...and happy new year, y'all! (he says, whispering so as not to aggravate any hangovers that may have resulted from possible over-enjoying last nite's festivities)

Now- How can ya tell I'm married with rugrats? Instead of partying, last night I built a model with my 3-year-old, watched the Leafs game, and installed a new steering servo in my 'crawler!
Hence the Happy New Steer title.

Again the object was to spend nothing. I dug up an old (like 15 years) Airtronics hobby servo. It was a three- wire setup, wich creates a problem) and it didn't appear to be working properly anyhow. I removed the little PCB inside and ran two wires straight off the motor to the factory plug on the 'crawler. My old crappy servo was too big to fit laying flat like the factory unit, so I had to mount it upright, using a combination of doublesided foam tape, and yet another piece of aluminum sheet. Not much left of that sign I nicked!

Knocked together a quick linkage and- It steers where I want, when I want, and has enough torque to push the 'crawler sideways away from an obstacle. Problems- yeah. The unit has too much sweep- about 185*, so cranking the steering's threatening to break something, and I don't have a servo saver that fits- might have to break the "no bucks" rule and get one. Might have to create some sort of idler arm affair like Charles' to take some of the sweep out of it. I've got no "return to center" either, but since I'm not doing quarter-mile time trials, I don't care. I fully expected that. Will post a pic later. Cheers!

This message has been edited. Last edited by: toystory_4wd,

The organ transplant...

Linkage detail. Is it too late to get a new Digicam for Xmas? Steering arm was a parts-box item. Bracketry? More of that aluminum sign!

I was unable to mount mine like that because I had frame rub on the servosaver, so I had to mount mine with the shaft towards the bottom.

That's funny! I couldn't mount mine shaft-down because of interference!

HAHA I finally got tired of replacing the servo arms when the broke because of torque so I tore it apart and rewired it so now im using just one pushrod and BAM! perfect steering with lots of power.

What about something like a 3-way switch? Middle setting allows normal power to the servo motor, left side turns of power and right side turns off power... then all you'd need to do is rig up someting that slides the switch so that when you're at max left or right theres no more power to the motor so you can't break anything.

Although that could be the exactl definition of a "servo-saver".... I'd have no idea.

The servo saver basic is a spring or plastic coushion on the servo that flexes so any hard hits or steering lockup IE (rockjammed against the tire not letting it turn) will not break the gearing in the servo itself. Kinda like a steering stabilizer on your full size rig. A pain and a power robber in the steering system but keeps your fingers from getting broke by the steeringwheel when ya hit something.

Yeah makes perfect sense to me.. although does it really have that great of an effect with low speed crawling? I could see if you've got a tmaxx and you're pushing it around 50mph and you smack a curb or something......

With a higher torque servo it really helps because there is no shock absorbsion in the steering setup and the servo will pull till it breaks if its in a bind. Try holding the tires and turn the wheel watch the front of the servo it will continue to try to turn by flexing the servo saver. without this little part you dont loose as much steering power to flex but you run the risk of trashing the servo gears or motor and the higher torque servos can get really expensive.

Yeah I agree a servo saver is key. I've chewed up the teeth in other RC rigs by trying to cheat and not use one. These rockcrawlers don't need much rotation so if you mount the linkage close to the center of the servo arm you should have enough swing, more torque and the servo saver won't just "give" as easy.

Alright so I took the crawler out tonight for its first official run on the rocks.... a little proving ground me and a buddy have for our other RCs. Instantly we could tell that the newbright kicked all out other toy RCs asses.... one small problem though... the steering was so underpowered it wasnt even funny.

So now I'm considering running to the hobby shop and getting the cheapest servo with metal gears I can find... im guessing minimum 85oz/in is what I need for crawling... just a guess though. Probably looking at $30 CDN... although I wanna make sure it'll work. As long as I run the leads straight of the motor it should work right?

The only way I've upgraded steering in other RCs was through putting slot car motors in em... didn't work on the NB... it was too powerful for the stock servo stops.

If ya find the right servo it will be a damm near strait swap actually just a little wire splicing and linkage fab I used 16GA piano wire for my linkage and drilled a small hole in the stock steering arm.