With the width of the vehicle worked out, it is time to make it drive like a crawler.
To slow the Slash down to believable crawler speed I actually kept the stock gearing in place (19.23 Final Drive Ratio for the brushed 4×4). Then I added a RC4WD 1:3 Gear Reducer, which would change the final drive ratio to almost 60:1 – a popular ratio amongst crawlers and close to the TRX-4 low-speed setting.
The gear reducer is normally a bolt on part, but there were some tweaks I had to do to get it to fit the Titan 550 motor. First the receiver hole in the gear reducer is too small fo the 550’s standard 13mm bearing enclosure (the part that sticks out right before the motor shaft). Which is strange because the age-old Tamiya 540 motor also specifies 13mm for this part of the motor.
The arms are going to be the single biggest difference maker when it comes to overall width. As part of my research I gathered a list of several Slash-compatible arms and their lengths. If you’ve got more arm lengths to add to that list, please comment below.
Bandit arms are 67mm wide, while the stock Slash 4×4 arms are 92mm. Just by making this switch we’re going to remove 50mm of overall width, bringing it from 296mm wide to potentially 246mm – less than the goal of 249mm. So we have some width we can add if need be.
Here you can see two sets of Bandit arms compared to the original Brushed 4×4 Slash arms:
Can a Slash 4×4 transform into a trail-worthy RC crawler? I don’t think this is a new question, in fact Ultimate RC did something very similar with a Stampede 4×4 almost 10 years ago.
I took some of the cues from that build and wondered if we couldn’t do it even better. I don’t intend to keep it track worthy like Jang’s Chimera, but can we make it truly trail worthy?
There’s a place I like to race at in St. Peter, MN called Shamrock RC Raceway. It’s an interesting setup because it’s a turf track set up outdoors in a hockey rink that would otherwise go unused in the summer. Rather than bring an insane extension cord to power my charger from the park restroom, I wanted to come up with a more portable (and green) charging solution.
So I put together this simple solar charging setup:
Continue reading →
