work

iTrader: (1)

Is this normal wear on the square alum drive cups? I got it new, raced it once with 23t. This wear only happened on the rear, the front still looks new

Dongskie

iTrader: (44)

WORK: Normally yes... why? basically because of the law of physics apply.

The motor turns the spur gear and the spur gear turns your cup, the load is then applied to the rear cup into the shaft and the front diff.. the wear is at its heaviest when the front wheels are turned (steeering) and when throttle is applied simultaneously...

Since the speed of rotation of the front and rear differentials differ during turning, much of the load is then applied to the rear cup because most of the power comes from the spur gear... A slight slack can also add to this wear.

floodo1

the hara edition comes with purple front input shaft (still uses plastic gear), and purple rear input shaft with integrated spur gear mount (still uses plastic gear)

the 2005 edition (japan) comes with silver input shafts that have integrated bevel gears. the rear shaft does NOT have integrated spur gear adapter, so it uses the reg spur gear adapter plate.

both hara and 2005 shafts are alum.

the purple shafts on the hara car have ALWAYS been availabe for the pro4 as a hopup.

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now which one to use?
if you're going through front bevel gears a lot you MAY want to get the front alum bevel gear. this will keep that gear from braking, but may cause you to go through diff gears

in the rear there seems to be NO reason to use the alum bevel gear. so using the purple hara shaft is a better idea. not to mention the spur gear mounting plate is integrated on the purple shaft so its a win win.

the alum bevel shafts are avail individually, however the purple shafts are sold only as a set.

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furthermore aftermarket companies (TiR & Square) sell titanium front input shafts, which should be lighter than the purple alum part.

floodo1

in my experience with the alum center drive cups i have NOT seen that much wear. i run 19t almost exclusively (D5 19t arm, handwound 24deg timing). i also use kit alum center shaft.

first off LUBE YOUR CENTER SHAFT. this is FAR less critical then dogbones (which see more angular movement), but still helps out some.

i'm really not sure why your cups are wearing so much. it must be that your shaft pins do not fit so well, or something. that is very wierd considering my experience with the drive cups.

are your drive cups HPI or some other brand?

and im not clear, but you say that much wear happened after only ONE race day? the cups had no wear prior to that?

AngryAsian

iTrader: (4)

Ahhhh....

i was just hoping to get rid of some of the slop! there seems to be a decent about of wind-up before all the seperate transmission parts are torqued enough for the car to launch. I put it down to the number of pins used to keep the gears and adaptors on the shafts. (I can only assume this gets worse with wear)

Using either the one-piece spur adaptor-shaft or the alu bevel gear shafts would eliminate some pins... and using the alu drive cups should eliminate any further slop from an ill-fitting plastic centre drive cup.
The only "free" pin would then be the spur adaptor... but a single pin versus 5 is a good reduction.

N.B my outdrives are in good condition, as are my cvd's and diffs so hopeuflly i've got all bases covered!

Wow.. those centre cups wear fast! You sure that's normal! kinda scary... my stock ones although not really true to the centre of the shaft show jack all wear and tear. Must be that they can flex and absorb some force?

work

iTrader: (1)

Thanks for that explanation. I'll bring the car over so you can help me eliminate some of the slack. Such a waste of bling if this wear continues

work

iTrader: (1)

I got the HPI graphite shaft used but in very good condition. Even before the race it was a perfect fit on the Square drive cups. Its the first race on a brand new car. I'll try swapping out the Graphite shaft cause I have a new one but I dont think that it might be the culprit.

Does HPI have the alum drive cups? I got the Square brand cause I had no problems with any of their products before. Maybe its made of softer material compared to the HPI. Any thoughts

Yup only one race. Everything was brand new except for the graphite shaft.

work

iTrader: (1)

I know, didnt expect this after only 1 race

AngryAsian

iTrader: (4)

you're using the "Square" units huh...

Those were the one's i was going to order preferrentially over the HPi units because they have 4 cutouts. I figured if they wore i'd do a flip and they'd be good again.

Actually, to be honest i thought they mix flex a little more than the hpi units (only two cutouts and more solid looking - heavier too i believe) and maybe lessen the wear.

might hold off until soemone with experience of the HPI units gives us some feedback!

floodo1

i have the actual HPI units. they also have 4 cutouts...2 positions.

perhaps the square units are of a softer material. not really sure.

thats an odd problem man, good luck, looks like you'll need it

Oasis

iTrader: (38)

Pro4 was fast last night..

floodo1

yeah pro4 can even beat ppl on foams sometimes

hahah nice that i finally have a setup that works decently got rid of all but the slowest speed oversteer!

yay for one-ways

fjm9898

iTrader: (11)

oneway with foam

Oasis

iTrader: (38)

I should have said Pro4's..

floodo1

hahah no no mike and i ran rubber tires (him with diff, me with oneway) against a guy with a non pro4 with foams