another bash, another breakage...

xlDooM

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My amp hasn't had a good run lately. First the servo went, then the dreaded shoulder screws, now the driveshaft. I was driving it very hard over some grassy knolls, not dissimilar to full-throttle jump landing. Still, didn't expect to break this part with the stock motor... Now I have to see what alternatives there are.
cvjoint.jpg
 
Doesn't matter how powerful your rig is, landing on full throttle will eventually do damage....

On the plus side, time for upgrades!
 
Tower Hobby has the Hot Racing SECT288 in stock. They are holding up well on my son's Ruckus with brushless power.

Side note, they do not fit Boom Racing rear hubs... but fit excellently on stock.
 

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Alright so that's option #1. The downside is that I'm in Europe and shipping is a bit steep for hot racing parts.

It seems traxxas rustler 4x4 rear driveshafts will work with a bit of drilling and sanding. Part #6852X. I'll check the LHS, they have a lot of traxxas parts in stock, and it's probably a good deal cheaper if it doesn't need to be shipped across the pond.
 
Shipping is about $12. I appreciate your offer, not sure you can beat that though ;) let me know if you got cheaper options, and I'll get back to you when I've been to the LHS.
 
I have. It didn't make too much sense to me but I'll see it when I have the part in my hand I think.
 
Fixed the driveshaft today. So what I bought was 2 x Traxxas 6852x. These are the heavy duty rear driveshafts for the Slash 4x4, and according to the internet they are an upgrade over the stock VXL shafts, which are themselves an upgrade over stock ECX shafts.
6852x.jpg
First thing I noticed was that on the Traxxas driveshafts, the outer tube connects to the wheel side instead of the motor side. So you can't swap just half of the shaft, it's all or nothing. But when you look at the Traxxas axles, you see that they are different.
axles.jpg
The thread end is the same diameter, and the bearing end is the same diameter, but the ECX axle has an intermediate part so it shores up against the inside of the hex, which has different diameter inside and outside holes. Here's the hex from both sides.
hex2.jpg hex.jpg
The solution is simply to drill out the hex with a 5mm bit.
drilledouthex.jpg
Next problem is on the motor side. The Traxxas shaft has two little plastic tabs to align it on the diff shaft, which won't work with the round ECX diff shafts. Also, the traxxas motor side cup is not deep enough to slide over the diff shaft far enough to use the lock pin.
drillout.jpg
Both problems are solved by drilling out the motor side cup all the way through to the ball, again with a 5mm bit. You may also want to shave just a bit off the inside collar, as the plastic has some manufacturing debris on it and it is slightly longer than the ECX collar. I took off maybe a quarter millimeter with a cutter. Then it slides on fine. CAUTION: the Traxxas lock pin is not a metric size. The tiny hex key you get with your ECX will fit, but it is a bit loose and you risk stripping out the lock pin. What you need is a 1/16" hex key.

One final note: the Traxxas axle is slightly shorter. It will only *just* reach the rubber lock ring on the wheel nut. Traxxas put some blue locktite on it, I put some extra on it just to be sure. Here you can see the thread reach.
threads.jpg

I put a battery pack through it and it held up fine, but then again the stock shaft held out fine for maybe 30 packs so time will tell if this really is a more solid option.
 

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i know this is an older thread but my grandson broke 2 shaft ends in a row after upgrading to brushless. i thought it was because he was on the throttle landing jumps but i discovered the slipper wasnt slipping. i backed off the nut all the way and it still would not slip. it finally broke loose, it was like they had it glued.
 
Your onto something, slipper adjusting and "Finger Control". The throttle is adjustable also. ??
 
Your onto something, slipper adjusting and "Finger Control". The throttle is adjustable also. ??
yep slippers save gears and shafts. ive also run the slipper too loose on high power and melted the plastic spur on a slash.
 

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