Average Feet per Second

I was just thinking what everybody is think about this competition as far as feet per second? Are you planning to zoom (100 f/s), lumber ( 1 f/s), or average ( :confused: f/s) Anything you provide for me as afar as stats will be deeply appreciated :smiley:

I think it states in the rules that you can only go up to 10 f/s…not sure on this one though.

as far as i know, there are no speed restrictions on driving. the 10fps is in reference to the vertical velocity limit of anything being launched from the bot to hang from the bar.

sorry If I made it sound wrong, but what I am looking for is what your team is doing as afar as f/s for this years competition (like the average) not what the rules say is the max

p.s. The whole hundred feet a second thing was just a bad joke I guess we dont actually plan on doing that

Well… the most that you’ll typically see on a really fast robot is somewhere around 15 ft/s. Our robots the last 2 years could go 13 ft/s in high gear, and 2 ft/s in low gear. Most robots you’ll see will fit somewhere in that range, or possibly a little bit above or below.

You can see lots of opinions here.

if your robot goes backwards as much as it goes forwards in a match, then its avearage pfs will be zero! :c)

BTW - does anyone know the speed you will get if you use the 12" KOP wheels and either of the two transmissions they gave us this year? (assuming you use the drill motors)

Ken,

My rough (in my head) calculations say that you will go about 18 ft/s in low gear, and about 72 ft/s in high gear. I think you would want to gear it down a bit. :slight_smile:

-Chris

aye…our robot is using a 1 to 4 ratio with sprocket and chain…roughly, we should be going like 6 fps in low gear if I remeber the calcs right…

FIRST gave a 10 tooth, 20 tooth and 45 tooth gears. If you use the 10 and the 45, you go 5.25 ft/sec in low gear, if my calculations are right with a 12" wheel.

We used that same ratio last year. I assume you are talking about the drill motors. If so, youre going to go something like 3-4 fps, with a lot of torque.

[edit] that is with a 7.5" wheel. You will go faster or slower accordingly, based on your wheel sizes.

Cory

I guess I got the calcs wrong then :stuck_out_tongue:

You might want get some new batteries for your head - those numbers don’t pass the sanity test. You’re going to cross the field in 0.67 seconds?

We’re gearing for 7-9 fps this year; we’ve found that at much higher than 12 you start to lose control.

Chris/Ken–
Using my whitepaper. (shameless plug).
With the FIRST given 12in wheels, and a 10:45 sprocket reduction.
I calculate:

Drill Motor in high:
18 fps free speed (probably closer to 16.5fps)

Drill Motor in low:
5.24 fps free speed (probably closer to 4.7fps)

John

Your bot 2 years ago (2002) went 13 FPS??? I seem to recall it goign about the same speed as us which was about 6 FPS :stuck_out_tongue:

Maybe you’re thinking of the midlevel gear we ran at MMR, which was around 6 or 7 FPS. I was referring to the “overdrive” gear, which we didn’t use until late in the season. It was theoretically 13 FPS. In practice it was less than that, as we found when we clocked it in the 10-11 FPS range in some testing last summer. It was quite a bit more than 6, for sure. Are you sure you have your numbers right?

This year we should be around 11fps in high and 3fps in low.

hopefully about 13 or 14 in high, 7 to 8 in low

Lets see Output of the Gearbox last year at 1600 RPM Max, reduced 3:1 into a 5" Pulley with treads gives us in the neighborhood of 8368 Inches/Min = 11.6 ft/sec in high (Just under 3 in low) and there were only a few robots that could stay with us in real life speed.

the drills work out pretty well,

last year we had 160 (inches or foot !?) pounds of torque on 494’s dyno with 6-8 fps.

in high we had 10 fps with an untested torque in high because we broke it’s 1/4 inch steel keyway with the amount of torque we put on it in low speeed

sorry guys on 494!