# pic: 1557's 2010 Robot

Actual size; Ball for scale…

Does anyone know how many FPS 21mph is?

We did the calculations ourselves and came out with around 31fps which is unreasonable

30.8 FPS. theres an app for that.

We did use an Iphone, but 31fps seems like way to much?

21MPH*5280(F/M)/60(S/H)/60(M/S)=30.8fps

Why? Do you believe your robot is traveling that fast?

It seem to be…We measured it with a radar-speed gun, then double and triple checked it…we came out everytime between 20-22mph…

I can’t believe it is going that fast, but it does look like it…

Is it about as fast as Usain Bolt? If so, then that’s about right.

There’s no way a driver could handle a robot with that speed… you’d be going end-to-end on the field in less than 2 seconds. Your radar gun clearly didn’t work properly.

That’s what I was thinking, but it is incredibly fast, over 20fps. It easily covers our 10 foot square of carpet in less than half a second…

interesting choice to go tiny, got any videos? looks good! say high to all the ex Mars folks for me. See ya all in a couple weeks!

Good lord. What’s your motor/gearing/wheel size?!

10x 6’ plaction and KIT wheels.

2x (12.75:1) ToughBoxes with 4 CIMs.

(roughly) 1.4:1 Chain Reduction

Let’s see… CIM free speed is 5300RPM… I’m assuming 6"(in) not 6’(ft) wheels

5300rpm/60 = 88.3[rev/s]…

88.3[rev/s]/12.75/1.40.53.14[ft/rev] = 7.77ft/s maximum top speed assuming no load, which of course is a bad assumption, so your real top speed will be a little lower. Quick, but not insanely fast.

Ya that makes more sense…We did this after we found 31fps untrue, and we got the same result.

But that still dosent explain how it moves faster that that…Ill put up a video as soon as it is emailed to me :rolleyes:

Looks like it’ll fly through the tunnels and ease over bumps, NICE.

With the given information, you should expect to see between 6.5 and 7.0 ft/sec.

In order to reach 31 ft/sec, you would need a final gear ratio between your CIM motors and the output wheels of aproximately 4:1, depending on where in the speed torque curve you would wish to operate at. For comparison, the first stage in the toughbox is 3.57:1.