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-   -   Tired of blowing cells.. (https://www.rc-monster.com/forum/showthread.php?t=25110)

Bondonutz 12.28.2009 01:42 PM

With that high of a KV motor I'd elect to get the 40C's !

http://hobbycity.com/hobbycity/store..._40C_Lipo_Pack

HomeGrown 12.28.2009 01:52 PM

Quote:

Originally Posted by J57ltr (Post 340984)
When I first got my mamba max and 7700 I ran Duratrax 4200's and they did ok as long as I was geared 87/15 in my rustler on the street when I went to a 17 tooth I actually popped one of the cells. The hobby shop replaced it under warranty. I got an eagle tree data logger and found out I was pulling 126 amps and pulling the pack down below 5V. For a while I still ran this setup but more closely monitered the temps. I still managed to kill a second pack. After that I got a different motor to tame it down a bit. I still run it from time to time but switched to A123 batteries and just run speed runs with it.

Jeff


i was running DTX 4200s i've blown like 6 cells of them.. never really had temp problems..


on another note i have a buddy that would trade my 7700 for a 5700 mamba.. think i should do so?.. and if i do wouldn't i be losing speed and torque? i love poppin wheelies on demand.. i only bash but race cars up my street often.. i like to see their :surprised: when my RC passes them.. :na: i guess i'll opt for the 40c packs.. does it make a difference with a hardcase? because i bash the hell outta my truck and hardcase just seems logical.. whats the pros and cons of a hardcased lipo?

also if i swap motors i could go bigger then just 2s.. i think that 5700 is rated for 5s or 6s lipo..

Unsullied_Spy 12.28.2009 02:41 PM

4s on a 5700 is pushing it, 5s or 6s is asking for trouble. I would go with a 4600 or 5700 depending on how hard you want to push it. I had a 5700 in my Rustler for about 2 years and it was very powerful and ran decent temps at 18/90 and 18/86 gearing. An FLM tranny case is a good investment. No more cracking at the hinge pins, runs smoother and quieter, and absorbs a ton of heat out of the motor (I've heard of people losing 20-30 degrees off their motor temps by going to the FLM case) and then put a clip-on heatsink on it with some thermal paste. That should be enough to get a 5700 running very reasonable temps in most weather.

EDIT: If you can afford it, get a Neu 1506 or 1509. I picked up my 1506/1Y off eBay for $105 shipped and it beats the pants off my 5700, Velineon, and the Hacker motor I had in there for a little while. It has the same fun, spunky driving characteristics of the 5700 but gobs more torque than the Velineon and runs cool no matter what I do to it. IIRC I have 13/56 gears in it (Jato spur with a 5mm bore 32p pinion) and it never gets more than luke warm on 2s lipos, no matter how long I go. With the FLM tranny case my MM would overheat before my motor would break 150 on 3s lipo and it was flipping over on it's lid at 50-60 MPH.

_paralyzed_ 12.28.2009 02:54 PM

the 7700 refers to how many rpm's per volt the motor turns. On 2s the motor spins at 56980 rpm (7700kvx7.4v=56980rpm)

The 5700 on 5s would be 105450rpm (5700kvx18.5v=105450rpm):surprised: that's way too much! You don't want to run the castle motors past 60,000rpm. You could go 3s on the 5700.

With the 5700 you would GAIN torque and lose speed. A lower kv motor has more torque than a similar higher kv motor.

The 5700 would still do what you want on 2s (wheelies at will) and run much cooler than the 7700.

I would sell off the 7700 and get a bigger motor(not castle).

HomeGrown 12.28.2009 03:10 PM

i wouldn't get enough out of my 7700 to get a bigger/better motor.. i'd like to just trade it off.. but that won't happen lol.. and when you say bigger motor wat exactly do you mean?

also wat other motors are out there?.. i know of Medusa, Novak, Neu, Feigo(sp)..

Unsullied_Spy 12.28.2009 03:28 PM

He means something more powerful than the Castle motors, they're a bit on the weak side for something as big and heavy as a Stampede. I think you should keep an eye out on eBay for a 1506 or 1509, either one will power your Stampede without issues.

HomeGrown 12.28.2009 03:35 PM

well isn't 1506/1509 castle motors?.. Castle Neu 1506... im lost.. lol..

_paralyzed_ 12.28.2009 04:08 PM

the 5700 and 7700 are both castle motorsfrom castle's cms36 line of motors.

Neu Motors and Castle Creations are seperate entitites. Neu motors are well known for the best r/c motors out there.

Within the past couple of years, Neu and Castle started working together, but are still seperate businesses. You can still buy "Neu" motors or "Castle" motors, and now you can also buy "Castle/Neu" motors.

The first "Castle/Neu" motors were the 1512 size 2650kv motor and the 1515 size 2200kv motor. Now they also offer a 1518, a 1520 and a 1717.

"Castle" motors are 2 pole motors. Anything with the neu name on it (neu-neu or castle/neu) will have atleast 4 poles and will be much more powerful than the little cms36 castle motors.

Even an "L" can feigao would run cooler than your castle motor. They're about $60 and you should be able to get $50 for your 7700 on ebay.

HomeGrown 12.28.2009 05:25 PM

even tho you guys are telling me not to get another castle motor i probably will.. lol.. its just less hassle if that dont do it.. theres plenty more demand for a 5700 then a 7700 so i should be able to get off of it easier then my 7700.. i'll just opt for 3s lipo on the 5700..

_paralyzed_ 12.28.2009 05:36 PM

Do it up! Part of the fun of r/c is trying different setups. Keep an eye on temps, it's hard to sell a burnt motor. Well, hard to sell it honestly.

2s would be plenty of fun with the 5700. 3s will be hard to keep cool. Maybe get one 2s pack and one 3s to switch it up?

maxair45 12.28.2009 06:14 PM

Quote:

Originally Posted by Bondonutz (Post 341021)
With that high of a KV motor I'd elect to get the 40C's !

http://hobbycity.com/hobbycity/store..._40C_Lipo_Pack

+1 20c is kinda lower these days with there already being 45c batterys available. They are out of stock though and sometimes it takes forever for them to restock so i'd say change your MaH, Maybe:
http://hobbycity.com/hobbycity/store...00mAh_2S1P_40C

HomeGrown 12.28.2009 06:16 PM

i'll get the batteries first then if i dont like it then i'll trade for the 5700.. thanks guys.. btw linc i'll be in touch..

_paralyzed_ 12.28.2009 07:01 PM

Quote:

Originally Posted by HomeGrown (Post 341074)
i'll get the batteries first then if i dont like it then i'll trade for the 5700.. thanks guys.. btw linc i'll be in touch..

will it be a "special" touch? Linc might just hook you up................:whistle:

J57ltr 12.29.2009 12:53 AM

Quote:

Originally Posted by HomeGrown (Post 341022)
i was running DTX 4200s i've blown like 6 cells of them.. never really had temp problems..


on another note i have a buddy that would trade my 7700 for a 5700 mamba.. think i should do so?.. and if i do wouldn't i be losing speed and torque? i love poppin wheelies on demand.. i only bash but race cars up my street often.. i like to see their :surprised: when my RC passes them.. :na: i guess i'll opt for the 40c packs.. does it make a difference with a hardcase? because i bash the hell outta my truck and hardcase just seems logical.. whats the pros and cons of a hardcased lipo?

also if i swap motors i could go bigger then just 2s.. i think that 5700 is rated for 5s or 6s lipo..

I bet it was one of the cells opposite the battery leads. :lol: I got the batteries real hot one time. We had a pile of dirt where a house was being built next door and a friend and I were climbing to the top. I was running the 7700 and it was geared pretty low (87/12) and I was also using my eagle tree with a temp sensor on the battery, ESC and motor. The motor and ESC was pretty warm around 130 and the batteries stopped at 200 at about 3 minutes into the 6 minute run. I have no idea how it really got because I had accidently set the upper limit to 200. That was measured under the wrap.

I used a Feigao motor (4436Kv) and they are just about identical to the castle cm36 motors. Like the guys said 5-6S would be death, although you can usually get away with it a time or 2. I have run the 7700 on 3S2P A123 and it cranks out some serious power. It's real hard to keep it from flipping a rustler on it's lid and it's kinda like going over a cliff, you still hit those brakes.

I also have a Nemesis blue 6 turn motor (5915 Kv?) and it does very well also. I would say it's probably right along with the CM36 and Feigao motors. I have run it on up to 4S2P A123 and it flies. I have run all these motors on Nimh and wouldn't recomend the 7700 with them. I run mostly on the street which is a little easier on batteries, so if you run offroad a lot you should probably try to get that 5700 or lower when you can.

Jeff

maxair45 12.29.2009 01:10 AM

Quote:

Originally Posted by _paralyzed_ (Post 341081)
will it be a "special" touch? Linc might just hook you up................:whistle:

He needs to find the dime in lincs pocket first:mdr:


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