LOSI 8T 10S Rocket........... - RC-Monster Forums

killajb · 12.04.2008, 01:35 PM

I agree.. A few weeks ago I purchased a used Lehner with supposedly "10 hrs" of runtime on it. Well, when the motor arrived one of the bullet connectors fell off after I removed the heatshrink! I was changing the bullets anyway to match my ESC, but that was a sure sign of foul play. In addition, the leads were all discolored and when I finally attempted to run it, the thing smoked~

I purshased my 1515 2.5D new and it's flawless. I purchased a 1515 2D new from TeknoRC and first ran it with 6S and an 18-tooth pinion on my Hyper 8. I only ran down the street, turned around and hauled back but the motor was getting pretty warm so I shut it off. I've since switched to 4S and a 14-tooth pinion, perfect temps and ideal for track use anyway.

I don't think I'll ever buy a used brushless motor again for fear that someone else will just ignore caution and beat the crap out of it.

speedracer1129 · 12.04.2008, 02:59 PM

Quote:

Originally Posted by killajb

I agree.. A few weeks ago I purchased a used Lehner with supposedly "10 hrs" of runtime on it. Well, when the motor arrived one of the bullet connectors fell off after I removed the heatshrink! I was changing the bullets anyway to match my ESC, but that was a sure sign of foul play. In addition, the leads were all discolored and when I finally attempted to run it, the thing smoked~

I purshased my 1515 2.5D new and it's flawless. I purchased a 1515 2D new from TeknoRC and first ran it with 6S and an 18-tooth pinion on my Hyper 8. I only ran down the street, turned around and hauled back but the motor was getting pretty warm so I shut it off. I've since switched to 4S and a 14-tooth pinion, perfect temps and ideal for track use anyway.

I don't think I'll ever buy a used brushless motor again for fear that someone else will just ignore caution and beat the crap out of it.

I agree, no more used stuff!! I am pretty picky about my stuff and I would feel bad if I was on the other end! I have spoken to a few companys already about the situation and they all seem to be on the same page that something happened to the motor before I got it. It seems that the a magnet came loose and rubbed against the can.

Oh well, I already spoke to Medusa and I am going to throw in a 80mm 1600kv when they come in.

jhautz · 12.04.2008, 08:05 PM

So you dont think that running the motor at its rpm limit and haveing the Center dif gears get chewed up when the dif bearing failed could have put any stress on the motor bearings? Seems pretty coincidental to me that the motor failed the next time you ran it. I wouldn't blame the guy you bought it from or the motor itself. Anything will break if you push it to its rpm limit and then add additional stress of chewing up gears. Thats the price you pay for pushing things to their bleeding edge IMO. You would have probably ruined a brand new motor doing that too.

speedracer1129 · 12.04.2008, 09:00 PM

Quote:

Originally Posted by jhautz

So you dont think that running the motor at its rpm limit and haveing the Center dif gears get chewed up when the dif bearing failed could have put any stress on the motor bearings? Seems pretty coincidental to me that the motor failed the next time you ran it. I wouldn't blame the guy you bought it from or the motor itself. Anything will break if you push it to its rpm limit and then add additional stress of chewing up gears. Thats the price you pay for pushing things to their bleeding edge IMO. You would have probably ruined a brand new motor doing that too.

j,

I understand what you mean but here is the thing. I have confirmed with both Medusa and Neu on my situation yesterday. Both of them stated that the setup was not the problem. I am not pushing the motor to it's "limit". The motor is rated at 60k continuous use max, not it's absolute max. On paper, the setup pushes slightly over 60k, but in the truck it will only about 45-50 so I am in no danger as far as that is concerned. The fact when I tested the motor with the wheels off the ground I was getting high heat already. Funny thing is that I got 2 different answers on that. Medusa said it was possible that the motor would get to those temps in that scenario. Neu told me that that was happening because a magnet was already rubbing in the can due to something from before. They both did say that it seems that the motor failed due to a magnet or magnets becoming loose and rubbing internally which caused the failure once it tried to pull the weight of the truck. Lastly, the center diff gears don't exist in this truck....In other words, this truck has a custom solid spool that uses a plastic spur gear on it...that is it! If you are picturing a bunch of chewed up metal, that is not what happened. If it was, we wouldn't be having this conversation!!

jhautz · 12.04.2008, 10:08 PM

Quote:

Originally Posted by speedracer1129

j,

I understand what you mean but here is the thing. I have confirmed with both Medusa and Neu on my situation yesterday. Both of them stated that the setup was not the problem. I am not pushing the motor to it's "limit". The motor is rated at 60k continuous use max, not it's absolute max. On paper, the setup pushes slightly over 60k, but in the truck it will only about 45-50 so I am in no danger as far as that is concerned. The fact when I tested the motor with the wheels off the ground I was getting high heat already. Funny thing is that I got 2 different answers on that. Medusa said it was possible that the motor would get to those temps in that scenario. Neu told me that that was happening because a magnet was already rubbing in the can due to something from before. They both did say that it seems that the motor failed due to a magnet or magnets becoming loose and rubbing internally which caused the failure once it tried to pull the weight of the truck. Lastly, the center diff gears don't exist in this truck....In other words, this truck has a custom solid spool that uses a plastic spur gear on it...that is it! If you are picturing a bunch of chewed up metal, that is not what happened. If it was, we wouldn't be having this conversation!!

I cant help but wonder if the 30k rpm separated the magnet or the 60k rpm.... Hmmm

speedracer1129 · 10:53 PM

Quote:

Originally Posted by jhautz

I cant help but wonder if the 30k rpm separated the magnet or the 60k rpm.... Hmmm

j,

Who knows but I will say this. I think we will all agree that a Neu is a better quality motor than a Mamba yes??

With that said, I have personally pushed AND measured several Mambas pushing the 58-62k range while in a car pushing 100 plus on my data logger. If they can take it, I am pretty sure the Neu would as well. Of course, there is always the token black sheep that slips through the QC cracks