Newbie Pinion Gear Question
I am new to Electric R/C and just picked up the Rustler VXL. For now, until I get used to it, I am sticking with the stock 3000mah battery that came with it, and I also picked up a 4200mah NIMH when I got the car a couple of days ago. I do mostly runs up and down the parking lot of my apartment complex. From what I understand the truck comes stock with a 25 tooth pinion and a 83 tooth spur, and has an optional pinion included, that I am assuming is a 28 tooth. What would I expect out of pulling the 25 tooth pinion and installing the included optional 28 tooth pinion? Is there a certain process to making the change properly? I heard about meshing them, and want to make sure I am doing it correctly (if you guys think I should even swap them), to not be stripping gears. Time for me to learn about all of this electric stuff and gear ratios. Thanks!
Smaller pinion gear (one with less teeth) will give you more torque and less top speed.
Bigger pinion gear will do just the opposite.
With the bigger pinion gear, you should watch your motor temps more...that gear is mostly for speed runs on pavement.
As for meshing, you just have to set it so that the gears are as tight as they can be without binding or making any noise.
make sure they spin freely.
Check the owner's manual for the proper procedure on gear installation. It will tell you how to exchange them and set the gear mesh properly using simply a piece of paper.
Thanks upbasher for the quick response. I am not sure I should change it out at this point, as I have no way currently to monitor the engine temp. Not knowing the process, is it or can it be common practice to have multiple sets, pinion/spur in various combinations, and just swap them out on the fly as needed? What would be some good combinations to have and for what purposes?
I've had a Rustler for about 3-4 years now but I honestly haven't messed with gears too much. That being said, I have nearly one of each, just so I can make just about any combination I want.
Traxxas lists these on the parts list:
2416 Gear, 16-T pinion (48-pitch)
1918 Gear, 18-T pinion (48-pitch)
2419 Gear, 19-T pinion (48-pitch)
2423 Gear, 23-T pinion (48-pitch)
2426 Gear, 26-T pinion (48-pitch)
2431 Gear, 31-T pinion (48-pitch)
4725 Gear, pinion (25-tooth) (48-pitch)
4728 Gear, pinion (28-tooth) (48-pitch)
4676 Spur gear, 76-tooth (48-pitch)
4683 Spur gear, 83-tooth (48-pitch)
4686 Spur gear, 86-tooth (48-pitch)
4690 Spur gear, 90-tooth (48-pitch)
I bought this a while back:
Also purchased some Traxxas spur gears. I am in the process now of completing the set, referencing the list above. I would say at least get the 76, 83, and 86 spurs, as they're inexpensive anyway. Then see what pinions you can match up for the desired result. Once again, there is a graph in the owner's manual on page 26 I believe that displays all of the gear ratios/combinations.
The lower the gear ratio, the more draw, which will require a good battery, and constantly monitoring temperatures. Mainly for pavement use. Factory gear ratio is 9.03 with the 25/83 combination.
Higher the number, steeper the gear, and the better off you are for offroad use from what I understand.
Last edited by AngryPirate; 03-31-2012 at 11:56 PM.
Thanks AngryPirate. Seems as if they are inexpensive enough. I guess once I get a way to monitor the motor (and I assume the esc), I should just experiment if i wanted to with various combinations. I am curious about the extra one that Traxxis included in the box, and what it would do. I assume that they wouldn't put it in there, if they didn't intend on you swapping it out.
edit to include: I did find the section about a small strip of paper being used between the gears. I had overlooked that, and thanks for pointing it out.
The included gear is a 28-tooth pinion. Traxxas recommends an 8.4V 7-cell 4,000mAh+ for use with this gear. The 28/83 combination will give you a little bit more speed.
You're going from a 9.03 to an 8.05 gear ratio. If you're a somewhat hard surface I doubt you'd hurt anything.
I use this. It's simple and works (assuming the temps are actually correct haha)
Last edited by AngryPirate; 04-01-2012 at 12:01 AM.
Wow, your a fountain of information, AngryPirate..lol. I thank you so much for the time to write all of this out. I am using it in a parking lot mainly, so that is good news. It doesn't seem like a huge ordeal to swap out a pinion gear and re-mesh it, if i decide to take it off pavement. I will look at getting a temp gauge such as that one. Looks like a great idea.
Swapping pinions is not hard at all...its one of the easiest and quickest changes you can make to your car.
After you do it once or twice, it will be second nature.
Ok, I went ahead and swapped the pinion out. It seemed to make a little bit of a difference, but not a whole lot. I could tell the difference was on the top end though. Knowing I was going to my brother-in-laws, and he had a backyard of dirt to thrash it around in, I opted to swap the pinions back out and put the stock one back in. You are right upbasher, it seems very simple to do and I have now done the swap with ease twice. Now to get me a temp gauge (Thanks again, AngryPirate) and some more pinion/spur combos to play around with. Oh, and some street tires too....these stock ones don't seem to grip too well. I sure appreciate the info you all have offered up.
Actually, I recommend taking your entire car apart piece by piece and then putting it back together!
You will learn a LOT about how the car works. Once you do this you will feel way more confident about working on your car.