Re: 2015 Beta Testing - The Components are Here.
 

But hot glue was not legal under the 2014 rules with certain inspectors...:(

Re: 2015 Beta Testing - The Components are Here.
 

What rule did they site? I can't think of any.

Re: 2015 Beta Testing - The Components are Here.
 

Search is your friend.

Re: 2015 Beta Testing - The Components are Here.
 

Yep. Good thing we're not competing right now.

We'll have to think of something else for the competition season if the rule isn't changed. That shouldn't be hard.

Re: 2015 Beta Testing - The Components are Here.
 

Wow, I have read the rules many many times since 2010 and never even considered hotmelt to be an issue even though it is very clear, and I have inspected for the past three years. I do not like hotmelt and it would not be accepted in a real piece of automation equipment but neither would a connector that comes out as easy as the PWMs. I also do not like securing the cables such that they force the connectors to stay on as it is not good for the thin conductors.

Looks like a good mechanical guy will just have to create something to lock them into the various devices where they are used....

Re: 2015 Beta Testing - The Components are Here.
 

Not to beat a dead horse, but I've seen/heard of hot snot/melt/glue used in nearly every industry, including aerospace. The only reason NASA doesn't use it is because it wouldn't pass degassing. If it weren't for the need to travel in space, you bet they would use it.

Re: 2015 Beta Testing - The Components are Here.
 

But there are so many locking connectors on the market. Components do fail and I want to be able to unplug a cable without having to cut through glue and not have to worry about it loosening up.

Re: 2015 Beta Testing - The Components are Here.
 

Low temp hot glue is very easy to remove w/o issue.

You also can't modify COTS electrical components in FIRST to include a locking connector unfortunately, so that's not an option.

Re: 2015 Beta Testing - The Components are Here.
 

I was thinking more of a sort of clip that would sit between the device and the board it is mounted on that would bend around and lock the connector in place. The clip part would be like the clip on the digital side car.

Re: 2015 Beta Testing - The Components are Here.
 

You can wire tie the pwm cable to the chassis close to the plug. You can make a bracket like this. I am not sure which team to credit for this.

Re: 2015 Beta Testing - The Components are Here.
 

The bracket is exactly what I meant. Positive locking of the connector without stressing the wires.

Re: 2015 Beta Testing - The Components are Here.
 

There's no difference in the performance of a compressor under the old control system vs. the new control system.
The only difference between systems is how they react to problems.
If the compressor is too large and tries to pull too much current for too long, the old system would trip a self-resetting breaker for longer and longer periods as it heated up, while the new system would react much faster and immediately cut power for a second, try again, cut power, etc.

Here's a plot of the current draw of an old KOP Thomas compressor filling one storage tank. There is a momentary spike when the motor is starting (locked rotor) of ~36a for a fraction of a second, then it drops way down before starting a climb as the pressure in the tank increases.

A ViAir 90C compressor draws much less current, but takes longer to fill the same small volume. The difference is more noticeable with more storage tanks.

This test was done with the new control system on an older robot that didn't have a pressure transducer to record the corresponding pressure. The same test on an older control system looks identical. Somewhere I've got time vs pressure graphs from tests we ran for these two models- here's a post comparing them.

Re: 2015 Beta Testing - The Components are Here.
 

Will it be possible to override the logic that controls the compressor via CAN? I have been seeing many teams suggesting that it can be beneficial to cut power to the compressor during a pushing match, which would not be an option this year if the code has no control over this.

Re: 2015 Beta Testing - The Components are Here.
 

Being able to control the on off of the compressor is important for power management. Is this ability present in the software?

Re: 2015 Beta Testing - The Components are Here.
 

Yes, we have the same control over enabling/disabling the compressor from user code as we did before.
We can check just it's status to see if it is currently on or not as well.

The only difference there that I can think of is that teams cannot bypass or ignore the pressure switch cutoff in user code any longer.
They have to use the given functions for compressor control that have always been there.
So user code cannot drive the compressor past the FRC legal limits, but it can shut it off whenever it wants.