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VEX V5 system
My initial take is that the legacy ports may no be be adequate.  But I am sure brighter minds than me will work out a good system.  What I am most interest in for BEST (based on our connection problems) is this snippet from the forums 

"As far as the radio is concerned, we use narrowband 2.4 (as opposed to Wifis broadband) and the current technology chipsets at 5.8 do not support narrowband. Narrowband is how we can have multiple robots on the field without interference at an event like VEX Worlds, etc. Broadband signals should not interfere with the narrowband 2.4 we use. If you think that is really happening, then you should check a different set of radios as you MIGHT have a radio hardware issue. When we tested 100 pairs of VEXnet 2.4 in our building, it completely rendered our broadband company wireless useless, but the robots never lost connection."
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VEX V5 system
Although it may be a bit early as VEX has only released basic product information...

Any thoughts or info about the new V5 components and BEST?


Basic V5 info from the VEX website:  https://www.vexrobotics.com/v5


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Friction Tape
As long as you are testing different ideas, here are a few other things my team has tried or seen over the years.
  • "knobby" wheels - not a smooth circle, but many small cuts/ridges around the edge
                  We've seen ridges from .125 in wide to 2 in wide
                  We've seen knobby tires with and without friction tape
  • instead of string tread, take a long strip of friction tape and twist it into a strand (use a drill)
  • Hex-head sheet metal screws as treads
  • Omni-Wheel rollers

One year we considered printing a strip of tread from a flexible filament as our TCP (coiled for compliance as jgraber suggested), but we have not seen that used on an actual robot.

I am guessing that your robot moved forwards and backwards well, but could barely turn.  If you have 4 wheels, you may want them to have different traction properties to reduce turning scrub.  We've have ended up using onmi-wheels the past few years.  We have tested other options, but have ended up with 2 omni-wheels on the robot each of the past 3 years.

I've seen teams use friction tape on two wheels and electrical tape on the other two so that they slide side to side easier.

Good Luck.

Post some general findings if you get the chance.

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Spirit And Sportsmanship
not pedantic at all.  Our team was docked 10 of the 20 points in this category.  judges comment: "I saw no one making adjustments to the robot."  we also won the most robust robot award.

Perhaps some modification to the wording of the rubric is in order.

Similarly to ptownrobotics... we were also docked 11 of 20 points by another judge who "saw" no evidence of our team helping any other.  They definitely did - quite often, just not in front of that judge.  One practice that we see at regionals, that we do not see at the local level is a ballot for teams to list those that have helped them.  They get a point for turning in a completed form.  and judges have more data as a basis for their scoring.
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Problem losing connection
purely on anecdotal evidence, I am more convinced that our issues this year are related to WiFi interference.  

our disconnects were shorter duration this year - probably 3-5 seconds on average.  Last year, some of them were quite long.  In fact, the cortex we used last year has not been upgraded to power pole connectors yet and it is easy to force a power disconnect on it.

Talking in more depth with our drivers, they confirm that there was a brief disconnect in most competition rounds... but our hub ran a "Chancellor's Challenge" event after the awards ceremony (College engineering club vs. regional bid winners - 4 rounds) and they do not remember a single connection issue during 4 consecutive rounds (same battery).  As this was after the awards, some teams were clearing out and a large amount of the crowd was also leaving.  There would have been a lot less noise.

FYI... small hub - only 7 teams this year - no game mode dongles
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Problem losing connection
Well... I spoke too soon.

Our drivers only reported 1 or 2 connection drops while practicing outside of the competition venue (at school, no other robots)
There were a few more drops during practice night at the hub, but not too many.

During the competition... our connection gremlins returned

I would not be exaggerating too much if I said the robot lost connection once per round. (easily more than 50%)
At times it lost connection while sitting in the starting box waiting for the round to start.
Other times, it was while simply driving forward (2 large motors on ports 5 & 6).
We had a driver stall a winch motor while also driving - the nylon cord eventually broke  -  did not lose connection (probably the largest power demand)

There was no consistency to when it failed, so I don't think it was an overheat/overload issue.
The cortex is different than the one we experienced issues with last year.
We switched out VEXnet keys.
The cortex is near 2 servos, but about 8 inches from the closest motor.
The cortex has power pole connectors wired directly to the cortex (no adapter).
Batteries were never used for more than 3 rounds before recharging, and drops occurred on fresh batteries.
tried to cause a disconnect by jolting the cortex/keys - could not

I was not aware of other teams having issues, but it would have been easy to miss.  (The hub did ask for hot-spots to be turned off at one point, so...)


I really think it has to be an interference problem.  I will give the team a brand new cortex for regionals (just in case) and have them test an extension USB, but I don't think we will be able to replicate the game day WiFi conditions very easily... we will have to try... maybe at a basketball game with robots from the engineering class running.

on the bright side... Our veteran drivers were used to the issue and handled it very well... and the taught the new drivers not to panic.  They also designed the gripping manipulators to "lock" into place to resist damage - they never dropped an item when connection was lost.

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Winning scores at hub competitions
From the Penn State DuBois hub today... completely unofficial...

highest single round score was 528
fastest manikin rescue (that I saw - could have missed a lot) was 21-22 seconds in the same round as the high score.  It could have been quicker as one manikin foot was out of the starter box and had to be pushed in after the robot dropped it.
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Problem losing connection
While I can't speak to exactly what is causing your issue,  I can say that jgraber has given you pretty good advice.  He helped us trouble shoot the issue last year.  We would have what we thought were connection issues almost every year.  We tried...

  • relocating the cortex away from motors
  • using a USB extender to relocate the VEXnet key
  • "shock mounting" the cortex to reduce vibrations
  • confiscating cell phones
  • programming solutions
  • multiple keys
  • Hub provided channel shunt (the radio dongle)
  • taping keys and battery connectors in place.
  • running tethered
  • and probably a few more

I think (fingers crossed) that we may have solved our problem.  The connection problem was not with VEXnet.  It was with the battery.

We talked to our hub and had the cortex converted to power pole battery connectors.  So far so good, but time will tell.  I've converted the batteries of our own vex kits to work with power pole adapters (for an engineering class) and problems have decreased drastically.  Once BEST season is over, I plan on changing them all over to power pole connectors directly wired to the cortex and completely eliminate the standard connector.

While most of the long list of things we tried did not solve the problem, they did lead to better design practices that I remind the team of each year

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Simulink Design Award 2017 - Win 1000$ in cash prize!!
Just to clarify;

At our kickoff, we were told that the cash prize had been reduced to $1000 now that there is a 5th regional.  (That is also what is referenced at the link you provided.)  Is it staying at the previous level of $1500 or is $1000 correct?
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Nationals Competition
I would have to agree with jgraber... for now...  the cost beyond regionals is too much for some teams.  My team is from one of the Pennsylvania hubs and our regional has always been in Alabama or North Dakota.  Depending on travel costs and # of students (usually 20 or less), our budget has ranged from $12K - $19K.  It requires a massive effort fundraising and we probably couldn't manage a national if we qualified.

Now, If we get the expansion that we are hoping for with BEST HQ moving to Pittsburgh... maybe we will eventually have a closer regional and it could be feasible... for us.  

With a national comp, you also have the logistics of disperse teams just getting their booth and robot to the venue.  It is normally cheaper (and safer in December) for us to fly from PA to ND.  That means we have to ship the booth & robot, make it simple enough to take on the airplane, or find a parent with a van willing to make the drive in who knows what weather.  All daunting tasks that we have to consider when designing everything way back in September... when we may not even qualify for regionals.
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Sheet Metal Bending Tools
Our kids have started using the inexpensive harbor freight brake and they usually get better results than their old way of bending in a vise.  

With that said... the brake can be very accurate IF the width of the bend is not too large.  Up to 3" or so and it works very smoothly.  6-8" requires more care (and clamps) but works fairly well too.  Once you get over that length, the bends are very imprecise and difficult to make.  

2 years ago, the kids bent a 16"x1" strip into a 16" long L.  It was a very difficult process that used a clamp about every 2 inches.  The brake deflected so much that someone else had to use a hammer to assist and only the edges were bent to a full 90 degrees.  They finished it by clamping it in a vise and hammering down the middle... it wasn't the best looking part, but it was functional.

So... if you have the budget, the cheaper brake is a nice tool to have, but you can survive without it too.  If you get one, you need to know its limitations and temper the kids' expectations.  I wish the thing was only 8-12" wide.  It would be cheaper, take up less space, and not mislead you to its capabilities.

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Honors Cord for graduates on a BEST robotics team
Definitely not an official recommendation...

in my opinion, the BEST (pun intended) option would be to use a multi-colored cord with the 4 BEST colors or Red-Yellow-Blue-Green.  

However, I don't know that I have ever seen a 4-color honor cord.  Most of them seem to have 3 strands.
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VEXnet connection and 9V backup battery
I seem to remember a document in the file manager that detailed the conversion of the cortex and batteries to powerpole connectors.  Does it still exist and if so, where?  I have not found it yet.  I would like to ensure that any changes I make to our own equipment is in line with the approved BEST changes that the hubs can do.

OK, so I now realize that the document I am thinking of is for hub personnel to use in preparing the kits.  It is probably no longer posted for the general BEST community.  
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VEXnet connection and 9V backup battery
Thanks for the input.  I will definitely have the students try to troubleshoot per your suggestions (although I cringe at them getting carried away with the hammer).

We already employ a basic slew rate solution through Simulink, but have wanted to refine it.  I will share this post with our programmer so he can keep in in mind as he looks into that.

I have brought the power connections to the attention of our hub director.  Hopefully I can gain some traction on having them updated.  In the meantime, I may make the power pole modification on a backup cortex/battery and see if it has an impact.

My gut (which has been known to be wrong) is that it is your hypothesis 1 is the cause.... or maybe 2b... we shall see

Of course, I don't remember any connection drops / power losses while running tethered (which we did during regionals semifinals a few years ago), but that is a much smaller sample size.
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Hydroponics Area
good catch... our hub missed the bolts but weighted the back corner of the assembly to prevent tipping
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