7XL gearing

[FordTrucker]

Hi guys its my first post but long time browser. I'm starting a revo conversion and ive got a question. I got a deal on a motor mount and 7XL motor(i know its not the best). But my question is on gear, it comes with a 22t and 18t pinions. im thinking of running the wide ratio gears keeping the 2 speed, 18t and trying different spurs. But id like to here some opinions from some more experienced guys. thanks in advance.

[Arct1k]

Hi welcome - This tool is your best friend - you can play with setups and see what speeds you get - Posting up your batteries and controller would help with guidance.

http://scriptasylum.com/rc_speed/

Rgds

[FordTrucker]

yes i have that page on my favorites.

I plan on a 7xl, mm, and either 12 or 14 cells.
and geared 18/40 with wide ratio and stock talons, on 14cells at 1.1v brings me to just under 37000rpm and 45mph.
would that set-up keeping the 2-speed and foc keep my motor at a decent temp?

[Arct1k]

I don't think the cells or motor will carry that happily - you maybe better off on NiMh aiming for mid / high 30s

[FordTrucker]

ok, 18/40 with standard 2speed, on 12cells at 1.1, estimates me a 36mph and just under 32000rpm.

does that sound like a good setup until i can get one on the new 2200kv medusa 36-70-2200 and 4s?

[Arct1k]

I'm sure others will jump in but I think that sounds like a good start... The revo is fine BTW with a Medusav2 60 2000 - Mike runs this - At $160 the 70m is pricing itself close to Neu, the Losi and the castle neus

[FordTrucker]

what voltage and gearing do you use with the 2000?
i liked the higer kv of the 70mm but i guess its not that big of a difference.

[Arct1k]

Mike was running on a e-revo on 4s geared for high 30's I believe...

[sjcrss]

Im running a 7xl w/ quark 125 on 4S, and it's geared 20/68......I only ran half a pack thru it so far....but hopefully I can do more testing tomorrow...weather permitting...that is

[sjcrss]

Well, I finally got a test run in on the erevo, with the setup stated above, and was able to run a full set of batts thru it, the esc remained fairly cool, no thermals or issues with it , also the motor was warm, but not to warm that i couldn't hold my hand on it for a long peroid of time...so, i think i can gear it up a little more possible, may stick with the 20t, and go to a smaller spur.....but i will see....and keep you all informed.....

[neweuser]

sjcrss-Good to hear. Me personally, sounds like you have comfortable temps and would not change a thing. But that is just me. What was your runtime? If you gear it up more, it will draw more juice.

[lincpimp]

The 7xl is gearing sensitive. I would go with the 12 cell setup and the smaller pinion and give it a try. Get a temp gun and check temps frequently on the first run. If the motor goes over 160 you need to get some more airflow over it and possibly gear down. The rcm heatsink clamp is a good idea if you have a smooth can motor, it will not fit a finned can. Airflow is important with these motors, as they are ineffecient and create a bit of heat regardless of the gearing. I have run a few successful setups with a 7xl, so it can be done.

[FordTrucker]

Thanks for the help guys, i think if i keep the factory speed and gear down temps will be reasonable. Now i just have to wait for a MMM to try out my conversion.

[sjcrss]

I actually did really check the runtime, as I was just testing it and seeing how it does....so far so good....