[FTC]: Using Anderson Connectors for wiring.

I found this document via Twiter:

http://www.usfirst.org/sites/default/files/Anderson-Powerpole-Guide.pdf

It’s a pretty cool description of a different way to connect your motor/servo controllers. And since it’s on the FIRST site I assume it’s legal.

I just checked out the link to the parts, and they are are suprizingly inexpensive. $11 will get you eveything you need for 5 connector sets. The only real expesne is the crimper if you want a nice one.

One of the additions I’d make to the idea is that you should replace the connector on your charger to be one of these Anderson types as well, and use it to plug into your system to charge the battery.

The problem that we had last year was that the current battery connectors don’t seem to be designed for the hundreds of connect/disconnect cycles that we put them through. Eventaully the copper pins loosen up and start glitching on robot-robot impacts. What look like telemetry dropouts are actually power resets on the Samantha module.

The Powerpole connectors have stainless steel springs built into the connectors so they are rated for 10,000 connect cycles. Plus they are rated for 45 Amps.

The bonus is that if this system removes the multiple wires in a screw terminal issue and the need to pull wires to replace a motor controller.

The additional connectors may add a bit of bulk, but if it increases reliability it’s worth it. Mine are on order now !!!

Phil.

[Strike]In the past it has not been legal to change the connector attached to the battery, I believe, which would be why the document doesn’t show this being done.[/Strike]
Nope, I see what you mean. Good idea.

Yeah,

It would be great if we could change the battery connection, but even if we can’t, using the proposed wiring we could just change the connector on the charger (or even make an adaper cable) and plug in the charger dowsntream from the power switch (using the Anderson connector).

You’d just need to make sure the switch was ON when you went to charge.

The existing battery connector is fine, as long as you don’t make it loose from many hundreds of connections.

ps: I do think we should lobby for being able to change the battery connector if we are fine with voiding the warrentee :slight_smile:

Phil.

Phil,
As much as I like these connectors (we have used them for years on our FRC robots) under 2011 rules they are not legal for FTC. Specifically, they are not official Lego or Tetrix parts and are not on the allowed materials list. While 2011 rules do allow for splicing electrical connections, they specifically call for tape to insulate such connections.

However, if you check my other posts on this subject, you will find that I highly recommend the West Mountain Radio crimp tool. We use these connectors for all FRC motor connections and a variety of other uses on our robots. If FTC rules will allow these in the future, I expect that battery connectors will be required to remain as they are provided from the manufacturer. If for no other reason than to have compatibility between teams.

Since the 2011/12 rules are yet to be released, I don’t know if they are legal or not this year, but it would amaze me if FIRST went to the effort of collecting this information from a team, and placing it on their website if they weren’t going to be legal. Plus they (FIRST) are pushing the document on Facebook and Twitter.

Phil.

Agreed but stranger things have happened in the past. We will know in a few days.

Just a followup now that the FTC rules have been released. Rule R5(c)-26 says:

Anderson 30 Amp PowerPole or similar Crimp style snap plug connectors and butt splice connectors for joining electrical wires are allowed. Power distribution panels may also be used (and is strongly recommended) to make wiring easier.

Hi Phil,

We thought we would try the Anderson 30 Amp connectors. Should we buy the unassembled or the permanently bonded? Also, the FIRST components list recommends a power distribution panel. Do you know what that is?
Thank you.
Ron Pittwood
Coach
FTC 2888

Ron,
There is/was a power distribution panel for FTC in the past. I have been looking for it but haven’t found it yet. It simply was a power terminal that connected the battery to multiple outputs. I believe that is what is referenced.

These PowerPole Splitters look interesting:

www.powerwerx.com/powerpole-power-distribution/ps-8-inline-8-way.html

www.powerwerx.com/powerpole-power-distribution/ps-4-inline-4-way.html

Nice find Michael.

It appears that it is a common bus bar with power coming into any lead and being shared across all others. This is a nice way to put in future options for adding devices later. Start with the 4 bus version and then swap it out for the slightly larger 8 bus version.::safety::

So, the ruling states the we can use up to 30Amp Anderson Connectors. I can’t believe there is anywere near this much current running through an FTC robot. The 15 Amp connectors greatly reduce the bulk of these connectors. The contacts are universal between the 15 and 30 Amp connectors, so you can use the larger 16 gage contacts for the folded over wire and still install them in the 15 Amp connectors.

Does anyone see a reason not to use the 15 Amp connectors?

Yes. You risk failing inspection, because they’re arguably illegal. (What is “similar”?)

It’s at least plausible that FIRST had a technical reason for mandating the higher-current connectors—maybe they were especially (perhaps inordinately) concerned about durability, for example.

And even if it’s just a mistake on FIRST’s part, ask about it in the Q&A forum before deciding to use the 15 A versions.

Actually, I think you are confused on the differences between the 15 and 30 amp connectors. According to this page:

http://www.powerwerx.com/anderson-powerpoles/powerpole-sets/

The 15, 30, and 45 amp connectors share the same housing, the only difference is in the contact.

The reason that FIRST specifies 30 amp connectors is probably because the battery is fused at 20 amps. It would be poor design to use a connector rated for less than the fuse on the circuit.

I hope this helps.

David, I think your assessment is correct. The safety of the contact is an issue and the 15 amp contact is not the same as the 30 amp contact. The housing is the same for 15, 30 and 45 amp contacts. I also agree with Tristan, only the Q&A can make a firm answer on this point.

I just want to point out this section of the Powerwerx page:

High current rating, low resistance
The size of the wire a Powerpole contact will accept is the primary limitation of their ability to carry a load. The size of the flat contact area is actually the same for all 15, 30 & 45 amp contacts. Powerpoles will safely handle higher loads or surges, please read the PP30 data sheet (PDF) for additional information.

This is the information we worked with when using these connectors on our FRC robot. However as many others have said, only a Q&A post can be the final verdict.

A couple of closely related questions:

  • The rules say “Motor power, power and encoder wires may be extended by splicing additional lengths of wire” (R14<c>). Does anyone know if it allowed to just replace one of the wires (say, the power wire to the switch) with your own one - of course, of required AWG rating.

  • The document about using PowerPole connectors specifically warns that you should NOT tin the wires. This is news to me: I have always tinned the wire end going into the screw terminals on motor controllers - it makes it so much easier to get in the hole. Any comments on this? Is there a real danger of the wire heating so much that the solder will melt?

Alex,
The quoted text is part of the “R14 Part Modification” section of the manual. There should be no problem with preparing a wire(s) with appropriate connector for the power switch extension under this rule. Use the same size wire or larger for this cable.
Wires for screw type terminals, the push terminals on the FRC PD and for the Anderson Power Products should never be tinned prior to installation. By tinning, you limit the surface area of the engaged wire such that it degrades the current capability by the equivalent of several wire sizes (AWG). The resulting loss in wire size results in localized heating of the wire joint. In crimped contacts, the crimp tool may make a substandard crimp resulting in not only heating but also may result in wire pullout.

I’ve been looking for an answer as to whether or not
it’s legal to swap out the Molex battery connector
for the more reliable Anderson connectors.

We’ve been having this problem with our batteries.

http://www.youtube.com/watch?v=WVAjSqUN5gk

Is there a definitive answer? I’ve searched the FTC Q&A
forums to no success.

Thank you.

<R03> s. … Also, the connectors on the TETRIX and MATRIX battery packs may be replaced or augmented with any compatible connector described in <R03>n above."

This means you can replace the connector on the battery, although you would have to ask the question on the forum to get an official ruling.

Just a note - remove the fuse first!