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-   -   will the 80mm medusa fit in an erevo? (https://www.rc-monster.com/forum/showthread.php?t=16728)

hendo6682 11.20.2008 05:01 PM

will the 80mm medusa fit in an erevo?
 
Just as the title says. I have done a little research and the largest motor I have seen in an erevo is a kb45xl which is 77mm x 45mm. In the pictures I have seen of this setup it looks like it just barely clears the shock mount. thanks

stum 11.20.2008 06:10 PM

medusa 70mm should do the job quite nice in an erevo, many have used the 60mm but really that is too little.. If you must have it, it should just fit due to only being 36mm, but that could very depending on gearing as well, hard to say till some try them out.

suicideneil 11.20.2008 07:26 PM

Linc has fitted a 1521 in his Erevo, so the 80mm Medusa shoud fit as its 3mm shorter, and 3mm smaller in diameter. :)

hendo6682 11.20.2008 07:29 PM

ok thanks, well i guess i have narrowed it down to the 36-70-2300 paired with mmm or the castle 2200 combo. i was thinking if the 80mm medusa would fit i could use the 36-80-2000 and have a ton of torque and low temps but i guess the 70 would do just fine.

hendo6682 11.20.2008 07:33 PM

oh wow, i didn't know he put a 1521 in an erevo, well i guess i am back to square one. i am leaning towards the longer motor in a lower kv.

suicideneil 11.20.2008 07:35 PM

The 70mm motor should be more than ample for any 10lb truck- Linc is just nuts, and Im hankering for the 80mm motors as my rig is 13lbs..

blueb8llz 11.21.2008 11:56 PM

13lbs with or without the battery?

kostaktinos_mt 11.22.2008 04:05 AM

a larger motor does not neccessarily mean better efficiency [lower temps]...
on the contrary, iron losses usually increase with the motor size...
it doesn`t work like a brushed motor...

a 60mm medusa is just fine for the erevo imo... excessive torque is a second reason to avoid "larger-than-neccessary" motors...

i guess it comes to one`s personal taste, so that`s just my own 0.02...

stum 11.22.2008 09:50 AM

Quote:

Originally Posted by kostaktinos_mt (Post 234948)
a larger motor does not neccessarily mean better efficiency [lower temps]...
on the contrary, iron losses usually increase with the motor size...
it doesn`t work like a brushed motor...

a 60mm medusa is just fine for the erevo imo... excessive torque is a second reason to avoid "larger-than-neccessary" motors...

i guess it comes to one`s personal taste, so that`s just my own 0.02...

60mm is too small and will overheat on even a fairly stock e-revo unless you keep it geared for around 38mph, trust me I raced w/ the 60mm and toasted some. The exception would be a VERY low kv w/ 6-10s lipo may hold up better but 4s and 5s don't cut it. Really the 70mm is ideal... for the size and weight of the e-revo. If you have too much torque you simply need to reduce the RPMs (less voltage but not under 4s) and balance btw gearing up and heat. Get lower KV motors to start and keep your voltage for best results! If you want low torque plan around 29 to 31k rpm, if you want moderate torque shoot for 32k-38k, and if you want sick torque go w/ 38-50k as it will just lay it down.

Mozzy 11.22.2008 10:23 AM

I've ordered the 80mm 2000kv for my BLST. On 5S it'll be pretty quick with 37,000 RPM. 1000 RPM less than the .32 nitro motor it used to have. So, it'll be a very good comparison with the same gearing.

I think the E REVO would be perfect with 4S & the 70mm 2300kv Medusa. 34,040 RPM Nice midrange as mentioned above.

suicideneil 11.22.2008 11:15 AM

Quote:

Originally Posted by blueb8llz (Post 234900)
13lbs with or without the battery?

With; if I take the wheels and batts out, it only weighs about 6-7lbs... :lol:

We dont use the larger motors for better efficiency, no arguements there, we use them because they produce more torque/power; efficiency comes down to design and construction more than anything really (and kv rating vs voltage I guess).

hendo6682 11.22.2008 04:24 PM

i was planning on running a 6s setup. i believe hoov is running a 1515 1y on 6 cells geared for 40-45 with really low temps. that is really what i am looking for, high torque and low temps all day long. i was under the impression that a lower kv motor paired with higher voltage would run cooler than a higher kv motor and lower voltage. is my logic correct?

suicideneil 11.22.2008 04:48 PM

100% correct.

Mid range kv + higher voltage and mild gearing will also give good results like Hoov found; the main distinction being that a mid range kv motor works equally well on lower and higher voltage (4-6s lipo), so long as you adjust the gearing accordingly.

shaunjohnson 11.22.2008 05:08 PM

ok then, i'm doing a revo 3.3 conversion.
i'm a big fan of reliability, heat is my worst enemy and fans are bad.

so i'm planning to run MM on 4s so i'm really limited to 4s lipo.
to keep temps down...what motor length should i go for...70mm or 80mm (i like crazy torque :P)???

and what KV should i run on 4s lipo???

thanks,
shaun

suicideneil 11.22.2008 05:12 PM

70mm, 2000kv. You could get away with the 2200kv motor also, as that would be equal to the 1515 1y almost, and those do fine on the MM (with a fan and extra capacitor usually). On a stock Erevo, that should be more than enough power- endless wheelies and back flips galore.. :yes:


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