ESC Motor turn limits

Discussion in 'RC General & Getting Started' started by ARC-Ltd, Nov 11, 2005.

  1. ARC-Ltd

    ARC-Ltd Guest

    I have a TL-01la which i am rebuilding to race.
    I am about to buy an APEX Multiplex ESC, yet i dont properly understand the way motors and their turn rates work, and how these apply to the limits that some ESC have on them.
    I understand that the lower the turn rate the more torque the motor has, but i am unsure what the limit rating on the ESC actually means for me and what motors i can run with it.
    I am planning on running my stock 540 for a while (which im not sure of the turn rating) then want to be able to run my super-stock motor if i choose- therefore i want an ESC that can do both.

    This is the specs for it


    Motor: 7.2V min 18T, 8.4V min 23T
    Forward: 0.0080(+/-)OHM, AMP PEAK 480A, AMP CONT. 123A.
    Reverse or Brake: 0.0120(+/-) OHM, AMP PEAK 320A, AMP CONT. 82A

    From this info, I understnad that this ESC will run 18turn motors and nothing under, but will go upwards of 18 to the likes of my 27 turn superstock motor.

    Can someone please put me straight.
  2. SpArKeY_STi

    SpArKeY_STi Guest

    Ok, to start, some simple information on motors. Turns. That means how many times the wire was wraped around the armature. The less times around, the more power. Not nessisarly torque, but the faster the motor will spin.

    Winds. This deals with torque. This is a VERY touchy subject... just stick to single winds, double if your doing hard core touring racing

    7.2v Min, thats a standard. Dont worry about that.
    18T limit, means the lowest Motor you can have is a 18T, no 17's or anything. You can run a 19T + tho.
    Amp Peak, means you can only push 320 Amps threw it... Check batt stats to see what it is pushing out. 82 Cont amps, if your running it more then a short burst (like 3-5 sec) only push 82 Amps threw it. Otherwise you'll fry it.
  3. ARC-Ltd

    ARC-Ltd Guest

    Thanks very much- extremely helpful,
    I dont have any batt testing gear - and how do I only push 82 amps thru it? and the rating says its 123A cont in forward and a 480 A peak - I think you quoted on the reverse ratings
    (Forward: 0.0080(+/-)OHM, AMP PEAK 480A, AMP CONT. 123A.
    Reverse or Brake: 0.0120(+/-) OHM, AMP PEAK 320A, AMP CONT. 82A) - even so, are these ratings fairly decent (i'm not doing hardcore touring racing, just pro-stock class)
    Also - how many turns are the stock 540 engines?
  4. SpArKeY_STi

    SpArKeY_STi Guest

    540 Motors can have from 1 turn to 32 i believe is the highest they've made. Dont worry about testing it or anything. 99.9% of all 6 Celled batteries follow the standards of the amp ratings. Its when your doing speed records and shoving close to 40 Sub-C 3300mAh batteries under the hood that you need to do some math. For pro stock class, i recomend a ESC such as Futaba's MCR230, or something similarly small. Any weight reductions you can get will help. Never thought the loss of .002g from a Alum screw would do much, but in Stock classes, EVERYTHING helps you pull better lap times. But also, be sure to check with the track to make sure they dont have a Minamum weight... if so, you can buy maluable 1g weights to put around your car to balance it out, as well as meet min weight req.

    And the Amp Peak and all that after the Reverse Brake OHM volts usually isnt refering to just that fuction, but more so the overall ableness of the ESC. You can really 'Just' push 82amps threw it... as they fluctuate constantly. You'll know if your pushing its limits because it will get unbareably hot. If you cant touch it due to it being overly hot, your doing something wrong, more then likely pushing or pulling to much threw the ESC at one time. But honestly, its not as complicated as it may seem. As long as your not trying to be mr. fast car and putting 80 batt's in your car, running a 2 turn motor, full speed all the time, going from reverse to forward quickly, you'll be fine. But once you get into Mod classes, it will help to research a bit to see what is best for your application. But for Stock, most anything will do as the feild is usually fairly even to begin with.
  5. ARC-Ltd

    ARC-Ltd Guest

    Cool- this Apex Mulitiplex has slightly higher amp ratings than the MCR230 and looks to be about the same size-
    That makes sense about the motor turns- i had it around the wrong way- thinking the higher the turn the more power....
    How far could you go with better motors before you would start being limited by an 18turn motor limit in terms of classes?I'd like to say I'll never go over 18turn- but i know that in reality i will eventually want a more powerful motor - but if this one can last me a while and be competitive then i think its a goer.....
    I just got a lightweight chassis for my 01, which is helping me lose 32 grams so i hope they dont have a minimum weight or itl blow my strategy!
  6. SpArKeY_STi

    SpArKeY_STi Guest

    Well make sure you dont loose to much weight. If the car is to light you'll notice it skid in the corners...

    Well, with the classes you have Stock, 27T's only. The Amature Stock, 20+, and Pro Stock wich it usually something like 17+. Then you get into mod and hot mod. But it differs for each track.

    Not sure what your asking with the going far with better motors...

    But i'll tell you something, i've been into RC Cars for 14 years now, 10 at a hobbiest level. I can honestly say i've never gone above a 19T mod motor. There is only so much fun in going up and down a street at 90mph with a hot mod 10 turn and such. Tho im exadurating a bit, my point is there. I mean, i've straped my car with a 10t mod, and even a 2 turn Trinity Midnight hot mod, and didnt have fun. You hit a wall your your paying out around $150 for a new front end/side and possibly electonics from all the damage. The only downside to useing higher turn motors is you have to REALLY keep them in tip top shape. Comm cutting, drops, bearing washing, no loss connections, and it can be VERY painstaking. In one weekends time i get an average 1 hour practice time in (im usually first on the track) then a good 45 min comm cutting lubing and tweeking. then its 5 min heats, 3 rounds... so 15 min racing, and after that, another 45 min cleaning, but then when i get home, if its been a week or so, i tear the whole car down, re-lube, fix anything, replace worn parts, check connections ect. And i do this all on my own, since i was about 8. But i love it. It may cause stress, but its fun. Then of coruse i have my T-Maxx wich i just tear it up with that thing... neighbors dont enjoy me much with that one. Or then i can strap on my slicks and drift. Or if its bad weather, get my mini T or RS4 out and race in the garage. Tho i cant do that any more as i have my Mini T running at about 50MPH... but i used to. I mean, i've learned so much from slower motors and what not. Im fastest at my track. Period. Electric, Gas, Touring, mod, anything. I just dominate. Why? Not because im fast... my car is accually slowest in drag racing... but because im consistant. Most people have trouble hitting a apex of the corner, they brake in the corners, ect. I just coast on by. I was racing the top driver in state, works for Top motors (Rex, Nova Rossi, ect) he was running le mans style, almost as if he was endurance racing, but with a sprint. Fastest at the track by a good 10 seconds. His car tops out at 75 with two speed, i hit a mere 35 on a downhill maby. But on that track, he couldnt pass me. Salom, schicane, sweeper, just couldnt over take me. But then we hit that stright, and he zips by me... he hits the chicane, and pass him and get a lead. I ened up looseing due to a clip on the corner wall, having him hit the back end of me, and getting under my body and flipping me. But it was a good race.


    Bascily, dont think you have to have the best, be the fastest. Just have fun and be consistant.
  7. ARC-Ltd

    ARC-Ltd Guest

    75 mph? thats nuts
    i thought my TL01 was fast at 60k's (30mph) tho not bad for a 540 motor.

    With my previous questioning I wanted to get some point of comparison with ESC's and how far you can go so not to sell myself short for the future- so thankyou- you have provided valuable insight into my descision making.
    my car is being rebuilt again at the mo with quite a few aluminium parts so i have no idea what it weighs its in 100 bits at the mo.... i'll just balance it up if its too big deal.
    by the way, in NZ they appear to have these rules for weights-

    Maximum overall height 200mm (with suspension fully compressed) *Minimum weight 2WD cars 1474gm
    *Minimum weight 4WD cars 1588gm
    Maximum size of rear wing 220mm wide x 80mm long
    Maximum wing side dam length 80mm

    Have fun? have some serious fun, oh yes i will....!!!!
  8. SpArKeY_STi

    SpArKeY_STi Guest

    Ya, i kinda answerd that question. But In the future, unless you want to go full blown racing (All Carbon Fiber, 10T mod ect...) if you want to drop a few turns for bashing, Duratrax makes some Intellitech ESC's that arnt bad, but very basic. They are really good for priceing, and they have them for all motor applications. So that one is good, and if you want to go faster for fun, theres always that option. With me, when starting, i had 27T only. But then got an unlimited from a friend who droped all his stuff on me for $20, and it IMO, wasnt worth it. Well, the $20 was, but for one new its like $230, and i didnt have much fun with it. My Mini T hitting 50 and doing wheelies whenever i please is enough for me.