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Very dissapointed

Discussion in 'Granite & Senton Mega 4x4' started by trout74, May 26, 2018.

  1. trout74

    trout74 Well-Known Member

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    im an ARRMA fan boy through and thourgh. I have 2 kratons and 2 outcasts all modded to the gills, and a youtube channel to back it up ( trout74) . I bought a granite 4X4 mega for my 7 year old to play along with me. Totally stock running a 2S lipo. First pack an 8000mah 2s lipo and it thermal shutdown in 15 minutes. let it cool off and 15 minutes later thermal again. Very dissapointed. First time ARRMA really pissed me off. I have to buy a real ESC to run a stock brushed motor???? SERIOUSLY? ARRMA this is terrible.
    TROUT
     
  2. GuyFromCanada

    GuyFromCanada Premium Member!
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    FWIW, I run 5300mA NiMH packs through my Granite's, and the motors have gone before the ESC...maybe the heat sink is poorly attached?
     
  3. trout74

    trout74 Well-Known Member

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    I ended up installing a Castle Sidewinder3 and 4500KV sensored green motor. Life is good. Used stock 14T pinion, so its not really much faster, just way more efficient.
    Trout
     
  4. GuyFromCanada

    GuyFromCanada Premium Member!
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    I'm interested in the same idea...is it the SCT version? Did you consider the 3800kV motor?
     
    #4 GuyFromCanada, May 26, 2018
    Last edited: May 26, 2018
  5. trout74

    trout74 Well-Known Member

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    3800 would be fine too, its the sensored one, I had it on hand. So I just popped it in.
    Trout
     
  6. GuyFromCanada

    GuyFromCanada Premium Member!
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    That's what I was thinking...I need to buy a set of pinions when I get a new power system. I guess this is where things start getting interesting.
     
  7. trout74

    trout74 Well-Known Member

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    yeah it woke it up a bit. Could go up a few in Pinion and get some good speed, but its for my 6 1/2 year old, so hes good.
    Trout
     
  8. ThatDrewGuy

    ThatDrewGuy Premium Member!
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    Would a good motor fan solve that problem you think? They are cheap, but made a significant difference (30 degrees) on both my Talion, and Typhon. I was running 190-200, and took it down to 165 which seems like a sweet spot for the 90+ weather I’m currently running them in.
     
  9. Jerry-rigged

    Jerry-rigged Premium Member!
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    When I was running the stock power system, I had the same issue - about 15 minutes in, the ESC would thermal, right at 175f. The motor would be around 190f-205f. Stock, neither the motor or ESC has a fan, and the ESC heat sink is kind of shallow. Fans might help the situation, but...

    I am not sure what Arrma should have done to fix the situation. 91/14 is already pretty low gearing, and a 550 /12t is about the most power you can get (cheaply) out of a brushed motor.

    For sure, the Mega 4x4 platform just begs for a brushless system. And a better diff input. The rest of the truck is solid. If/When Arrma releases that version, it will be a killer truck!
     
  10. Bri26

    Bri26 Well-Known Member

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    Do you think the electronics aren't getting good airflow with the tall chassis dirt guards in the front?

    Best regards,
    Brian
     
  11. Jerry-rigged

    Jerry-rigged Premium Member!
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    Maybe less airflow than without the guards, but I suspect that even if the guards were removed, you would still have heat issues. A fan on the ESC and motor would also help, but the ESC and motor would still be overworked. The truck just needs more power than you can get from a brushed motor. Or it needs lower gearing.
     
    KMS likes this.
  12. trout74

    trout74 Well-Known Member

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    Agreed. It needs brushless setup and better esc. We’re many many packs in on 2s and we’re good to go.
     
  13. Jfpryde

    Jfpryde Well-Known Member

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    I don't know that many entry level brushed rigs do any better. I had similar issues with ECX brushed stuff and my older rustler until I upgraded to the beefiest brushed esc I could find. I woulda just gone brushless on that one if it weren't for my kiddo. I didn't want him to have too much power.
     
  14. Jerry-rigged

    Jerry-rigged Premium Member!
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    If you don't want too much power, but are tired of burning up brushed motors, look into one of the "F540" motors - they are 380L (long) brushless motors, with big cooling fins. Power is similar to the 12t 550 motor in our Granite mega 4x4. I ran one in my Mega 4x4 for a few batteries, it worked well, and kept the speed similar to stock.

    The motor I have is a Racerstar, but there are a lot of different ones out there... Here is a longer write up I did on my F540-
    https://www.rcgroups.com/forums/showthread.php?2713040-Racerstar-F540-45A-ESC-combo-Review
     
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