Minibot climb rate

[Travis Hoffman]

I just received my (free, with hundreds left in stock - I will not be providing details [again] - search for it - I feel like Gary and Eric now) FIRST Choice FTC Mini Kit. Rushing (imagine me doing that) back to one of our labs, I measured the following weights for the FTC DC motor and battery pack:

Motor: 210.35 g
Battery Pack: 599.69 g

What are these strange Copiolian measurements of which I speak?

Motor: 0.464 lb.
Battery Pack: 1.322 lb.

Originally Posted by engine1320

Where do you order these kits. We have never done anything with FTC. It is a stretch for us to do FRC. This is a challenge we have. Where do I order the 2010 FTC Base Kit. I looked on line but all are Back ordered. Where have you bought these from. Thanks

Also, enclosed within my effectively-packaged AndyMark box was a sheet proclaiming a 30% discount on additional *in-stock* TETRIX parts for FRC teams via www.legoeducation.us/FRC. No blar comments from the peanut gallery - this is one thread that hasn't given me a headache yet.

[Gary Dillard]

ALL RIGHT! Travis is the go-to guy for FTC questions

A couple quick ones -

Weight of the wheels?

Thickness of the gears? (and weight, but I can calculate close enough)

Verify 32 diametral pitch on the gears (is the 120 tooth gear 3.75 PD?)

Thanks

[Travis Hoffman]

Originally Posted by Gary Dillard

ALL RIGHT! Travis is the go-to guy for FTC questions

A couple quick ones -

Weight of the wheels?

Thickness of the gears? (and weight, but I can calculate close enough)

Verify 32 diametral pitch on the gears (is the 120 tooth gear 3.75 PD?)

Thanks

Travis is surely not the only one with an FTC mini kit handy, as at least 800+ other teams have ordered these.

Did you know that the gears were "Assembled in USA"? Probably the reason behind the cost.... Go go gadget globalization.

Mr. Ruler sez that the 120 tooth gear's PD is 3.75", and its thickness is 0.25"-ish.

Mr. Scale sez that the 120 tooth gear weighs 114.71 g / 0.25 lb. (in its thin plastic packaging - didn't want to mess up the shiny finish).

Mr. Scale also sez that the 4" wheel weighs 117.24 g / 0.26 lb.

[billbo911]

Originally Posted by Travis Hoffman

Travis is surely not the only one with an FTC mini kit handy, as at least 800+ other teams have ordered these.

Did you know that the gears were "Assembled in USA"? Probably the reason behind the cost.... Go go gadget globalization.

Mr. Ruler sez that the 120 tooth gear's PD is 3.75", and its thickness is 0.25"-ish.

Mr. Scale sez that the 120 tooth gear weighs 114.71 g / 0.25 lb. (in its thin plastic packaging - didn't want to mess up the shiny finish).

Mr. Scale also sez that the 4" wheel weighs 117.24 g / 0.26 lb.

Did you get a weight on the 80 tooth gear? Or would I be close enough by extrapolating it from the 120 tooth?

By extrapolation I'm guessing the 80 tooth gear is 76.47 g.

[Travis Hoffman]

Originally Posted by billbo911

Did you get a weight on the 80 tooth gear? Or would I be close enough by extrapolating it from the 120 tooth?

By extrapolation I'm guessing the 80 tooth gear is 76.47 g.

I'm not in a position to do any more measurements today. Perhaps another can help out with additional measurements?

Is your math right? Gears are same thickness and have the same number/size of holes.

120T area = pi * ([120/32] / 2) ^ 2 = 11.045 sq. in.
80T area = pi * ([80/32] / 2) ^ 2 = 4.91 sq. in.

Density Ratio = 0.444

80T Weight estimate = 0.444 * 114.71 = 50.93 g

[DonRotolo]

Originally Posted by JamesBrown

Correct me if I am wrong but isn't it possible to use the Tetrix continuous rotation servos in addition to (or instead of) the allowed motors per rule <R92> A?

Interesting, but <R92>B states

B. no more than two motors (PN W739083)

No more than seems to exclude a third motor.

(Team Update 1 changed A to read "A. TETRIX components that are not in violation of any other rules", and B is an other rule)

[billbo911]

Originally Posted by Travis Hoffman

Is your math right? Gears are same thickness and have the same number/size of holes.

120T area = pi * ([120/32] / 2) ^ 2 = 11.045 sq. in.
80T area = pi * ([80/32] / 2) ^ 2 = 4.91 sq. in.

Density Ratio = 0.444

80T Weight estimate = 0.444 * 114.71 = 50.93 g

Fat finger on the calculater some where. Yours looks accurate..
Thank!

[Travis Hoffman]

Originally Posted by billbo911

Fat finger on the calculater some where. Yours looks accurate..
Thank!

80T Weight = 46.00 g (in packaging) - checked last night

[Madison]

Originally Posted by Gary Dillard

ALL RIGHT! Travis is the go-to guy for FTC questions

A couple quick ones -

Weight of the wheels?

Thickness of the gears? (and weight, but I can calculate close enough)

Verify 32 diametral pitch on the gears (is the 120 tooth gear 3.75 PD?)

Thanks

The gears are .25" thick. They do have a diametral pitch of 32.

They have a bore of 8mm with four 3.5mm holes on a 16mm bolt circle. There are also eight 8mm holes on a ~59.58mm bolt circle. I think these are decorative.

I can corroborate Travis' weight measurements.