Re: "The Little Things" - Helpful hints for all
 

I think most of us can agree that hot gluing your PWMs is not an elegant solution. We can put this aside and focus on whether it's really a practice that can cause equipment damage.
This particular concern sounds silly. Your standard 99.3Sn-0.7Cu lead-free solder melts at ~440 F (PDF link). Eutectic 63Sn-37Pb solder melts at 361 F. Low-temperature "hot melt" glue guns range from 170 - 250 F.

Re: "The Little Things" - Helpful hints for all
 

Nate, it isn't desoldering I am concerned about. It is the thermal shock and the resulting expansion/contraction that may force components off the board or produce cracks in the circuit traces.

Re: "The Little Things" - Helpful hints for all
 

So, I'll admit to 1551 being hot gluers... (We didn't realize it was a violation, had always passed inspection even at CMP, and will not be doing it in the future now that we realize it's illegal.)

In our experience, the pwm connections tend over time to jiggle free, even with strain relief. Once we started hot gluing, we never had another problem.

Given that this is a helpful hints thread, what do teams do to secure pwm connections on the sidecar and on speed controllers without using hot glue?

Re: "The Little Things" - Helpful hints for all
 

We're talking about the PWM connector on a Victor here, right? The top of its shroud is nowhere near any circuit boards or components, and the typical practice has been to use less than a pea-sized bit of glue to keep the plug from vibrating. Removing it is trivial if you have a thumbnail. I do not believe there is any danger at all of thermal shock to the board. The only thing that will get remotely warm is the surface of the plastic. It's not like anyone is suggesting using the hot glue to make a watertight connection around the entire connector.

That said, it's still glue, and gluing a speed controller has been explicitly forbidden by the rules.

Re: "The Little Things" - Helpful hints for all
 

Don't disconnect plugs by pulling on the wires. Be it battery connectors or PWM cables.

Keep metal swarf away from electrical components.

I am going to leave off with the hot glue thing with "it is against the rules so don't do it." Makes the advantages/disadvantages of doing so moot.

Re: "The Little Things" - Helpful hints for all
 

Alan,
Some of the applications of glue I have seen give me nightmares.

Re: "The Little Things" - Helpful hints for all
 

Has anyone ever had problems with velcroing (or wire-tying) electronics like motor controllers? We don't do it, but I've always been sketchy on the explanation.

Re: "The Little Things" - Helpful hints for all
 

I've always consider hot glue to be okay. Similar to the adhesive on velcro is that still allowed? I have also seen teams use clear nail polish to hold PWM cables into speed controllers would that also be illegal?

Re: "The Little Things" - Helpful hints for all
 

When cutting or drilling parts that are already on the robot, make sure to protect your electronics from metal shavings and the like.
We have a blanket that we throw over our electronics when necessary, but when possible, we take the part off the robot to machine it first.

Re: "The Little Things" - Helpful hints for all
 

Yes. We think we had some problem with that. "The Little Things" must have been falling in :)

Re: "The Little Things" - Helpful hints for all
 

We've been velcroing just about everything on the control board for as long as I can remember, and we haven't had any problems so far. However, don't velcro the main breaker. There isn't enough surface area on the bottom for velcro to effectively hold it in place, and it's too important to have flopping around in there.

As for things that I'd suggest, I've got:
-For Chairman's, always have at least one boy and one girl on the presentation team. Trust me on this one.

-Also for Chairman's, practice the presentation ridiculously slow in front of the entire team. In addition to making you look like fools, it serves a few purposes: giving the presenters practice under pressure, making the presenters used to going slowly, and giving the entire team at least a basic understanding of what the Chairman's submission contains. Which leads into my next one...

-Everyone on the team should be able to talk to the judges about the team's outreach. Without fail, judges always come by when the spokespeople are in the bathroom, so others should be able to cover until they're back.

-In terms of outreach events, I think Karthik said it best when he said that you should find that "pie in the sky" and MAKE IT HAPPEN. That's where amazing Chairman's submissions come from--that crazy idea that worked.

Re: "The Little Things" - Helpful hints for all
 

My take on the Glue vs No Glue debate :D

Re: "The Little Things" - Helpful hints for all
 

My opinion is that the adhesive on velcro is not considered "glue" for this purpose, it fits in the same group as labels. Nail polish on the other hand may be considered more than adhesive backed materials.
We used velcro in the past but abandoned it in favor of tie wraps. They are cheaper, easier to use and just as fast to replace components.
As a side note, the Q&A is the only place to get definitive answers to rules questions. My posts are my interpretation of the rules. I have been wrong before.

Re: "The Little Things" - Helpful hints for all
 

Yes. Make sure your whole team knows about your outreach and can speak semi-intelligently about it.

However, I have heard stories from several years-worth of my students at different regionals saying judges have "interviewed" them in the bathrooms - so you should always be prepared to answer questions about your team!

As a corollary, make sure your non-robot students have a basic understanding of your robot's functionality. Our non-engineering captain last year claimed to the judges that everyone on the team was instructed on how the robot functioned even if, like him, they didn't work on it. They called his bluff and made him explain the systems. He did a good job!

Re: "The Little Things" - Helpful hints for all
 

I can cite many instances of an all-male or all-female presentation team winning a Chairman's Award (at both Regional and World Championship levels).

Re: "The Little Things" - Helpful hints for all
 

Al, how would you feel about using nail polish as a marking to help quickly ID which direction the connector goes in and where? Reason - Nail polish comes in a lot of colors, is pretty cheap, readily available. It COULD be considered adhesive holding the connector in.

(Obviously, if I plan on doing this and there is ambiguity in the rules I will post in Q&A during season. Just trying to get a bearing here)

Re: "The Little Things" - Helpful hints for all
 

The trouble is the Q&A often creates more ambiguity than they resolve.

Re: "The Little Things" - Helpful hints for all
 

"To Glue or Not To Glue"...as an electrical engineer I don't see any problem using regular hot glue to stick PWM wire to Victor/Talon or any controller. Though I think this is not tampering (no cutting, damaging or enhancing the functionality to take advantage, not a source for safety concern etc.), but the inspector may not have the same opinion. We avoid this situation by using hot glue or electrical tape to secure the wire to the robot frame, a little before it reaches the motor controller. Typically we use velcro to secure the motor controllers and the power wires (both in and out) are secured by zip tie. The motor controllers don't move as much as the loose PWM wires. Then we use electrical tape to fasten the PWM wire to the fan without blocking the air circulation. On the other end, pins on the side car will keep them secured.

Re: "The Little Things" - Helpful hints for all
 

Re: "The Little Things" - Helpful hints for all
 

That is awesome.

Re: "The Little Things" - Helpful hints for all
 

We never had any PWMs falling out. However, I love that clip and will forward it it my team!:D :D :D :D :D

Re: "The Little Things" - Helpful hints for all
 

Can the speed controller sit flat with it on?

Re: "The Little Things" - Helpful hints for all
 

No, but if you use spacers under all speed controllers you can run pwm cables under them.

Re: "The Little Things" - Helpful hints for all
 

Some redesigning can be done!

Re: "The Little Things" - Helpful hints for all
 

ifi (before it became vex) used to make a sheet metal clip like that

http://www.robotmarketplace.com/prod...C-PWMCLIP.html

Re: "The Little Things" - Helpful hints for all
 

I like that!

Re: "The Little Things" - Helpful hints for all
 

Me, too. Now that we have sometimes-access to a CNC plasma cutter, we may have to make a few gazillion of them. :)

Re: "The Little Things" - Helpful hints for all
 

Had one of our programming students summarize and categorized this list. He specifically told me I was making him do busy work. which I was not, I just thought that there was a ton of good information in this thread that I wanted to capture.

Thanks to all that contributed to the thread.

Thanks to e2 (MasterEric on CD) for compiling the list and categorizing.