Losi 2.0 Conversion

[Shark413]

Yeah I agree if 13T runs cool and 15T is ok, why would 14T cause temps to go high. I am thinking your on the right track on the gear mesh. The only thing that was different was the pinion and gear mesh. The buggy, spur and batteries were the same. What has me stumped is I tried the test two different times and had similar results (14T caused higher temps), I find it hard to believe I messed up the gear mesh twice and only when I tried the 14T pinion. Well, I plan on running the test a few more times.

13/45T - motor=128 degrees, battery=88 degrees
15/45T - motor=142 degrees, battery=98 degrees
14/45T - motor=176 degrees, battery=103 degrees

[Sower]

Or you can just say "screw it" and run the 15t

[Shark413]

Originally Posted by Sower

Or you can just say "screw it" and run the 15t

You know that's what I was thinking. The 15T feels pretty good, faster than the 13 or 14T setup. I am just concerned that the temps (142) well pretty good, would be too high when summer gets here. I like the temps the 13T pinion was giving me but I like the speed the 15T was giving me. I figured 14T would be in the middle and be perfect, but for some reason I am seeing the highest temps with a 14T setup.

What was the kv of the motor in question here?

[Shark413]

Originally Posted by Electric Dave

What was the kv of the motor in question here?

Dave, it is the MMM 2650kv motor.

[Shark413]

I am a little worried because the Losi support site recommends a 13 or 14T pinion with a 45T spur on 4s and that is with there Xcelorin 2400kv motor, and I am using a MMM 2650kv motor which is even hotter.

[Shark413]

Losi is not helping much either, in the Excelorin combo manual they say you should use a 14t Pinion with a 45T spur on 4s in a buggy using the 2400kv motor. In the 8ight-E manual they say you should use a 13T and finally the conversion kit comes with a 15 and 16T pinion (but with no recommendations on what to use). Kind of confusing. I think I will go back to the 13T just to be on the safe side.

Going back to a steel spur?

Do you really think 2 teeth will make that big a difference?

Time will tell I suppose.

[Shark413]

Originally Posted by Electric Dave

Going back to a steel spur?

Do you really think 2 teeth will make that big a difference?

Time will tell I suppose.

Dave, it's probably just me but I stripped the Losi plastic spur after about 5 packs. So yeah I think I will be going back to steel, the Losi spur cost as much as a hardened pinion and when using the Robinson wide spur the steel pinions last a long time. Without a slipper the spur takes a beating, both during acceleration, braking and I just had too many failures using the plastic spur which could cause a DNF during a race. Also, the 47T spur will allow me to use slightly bigger pinions which will last longer (more surface area/teeth).

That is unfortunate news. I just got my new 8T 2.0 and converted it ( http://www.rc-monster.com/forum/showthread.php?t=19101 ) with a Losi plastic Spur. I can't stand the sound steel on steel makes and was hoping the Losi would be as durable as my old Kyosho's were on my CRT.

Did you burn up only one? Any chance it was just some bad plastic?

[Shark413]

Originally Posted by Electric Dave

That is unfortunate news. I just got my new 8T 2.0 and converted it ( http://www.rc-monster.com/forum/showthread.php?t=19101 ) with a Losi plastic Spur. I can't stand the sound steel on steel makes and was hoping the Losi would be as durable as my old Kyosho's were on my CRT.

Did you burn up only one? Any chance it was just some bad plastic?

Dave, the gear failure was kind of strange. I ran Kyosho plastic gears in my truggy/buggy and what would happen is I would knock off a few teeth from either landing with the throttle on or heavy braking coming off a big jump (both are mistakes). With the Losi spur it looks like it melted, or at least the plastic softened. I had an issue with my last run of the day (when the spur gave out) where one of my eagle tree sensor wires got caught in the rear drive shaft. This could have caused binding, heated up either the motor/center diff causing the spur to get soft. I didn't temp the motor on the last run because the sensor that got ripped out was the motor temp sensor, and by the time I temp'd it with my handheld Raytek it had been sitting for a while and cooled off. Until I hear more feedback on how the Losi plastic spurs hold up I will stick with my steel spur. I am also going to try a 2200kv motor to see if I can get my temps down to an acceptable range.

Originally Posted by Shark413

Dave, the gear failure was kind of strange. I ran Kyosho plastic gears in my truggy/buggy and what would happen is I would knock off a few teeth from either landing with the throttle on or heavy braking coming off a big jump (both are mistakes). With the Losi spur it looks like it melted, or at least the plastic softened. I had an issue with my last run of the day (when the spur gave out) where one of my eagle tree sensor wires got caught in the rear drive shaft. This could have caused binding, heated up either the motor/center diff causing the spur to get soft. I didn't temp the motor on the last run because the sensor that got ripped out was the motor temp sensor, and by the time I temp'd it with my handheld Raytek it had been sitting for a while and cooled off. Until I hear more feedback on how the Losi plastic spurs hold up I will stick with my steel spur. I am also going to try a 2200kv motor to see if I can get my temps down to an acceptable range.

Well, in a few more weeks off-road should begin here in the northeast and I'll be happy to give you feeback on the Losi spurs. I plan to try them in both buggy and truggy and hope for the best.

[Shark413]

Originally Posted by Electric Dave

Well, in a few more weeks off-road should begin here in the northeast and I'll be happy to give you feeback on the Losi spurs. I plan to try them in both buggy and truggy and hope for the best.

Dave, yeah let us know how your vehicles perform. As for me I am going to switch to a lower kv motor. The 2650kv just runs too hot for SoCal summers, so I am dropping down to a 2200kv motor which I have used in the past with good results (performance ans temps).

[Shark413]

Update:

I have been using my MMM 2650kv motor for the last month or so and just have not been able to get any consistant temps. No matter what gearing I tried the temps seemed higher than they should be. So I decided to change out the motor for a 1515 size. I had a spare TeknoNeu 1515/1.5D, so I decide to install this into my buggy. The TeknoNeu 1.5D I have is a square can, so I had to remove some of the material from the side of the can. I have found that the 1515/1.5 runs cooler and I can use more gearing options because of the added torque. The extra wires are for my Eagle Tree data logger sensors, they are just temporary and will be removed once I get the motor/ESC/Battery temps where I want them. Also I mounted a 40mm fan to the top of the motor to help with the cooling.

[SpEEdyBL]

It was running cool before, wasn't it? For me I don't see how gearing the 2650 with a pinion larger than a 12 tooth (40 mph) would be suitable for racing, given the fact that most people like to run 2000 kv motors on 4s.