle Spur Gear will work with the 28-T Pinion Gear, 48P I just ordered?

  13. #13
    RC Turnbuckle Jr. Petertje60's Avatar
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    Quote Originally Posted by Johnit99 View Post
    Can anyone tell me if my 1.0 Metric Pitch 20 Pressure Angle Spur Gear will work with the 28-T Pinion Gear, 48P I just ordered?
    M1 (25.4P) won't work with 48P (around M0.53).
    Nobody is born with experience

  14. #14
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    Ok, all this info has got my head spinning. I feel like Spicoli "i'm so wasted, that's my skull!" So to clarify, as an example no matter what pitch or diameter of the resulting gear is a 20 tooth pinion and a 60 tooth spur will give you the same effect except for maybe a small loss in efficiency with the larger pitch gears?

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  15. #15
    RC Qualifier ElectricPropils's Avatar
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    Thank you guys so much for the info, you learn something new every day!
    The present is theirs; the future, is mine.

  16. #16
    RC Qualifier ElectricPropils's Avatar
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    Quote Originally Posted by dgechrgr469 View Post
    Ok, all this info has got my head spinning. I feel like Spicoli "i'm so wasted, that's my skull!" So to clarify, as an example no matter what pitch or diameter of the resulting gear is a 20 tooth pinion and a 60 tooth spur will give you the same effect except for maybe a small loss in efficiency with the larger pitch gears?

    Sent from my VS996 using Tapatalk
    No, the gears need to be almost exactly the same pitch or else they won't mesh properly.
    The present is theirs; the future, is mine.

  17. #17
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    Yes, i understand that, but the overall determining factor is gear count. One style pitch has no numerical advantage over another is my question. But now that i've had some rest i believe i know the answer.

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  18. #18
    RC Champion grizzly03's Avatar
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    Quote Originally Posted by dgechrgr469 View Post
    Yes, i understand that, but the overall determining factor is gear count. One style pitch has no numerical advantage over another is my question. But now that i've had some rest i believe i know the answer.
    Yes you have it right. 10T pinion/60T spur in a 48p has the same ratio as 10T/60T in MOD1. Or any other gear pitch. The ratio will stay the same.

  19. #19
    RC Qualifier ElectricPropils's Avatar
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    Quote Originally Posted by grizzly03 View Post
    Yes you have it right. 10T pinion/60T spur in a 48p has the same ratio as 10T/60T in MOD1. Or any other gear pitch. The ratio will stay the same.
    There you go, I was having trouble understanding what he was saying.

    Just know that if you have a different pitch your gears will be different sizes. If you try upgrading the size of your teeth then you will have to make sure that the gears you are converting to can still fit in your transmission. Though if you are buying ones that specifically fit your model then I don't see why they wouldn't fit without modification.
    The present is theirs; the future, is mine.

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