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Shaft Shearing Force

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frickenjoey

frickenjoey

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Misawa-shi, Aomori, Japan
RC Driving Style
  1. Bashing
  2. Racing
I have a little problem with shearing my rear/center driveshaft. I have twisted off two in a week making my Savage XSS a front wheel drive. The LRP .28 just likes to break stuff...lol. Does anyone know where I can get stronger dog bones or has tried the MIP CVDs. I can't keep breaking like this....it is such a PITA to have to replace them every time I go bash. Need something stronger.
 
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It only proves that you had fun.
Are they stock HPI parts? If so, I'll need to stock up on spares. When they snap like that, it's a sign of the metal being TOO hardened. There's no movement left, so they will snap.
From past experience with other parts, I would go with MIP.
 
Cool I will order me up a set of the MIPs then. Yes they were the stock bones. They do say they are hardened.....so it makes them brittle. That sucks. What can you do......I had to run around tearing up crap with the fronts only......looked stupid. I never had this problem with the stock engine....the LRP has retard strength....so to race to keep the front down I just kept gearing up... 19/47 is where I am at now....Now the driveline can't take it.....Hey that is that way it goes. Nickel and dime you to death
 
How do your cups look? Are they notched out at all where the dog ears rub? That will cause premature breakage as well. I'm sure the extra power isn't helping matters much.

Maybe loosen up the slipper a bit.
 
You could try putting a restricor venturi in the carb to take some of the bite out of that mill. Just a thought, then again screw it. Stick with the fun and keep wrenching on it when it breaks.
 
If it's shearing shafts like that, I know what my next engine for the savage will be!
 
frickenjoey said:
They do say they are hardened.....so it makes them brittle.
Click to expand...

They are all hardened. If they weren't, they would twist and bend. It's the degree of hardness and the carbon content of the steel that determines if they are super strong, or gone to the brittle side.
 
The diff cups are shot, I noticed that after the first broke shaft. Kinda sucks since the whole truck only has about a galon of fuel trough it. I did loosen the slipper.....then I started eating slipper pads. The stock HPI clutch shoes only lasted three tanks after break-in. The LRP is an aluminum clutch only engine...unless you change them every few days. Hey Heartbreak I would give the engine a shot....so far the only rigs here in Japan that have given me a run for my money is one with a Tamyia 5.2 in it. I have taken several OS .30 V-mods. So I guess I will just have to beef up the center shafts and see what breaks next......
 
When my F4.1 wears out, I'll do HPI's trade-in program. Or maybe even rebuild it and sell it. I'm sold on the F4.6, based on this thread. I don't want the truck to puke parts, I just want it to have massive grunt.
 
That's odd about the shoes not holding up for you. I have an LRP 28 S3 in my aftershock and I run HPI teflon shoes that I've lightened a bit (so they engage later). I have at least a full gallon on them so far with no problems.

I lightened them because I think the losi flywheel pushes the shoes out further in their resting position which makes them engage at a very low RPM. It would creep on idle. I drilled a few holes in the backsides of the shoes to make them lighter since I wasn't sure what springs are heavier than HPI's. Worked pretty good.
 

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