Ordering Materials

[ebrnc]

Quick question: how is the wireless bridge hooked up to the new RoboRIO? What kind of cable do we need? Also, are Weidmüller connectors needed for connections to the PCP? I heard this somewhere, but I am not sure if it is true or not. Thanks!

[TimTheGreat]

Based on the image of the new control system (http://www.usfirst.org/roboticsprograms/frc/blog-2015-control-system-kop-survey) the wireless bridge will be connected via USB. I imagine that the cable will be provided in the KOP

[ebrnc]

That would make sense. However, I do not think my team is choosing to receive the KOP this year. Hmmmmm.

[Mark McLeod]

The DLink, Rev B will be connected via the roboRIO Ethernet port.
Pretty much the same way it got connected on the older control system.
So you just need an Ethernet cable.
Power will come via the Voltage Regulator Module "5v/2a" Weidmüller connections.

That sample wiring diagram on the FRC Blog is out of date.

Also, are Weidmüller connectors needed for connections to the PCP?
What's a PCP?

[RamZ]

That would make sense. However, I do not think my team is choosing to receive the KOP this year. Hmmmmm.

I think you're mistaken, as the Kit of Parts is a tote with various parts that is given to every team every year at kickoff. Your team may have opted out of the KOP Drive Base, but that's a totally different thing.

[ebrnc]

Awesome. Thank you! Haha whoopsies... Typo: PDP. And that makes more sense about the KOP:) I was unsure of what was included in the portion given to all teams!

[adciv]

The PDP has two different connections on it. For the traditional 40/30/20 Amp breakers, it uses the same connectors as we have previously.

For the Rio, and your first VRM & PCM, you use the Weidmüller connectors. The Weidmüller take bare copper and do not require anything to be crimped to it. That said, I recommend tinning the wires to prevent them from getting "mashed" after repeated insertions/removals.

[Al Skierkiewicz]

EB,
The Weidmuller connectors are designed for wire or ferrule termination. It is not mandatory for the ferrules but they might make termination easier in a tight robot. Get very good at twisting the wire and inserting it on the first try. I suggest teams practice outside of the robot. 'No whiskers' should be your watchwords.

[JCharlton]

I'd never used ferrules before, but after trouble inserting wires into the new PCM (particularly for the larger compressor wires) I ordered a kit from ferrulesdirect.com. Well worth it, much easier to work with and I'd guess more reliable too. If your team can afford it I'd recommend purchasing a crimping tool and ferrules.

[AdamHeard]

EB,
The Weidmuller connectors are designed for wire or ferrule termination. It is not mandatory for the ferrules but they might make termination easier in a tight robot. Get very good at twisting the wire and inserting it on the first try. I suggest teams practice outside of the robot. 'No whiskers' should be your watchwords.

Which ferrules would you recommend.

[Al Skierkiewicz]

Adam,
I don't have the Weidmuller part number but I wouldn't use anything else. Get the right crimper as well.

[mklinker]

Having not seen the new control system can someone recommend a length for posts on the Weidmuller wire ferrules?

[JCharlton]

Having not seen the new control system can someone recommend a length for posts on the Weidmuller wire ferrules?

The recommended strip length is 8mm. This is quite long for strands, easy to get them bunched up.

Ferrules avoid all this. Another benefit is that with plastic collar ferrules it's easy to verify visually that all the wires have been inserted to the correct depth.

[AllenGregoryIV]

Adam,
I don't have the Weidmuller part number but I wouldn't use anything else. Get the right crimper as well.

Here's the relevant information from this spec sheet. (http://media.digikey.com/pdf/Data%20Sheets/Weidmuller%20PDFs/1825640000.pdf) I believe that is the series connector the new control system uses.

With wire end ferrule, acc. to DIN 46 228/1, min. 0.25 mm²
With wire end ferrule, acc. to DIN 46 228/1, max. 1.5 mm²
w. plastic collar ferrule, DIN 46228 pt 4, min. 0.25 mm²
w. plastic collar ferrule, DIN 46228 pt 4, max. 0.75 mm²

I haven't used these connectors yet so I could be reading this wrong. From what I see it looks like many manufacturers make ferrules that meet those specs. Does that all look right Al?

[ChuckDickerson]

Al,

Given we all get $30 to spend at Inventables what are your thoughts on these ferrules (https://www.inventables.com/technologies/insulated-ferrule-kit) and associated crimper (https://www.inventables.com/technologies/ferrule-crimper) for use with the new control system Weidmuller connectors?

[Al Skierkiewicz]

Chuck,
I am usually against buying assortments because there is likely to be things I will never use. However, this might be a good starter kit. The crimper looks to be a mil style four point crimp although there is no real description in you linked site. As you know, we are between homes here and have not had access to robot parts or tools for more than a month. I would love to hear from anyone who has purchased these already. One fear I have is the close spacing on some of the module terminals. They may not allow ferrules.

[ChuckDickerson]

Chuck,
I am usually against buying assortments because there is likely to be things I will never use. However, this might be a good starter kit. The crimper looks to be a mil style four point crimp although there is no real description in you linked site. As you know, we are between homes here and have not had access to robot parts or tools for more than a month. I would love to hear from anyone who has purchased these already. One fear I have is the close spacing on some of the module terminals. They may not allow ferrules.

Ok, so I spent our $30 PDV at Inventables (and then some) and ordered the ferrule kit and crimpers. I'll post here my impressions once received and tested.

[joeyoravec]

We ordered the inventables kit (link (https://www.inventables.com/technologies/insulated-ferrule-kit)), and decided it is inappropriate for RoboRIO. My observations:


The crimper is pretty good

The kit includes 7.5mm depth ferrules, which are too short. The weidmueller connectors on roborio need 10mm recommended, 8mm minimum..

The kit does not come with documentation on sizes. We checked with wire and calipers and believe the kit includes: 2x 22-24awg, 2x 20-22awg, 2x 20awg (1.5mm od), 3x 18-20 (1.8mm od), 1x 14?-16awg.

Even if these connectors were long enough, we can't make them work with 18awg power wires. The RoboRIO accepts 1.5mm maximum. The 1.8mm accept 18awg but won't fit in the RoboRIO. The 1.5mm fit in the RoboRIO but won't accept 18awg.

We're going to order try ordering some weidmueller brand ferrules from digikey (link (http://www.digikey.com/product-search/en?pv183=3138&pv92=4&pv799=16&FV=fff40016%2Cfff803ad&k=weidmuller+ferrules&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25)) that have a thinner wall and might work for 18awg.

[Al Skierkiewicz]

Joey,
The connectors are the same, the inter terminal spacing is the only difference.

[joeyoravec]

The connectors are the same, the inter terminal spacing is the only difference.
I'm sorry? I don't understand.

We were looking at:


Weidmueller 9025860000 (link (http://catalog.weidmueller.com/catalog/Start.do?localeId=en_DE&ObjectID=9025860000)). Collared. L2=10mm. 18awg. Should mate with the 1.5mm.
Weidmueller 0542500000 (link (http://catalog.weidmueller.com/catalog/Start.do?localeId=en_DE&ObjectID=0542500000)). Uncollared. L2=10mm. 18awg. Should mate with the 1.5mm.

Both look like they might work for the required 18awg power wires. Like I mentioned above, the ones in the inventables kit did not.

[Al Skierkiewicz]

The spacing from one terminal to another is different on the female blocks. On the RoboRio, the spacing is 5 mm as I remember. The other components are only 3.5mm from one terminal to another. The two parts you link to are ferrules. One is meant to slip over stranded conductors only and the other is used in the same way a crimp on terminal is used. Please note that the crimp on insulator is 2.8 mm nominal diameter which is pretty close for terminating a 3.5mm spacing on the control system components. Once crimped, this ferrule is likely to change cross section to be greater than the 2.8 mm nominal diameter.