RCCrawler Forums - my Sumo Crawler build

RCCrawler Forums (http://www.rccrawler.com/forum/)

- Micro Scale Rigs (http://www.rccrawler.com/forum/micro-scale-rigs/)

- - my Sumo Crawler build (http://www.rccrawler.com/forum/micro-scale-rigs/502774-my-sumo-crawler-build.html)

my Sumo Crawler build

A work in Progress.... here is what ive done so far

stock sumo after unboxing
http://img.photobucket.com/albums/v6...r/IMAG2886.jpg

First mod was to change shock mounts and upper link locations & cut the springs
http://img.photobucket.com/albums/v654/Vasner/sumo1.jpg
http://img.photobucket.com/albums/v654/Vasner/sumo3.jpg

Next was to router out the battery boxes to make room for new NanoTech 300mah Lipo and relocate the reciever/esc board
http://img.photobucket.com/albums/v6...r/IMAG2902.jpg
bend servo pins 90 degrees
http://img.photobucket.com/albums/v6...r/IMAG2907.jpg
receiver/esc board and low voltage alarm wired up
http://img.photobucket.com/albums/v6...r/IMAG2914.jpg
I recommend etching or labeling the pins on back of battery box
http://img.photobucket.com/albums/v6...r/IMAG2915.jpg
coiled up servo leads, in a later mod i shorten the lead and solder directly to the pins, also changed out as many phillips head screws with 1.5mm hex head screws as i could
http://img.photobucket.com/albums/v6...r/IMAG2916.jpg
new servos, same spline as stock, so able to use servo savers if you want
http://img.photobucket.com/albums/v6...r/IMAG2918.jpg
I knew i was going for a bigger motor to start with, so heres how i did it
http://img.photobucket.com/albums/v6...r/IMAG2912.jpg
http://img.photobucket.com/albums/v6...r/IMAG2921.jpg

climbing toy blocks
http://img.photobucket.com/albums/v6...r/IMAG2925.jpg
http://img.photobucket.com/albums/v6...r/IMAG2928.jpg

time for new wheels & tires. RCTrax MiClaws on RC4WD beadlocks
http://img.photobucket.com/albums/v6...r/IMAG2993.jpg
http://img.photobucket.com/albums/v6...r/IMAG3002.jpg
http://img.photobucket.com/albums/v6...r/IMAG2991.jpg
http://img.photobucket.com/albums/v6...r/IMAG2999.jpg

http://img.photobucket.com/albums/v6...r/IMAG3003.jpg
http://img.photobucket.com/albums/v6...r/IMAG3007.jpg

servo leads shortened and soldered to pins on board
http://img.photobucket.com/albums/v6...r/IMAG3010.jpg

new motor sourced from a tower pro MG946 servo, slower than stock but tons more torque... im thinking gear reduction change get this faster and still have good torque,
has far too much torque and very little speed with this motor
http://img.photobucket.com/albums/v6...r/IMAG3013.jpg

Rock crawling in the yard
http://img.photobucket.com/albums/v6...r/IMAG3012.jpg
http://img.photobucket.com/albums/v6...r/IMAG3011.jpg

Ill keep updating as things move along.... Ive got a lexan hummer body coming soon. Also planning on ditching the receiver/esc board combo in favor of separate FlySky receiver for my iT4 and separate brushed ESC. Ive ordered a few gear reduction units to see if i can get good combo figured out with a brushless motor setup.

Re: my Sumo Crawler build

I'm curios about the low voltage alarm. I'm not exactly familiar with them, but I understand their purpose. Could you tell me which one you used, and how you wired it in? I feel I might need one on my current build using a redcat esc, but I don't know much about them. Any info would be appreciated.

Re: my Sumo Crawler build

Quote:

Originally Posted by R.Billy Rob (Post 4844374)

Only need a low voltage alarm if you are going to be using a Lipo battery. dropping Lipo voltages too low cause significant damage/life shortening to them. Newer ESC designed with Lipo batteries in mind, usually have them built in. I used a Hobby King low voltage alarm that goes off with loud beep/tone when any cell is under 3.3 volts, it was about $2.

In the pic you can follow the wires... black = common/negative, yellow = first cell, red = second cell.... if you were running a 3s pack a fourth wire would go to the last pin(that i cut off the board) to the third cell.
I have a Trex 150 that uses the balance lead rather than a separate plug for main power, so i set my Sumo up to run the same way(current draw isnt high enough to require larger gauge wire to "feed" the truck). Most batteries are the same.... first and last pins of the balance plug are your + and -, which would get connected to the ESC.

Re: my Sumo Crawler build

Curious how that ESC works as i'm offered a Losi micro crawler with no TX (and ESC/RX is one combo deal like this) and i've already got a flysky GT3C and receivers.

Either way, slick build thus far!! The tire size on this stock is aesthetically painful

Re: my Sumo Crawler build

So far the ESC is working great... but ive only had one full battery through it(approx 40min). The only thing i dont like about it is that its setup for FWD/brake/reverse. So quite often getting reverse requires a "double tap" to get moving.... Overall for the price i dont think it can be beat. $7.50 from banggood, just be prepared for 7-10 shipping time.

Re: my Sumo Crawler build

Got Hummer body painted and mounted up yesterday.... Its too plain... needs decals & finishing details.
http://img.photobucket.com/albums/v6...r/IMAG3034.jpg
http://img.photobucket.com/albums/v6...r/IMAG3035.jpg

Also tried out a new motor. 20mm coreless motor out of a stripped Turnigy TGY 3509mg servo. Speed is better now, about 2/3 to 3/4 walking speed & still lots of torque. Definitely not a cost effective motor option, but i had one laying around so i figured i might as well try it. Larger diameter meant i had to widen things up... Feathering shafts from my TREX 250 worked perfect to get the extra 3-4mm i needed to make room for this motor. Previous motor came very close to the front steering servo, this motor has a shorter can, so its length(or lack of) makes it more ideal.
http://img.photobucket.com/albums/v6...r/IMAG3036.jpg