gear ratio's direct drive emaxx tranny

[sly118]

hi there , ive converted my UE - maxx to a direct drive centre gear from a ofna 1/8 buggy but now im stuck with matching a gear ratio , please help with suggestions , currently got 9L with 20 pinion and 66 spur and that was sweet , centre diff has 46 spur atm but ill have to wack a 51 tooth plastic spur on .. but what pinion ?? also have to keep in mind the ratio change from the tranny . b4 it was 1.75 turns of spur = 1 turn of output shaft , but now its 1=1

please help ?? mike ? any ideas ?

[Serum]

w[- lc0m[- 2 t|-|is f0ru/\/\ /\/\8!!,

;)

it sure took me some time reading your post, but I finally get what your saying (i'm foreign, don't blame me)

The best you can get is a 10 tooth pinion.. with how much cells are you driving your truck? (end ratio of 16.9 to 1 )

The ratios are somewhat limited with those centerdiffs!

[sly118]

yeh i was guessing 10 tooth would be anout right , ill probly also buy 12 t too .. one guy is running big maxxium plettenburg with 12/51 combo with similar drive setup .. i only running 12 cells , as that is what our rules say in racing .. i was also thinking of getting a 10L as it has lower rpm / v and i could run the slighty taller gearing . anyone else had any experiance? ( should be a bullet proof setup , drops 80grams off weight also lowers centre of gravity by heaps ,

[Serum]

I would use a 7XL on 12 cells with the centerdiff. (or on 14 cells as well)

[sly118]

have to see what i can come up with , i might look into adapting a stock 66 tooth spur to the ofna centre , and run a 12 t pinion as that equals 10/51 in mod 1 pitch ( but just noticed that mike only goes down to 14 t 32P 5mm shaft , damm migh just have to get a 10t and try it ..

[Serum]

Don't you know anyone with a lathe?

making the 3.2mm hole 5mm is rather easy..

I'm not sure how the pitch 32 gears hold up the power..

You could also get a 72 tooth spur (if that fits the frame)

[MetalMan]

At one point in time I was experimenting with using T/E-Maxx diffs on a custom monster truck with "direct drive" (just pinion/spur for reduction), and I found that for a Feigao 8L, even 12/72 was barely a low enough ratio. But that was with a motor spinning 40,000RPMs at full throttle. I gave up on that project due to the complexity of getting the custom bulkheads/a-arms/general parts machined well enough to fit together, while getting these parts for a low enough price.

[coolhandcountry]

Let me get this straight you running a 66 spur and 20 pinion with 1.75to 1 ration tranny. That would make the spur and pinion ratio at 3.3to 1 x 1.75 to 1 ratio = 5.775 ratio. Maxx bling ran a 56 ofna second gear spur. with 10 tooth pinion would put you at a 5.6 to 1. A slightest bit higher but with the weight lost should be good.

[Serum]

Yea, i don't see no problems either.

I am currently cooking a new project, it uses some words as ; centerdiff, 20cells, 9XL, savage suspension/drivetrain and a flat based design of frame.. (with less aluminum than my other cars, i need one for pure bashing..)

[coolhandcountry]

I like to see some pics of that serum. That sounds like it would be awesome.

[Serum]

I will start a topic about it, once i get my savage .. (it might take a week or two though..)

I don't know what to use for the frame, aluminum or CF, CF is nice but i have got no expreience working with it, my guess is it takes a high rpm with a small diameter bit to route it.. (just like epoxy board)

I am cooking on some plans as we speak, it will be low cg and a truggy like design (like a gmaxx converted emaxx) only with a longer frame, capable of holding 10 cells on each side

[coolhandcountry]

You going to shot for about he length of mine there serum. I can tell you it handles great. I will wait and see.

[sly118]

yes max bling running 56/12 but what is the specs on his motor , im sure it would out torq a 9L 2-pole , as his is 4-pole , and yes i could go bigger spur but that means grinding out the side of the chassis braces , and/or raising the diff centre , which puts a great angle on the drive shafts , also higher centre of gravity , i will get pics later and post them but i think ill have to just try with 51/10 and hope for the best

[coolhandcountry]

It will gear you up a little more. Try it. You may like that setup better now that you lost some weight. Have to let us know how it turns out.

[sly118]

oh i also run imex pinns , which are less diameter to stock maxx tryes ( eg bowties ) these pinns are awesome on blue groove / hard pack !!