Wiring Kit

[Anthony4939]

We are looking at several wiring kits.

Should we opt for Futaba J connectors or universal connectors?

Also, looking to stock up on wire. What gauges are most common? 16, 18, 20?

Looking battery wire and servo wire.

[Joe G.]

Get the universal connectors. They will work with everything, the J-style doesn't necissarily.

Most common wire gauges:

6AWG for battery leads and main breaker
10AWG or 12AWG for most motor power distribution. 10AWG will have less resistance, which can really add up, but also weigh more. There is also this cool technology available in 12AWG which makes a big difference in moving components, and routing wire in tight spots.
18AWG for lower current components
22AWG servo wire.

[timytamy]

Originally Posted by Joe G.

6g for battery leads and main breaker
10g or 12g for most motor power distribution. 10g will have less resistance, which can really add up, but also weigh more. There is also this cool technology available in 12g which makes a big difference in moving components, and routing wire in tight spots.
18g for lower current components
22g servo wire.

I was really confused as to why you were measuring your wire in grams for a moment

But more seriously, that's pretty much stock standard. You can also use 14AWG for 30A circuits [Standard 2014 vs 2015 rule warning], but we generally only use 12AWG or 18AWG. We actually prefer 26AWG for servo wire, since they're generally only taking TTL signals, the extra resistance isn't an issue and we find it's easier to insert into the housings.

Also whenever possible get bonded/zip cable such as this, it makes your wiring much cleaner and easier.

[Joe G.]

Originally Posted by timytamy

I was really confused as to why you were measuring your wire in grams for a moment

But more seriously, that's pretty much stock standard. You can also use 14AWG for 30A circuits [Standard 2014 vs 2015 rule warning], but we generally only use 12AWG or 18AWG. We actually prefer 26AWG for servo wire, since they're generally only taking TTL signals, the extra resistance isn't an issue and we find it's easier to insert into the housings.

Also whenever possible get bonded/zip cable such as this, it makes your wiring much cleaner and easier.

We used 26AWG servo wire this year and won't be doing so again. We failed quite a few PWM crimps due to wire either slipping out or repeated bend stresses. May have had something to do with the strand count of the wire we used as well, but moving forwards, we'll take the extra reliability insurance.

[timytamy]

Originally Posted by Joe G.

We used 26AWG servo wire this year and won't be doing so again. We failed quite a few PWM crimps due to wire either slipping out or repeated bend stresses. May have had something to do with the strand count of the wire we used as well, but moving forwards, we'll take the extra reliability insurance.

That's interesting, do you have a P/N for the wire/crimps/crimper that you used? The only failure we had this year was a student getting a bit too excited over cutting cable ties :| However this year we had the luxury of set-and-forget electronics, most cables were installed once in their permanent position, so they weren't stressed too much.

[Joe G.]

Originally Posted by timytamy

That's interesting, do you have a P/N for the wire/crimps/crimper that you used? The only failure we had this year was a student getting a bit too excited over cutting cable ties :| However this year we had the luxury of set-and-forget electronics, most cables were installed once in their permanent position, so they weren't stressed too much.

We use all the standard Hansen Hobbies stuff:

Crimper
Terminals
Wire

We had used the exact same crimper and terminals for a few years, and most of the failures took the form of bending failure of all wire strands, so we blame the wire. I don't know off the top of my head the wire that 1687 used before this year (I know it was a lower gauge), but my team plans to use this stuff moving forwards, although we may experiment with other gauges of the high-strand stuff.

The vast majority of failures were of sensor leads related to our shooter gearbox, which we removed for maintenance a few times, and between each event as part of our withholding allowance. Wires that didn't need to be touched after installation such as victor PWMs fared much better.

[MrRoboSteve]

Also consider using your DigiKey voucher for this (assuming there is one this year):

PWM/signal cable supplies:
WM2517CT-ND - CONN TERM MALE 22-24AWG TIN
WM2510-ND - CONN TERM FEMALE 22-24AWG TIN
WM2800-ND - CONN HOUSING 2POS .100 SINGLE
WM2801-ND - CONN HOUSING 3POS .100 SINGLE
WM5354-ND - CONN HSG 2POS .100 SINGLE VER D
WM2872-ND - CONN HOUSING RCPT .100 3POS
WM9999-ND - TOOL CRIMP 14-24AWG UNIVERSAL

We use 22ga 2/3 conductor stranded security system wire for PWM cables. If you hit up a local security system/low voltage installer, and are _specific_ about what you ask for (you don't want ethernet cable as it is solid), you can get enough for several years for free from their scrap.

Be sure you are using the correct wire, and are crimping properly.

[Anthony4939]

Thanks for the replies everyone. We are a second year team and are looking to start building a supply. The wire kits were going to be ordered from Hansen Hobbies.

Any suggestions for a good pneumatics supply kit?

[timytamy]

Originally Posted by Joe G.

We use all the standard Hansen Hobbies stuff:

Crimper
Terminals
Wire

We had used the exact same crimper and terminals for a few years, and most of the failures took the form of bending failure of all wire strands, so we blame the wire. I don't know off the top of my head the wire that 1687 used before this year (I know it was a lower gauge), but my team plans to use this stuff moving forwards, although we may experiment with other gauges of the high-strand stuff.

The vast majority of failures were of sensor leads related to our shooter gearbox, which we removed for maintenance a few times, and between each event as part of our withholding allowance. Wires that didn't need to be touched after installation such as victor PWMs fared much better.

We used exactly the same setup, except we used this crimper, regardless of what gauge you do use in future I'd recommend you invest in it or something similar. As a rule we don't allow any crimps on the robot that are not ratcheted, as it is much harder to guarantee a good crimp between students.

@OP: I'd recommend you purchase this kit, and then some extra wire (with a gauge of your choice), terminals and housings.

In terms of pneumatics, you should have a look at the kits from AndyMark here. Personally, we prefer 24V Solenoids mainly because they are easier to source in Australia, but also we have a large stock as it's what usually comes in FIRST Choice. Also the 24V supply was guaranteed in the cRIO control system, but the 12v wasn't. AndyMark however only sells the 12V version. Regardless of which you go with, it's a good idea to pick one and stay with it.

[Joe Ross]

Originally Posted by timytamy

Also the 24V supply was guaranteed in the cRIO control system, but the 12v wasn't.

The same is true in the 2015 control system.

[cgmv123]

Originally Posted by timytamy

Also the 24V supply was guaranteed in the cRIO control system, but the 12v wasn't.

Originally Posted by Joe Ross

The same is true in the 2015 control system.

Are we sure the PCM doesn't have a regulator? We know there's an booster because the 24v supply is created inside the PCM, instead of the PDB like the previous system.

[Mark McLeod]

I confirm that the PCM's 12v solenoid output is just the current battery voltage.