New Control System How To

[BrentJ]

Travis you have done a great job.

This will make life so much easier trying to keep track of everything.

Thanks again for taking the time to do this.
Brent

[vivek16]

Originally Posted by BrentJ

I am new to FIRST so I may be misinterpreting the rules. But if your mentor gets the Midwest teams a discount on parts then those may become illegal if used on next year's robots.

I am sure someone more experienced will correct me if I am wrong. Also please don't take this personally as I am trying to learn how to interpret FIRST rules. I am basing my opinion on the 2008 Financial rules, I don't think 2009 rules will be much changed.

Just taking your statement at face value. Say the midwest teams are given a midwest only discount on Wago parts. If these parts are only used for pre-season training and not put on the 2009 robot not a problem.
But use them on the 2009 robot and they become illegal as other teams outside the Midwest can't buy these COTS at the same price. From reading of the rules if a COTS part can not be brought by all teams for the same price then it can't be used?

Am I reading the rules correctly?

Originally Posted by Elgin Clock

Almost there. It is my understanding of the accounting rules, that any team can get anything allowed on your robot (material, component, etc..) for any price they can manage to get their hands on it for. (Free works best btw..lol)
But, for Bill Of Material purposes, all teams must account for COTS prices.(Re: Non-discounted prices).

For example, say I got a local metal distributor to give me 50% off for every metal piece my robot requires. (material).
I can jump for joy because I just saved my team 50% of the price & could potentially buy twice as much now with the money I had, but for legal competition documentation intents & purposes, I can not use more than the allowed cost of the robot in metal, or combined for everything used on the robot, & have to accurately account for the COTS price (Price of all that metal without a discount) in my BOM.

Bottom line is, that just because I can buy a bunch of metal for 50% off & you buy it at full price, I still have to account in my BOM the exact same price you do if we built the same exact robot with the same amount of metal. I can't build a robot twice the cost amount of you just because I got everything for 50% off.

What Elgin said. You must still put the parts in the Bill of Materials at full price but can receive a discount or even have the parts donated.

-Vivek

[Al Skierkiewicz]

Phil et al,
My attempt here is to get as much information to as many students and mentors as possible. Regardless of your favorite posting environment or the First websites, CD has more than 20,000 members. I just want to be sure that the maximum amount of information gets out there. If need be, try to post accurate facts in multiple locations. All will benefit.
Since it appears from the available documents, that the breaker size will remain the same as in the past, I will go out on a limb and predict that wire rules will remain relatively unchanged. Remember that minimum wire size is limited by the breaker feeding it. Breakers are chosen to protect the wiring, not the load. Thanks to Kevin for posting the links to the terminals.

[Al Skierkiewicz]

This is a link to the general brochure on WACO terminals...http://www.wago.us/downloads/51017243.pdf

This is a link to their e-learning on the "cage clamp" terminals...https://admin.na3.acrobat.com/p35541967/
It is a powerpoint style tutorial in PDF format and has some interesting info on current, testing, temperature, etc.

[Mike AA]

The real test on the control system will be when we start putting high current through these WAGO connectors. I have seen more failures with these things than not under high current. The little metal tab which contacts the wire (typically about 1/4 the wire size) has a tendancy to heat up and cool down losing its spring ability and thus losing contact. Expecially with constant movement and shock.

At our new Menards in Holland I have personally replaced about 40 of their wirenut versions which use the exact same concept, 6 of which had such a catastrophic failure that the fire department was called.

-MIke

[Kevin Sevcik]

This brochure is probably a little more enlightening on the WAGO Cage Clamp system. Particularly page 2, which shows how the installation process works.

Mike,

What kind of currents are we talking about here? As I understand the system, all/most of the current should be flowing through the copper current bar. The spring steel clip shouldn't see much current, given the relative sizes and resistivities of the clip and current bar. So I don't really see a mechanism for the extreme kind of heating needed to take the set out of the spring steel, save a rather poor installation.

[Al Skierkiewicz]

Originally Posted by Kevin Sevcik

This brochure is probably a little more enlightening on the WAGO Cage Clamp system. Particularly page 2, which shows how the installation process works.

Kevin,
That is a good find, thanks.

[Alan Anderson]

Originally Posted by Mike AA

At our new Menards in Holland I have personally replaced about 40 of their wirenut versions which use the exact same concept, 6 of which had such a catastrophic failure that the fire department was called.

That was the installation where aluminum wiring was quietly substituted for the copper that got stolen the night before the work was done, right? I remember reading something about that this summer in an electricians' newsletter. The connectors involved (I think they were called something like "WAGO Wall Wire") were explicitly not intended for use with aluminum.

[Kevin Sevcik]

Originally Posted by Alan Anderson

The connectors involved (I think they were called something like "WAGO Wall Wire") were explicitly not intended for use with aluminum.

WAGO Wall-Nuts then. And yeah, it does say Cu/Cu only. Aluminum in copper fittings is definitely a bad idea.

[DonRotolo]

Originally Posted by Mike AA

The little metal tab which contacts the wire (typically about 1/4 the wire size) has a tendancy to heat up and cool down losing its spring ability and thus losing contact.

The spring tab that contacts the wire isn't where most of the current flow happens - instead it is the large flat (and thick!) surface that it is pressing the wire against. I will suggest that (for these connectors) the temperature rise in the wire will exceed that of the connector.

[willson.thomas]

Originally Posted by Greg Marra

I feel like in many ways, the amount and format of information regarding the new controls system would be best captured in a Wiki, not a bunch of individual forum threads.

FIRSTWiki didn't seem to catch on the first time around, but maybe we can revive it with information about the new controls system? A page about each of the components, edited by people who know about them, would quickly result in a fairly comprehensive "how to" manual.

Well, at this risk of adding yet another place too many for info, I have installed MediaWiki on my server. I am currently working on adding all the necessary pages, syntax coloring, and possibly purchasing a domain name.

It is located at http://tom-tech.com/first/wiki in case anyone is interested.

Update: Should be up any minute at http://frcwiki.com

[Mike AA]

Originally Posted by Kevin Sevcik

Mike,

What kind of currents are we talking about here? As I understand the system, all/most of the current should be flowing through the copper current bar. The spring steel clip shouldn't see much current, given the relative sizes and resistivities of the clip and current bar. So I don't really see a mechanism for the extreme kind of heating needed to take the set out of the spring steel, save a rather poor installation.

Kevin,

The Wall-Nuts which failed were rated for #10 wire on an AC installation so atleast 30amp.

Originally Posted by Alan Anderson

That was the installation where aluminum wiring was quietly substituted for the copper that got stolen the night before the work was done, right? I remember reading something about that this summer in an electricians' newsletter. The connectors involved (I think they were called something like "WAGO Wall Wire") were explicitly not intended for use with aluminum.

Alan,

Our store did not have that issue. I have viewed nearly 100% of the runs of wire in our store ( I work at the Holland Menards and work with my dad (master electrician) when issues arise). The wires are all copper some larger than needed. The article was not about our store.

Originally Posted by Don Rotolo

The spring tab that contacts the wire isn't where most of the current flow happens - instead it is the large flat (and thick!) surface that it is pressing the wire against. I will suggest that (for these connectors) the temperature rise in the wire will exceed that of the connector.

Don,

Now if you look at the locations of the large flat surface this is right next to the steel spring which will conduct heat and wear out the spring when continuously pushed to maximum current ratings. These are a different and much improved form of connector than what WAGO has had in years past.

[Gdeaver]

In the past the victors had no current monitoring or thermal protection. Having 4 cims in locked rotor or near stall combined with the other loads provided a real shock to the power distribution system and battery. With the new speed controller they have the ability to limit the current profile to the motors. If they set the proper profile the days of clicking circuit breakers should be over. The breakers would protect from wiring faults still. This can make our power distribution system more reliable going forward.
How about the low voltage stuff. What do the beta testers think of the bumpers and side car connectors? From the picture the pneumatic bumper looks a little flimsy. Does it need mechanical support?

[jgarski]

Ah yes, the Wall Nut.

The Wall Nut product we make is designed solely for use in solid wire, and copper only.

It does not utilize the same technology as the terminal blocks. The Wall Nut uses a leaf spring design, not the Cage Clamp. If you want to use a Cage Clamp, we make a product called the LeverNut, which is very cool. Same idea as the Wall Nut or any wirenut, but uses the Cage Clamp inside of it. It can handle 12-28 awg (I think, I don't have the spec in front of me) and solid or stranded. It also has a test port for probing with your multimeter.

The cage clamp connection is used in applications on just about every US aircraft carries, as well as all over the oil fields. These high demand environments show the robustness of our product.

It's unfortunate that someone had a problem. But that is a rare event.

[vivek16]

Originally Posted by jgarski

Ah yes, the Wall Nut.

The Wall Nut product we make is designed solely for use in solid wire, and copper only.

It does not utilize the same technology as the terminal blocks. The Wall Nut uses a leaf spring design, not the Cage Clamp. If you want to use a Cage Clamp, we make a product called the LeverNut, which is very cool. Same idea as the Wall Nut or any wirenut, but uses the Cage Clamp inside of it. It can handle 12-28 awg (I think, I don't have the spec in front of me) and solid or stranded. It also has a test port for probing with your multimeter.

The cage clamp connection is used in applications on just about every US aircraft carries, as well as all over the oil fields. These high demand environments show the robustness of our product.

It's unfortunate that someone had a problem. But that is a rare event.

They are 12-28. I love these, the only way the will fail is if you shear the wire strands themselves. They are very robust little things. They should cut the time it takes to wire the robot in half when paired with the wago connectors (not to mention repair time during competitions!).

thanks, Vivek