Need help choosing gear ratio - I plan on using 6 wheels. Currently debating between 400rpm on 3.25" or 480rpm on 2.75" (side note, for High Stakes, is 450rpm on 2.75" too slow? cuz the spacing is alright, just scared that it’s too slow). I also want to fit everything in 3 wide if possible. Which drive setup is the best for this? Where should I use ls and hs gears? I’m currently cadding a 480rpm on 2.75" and I’m having trouble fitting it under 3 wide. Do I need to shave gears? I’m already using ls gears.
There is no “best gear ratio” - that’s on you to decide what you want your gearing to be. For your 480 2.75 comparison to 3.25 400, they are actually at about the same speed ~(68 in/s). Most teams I’ve seen have around that same speed. As for 3 wide, it’s possible on drivetrains - its more difficult for some since the gears might not fit into the wheels. For 480 and 400, you might need to change the 48T gear as well - check your spacing Using ls and hs gears is at your own discretion - I would say whichever one has better meshing with how it’s positioned is better. Hope this answers your question! If you need any other advice, I would recommend looking at this post. Posting pictures of your CAD may also help us understand.
6 Likes
I made a video guide about a year ago I still mostly agree with: https://youtu.be/VbLf8aXQSpg?si=Vx0UChahwtBKWQoB
Now more so onto your specific case. Drive speed itself is not as important as most teams make it about to be. The speed difference between 450 2.75 and 480 2.75 will be negligible in most cases. Especially at this point in the season when there is still plenty of optimization to be done. Spacing on a drive is usually more important imo.
As for 3 whole gap, with most ratios (450 3.25 is an exception I believe) you will either need to only use Ls gears or beveled high strength gears. Whatever is easier depends on your spacing. Here is another drivebase related guide that uses 360 3.25 although other ratios like 2.75 450 are mentioned. (around the 10 minute mark is where I start talking about 3 hole gap)
7 Likes