Re: Minibot climb rate
 

3 seconds is doable. I don't think Frenchie is implying that the deployment time is included in their claim.

Re: Minibot climb rate
 

Is the mini bot allowed to have springs on it

Re: Minibot climb rate
 

We just got 2.93 seconds with our mini bot...in heavy mode. We haven't even started shaving weight off.

Re: Minibot climb rate
 

our minibot is going up in about 2.8 seconds. Not including deployment time, so it is doable, but deployment is where the race will be won.

Re: Minibot climb rate
 

theres no springs allowed on the minibot or for deployment--team update #1 said no stored energy in deployment.
and how did you ever get it in under 3 seconds if not with a spring/launcher thing??

Re: Minibot climb rate
 

The TETRIX motors are actually about 16W at peak power, not 8.43W as the spec sheet suggests. Surprisingly fast times are feasible.

Re: Minibot climb rate
 

Getting similar times on direct drive prototypes and 2-1 gear ratio prototypes... we are assuming similar times is due to gearing inefficiency and the added weight of all the extra gears, spacers, etc... The question is, how much better can we expect if we lighten up the Tetrix gears and improve gear alignment???

Re: Minibot climb rate
 

Strictly based on calculations and the specifications available, the difference in times when directly driven and when a 1:2 gearing increase is added is only 1 second.

The calculation with the gearing did not include the additional weight of the extra hardware and gears requires to add the gears.
When I calculated with the weight added, I only see a difference of .8 seconds.

Therefore, I am not surprised in the least that your times are very close. Add in a factor of human error if manually timing, and you could easily have a dead heat.

So, would lightening the hardware help? You bet!

Re: Minibot climb rate
 

I know this is a bit off topic but what size wire do you happen to use for wiring the motors?

thanks

Re: Minibot climb rate
 

So... we saw smoke when we made our bare bones minibot try to climb, with a modest overgear (0.5:1). These things can't be stalled for even a half second, apparently? I have no idea what smoked or whether or not the motors still worked, but if the motors are that delicate...

Re: Minibot climb rate
 

Does rule include using surgical tubing as a drive belt and a friction surface on the wheel?

Re: Minibot climb rate
 

We smoked a motor hitting the top of the pole and not shutting off...probably a maximum of about 3 seconds of full voltage on a jammed motor.

This happened on the very first occurrence.

My suggestion is make sure you put in the motor cutoffs at the end of the race or make sure your wheel contacts are slippery enough to keep that motor turning.

I'm glad we ordered two extra motors. I expect many teams will fry motors before getting a working minibot. ::ouch::

---

BTW, our prototype uses solder on the motor contacts and uses standard tab and receptacle electrical connectors- not wire nuts.

If they didn't want us to use solder, then it would have been nice for them to supply Tetrix "DC Motor power cables". http://www.legoeducation.us/store/detail.aspx?ID=1629

Re: Minibot climb rate
 

Nope - I meant "surgical tubing to store energy" rather than "surgical tubing". If the tubing isn't storing energy there's no rule broken.

Re: Minibot climb rate
 

as a referance, Today, team 2200 made it to the top (no top plate yet) of the pole in 2.6 seconds, with a minibot that weighed 4.9lbs. and we still have LOTS of room to save weight.

Re: Minibot climb rate
 

What type of gearing are most of you advanced minibotters using?
Bruce