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trx4m F150 high trail with flipped fcx24 2 speed transmission

Whats_a_dickfer

Rock Stacker
Joined
Nov 17, 2020
Messages
61
Location
West Fargo
Got this project done using a 3d printed skid from oppaifactory on etsy. Wasn't too keen on any of the other 2 speed options for the 4m, and I have a pile of spare fcx24 parts, and too much time on my hands.

The trans mounts are symmetrical so it was simple to run it with the motor forward. Trans is from an fcx24 with FMS metal gears installed, motor and shift servo mount are stock fcx18 parts.

Electronics wise I'm running dual 300mah 3s packs, meus 8.5kg servo, injora mb100 esc, and a dumborc x6pm transmitter.

Front shaft is half fcx24 and half atlas 6x6, rear shaft is injora trx4m with the transmission yoke filed down a bit. Will be replacing the front shaft with the other injora one once I shorten up the yoke.

How's it drive? Like a trx4m and fcx24 loved each other very much. Really good slow crawl, speedy in high gear, very quiet and smooth overall. I previously had a furitek cedar motor and moforc esc in this truck, but those got moved to my tarantula build. I'm considering putting the cedar in this truck with the 2 speed, but then I'd need to buy another brushless combo for the tarantula. I hate spending money almost as much as i hate leaving anything stock so, I dunno.
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So after getting a good amount of driving in with the 2 speed and the brushed motor, I installed my furitek cedar to the 2 speed. Spent some time with that setup, and ultimately went back to the single speed gearbox.

It's the weight, guys. I don't have the exact numbers in front of me, but with the same motor, the 2 speed trans with metal gears and the shift servo weighs like twice as much as the single speed with metal gears. Not only that, but the bulk of it is higher up and farther back. I could  really feel the difference in the rocks. In terms of slow crawl and wheel speed with the fcx trans, it's just not useful enough to justify the extra weight and the negative effect on C.O.G. and f/r distribution.

It was a fun experiment, but IMO the furitek cedar motor on 3s with the in-between ratio injora trans gears (24.something:1) is the clear winner.
 
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