"The Little Things" - Helpful hints for all

[Nate Laverdure]

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.

Originally Posted by Al Skierkiewicz

Hot glue is 'HOT' by nature and the devices you are trying to glue are not. [snip] Rapid heating and cooling can tear parts from the circuit board.

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.

[Al Skierkiewicz]

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.

[pfreivald]

Originally Posted by Al Skierkiewicz

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.

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?

[Alan Anderson]

Originally Posted by Al Skierkiewicz

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.

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.

[FrankJ]

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.

[AllenGregoryIV]

Originally Posted by Alan Anderson

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.

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?