Passing inspection at worlds

VEX Robotics Competition Discussion VRC > Skyrise (14/15)
1

Next week some of you will be in Kentucky for the 2015 world championships. There are some things you can do ahead of time to help get yourselves smoothly through inspection.

1. Software
Update to the latest software now, that’s cortex V4.25, joystick version 4.25 and VEXnet V1.46. As mentioned in a previous email, worlds will be a VEXnet 2.0 only event and you will be receiving two keys which will presumably be on V1.46.

If you are a ROBOTC user then also update to the latest version of that, either V4.30 or V3.65, both of these versions are compatible with the latest VEX firmware and are stable.

If you are an EasyC user then update to V4.2.1.9

If you are using PROS or ConVEX I wish you good luck :slight_smile:

Don’t leave this update until the last minute, do it this week if possible.

2. pre-inspection
Download the inspection sheet from here and do a pre-inspection yourself.
http://www.roboticseducation.org/vex-robotics-competitionvrc/game-day-running-an-event/

There is pretty much a zero tolerance policy regarding the items on this sheet. A robot that is 18.1 inches in height will not pass, polycarbonate that is thicker than 0.07" (1/16th inch) will not pass, acrylic used in place of non-shattering plastic will not pass. Now this should be the case at all events but you have to remember that this is the world championship, we have several hours for inspection and everything must be correct.

3. Motors
Motors will be checked in the same way as last year using the test described here.
http://www.roboticseducation.org/documents/2014/08/ptc-verification-testing-guide.pdf

My best advise here is “do not modify your motors”. It would be wonderful if no teams were caught cheating this year.

4. Accessories
When you come to inspection remember the following so we don’t have to send you back to your pit area to get them.
Batteries
Joystick
VEXnet keys
Backup battery
Two Team ID plates on the robot.
A flag holder (Karthik ruled this was required earlier today, just add a 1 inch standoff somewhere).

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2

This is my first year going to worlds and I was wondering if they test all ten motors? I am curious because certain mechanisms on my robot might be damaged before the motor stalls. More specifically, I think the 84 tooth gears on my lift mechanism might possibly crack because they are not the high strength kind.

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You need to be prepared for any of the motors on your robot to be tested. At least one motor from every sub-system will be tested and perhaps more. We did not see any damage caused by these tests last year so I would’t worry too much. Remember, I’m posting this unofficially but it’s pretty accurate information.

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4

In the ptc instruction sheet, it says that preferably one motor per robot system like one motor of the lift, one motor of the drive, etc. Your motor will probably stop before the gear will be damaged because only one motor per robot system will be tested at a time, which won’t be as much power.

5

OK, thanks for the info. I just held back my lift mechanism very cautiously, and the motors stalled before I heard any cracking sounds, so it might not even be an issue.:smiley:

6

As davinciguy said, you probably have more than one motor operating your lift. One motor will be tested by unplugging and connecting it to another cortex to test it. This reduces the stress on all of the mechanical parts and is very unlikely to cause any damage, don’t worry.

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7

Some motors have hard to reach connectors. Can the 3 wire interface to the cortex be used to test things? Or just the two wire connections?

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The document said that either 2 or 3 wire connections could be used.
See page 4, step 2, the motor is shown plugged in both ways.

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According to the PDF that jpearman posted the link to, it does not look you will need to unplug the connection between the motor and the motor controller. I agree that it will be very hard if you need unplug the two wire connections. Maybe jpearman can confirm what I just said.

10

Yes, either. Hard to reach connectors won’t mean that an inspector will ignore those, in fact, they are more likely to want to test those motors.

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11

I’m a little confused about what you mean. Will the inspectors want you to unplug motors from motor controllers or unplug motor controllers from the cortex or both?

12

Thanks.

I think I will set up a black market/popup/illegal stand selling zip ties and snips next to the inspection stations. Must be lots of rework to your wiring after inspection.

:smiley:

13

The document then shows the cortex with a 2 wire wire in port 10 and a motor controller 29 into port 4.
The next image also shows just unplugging the mc29 from the competition cortex and into the testing cortex.

14

Ok, this is not rocket science.

Somewhere between your cortex and your motor a wire will be disconnected and plugged into the test system. The inspector will identify the easiest place to do this, that may be back at the cortex or perhaps after an MC29, all depends on how the wire is routed. Whether the MC29 is also part of the test or not does not matter, it’s the motor that’s being analyzed.

If you say to an inspector, “no please don’t test that difficult to get at motor”, they might suspect you are trying to hide something and want to test that one.

The inspectors are not trying to make your life difficult and will not want to damage your robot, but we all want this to be fair competition and, unfortunately, this is one measure that’s being taken to ensure that.

I would assume that there will also be spot checks during the qualification and elimination rounds so be prepared for motor tests at any time during the event.

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15

OK, thanks.

16

Does this mean we may get to meet you at worlds?

17

Does this mean our kids will need to unscrew all of the stainless steel lines pumping liquid nitrogen to their PTCs or only some of the lines?

18

HaHa, for all you know we are on the same flight next week.

Yes, I am a field tech for Arts Division, same as last year, and will be involved with HS inspection as well.

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19

Personally I use Fluorinert

(joke)

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