Gearbox ratios?

[Jamus]

Does anyone happen to know the reduction ratios of the planetaries in the 1:18 axles? Even a ballpark estimation would be helpful. I'm planning on getting the Tamiya gearbox to use as planetaries for a lower low. Here's the link if you haven't already seen it. And to give props where they're due. http://www.toyotaoffroad.net/afertig/88/nylintredux.htm
Anyway, I see the Tamiya gearsets are 4:1 or 5:1 and was wondering how much of a difference there was. I'm thinking it may be too mch gear, might go with the 4:1. Or I could not know what I'm talking about, entirely possible.

[low_range]

I was wondering the same thing. I just finished putting the 5:1s in mine (in prep for 2.2s), and high range is now about as low as Low used to be. Low is loooooow
I was wondering what the ratio of the initial white planetary is; id swap them out for the extra 4:1s w/o thinking twice if i knew for sure it would get me a lower crawl ratio.

[getbent]

i just did my rear axle and the initial white planetary is a 5 to one. i was curious

too so i counted revolutions of input and output. as far as the other planetaries

it doesn't really matter because the white one is the only one you could swap.

[bigtimecrawlers]

i just did it the old way and bought 2 jeeps to start with and scraped one... just add one black planatary to each axle...

[low_range]

Originally Posted by getbent

i just did my rear axle and the initial white planetary is a 5 to one. i was curious

too so i counted revolutions of input and output. as far as the other planetaries

it doesn't really matter because the white one is the only one you could swap.

Oh well. Thats ok, its still pretty low.
Whats the formula for finding the gear ratio of a planetary? im not real hip to this r/c stuff.

[Jamus]

I have recently been learning about automatic transmissions in prep for a rebuild. I'm still hazy on planetaries, but reading about the auto tranny helped some. You can achieve more than one ratio depending on what part is held, opwered, or spinning freely. Another example is newer transfer cases. They have 2 gears with 1 planetary assembly. I know, this doesn't help, but that's why I had to ask in the first place. I guess it'll be trial and error. That usually works better in the real world as opposed to theory anyway.

[AdamF]

The nylint redux box starts with a 4.1 gear, and then 2 5.1 gears.


You can't add a 4.1 instead of the 5.1 using the tamiya gears. It's hard to explain, but trust me on this one. The inputs and outputs won't match up.

[Jamus]

OK, maybe a good thing I haven't ordered yet. This is what I was thinking, and you can tell me I'm wrong, haha. The math looks like the Tamiya gearbox has 2 4:1 and 2 5:1 planetaries for a total of 4, enough for 2 pair of axles or 2 vehicles. Is this right? I was thinking I could use one Tamiya box for 2 different vehicles.

[getbent]

OK guys I lied to you the initial white planetary is a 4 to1, the black is a 5 to1.
So using the tamiya 5:1 will give you the same reduction as adding a black planetary from another nylint, only alot cheaper.

ADAMF, I haven't actually driven it this way, but I tried putting the 4:1 in instead of the 5:1, and it worked if you put it between the motor and the first white planetary.
the pinion gear on the motor will spline into the tamiya 4:1 gearset and the tamiya
output will spline into the white planetary on the nylint, making the white one the second in the line up.

So as far as building two nylints with one tamiya gearset, I am 99% positive it can be done. I just built mine with the 5:1's and i am going to put the 4:1's in a friends jeep
later, if it doesn't work i wiil let you know.

hopefully this wasn't too confusing, but i described it the best i can.

[low_range]

Yeah, one box is enough to build one jeep (or scorpion), since it comes with two 5:1s. youll need to get a couple screws though; the kit comes with 3 that are long enough to use, but youre gonna need 6 (3 for each axle).

AdamF...i assume you mean that the input spline count is higer for the 5:1, meaning that youd have to change the drive gear on the motor?

[getbent]

just drove mine after the loooooow gear mod and you guys weren't kidding, holy cow that thing is waaaaaaaaay lower than before. it is almost too slow unless you have a tight technical course. Not to worry though because you still have the same factory low if you want it. Needless to say there is a lot more control in supa-low range.

i don't have any formula for figuring planetary ratios, i just know that 4 to 1 means that the input spins 4 times to every one turn of the output. So i simply marked the input and output and counted how many times i had to turn the input to get the output to turn once. 4 turns input gear, one turn output gear = 4 to 1 ratio.

[Jamus]

So then, you did get the 4:1 gearset to work? If so, buying one gearbox would give you and extra 4:1 for one truck and 5:1 for another. Need to know for sure if one gearbox will do 2 vehicles before I order. Thanks for all the input guys.

[hotchi]

so, if u are using a hobby grade radio u dont need to do this???

cause i dont really now if i need any more torque. and i can ease onto the throttle

[getbent]

if you are using a hobby grade radio and speed control then there is no need to do this mod. i have one that i four linked and switched to hobby electronics and i definitely don't need any more torque with 2.2 moabs. works awesome!

i am going to try to swap in the 4 to 1 gears into my stock nylint tonight, the 5 to 1 is just too low. i will let you guys know if it worked and if i like it better than the 5:1.

[getbent]

ok i did it, i put the tamiya 4;1 planetary in instead of the 5:1. i like it better, not a huge difference from the 5:1, but it moves a LITTLE faster and i think its just about right. the 5:1 was just too slow.

anyway there was some doubt about the tamiya 4:1 fitting, not a problem, just put it between the motor and the nylint white planetary. i will try to explain it where there is no confusion. here is the line up: nylint motor-tamiya 4:1 planetary-nylint white 4:1 planetary-nylint black 5:1 planetary-nylint yellow 5:1 planetary. hopefully this will help some. BTW thanks to you guys you have all given me a lot of good ideas for my semi stock build up!!!

[getbent]

oh, and Jamus, yes you can build two jeeps with one tamiya set.two axles with 4:1 and two axles with 5:1.

[Jamus]

Great, thanks for the clarification. Guess I'll order monday.