[FTC]: Using Anderson Connectors for wiring.

[PhilBot]

I found this document via Twiter:

http://www.usfirst.org/sites/default...pole-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.

[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.

[PhilBot]

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

Phil.

[Al Skierkiewicz]

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.

[PhilBot]

Originally Posted by Al Skierkiewicz

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.

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.

[Al Skierkiewicz]

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

[jtdowney]

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.

[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).

[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.

[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 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.