Electrical connectors on control system items [Archive]

Greg Needel

15-06-2016, 21:34

Hey All,
We have been working on a bunch of new products for upcoming seasons and wanted to get the community's opinion on an internal debate we have been having at REV.

In the current control system there are numerous styles of electrical connectors, each one has it's own advantages and disadvantages (cost, size, current carrying ability, easy of installation, robustness, etc) and there have been a few "standards" that have appeared over the years. While we are still in the phases of working on new projects I always think it is a good idea to question previous assumptions rather than just assume they are correct.

Here are all of the connectors that are commonly used

.1inch headers (PWM) - used for all signals to the roboRIO & motor controllers - minimal retention but cheap

Weidmuller wire-to-board - Used for CAN connections & module connections - expensive, good retention, requires precise wire striping

Wago - Used for the Power distribution board - Expensive, good for high current, very reliable

Screw terminals - Used on SPARK motor controllers & others - low cost, good retention, small, screws can strip/get lost

Spade terminals - Used on the Spike relay and wire to wire connections - cheap

Anderson Powerpole - main battery connector & commonly wire to wire connections - medium price, good quick release, hard to crimp without special tool

IDC connectors - used for MXP, SPI, & talon motor controllers

USB - Used on the roboRIO & other places

Barrel jack - used on the radio

RJ45 (ethernet) - Used on the radio & roboRIO

RJ11 - used on Jaguar motor controller

Here are some new connectors I would like opinions on.

JST connectors (PH series for example ) http://www.jst-mfg.com/product/detail_e.php?series=199 - As a replacement for PWM cables
XT Connectors (30 or 45) https://www.amazon.com/OOOUSE-XT60-Connector-Pairs-pairs/dp/B005FAPYXS instead of power poles or wagos
Deans connectors - https://www.amazon.com/dp/B00S7G4A14/ instead of power poles or wagos

So you tell us, What frustrates you or makes you happy about the existing connectors? What connectors do you hate and which ones do you like.

We are also open to other suggestions let your opinions fly.

Christopher149

15-06-2016, 22:24

otherguy

15-06-2016, 22:39

I'm personally not a big fan of JST connectors for items that need to be plugged in/out with any frequency. I find the pins to be easily damaged if you try to seat a connector that's not properly aligned. As a result they are nearly impossible to plug in to a sensor that's buried in the robot. The Sharp IR sensors have this style connector on them, and we always terminate an adapter cable to 0.1" header pins in the event something needs to be swapped out between matches.

For a low conductor count cable (like PWM you mention) what would be the advantages of a JST connection? The only thing I can think of is that it's keyed, can't see there being appreciable space savings on a 3 pin cable.

For the XT and Deans connectors, I don't have much experience with them myself, but i know they are the standard I'm the hobby RC market. I'm open to their use. Instructions on how to connect to them correctly, tools required, what gauge cable, sources for tested wire & tools, tips/tricks would probably be helpful for most teams as I'm not sure I've ever seen one on an FRC robot in the past 8 years. Maybe I'm not looking hard enough.

I'm a fan of male/female spade terminals. They're cheap and reliable when crimped correctly. We usually mount little right angle male spade adapters on all motor controllers with screw terminals so that they can be swapped out quickly.

Sent from my LGLS751 using Tapatalk

randantor

15-06-2016, 22:43

I'm really not a fan of XT-series connectors, and solder-type connectors in general. It's much harder to judge the quality of a solder joint than a crimped connection.

In my experience using these connectors with stranded wire causes solder to wick up into the wire a bit, causing the wire around the connection to become brittle and prone to have issues if not given adequate strain relief. Soldering in general is much more error-prone and time consuming than crimping a connection with the proper tool.

sanddrag

15-06-2016, 22:51

As the teacher on a team that prides itself on clean wiring, I like this thread and feel inclined to comment.

.1inch headers (PWM) - annoying and really time consuming to crimp and/or solder. All the cheap tools suck. I wouldn't be opposed to something better (or maybe I just own the wrong tools).

Weidmuller wire-to-board - has been fine
Wago - Can be tough to access in tight spaces. Need to plan for tool access in the design and assembly processes. The big ones on the PDB are fine. Small ones can be annoying, but workable.
Screw terminals - Not opposed to these in the right application, but the problem with Victors in the past was finding a non-insulated flanged spade terminal for a #12 wire and s #6 screw that was narrow enough in width to properly fit the Victor.
Spade terminals - Works well, fast crimping, can be tough to get off sometimes.
Anderson Powerpole - These work very well. Crimping is not an issue for us. I really wish there was a 4AWG SB50 terminal though. We also sometimes have issues with the PP30/45 and SB/50 series getting the terminal all the way in after crimping if the insulation is large or the crimp is slightly malformed. But once you get the terminals over the clip, it's flawless. It's a training issue more than anything.
IDC connectors - seem fine I guess
USB - Haven't used them in an FRC sense.
Barrel jack - Always concerned about losing contact. We put a lot of thought and effort into properly retaining this connector so it cannot come out.
RJ45 (ethernet) - We do not use off the shelf pre-made cables, to eliminate excessive length. We've had some issues properly crimping these. Also, the clips are fragile, and if there's a stiff boot on it, you risk breaking the port itself if the user does not have the finger strength to fully depress the boot before pulling the cable out. So for that reason, I'm weary.
RJ11 - Similar to what I mentioned above, but I haven't used RJ11s specifically.

Here are some new connectors I would like opinions on.

JST connectors (PH series for example ) - Seems plausible. I'd need to see and try the terminals and crimper.
XT connectors - Never. Short circuit risk on the solder cups and just the fact that you can't crimp it.
Deans connectors - Never. The exposed terminals on an unplugged connection are a serious short circuit hazard for teams who don't know what they're doing and install that half of the connector to the wrong side of the circuit. PowerPoles do not have a male or female side.

pilleya

15-06-2016, 22:59

For me I value the ability to combine connectors into one main block and the ability to easily differentiate between positive and negative connectors. The power-poles also come standard with quite a few different colours and accessories such as retention pins.

For the 2016 season, we built a turret mounted shooting mechanism. We had 5 motors on the shooting mechanism, with 3 CAN Talon SRX’s mounted onto the rotating component with all sensors going into the SRX’s via CAN. We utilised Anderson Powerpoles(45amp) because they enabled us to join the plugs into one central block, including the CAN via green and yellow powerpoles. We were able to unbolt our entire shooting mechanism and simply unplug the main plug in order to quickly switch out our turret mechanism with our spare.

I don’t believe this block mounting style is possible with the XT connectors or the Deans Connectors.

FrisbeeFunTime

15-06-2016, 23:01

pilleya

15-06-2016, 23:11

I really wish there was a 4AWG SB50 .

If you are wanting to use 4AWG or larger for battery cables, it is legal to utilise a SB120 connector,

Any size a single pair of Anderson Power Products (or APP) 2-pole SB type connectors

mman1506

15-06-2016, 23:30

I have a lot of experience with XT connectors as they are connector of choice for personal projects. I used to use Deans connectors but they are much easier to melt when soldering and occasionally the spring tabs would bend ruining the connector. XT connectors are also easier to solder than Deans because of the cups on the terminals.

Personally I would rather solder connectors than crimp as it requires less specialized equipment and lessens the chance of a intermittent or high resistance connection which can be very difficult to diagnose.

Another advantage of RC connectors is that they are gendered(male and female) unlike Anderson connectors. This prevents a user from plugging a battery into another battery or the motor side of a speed controller into a power source and destroying it.

I've never been a fan of JST connectors, they are very low amperage and only really useful for something like LEDs. They are also difficult to grip and pull apart without tugging on the wire.

Sparky3D

15-06-2016, 23:44

I personally prefer powerpoles over both the Dean's and XT connectors. You have to have a proper crimper for them, but once you do, they are pretty hard to mess up. Our electrical students use them wherever possible because they are quick, easy and they rarely have issues with them. Our students soldering ability tends to vary a lot, so soldered connections tend to require more TLC to ensure everything is solid.

Tom Line

16-06-2016, 00:11

I've never had any experience with the jst connectors or the xt connectors but I would imagine the xt connectors to be pretty good. The deans connectors I have had experience with before. They are a bit of a pain to solder to but they are done correctly they hold well and when plugged together they are almost impossible to take apart. They also take up a small footprint compared to other connectors which is always a nice thing.

I absolutely hate deans connectors. My kids all participate in RC (boats and cars). And these things are the #1 reason I see cars dead on the track. I've gotten packages of things where no matter how hot you get it or how careful you are they simply will not pass a pull test after you solder them. I've taken said packages to the hobby stores and they tried one and threw the rest away, and opened a new package.

I will stick with crimp style connectors. In marine applications, soldered connections are highly frowned upon by the certification organization because they are uncertain and are a brittle failure point in high vibration environments.

asid61

16-06-2016, 01:32

".1inch headers (PWM) - used for all signals to the roboRIO & motor controllers - minimal retention but cheap"
I like the Hansen Hobbies latching connectors way more; the peace of mind and ease of use is great. Not too expensive either. That being said PWMs work fine for me too.

"Anderson Powerpole - main battery connector & commonly wire to wire connections - medium price, good quick release, hard to crimp without special tool"
I love how you can stack them into bunches, but they are very hard to put together and remove this way, especially if a single component in a bundle fails.

"RJ45 (ethernet) - Used on the radio & roboRIO"
I've thought about using these for non-ethernet applications due to the availability of crimpers, crimps, and cheap cable cost of many different lengths from digikey. I have used a few of these in non-FRC non-ethernet applications, and they've performed admirably.

cad321

16-06-2016, 02:06

I like the Hansen Hobbies latching connectors way more; the peace of mind and ease of use is great. Not too expensive either. That being said PWMs work fine for me too.

I had not seen these before. They look like a great alternative to pwm cables. However I don't see much of a need for them unless they were to become a standard connector on most FRC products. Great if you are joining 2 cables (such as at a joint or turret for quick removal). However if you dont have the latching socket on say the roborio, it just becomes a standard PWM with an extra piece of plastic.

I would love to see something like this become a standard.

Knufire

16-06-2016, 02:38

adciv

16-06-2016, 07:19

So you tell us, What frustrates you or makes you happy about the existing connectors? What connectors do you hate and which ones do you like.
I *HATE* JST connectors. You can't make them yourselves, they use 24 AWG wire (prone to breaking), and you have to tug on the wire to get them to disconnect (more damage potential). I'm trying to find an alternative to US Digital encoders solely because they use connectors with the same issues.

As to the others, I don't like soldering when I can avoid it. I much prefer crimping as it is easier to assemble & maintain. I prefer the Anderson power poles over what are shown for a number of reasons. The individual parts aren't polarized (but I can polarize them by how they are assembled). I don't have to worry about keeping M & F components in stock. Can be assembled into larger blocks.

.1inch headers (PWM) - annoying and really time consuming to crimp and/or solder. All the cheap tools suck. I wouldn't be opposed to something better (or maybe I just own the wrong tools).
We use the Hansen hobbies crimper and it works well (~$40).

timytamy

16-06-2016, 09:35

The screw connector for powering the roboRIO (and previously cRIO). I don't know if we were using it wrong, but especially on the cRIO, the wires would too frequently come out or be loose.

I like to call screw terminals like these the best bad connector you will use. They're relativley versitile, flexible, easy-ish to use with medium pincounts. However they will never be better than a more specilised conector.

On to the OP's question:
I'm not interested in any new connections unless there are some very good reasons. Inventory management is a PITA, and it's much easier to maintain an inventory of 100x of one conector, vs 25x of 4 different ones. For this reason I'm willing to make reasonable comprimises on all the advantages/disadvantages you mentioned, for connectors already in common use.

This is all the more important if your intended market is ALL of FRC, ie not just the average to powerhouse teams that already have things like this worked out. Having helped many rookie and low-resource teams wire up robots, trust me when I say there is enough in the combination of Wago, Weildermuller, [3-pin only] PWM etc already.

It's a little different if your targeting just the medium-powerhouse teams. As other others have already mentioned Powerpoles, custom .1in (ie other than 3pin PWM), rings and spades, IDC, USB and ethernet etc all have some really good use cases.

Ernst

16-06-2016, 14:58

I really like the connectors on the US Digital S4/E4 series encoders. Browsing around on their website, it looks like it's a 1.25mm pitch Molex PicoBlade connector.

https://youtu.be/0bRyezC_P0M?t=141

The big thing I enjoy about them are the friction locks, they feel much more secure than standard 0.1 header connectors. I wouldn't mind a bigger pitch than 1.25mm though for FRC use though.

Huh, I've always hated those. The attached wires were always a pain and usually messy, plus unplugging them didn't always go well.

We started using some custom .1in connectors this year for different sensors, like a 5-pin one for Grayhill encoders and some 2-pin ones. Those worked well when done correctly, but our quality control wasn't great, and a few connectors made it onto the robot that might have given us some intermittent signals. We're learning, though, and I think we'll go back to them and use more next year.

We also had some trouble with several Weidmuller connectors. No matter how many times we tried with different wires that were the correct gauge and stripped the correct length, a few connectors just wouldn't work. Others were perfect and lasted all season. We picked up some ferrules to try to address that next year.

The 3-pin connectors are decent. We wound up taping and zip-tying a lot together, though, so we might pick up some VEX EDR connector clips (http://www.vexrobotics.com/vexedr/products/accessories/electronics/276-4128.html). I'm a bit disappointed that the RoboRIO has male pins. We had one of those connectors come loose despite us using 3D printed cable management/spacing inserts. Other than a giant 10-connector female-to-female converter that plugs into all of them and reinforces everything, I don't really know how to address that.

I haven't personally used the XT or Deans connectors, but, given the option, I would stick with Powerpoles. They can clip together to make large plugs, they're easy to lock together, and we have tons of them stockpiled.

MattRain

16-06-2016, 16:18

Anderson Powerpole - main battery connector & commonly wire to wire connections - medium price, good quick release, hard to crimp without special tool

Deans connectors - https://www.amazon.com/dp/B00S7G4A14/ instead of power poles or wagos

Deans Connectors: Hate these things. A'lot of RC's use them, but I've always had issues with them.

Anderson Power Poles: Go with these. I absolutely love these. FTC switched over to a new control system that uses these in pretty much everything, so my teams have a large stockpile of them. After having the right tool, they are easy to work with! My teams love the fact that you can create large blocks of connections, which has already been said in this thread. Allows us to remove parts easily to work on parts of the robot or to switch out. Some of the electrical students on my FRC team saw them this past year, and want to make the switch to them next season.

AustinSchuh

17-06-2016, 00:06

Molex connectors (http://www.molex.com/webdocs/datasheets/pdf/en-us/0022013047_CRIMP_HOUSINGS.pdf). They are polarized and latch pretty well. We've gotten pretty good at crimping them.

Jefferson

17-06-2016, 07:26

Molex connectors (http://www.molex.com/webdocs/datasheets/pdf/en-us/0022013047_CRIMP_HOUSINGS.pdf). They are polarized and latch pretty well. We've gotten pretty good at crimping them.

Looks like you got that close parentheses in your url. Here's a working link (http://www.molex.com/webdocs/datasheets/pdf/en-us/0022013047_CRIMP_HOUSINGS.pdf).

anthonyttu

17-06-2016, 11:45

I think it would be nice to see a pair of two or a single four pin connectors on the CAN cables for the Tallon SRX's. That way if you pre-terminate spare controllers it could be changed out with mounting the new one and plugging it in.

http://www.digikey.com/product-detail/en/hirose-electric-co-ltd/DF3-2S-2C/H2083-ND/141479

http://www.digikey.com/product-detail/en/hirose-electric-co-ltd/DF11-4DS-2C/H2019-ND/141249

Peter Johnson

17-06-2016, 12:14

I think it would be nice to see a pair of two or a single four pin connectors on the CAN cables for the Tallon SRX's. That way if you pre-terminate spare controllers it could be changed out with mounting the new one and plugging it in.

We do exactly this with the 2-pin Latching Polarized (LP) 0.1" connectors from Hansen Hobbies (1). Put male on one pair and female on the other pair and daisy chaining is a cinch. The connectors have a plastic spring latch so won't come apart under vibration and are polarized so they can't be plugged in backwards. We put stub connections (short wire and connector) on other devices like the roboRio and CTRE products so we only need to deal once with insertion/removal into those connectors.

1: http://www.hansenhobbies.com/products/connectors/pt1inlpconnectors/

GeeTwo

17-06-2016, 12:18

On to the OP's question:
I'm not interested in any new connections unless there are some very good reasons. Inventory management is a PITA, and it's much easier to maintain an inventory of 100x of one conector, vs 25x of 4 different ones. For this reason I'm willing to make reasonable comprimises on all the advantages/disadvantages you mentioned, for connectors already in common use.
This, this, this.

Also, while many teams have Power Poles as an internal standard (3946 among them), I am not aware of any standard FRC parts which require/strongly encourage teams to use them. They do meet all the requirements (current capacity, well insulated, vibration resistant) and many "desirements) (modular, customizable, polarizable). They also have a great customer base outside of FRC (ham radio and R/C modeling, and probably others).

wireties

17-06-2016, 12:25

Peter Johnson

17-06-2016, 12:58

My biggest concern is non-latching connectors. In a high-vibration and relatively high shock environment like a FRC robot it is mal-practice to use non-latching non-polarized connectors. They don't have to be fancy or super expensive but really should have a latch.

While power poles aren't natively latching, we use the little orange clips that powerwerx sells. They're easy to install and have been very robust for us. My only other complaint with power poles is that the crimp doesn't grab the insulation (only the wire) so pull-out can be an issue. We make sure to tug-test every crimp and prefer the 45a contacts for all but the smallest wires as they seem to grab the wire better.

Chris is me

17-06-2016, 13:02

228 uses Deans connectors and I think they're fine. You have to solder the wire to them, sure, but other than that they are a robust connector that clips together securely and nicely. Soldering and shrink tubing the wires to each lead helps them hold securely. Never had an issue with them failing a pull test.

If you go all in with the tooling, Anderson connectors are very robust. I don't particularly care for the whole snapping multiple connectors into one big block thing. Spade connectors are okay I guess.

Almost any connector, latching or otherwise, can be made more secure with heat shrink tubing to hold it together. It's difficult to accidentally pull apart a spade connector if the tubing constrains it geometrically.

Michael Corsetto

17-06-2016, 13:48

Molex connectors (http://www.molex.com/webdocs/datasheets/pdf/en-us/0022013047_CRIMP_HOUSINGS.pdf). They are polarized and latch pretty well. We've gotten pretty good at crimping them.

+1. We've been using molex connectors ever since we started using the Spartan Board in 2015. The latching is very nice :)

-Mike

Andrew Schreiber

17-06-2016, 13:53

We do exactly this with the 2-pin Latching Polarized (LP) 0.1" connectors from Hansen Hobbies (1). Put male on one pair and female on the other pair and daisy chaining is a cinch. The connectors have a plastic spring latch so won't come apart under vibration and are polarized so they can't be plugged in backwards. We put stub connections (short wire and connector) on other devices like the roboRio and CTRE products so we only need to deal once with insertion/removal into those connectors.

1: http://www.hansenhobbies.com/products/connectors/pt1inlpconnectors/

We did the same on our can bus this year. Worked wonderfully.

wireties

17-06-2016, 18:36

While power poles aren't natively latching, we use the little orange clips that powerwerx sells. They're easy to install and have been very robust for us. My only other complaint with power poles is that the crimp doesn't grab the insulation (only the wire) so pull-out can be an issue. We make sure to tug-test every crimp and prefer the 45a contacts for all but the smallest wires as they seem to grab the wire better.

We use wire ties to make sure the power poles stay together. I always forget to buy the little orange clips.

Gregor

18-06-2016, 23:56

We use wire ties to make sure the power poles stay together. I always forget to buy the little orange clips.

Tiny zip ties work really well for securing PowerPoles too, that's how I've always done them.

GeeTwo

19-06-2016, 08:23

While power poles don't natively latch, they do natively restore a temporarily loosened connection. Retention is not through friction, but through the spring force of the two contacts. If the contacts are properly assembled, and the cable is not under tension, the contact won't just vibrate loose; it would take a shock load in which the connector's inertia provides the breaking force. If you partially disengage a power pole and release it (or don't engage fully on insertion), the spring contacts will [re-]complete the engagement for you.

caume

19-06-2016, 10:39

I'd love a self crimping .1in connector, also possibly a latching .1in connector.

Anderson Powerpoles are a gift from god if you asked me. Nothing should replace them.

Peter Johnson

19-06-2016, 11:09

I'd love a self crimping .1in connector, also possibly a latching .1in connector.

There are latching, polarized (LP) 0.1in connectors (http://hansenhobbies.com/products/connectors/pt1inlpconnectors/). However, they aren't self-crimping, but practice helps! Also, I've found the Hansen LP housings and inserts easier to put together than the standard ones for some reason (I can just crimp with the Hansen cheap crimper and they slide right in most of the time), although I'm sure the correct solution is to buy the "real" crimper ($$$).

Alan Anderson

19-06-2016, 13:25

I'd love a self crimping .1in connector, also possibly a latching .1in connector.

The 3M Link connectors sound like what you want. They were in the 2014 Kit of Parts.

http://www.digikey.com/product-detail/en/3m/38104-0018-000-FL/3M12000-ND/1238395

marshall

19-06-2016, 13:42

The 3M Link connectors sound like what you want. They were in the 2014 Kit of Parts.

http://www.digikey.com/product-detail/en/3m/38104-0018-000-FL/3M12000-ND/1238395

I wish they were a bit smaller...

Ben Wolsieffer

19-06-2016, 17:35

The 3M Link connectors sound like what you want. They were in the 2014 Kit of Parts.

http://www.digikey.com/product-detail/en/3m/38104-0018-000-FL/3M12000-ND/1238395

We used these as CAN connectors and they worked well.

GeeTwo

20-06-2016, 00:01

I'd love a self crimping .1in connector, also possibly a latching .1in connector.

Anderson Powerpoles are a gift from god if you asked me. Nothing should replace them.

What do you mean by "self crimping"? Wow. Damm.

Again, I'd like to note that while APPs are internal standards of many FRC teams, they are in no way (to date) an FRC-endorsed standard. That said, if Talon SRXs or Victor SPs were [additionally/alternately] available COTS with APPs on the output (green and white) wires, leaving the red and black as stripped wire ends, 3946 would be sure to buy a bunch expecting to step around the difference between R13 [fabrication schedule, in particular R13-D] and R18 [Witholding Allowance rules] for 2016 and similar rules in recent years.

Peter Johnson

20-06-2016, 01:12

That said, if Talon SRXs or Victor SPs were [additionally/alternately] available COTS with APPs on the output (green and white) wires, leaving the red and black as stripped wire ends, 3946 would be sure to buy a bunch expecting to step around the difference between R13 [fabrication schedule, in particular R13-D] and R18 [Witholding Allowance rules] for 2016 and similar rules in recent years.

I would think an easier solution would be for FIRST to fix R18 to add an exception similar to R13-D and R18-A thru -C, and such a fix would be consistent with what appears to be the intent of R13 (reuse of motor controllers from year to year). Excepting that, you could put a couple of spare motor controllers in the bag with the robot so they aren't covered by R18.

With regards to connectors on Talon SRXs, my team puts APPs on both ends of the motor controllers and populates the PDP with short stubs to APPs. Yes, it adds a tiny amount of resistive loss, but it also makes it much much faster to swap and/or disconnect (we never have to pull a breaker!).

Mike9966

20-06-2016, 18:35

Hi all, Just had to throw my 2¢ in on this one.

As someone said, the powerpoles are a gift from God! lol, True, you do have to shell out $40 for a nice crimper, and you do have to train the students on how to use it, but once this is done, life is good.
Yes, do zip tie them if you are worried about them separating, one small one laterally does the trick.
We put these on all our SRX's pretty much straight away when they come in.

Someone mentioned confusing the input and output. Our method is to use Red/Black on the input (anything that's always hot), and Pink/Black on the control side. Motors get Pink/Black too, that way you should only ever see pink to pink, and red to red. Pretty simple.

I don't like deans due to the exposed contacts, and soldering necessary.

We use latching polarized (like the Hansen hobbies ones) that we buy from Digikey. Again, when the SRX's come in we put one male, and one female on each unit. I like to use the 3 pin ones so the connections can be used for either can or PWM.

The Coaxial barrel jacks are awful and should be banned! True, you can zip tie them down, but what a pain, just bad all the way around.

The worst connectors bar none though are the stick pin headers on the roborio. There is nothing to tie things down with, one has to add sticky squares and so on, and even then we had one or two pop out this year after doing the dukes of hazard thing over the chevys. Grin.

I'm not in favor of spring cage clamps as in the PDP and elsewhere, screw cage clamps would be my preference.
Space, and student strength are the main problems here.

Faston (spade, aka bladed, etc) I don't like as the nylon shrouded females frequently aren't pushed properly onto the male side. The male blade ends up between the plastic and the connector. (and then falls off).

Don't like JST, too small and fragile.

Screw terminals are ok, we used them on Jag's for years, but I'd prefer a built in power pole connector, not the flying leads on the SRX.

Mostly one has to simply do a good job with any of these and they will serve you well if they are used for what they are meant for.

One final thought, use good wire! Not something stiff as a board, or the wrong size!

Have a good one, and don't forget to pull test EVERYTHING.

Mike

jwfoss

21-06-2016, 07:25

Does anyone have any experience with the Traxxas Connectors (https://traxxas.com/products/parts/3060)?

Greg Needel

21-06-2016, 12:25

Does anyone have any experience with the Traxxas Connectors (https://traxxas.com/products/parts/3060)?

patented proprietary connectors :-(

One of the reasons I like the XT series of connectors as a new option is that they are completely open so there are lots of low cost options and carry some of the same advantages of anderson (compact high current, polarized connector)

When REV is looking at options for our products the cost of things like connectors is really heavy on our minds since we are trying to help teams do more with less $. Take Anderson Power poles for example, we could build a version of the SPARK or any of our other new products with integrated Anderson (similar to what modern robotics did for FTC). The issue is that because Anderson has IP on those connectors they cost us .32 for each terminal and .20 for each plastic cover. So on a product like the spark there would be 2.08 in materials cost just for the connectors, not counting the labor of inserting through hole components and installing the plastics. We would also feel obligated to provide 4 mating connectors in the box, so teams who have never used them before have some to start with (customer experience), so add another ~1.50.

So at the end of the day, is it worth it to teams to add a minimum of 3.58 to every single product just so they have have a slightly better connector?

That's the reason for this thread, we are trying to make these decisions with the team experience in mind, both in terms of cost and performance and it is always a difficult trade off.

*we used screw terminals on the SPARK (and likely some future projects), because they are easy to source, cost ~.15 each in bulk, and ring terminals can be found at every home depot, lowes, radio shack, etc for pennies each.

RyanN

22-06-2016, 13:32

I've been involved with FRC electrical since 2005, so I feel I have some experience here. :)

Greg, I think screw terminals are fine. My only nit picky thing with the Sparks was the PWM retention. I really like how the old Victor 888s did it with a full enclosure around the connector; however, that comes at a cost of having straight PWM pins that slip into place.

I'll be the first to admit that our robot's electrical wasn't great this year. It worked... but the wires did jar around with the defenses and we have had the PWM cables get tugged. We found that the PWM cables going to our Sparks bent. If it was a straight tunnel case, I don't think that would have happened.

I'd say the PWM cables are adequate because... well, you have to have PWM cables for the RoboRIO as well.

Now, for the Spark 2. Can we can some CAN? I like the Weidmuller connectors, but at the same time, I don't mind screw terminals. I think you could pull off a full CAN connector that binds the wires between two plates that would achieve the daisy-chain topology of CAN. I'd very easily pay $10 more for CAN integration, and I don't necessarily care about all the crazy features the SRX has. You'll have me happy with speed, direction, brake/coast, and limit switch control and feedback. I don't care about current (I can get that from the PDB, I don't care about voltage control, current control, motion profiles, etc...) I do care about reducing the number of wires on my robot and making it more reliable.

mman1506

22-06-2016, 14:05

Does anyone have any experience with the Traxxas Connectors (https://traxxas.com/products/parts/3060)?

Hobbyists usually consider Traxxas connectors inferior to deans or XT.

taichichuan

22-06-2016, 14:22

I'd have to second the comments about hating JST connectors. While the retention is fairly good, these connectors are nearly impossible to fabricate reliably.

The T-plug connectors are fine for singleton connection. But, we frequently find ourselves with bundles of cables that the APPs allow us to gang together and key the connection in such a way that the connections can't be mis-connected. Yes, you really need the specialized crimper. But it's less than $50 and most other types of connectors (like the .1" PWM connectors), regardless of the type, require a specialized crimper to do it right.

The XT60 connectors are like the T-plug connectors. Great for singleton connections. The mechanical connection seems more robust to me over the T-plug connections. But, these connectors look like they need a special crimp tool or need to be soldered. So, I don't really see that these are any better than what we have already.

HTH,

Mike

sraque

01-07-2016, 22:14

I don't favor JST connectors. They are fine connectors, I don't hate them as others seem to, but they are difficult for a team to fabricate because the crimpers made for them are outrageously expensive. You can find generic crimpers, but they require figuring out the right size to crimp both the conductor and insulation. I would not want to deal with any more small JST, Molex, etc. connectors than we already have to for some of the sensors we use.

I don't favor connectors that require soldering either. We produce crimped connections more reliably and quickly, and they hold well under abuse when the crimp is done well.

We love the Anderson Powerpoles and the (cheaper) version of the Hansen Hobbies Molex connectors from Digikey.

adciv

05-07-2016, 10:25

We love the Anderson Powerpoles and the (cheaper) version of the Hansen Hobbies Molex connectors from Digikey.

can you post the part number for these cheaper versions?

Al Skierkiewicz

12-12-2016, 08:40

Greg,
The JST style you linked are used in equipment I work on everyday. They are good for small signal and DC or status. Most manufacturers will use different size connectors to avoid having assemblies plugged in to the wrong connector.
The other connectors you link I dislike for some very serious reasons. I have seen these appear on robots from time to time because the sellers claim high current specifications for these connectors. However, in real life, none of the specifications match the capabilities of the connectors. I have done some research into these connectors and the same connector is rated anywhere from 5 amps to 60 amps and none of the connectors carry a UL rating. The Anderson contacts are extensively tested by UL for continuous current over a 24 hour test period. The testing includes temperature rise, contact retention and series resistance measurements. Above all else, they are a positive locking connector where the others are not. Gold plating is not going to make them better especially when the gold breaks off the base metal.
My humble opinion.

arichman1257

20-12-2016, 09:22

This is just my opinion on the connectors mentioned.

.1 inch headers (PWM) - As long as the pins on the roboRIO or on the male connector don't bend they're great to use. The cables themselves are somewhat bothersome when they're not long enough to reach because the connectors don't provide an easy way to connect wire to wire without being prone to disconnecting.

Weidmuller - Probably my favorite connector that is used for the small wires. They are easy to press (I have been known to just use my finger in a pinch) and hold the wire well when they have been used properly.

Wago - They work very well for large wires. When the PDP isn't in a convenient position they can be hard to work with if not given the proper care. I don't really have a problem with them but I know that some people do.

Screw terminals - Annoying when they're not placed well and sometimes the screw is dropped. But otherwise reliable if used correctly.

Spade terminals - I don't like them. They always break on me.

Anderson Powerpole -My favorite way to connect wires to each other hands down. (When current draw allows)

IDC connectors - They work well enough. Good way to join many wires to pins.

USB - I haven't really had them in use on an FRC robot enough to give an opinion.

Barrel jack - They pull out when tugged on and should be secured with a ziptie or something like that. but if theyare not abused (pulled on) they work well

RJ45/RJ11 - They're great until the little clip on them breaks

Coach Seb

20-12-2016, 09:40

arichman1257

20-12-2016, 09:50

I don't personally have experience with the other 3 but the XT and dean's connectors look good.

Bkeeneykid

20-12-2016, 10:09

I appreciate all the post and comments. Wiring, connectors and plugs is on our list of improvement this year.

Is there a web page or document that describes the most used wires type and connectors used in FRC and different options that are available? even a poster to use as a reference? does your team have a document that describe the standard you are using?

Any info would be appreciated.

<shameless plug incoming>

As far as I know, but this could be a great resource to put on the FIRST Wiki (http://firstwiki.github.io)! In my free time over the next few days I may start this page.

EDIT: Went ahead and created this page with some basic info, feel free to add more to it here (https://firstwiki.github.io/wiki/connectors)!

AllenGregoryIV

21-12-2016, 14:51

can you post the part number for these cheaper versions?

We just put in an order for the Molex latching .1 connectors from Arrow.com

Name | Part # | Qty | Price | Link
Male Housing| 701070002 | 100 | $0.20 | https://www.arrow.com/en/products/0701070002/molex
Female Housing | 50579403 | 100 | $0.11 | https://www.arrow.com/en/products/0050579403/molex
Male Pin* | 16020107 | 300 | $0.05 | https://www.arrow.com/en/products/0016020107/molex
Female Pin* | 16020086 | 300 | $0.04 | https://www.arrow.com/en/products/0016020086/molex

*Note that these pins aren't Bulk packaged they are still on their cut strips.