paper: Gear Reduction

[maxsealy99]

Thread created automatically to discuss a document in CD-Media.

Gear Reduction by maxsealy99

[ThaddeusMaximus]

Uh, posting a paper isn't the correct method of asking for help (post a thread), but...

JVN's Design Calculator will give you rough ideas

... Or you could use a hyper mathy approach

For this game, my suggestion is somewhere between a reduction of 8 and 10. There's no straightaways to accelerate down.

[GeeTwo]

Originally Posted by ThaddeusMaximus

For this game, my suggestion is somewhere between a reduction of 8 and 10. There's no straightaways to accelerate down.

For 8 inch wheels? That's 18-23fps. Way too fast for the confined field of this game. We're using 8 inch wheels and a 4 CIM drive train. We're using the lowest gearing on a TB-mini (10.9:1) and gearing down another factor of two with chain for a total of about 21.8:1. It's only about 8.5 fps, but we should reach it rather quickly on carpet (with both sides working we'll be traction limited) and have plenty of push to get over the obstacles even if only one wheel can get some bite. If you're not planning to cross the terrain, wall, moat, or wrong side of the ramparts regularly, of if you are going to be really light, gear a bit higher, perhaps 14 or 18 to 1.

Edit:

Originally Posted by apm4242

I thought the highest ratio on a Toughbox Mini was 12.75:1? ]
Quite right, and that's what we're using. Our total gearing on the 8 inch wheels is 25.5:1. We had started with the AM-14U2 (so we could have two in hand at kickoff), and ordered the lower gears for an earlier drive train that had much larger wheels.

I did free speed calculations above using 10.9 from memory, and forgot to adjust. It looks like our total will be about 5.7 fps. We're willing to be that slow as we will be a breach specialist, working towards solid high goal capability. If you're planning to focus on scoring boulders, you'll want to be faster than that to get your cycle time down.

[apm4242]

We're using the lowest gearing on a TB-mini (10.9:1)

I thought the highest ratio on a Toughbox Mini was 12.75:1? We plan to use that with 4 CIM drive and 6 AM 8" Pneumatic wheels. JVN gives a final speed of about 12 ft/s. Probably a little high for this game but should be manageable.

At 10.71:1 (the Toughbox Mini gear ratio included in the KOP), JVN gives 14.5 ft/s for the same setup.