Minibot Time Showcase

FIRST General Forum
#71

<R25> has an exception clause which refers to <R33>

Exception: A limited amount of FABRICATED ITEMS (not to exceed the limits specified in Rule <R33>) may be reatained as part of the WITHHOLDING ALLOWANCE and brought back to the teamā€™s home facility for continued development.

<R33> Exempts the minibot from the WITHHOLDING ALLOWANCE allowing you to work on it even if youā€™ve already used your 30 pounds.

If we can work on the minibot at home after the ship date, I donā€™t see how Thursday night of a tournament would be any different.

#72

Can teams close to home use their fabrication capability outside of the competition site during Thursday through Saturday? I would not think so.
Withholding applies to everyone and I thought it meant material can be brought in Thursday. No fabricated material can be brought in or out between Thursday and Saturday. COTs and raw materials can be brought in any time during competition and worked on during open pit times.

Fabrication outside the competition site and during the Thursday through Saturday time frame, either ā€œin the hotelā€ or at the home base facility does not seem consistent with the intent of the rules.

I could be misinterpreting.

The ā€œhomeā€ teams only advantage should be knowing where to get COTs locally.

#73

I donā€™t believe the Withholding Allowance applies between individual competition days. That would be a rather large loophole.

#74

When I read the exception, I assumed it only applied to the last part (shipping the robot after the event). However, I can see how since itā€™s separated, it could be applied to the entire rule. If you are concerned about that, it would make a good Q/A question.

#75

I canā€™t wait to see how many minibots actually come in at the times people said they would!

#76

Indeedā€¦ Some people have been quiteā€¦ exhuberantly misleading when it comes to minibot timesā€¦

(I wonā€™t mention any names, but one of these people has the initials ā€œJason Reesā€ā€¦) :stuck_out_tongue:

#77

I did not think those times were possible until we hit a breakthrough last night. Now I am sure 1.6-1.7 is possible to do reliably. :slight_smile:

#78

Whoops.

#79

team 3467
first minibot goes up in 2.6 seconds
http://www.youtube.com/user/frc3467?feature=mhum
we also are making anther one that we estimate for it to go up in 2.2 seconds
god way to start our first rookie year

#80

We are arround 6.5 sec complete-- You can view here


Unit is about 7 LBS and has quite a bit of friction but after 4 weeks of protos that didnā€™t work, we are happy

#81

Oh, Iā€™m sure of it, too. We have about 1.8 seconds reliably. I was just picking on Mr. Rees. :smiley:

#82

Nice job. I have talked to a whole bunch of ā€œ3 secondā€ teams that still canā€™t deploy there mini and hope to figure it out laterā€¦

At a minimum it is worth 10-15 points. If it works every time, I would wager this will get you picked up for eliminations and thus well worth the effort.

#83

That is so true! We had a fast bot but it took quite some effort to get it onto the pole!

#84

Team 241 had a breakthrough on minibot design # 5.

Design #1 - tank= The All Tetrix Aluminum, nuts and bolts - direct drive 4" wheels on Tetrix gearbox and motors. Mousetrap action to connect to pole.
**
Weight 4.4# Time 4.5-5 sec
Reliability - 10/10 trials
Deployment 0.5 seconds - self-aligning to pole prior to End Game**.

Design #2 - add 2:1 external gearing to design #1 - mostly built but not tested. Stopped work when Richard published his dynamometer results of Tetrix motors with and without gearboxes.

Design #3 - direct drive motors w/o gearboxes with motors with 3/16" shaft covered in thin surgical tubing running on the inside rim of the 4" wheels.
Weight 4.5# Time - fail - the motors would slip on the inside of the rims.

Design #4 - ā€œthe crossbowā€ - direct drive motors w/o gearboxes with motors with 3/16" shaft covered in thin surgical tubing running on the inside rim of the 4" wheels. Inside rim covered with rubber band material to provide extra grip.

Weight 3.3# Time 7 seconds - too much friction on rubberband to surgical tubing contact. Very disappointing.

Design #5 - midget - direct drive to 3/8" wheels, Mousetrap action to connect to pole. Uses bare motors, battery, nylon standoffs, OFF switch and 3 or 4 nuts and bolts from the Tetrix kit.
Weight 2.1# !!! Time ~2 seconds
(still need to adjust deployment to allow either the midget or the tank and mount the turnoff switch) may add another 0.1 lbs.
Reliability - not known yet

No magnets.

#85

http://www.chiefdelphi.com/forums/showthread.php?t=92246&highlight=minibot+time+poll

Repeat threadā€¦

#86

In case you canā€™t read a date, this was first, by far

#87

Well, This is the culmination of six hours of work. Our team didnā€™t take the minibot seriously, so when the minibot team failed to produce in 6 weeks, I took it upon myself to fix it. When calculated, from the base of our deployment to the top, it will take a little over 4 seconds. Sorry about the video, I almost broke the robot. :ahh: It uses direct drive to two 3" wheels. The wiring has been planned for deployment, but has not been fixed yet.

Team3344mini.zip (1.24 MB)


Team3344mini.zip (1.24 MB)

#88

Pretty great weight. We have a similar super minibot that uses magnets and we are sitting at about 2.5 lbs.
How are you protecting the motors from smoking in case of a misfire? And how many motors have you gone thru?
We have inadvertently smoked 3 motors early on and since have been more careful.

#89

We have ruined the same amount :smiley:

#90