[FTC]: Using Anderson Connectors for wiring.

[jtdowney]

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.

[Sasha]

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?

[Al Skierkiewicz]

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.

[skatefriday]

Originally Posted by PAR_WIG1350

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.
Nope, I see what you mean. Good idea.

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.

[jcarr]

<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!

[PhilBot]

It is 100% legal to replace the battery connector with the Anderson Power Pole connector.

See <03> n,o and s. This is very well stated here.
No need to ask the forum.

It was legal in 2011/12 and it is in 2012/13. We have done it both years.

It's also recommended that you build your own power wiring harness and use connectors to make it more modular.

We have also used the andderson connectors to make our motor connections more reliable. We solder short wires onto the motors and then add a connector.

The Anderson connectors are MUCH more reliable than any of the other FTC connectors becasue they incorporate a two-part contact. One part is a stainless steel leaf spring to provide contact pressure, the other part is the actual conductor contact. You can get two different contact, based on the wire size you are using. I recommend also purchasing the wire to go with the connectors. It's color coded zip wire that is very flexible and easy to use.

We purchase from http://www.powerwerx.com

And as said earlier, remove the fuse before you do it. Just cutting off the connector in one action will short the battery and blow the fuse (at best).

[Al Skierkiewicz]

Skate,
While I believe the rules do not provide for you to change to a different battery connector, it is possible to replace/repair the one provided. The Molex connector is not one of my favorites but it is the one provided on the battery and the charger. There are two regular failures with these connectors. The first is that the wires pull out of the crimp or break off. The only fix is to replace the connector. The second is the female pin opens with time and becomes intermittent as shown in your video. (If you look into the end of the connector you will see the "c" shaped pin) If you use a small jewelers screwdriver, inserted between the pin and the housing (on both sides of the opening), you can return the inside diameter of the female pin to it's original size. This will give maximum contact when inserting the battery connectors.
Replacement pins and housings are available from several outlets such as Digikey and other parts houses. When you buy the pins, be sure to buy the universal crimper. It costs about $50 and I think the part is WM9999-ND. This is a two step crimp but it does the job.

[PhilBot]

Originally Posted by Sasha

- 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.

It's a tough question.

I know that there are potential problems with tinned wire in screw terminals. My concern was always that since solder is soft, there is the potential for the solder to get compressed, which will cause the wire to loosen in the connector.

BUT I also know that without tinning it's VERY hard to get all the strands of copper into the screw terminal. And there is NOTHING worse than stray strands sticking out of the terminal. It reduces the effective gauge of the wire, and it';s a shorting hazard.

I suspect this is why the wire from the power switch/battery is already tinned.

My solution is to split the difference.

When I strip wire for the screw terminals, I strip some extra length. Then I tin just the last part of the exposed wire with minimal solder. This acts as a binder to hold the strands together. Then I snip off most of the tinned end, leaving almost bare copper wires with some internal solder for binding.

This lets us insert ALL the strands into the connector, but once in, the screw terminal is pressing down on mainly bare wire. It's a compromise. But for me, not having any stray/exposed strands is paramount.

[PhilBot]

Originally Posted by Al Skierkiewicz

Skate,
While I believe the rules do not provide for you to change to a different battery connector,

Hi Al.

Here are the specific rules that apply here....

<R03>n. Anderson PowerPole, and similar crimp or quick connect style connectors for joining electrical wires are allowed.

<R03>o. Non-NXT power, motor control, servo, and encoder wires and their connectors may be extended, custom made, or COTS subject to the following constraints:
1. Battery wires are 16 AWG or larger

<R03>s. Electrical components that are not specifically allowed by the rules (i.e. sensors, batteries, microprocessors, etc.) are not permitted. Motors, sensors, controllers, and any other electrical
components may not be altered from their original state in ANY way unless specifically allowed by the Robot rules. Also, the connectors on the TETRIX and MATRIX battery packs may be replaced or augmented with any compatible connector described in <R03>n above.

It seems pretty clear cut to me. Where do you see that replacing the battery connector would not be allowed.

[Al Skierkiewicz]

Phil,
the part of the rule that triggered my response is the
o. Non-NXT power, motor control, servo, and encoder wires and their connectors may be extended, custom made, or COTS subject to the following constraints:

followed by:

s. Electrical components that are not specifically allowed by the rules (i.e. sensors, batteries, microprocessors, etc.) are not permitted. Motors, sensors, controllers, and any other electrical components may not be altered from their original state in ANY way unless specifically allowed by the Robot rules.

Emphasis mine. Since the battery is an NXT power device under par. o and an electrical component under par. s, I read this as no mods can be made to batteries. I did not check the FTC Q&A to see if there is any response there. That does not mean that APP connectors are the better choice, just that I believe the battery cannot be modified.

[PhilBot]

Originally Posted by Al Skierkiewicz

Since the battery is an NXT power device under par. o and an electrical component under par. s, I read this as no mods can be made to batteries. I did not check the FTC Q&A to see if there is any response there. That does not mean that APP connectors are the better choice, just that I believe the battery cannot be modified.

Al, I'm afraid you are giving bad advice based on incomplete information.

1) "NXT Power" means the NXT's internal battery pack, and thus not allowed to be modified. The 12V Battery is Tetrix, thus it is "Non-NXT Power" so it IS allowed to be modified acording to 'o'.

2) Apparently you are going to totally ignore the final caveat in the 's' rule that specifically states that Battery Mods are legal? It says....

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

I'm not sure how they could have stated it any more clearly. TETRIX battery mods are legal. Period! Why put that sentence in, if you are not allowed to modify the battery? They even refer directly back to the Andserson connector clause. This is 100% clear.

Rule S is NOT inconsistant with itself if you read the whole thing. It states that you can't change any other electrical components UNLESS it's allowed by the rules... and then it goes on to specifically allow modifying the battery connections. You can't just choose to apply some of the rule to make your point.

---

For the record, last year's rule was ambiguous about the battery connector. The rules said you could use the connectors, but couldn't change electrical components. So we asked the Q&A about the battery connector, and it was approved. This year they have added that last caveat to make it clearly legal.

And... although it doesn't prove anything more than the rule itself, the #2 robot at worlds last year used Anderson connectors on it's batteries, and it never had problems with inspections (or power). And we know all the rules have openned up since then.

I'm going to let the dead horse lie now...

Phil.

[Al Skierkiewicz]

Phil,
You are correct. I had forgotten the last sentence was added this year.

[PhilBot]

No Problems...

Phil.

[skatefriday]

Originally Posted by PhilBot

It is 100% legal to replace the battery connector with the Anderson Power Pole connector.

See <03> n,o and s. This is very well stated here.
No need to ask the forum.

It was legal in 2011/12 and it is in 2012/13. We have done it both years.

It's also recommended that you build your own power wiring harness and use connectors to make it more modular.

We have also used the andderson connectors to make our motor connections more reliable. We solder short wires onto the motors and then add a connector.

The Anderson connectors are MUCH more reliable than any of the other FTC connectors becasue they incorporate a two-part contact. One part is a stainless steel leaf spring to provide contact pressure, the other part is the actual conductor contact. You can get two different contact, based on the wire size you are using. I recommend also purchasing the wire to go with the connectors. It's color coded zip wire that is very flexible and easy to use.

We switched to an Anderson Powerpole based bus late last year and it
has proved to be quite an improvement over daisy chained power.

Thank you for the rule clarification. I had read that rule earlier in the season,
but I was looking for a rule that would allow our team to use an Arduino
to control decorative lights. I therefore was not focusing on the battery
and I missed that.

Thank you for pointing it out. We are cutting our Molex connectors off
at our next meeting.