frostic Posted June 9, 2014 Share Posted June 9, 2014 Bit of a n00b post here. Recently converted my X1-CR to brushless. After 3 runs the rotor shaft snapped, seemingly without warning. The motor and the ESC were both nice and cool to the touch (Not got a temp gun). A new rotor has been ordered but does anyone know any likely causes, so i can avoid this in future? If its any use the motor is a LRP Dynamic8 2200kv Quote Link to comment Share on other sites More sharing options...
big turbo Posted June 9, 2014 Share Posted June 9, 2014 (edited) Could of been a dodgy rotor/badly made as you can see the darker grey colour of the metal about 3 o'clock to 7 o'clock looking at the shaft stub with the little line bit coming off it. But that's just my opinion. Or maybe a stone got court up in the pinny and spur and that's what made it snap but doubt it as it's a 5mm shaft. Edited June 9, 2014 by big turbo Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted June 9, 2014 Share Posted June 9, 2014 Don't think you went wrong anywhere. Unless you had the motor come loose in the mount or some other serious failure....there is no reason why a motor shaft should just fail. Overly tight mesh can stress a shaft, but there are usually other symptoms too. Could simply be a bad shaft that has snapped. As far as avoiding repeats, just make sure the mesh is good and the bearings in the motor case are fine too. Quote Link to comment Share on other sites More sharing options...
pieman5 Posted June 9, 2014 Share Posted June 9, 2014 May seem a stupid question but were you using the correct pitch pinion gear? Quote Link to comment Share on other sites More sharing options...
Jaycool Posted June 9, 2014 Share Posted June 9, 2014 (edited) Sorry to jump on this thread - just wondering Nitroholic - What are the symptoms of an overly tight mesh which can stress a shaft? And is there a technique of doing a good mesh between the pinion on the motor shaft and spur gear? Thanks in advance - I am new to the brushless scene Edited June 9, 2014 by Jaycool Quote Link to comment Share on other sites More sharing options...
suicideneil Posted June 9, 2014 Share Posted June 9, 2014 Sorry to jump on this thread - just wondering Nitroholic - What are the symptoms of an overly tight mesh which can stress a shaft? And is there a technique of doing a good mesh between the pinion and motor shaft? Thanks in advance - I am new to the brushless scene The piece of paper trick works quite well- place a sheet of paper between the spur & pinion, then mesh them together, tighten the screws, and pull out the paper. This should leave a nice small gap & a perfect mesh.Personally, I use The Force; just eyeball & go by feel- there should be a tiny bit of play between the gears, not totally solid as such, so that you can rock the spur back and forth ever so slightly. Make sure you check the mesh by rotating the spur completely so that there are no tight spots at any point. 1 Quote Link to comment Share on other sites More sharing options...
frostic Posted June 10, 2014 Author Share Posted June 10, 2014 Thanks for all the replies. For pinion pitch I went for mod1 as that's what comes with the conversion kits. Is that wrong? Quote Link to comment Share on other sites More sharing options...
suicideneil Posted June 10, 2014 Share Posted June 10, 2014 Thanks for all the replies. For pinion pitch I went for mod1 as that's what comes with the conversion kits. Is that wrong?Nope, perfectly fine- it was more a question of is the pinion the same pitch as the spur I think ( 32p won't work with mod1.0 obviously ). 1 Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted June 11, 2014 Share Posted June 11, 2014 Personally, I use The Force; just eyeball & go by feel- there should be a tiny bit of play between the gears, not totally solid as such, so that you can rock the spur back and forth ever so slightly. Make sure you check the mesh by rotating the spur completely so that there are no tight spots at any point. I started off with the paper method.... but after you do it a few times, you quickly get a feel for the amount of play you need. 1 Quote Link to comment Share on other sites More sharing options...
AX10 Posted June 11, 2014 Share Posted June 11, 2014 Just changed motor on my Telluride, got a nice little rocking motion on the spur before it bites. Agree with Nitroholic about the 'feel' that all is well. Too tight will be sluggish to drive and whine a lot. STOP immediately, and loosen things off. Not later when you get home! Quote Link to comment Share on other sites More sharing options...
barnestah Posted June 11, 2014 Share Posted June 11, 2014 I've always done it like this. http://m.youtube.com/watch?v=G4TIMyAHrD8 Quote Link to comment Share on other sites More sharing options...
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