I need an opinion on my setup - RC-Monster Forums

crazyjr · **I need an opinion on my setup -** 06.20.2007, 11:29 PM

Actually i think i know what to do, But value you're opinions and follow them when given.

My associated rc10T4 has a 4600 mamba package with 23/87 gearing running 2s 8000 maxamps packs. I ran it for about 30 minutes today and remembered to grab the temp thing, to see how it was actually running. Over the 30 minutes the motor temp was about 160 to 170 and the esc was around 120. Am i running too high a gear? Over the half hour run it never got higher or fluctuated, power was awsome and never thermaled. Should i go two teeth smaller on pinion? or, Is it good the way it is?

skellyo · 06.20.2007, 11:42 PM

Sounds like you're undergeared a bit...a taller pinion of a tooth or two should lower the motor temp and bump up the ESC temp a little. However, if you're happy with the power, the temps are well within normal ranges.

crazyjr · 06.21.2007, 12:29 AM

The track was a little slick and there was a lot of wheelspin. I am as big as i can go without serious mods, pinion wise. I guess i need a smaller spur. I am running a 4 tooth pinion bigger than stock recomendations and its undergeared? ;)

skellyo · 06.21.2007, 07:20 AM

Yep, apparently so. Maybe drop to 84T spur and keep the 23T pinion. That will help a little, but a 24:84 might work out even better.

sleebus.jones · 06.21.2007, 08:24 AM

Yup, undergeared. Hot motor and cool ESC = undergeared. I agree with skellyo, if you are happy with the performance, I don't see any reason to change. Temps are definitely fine where they are.

Sleeb

06.21.2007, 10:24 AM

It sounds to me like you have a good combo going with room to gear up if you need to. The motor temps are within the acceptable range. If you are comfortable with the level of performance that you are getting, I wouldn't gear up just to drop the motor temps.

crazyjr · 01:04 PM

Honestly, its on the edge of my driving abilities on the track. maybe its the torque, but it feels faster than the 5700 in the same setup, with a 17 tooth pinion. The best part is that i can put a 3s 5000 mah in it and all that changes is i can't keep the front down. It makes me wonder, how it would do in a touring car with an extreme gearing on it

sleebus.jones · 06.21.2007, 01:32 PM

All of the MM motors have the same "torque"; the difference comes from your battery system being able to supply the current the motor needs. The 4600 has less draw than the 5700, so with the same battery it will appear to have more torque, when in fact the reason for it appearing to have less torque is because battery can't keep up with the motor as well.

One of these days i'm gonna get off my lazy butt and show the plots from my eagletree logger so you can see it. :)

Sleeb

crazyjr · 06.21.2007, 04:35 PM

I understand, Here is how i see it. The wind is like cam and heads on a real engine (car/truck) the lower the wind the higher the powerband, like bigger duration of cam with equal lift, it won't really give you more power but move it up or down depending on wind/duration. Thats why you need to gear them different. Sorry for the gas engine analogy, grew up with two mechanics.

sleebus.jones · 06.21.2007, 04:58 PM

Weeeeeel, it doesn't really work like that. The torque of the motor is decided by the length of the can. Once you hit magnetic saturation, you aren't going to get any more torque unless you expose more rotor to more coil...which is only possible by going from S can to L can to XL can. That's why the XL cans are such torque monsters and the S can motors aren't nearly as torquey. All the winds do with BL is change the current draw and the RPM/volt. The torque is the same. It's just with higher KV motors you have to draw a lot more current to reach saturation, which gives the illusion of less torque. If you can feed the motor the power it needs, you'll see that all the motors of the same can dimension (i.e. the Mamba Max family or the S can series of Feigao) have the same torque.

Sleeb

crazyjr · 06.23.2007, 12:24 PM

But if you look at the winds, the less turns the less wire overall. There may be more strands in the turn, but less wire overall, less resistence. I think the lower resistence will allow more energy but create higher KV, so will move the peaks up in the powerband. I'm sorry, but i can't see a 7700 having the exact same peak ratings as a 4600. The numbers may be the same, but at different RPM