pic: 931 Preliminary Electrical Layout

[Richard Wallace]

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[MrForbes]

Nice, thanks for letting us see what it looks like. Lotsa stuff on there!

The negative terminal post in the top right corner of the picture is not show on the 2007 Robot Power Distribution Diagram, and does not appear to be from the KOP. It also seems to defeat the purpose of the black Power Distribution Block (whatever that purpose might be). Are you sure it's allowed by the rules?

[Richard Wallace]

Originally Posted by squirrel

The negative terminal post in the top right corner of the picture is not show on the 2007 Robot Power Distribution Diagram, and does not appear to be from the KOP. It also seems to defeat the purpose of the black Power Distribution Block (whatever that purpose might be). Are you sure it's allowed by the rules?

Well spotted.

The 3/8" stud you see was a KoP item in previous years, and would be considered a COTS COMPONENT now. As such we will need to account for its cost in our materials list, and make sure that it complies with <R63> since, as an electrical conductor, it might be considered a custom circuit.

EDIT: of course under <R47> the stud is an additional electrical component, and as such would not be allowed if it is not COTS.

EDIT: Post Count = Team Number.

[MrForbes]

<R57> does not seem to specifically address the negative power distribution, but from the specifics of the positive power distribution description, I would feel much safer about passing inspection by using only the new power distribution blocks and fuse panels for all intermediate connections.

[Mike AA]

I honestly think that you could simplify your wiring and lose some weight if you moved the din rail closer to the radio and got rid of the stud and crimps. Thus causing one less location for something to come loose. Or better yet use the Negative posts on the smaller breaker panel. Or, I'm not sure if its required to use the din rail but you could totally eliminate the din rail and run the negative to the stud and the positives through the maxi-block.

Just a thought. I dont plan to use additional items.

-Mike

[Richard Wallace]

Originally Posted by Mike AA

I honestly think that you could simplify your wiring and lose some weight if you moved the din rail closer to the radio and got rid of the stud and crimps. Thus causing one less location for something to come loose. Or better yet use the Negative posts on the smaller breaker panel. Or, I'm not sure if its required to use the din rail but you could totally eliminate the din rail and run the negative to the stud and the positives through the maxi-block.

Just a thought. I dont plan to use additional items.

-Mike

Thanks for the weight saving idea. We do plan to compress the layout after some other chassis decisions are finalized, and we may lose the stud at that point.

However, I am pretty sure the DIN Block is required per <R57>.

EDIT: also I am pretty sure that wiring 40A circuit returns to the smaller breaker panel is not allowed.

[clydefrog88]

are you using the plywood for your final board? we've saved a lot of weight in the past few years by using 1 or 2ply of hand laid fiberglass on both sides of a balsa core. it weighs almost nothing and is strong enough for a electronics board.

[Richard Wallace]

Originally Posted by dragon ninja

are you using the plywood for your final board? we've saved a lot of weight in the past few years by using 1 or 2ply of hand laid fiberglass on both sides of a balsa core. it weighs almost nothing and is strong enough for a electronics board.

That sounds cool.

We have not used plywood for the electrical system board in previous years and probably won't this year either. Usually we have laser-cut 0.22" thick acrylic sheet. Wood is nice and forgiving though, and will let us experiment with layout ideas until we feel comfortable.

A factor to consider is that the kitbot frame needs some stiffening anyway, so our choice for final electrical board material may be based partly on overall robot strength requirements, not just being "strong enough for an electrical system". Sometimes adding weight to one subsystem lets you take even more weight out of another.

[xghost]

The connectors on those speed controllers(red/black)...They seem very nice...look like mini battery connectors and easier than two quick disconnects terminals. Where did you get those?

[Richard Wallace]

Originally Posted by xghost

The connectors on those speed controllers(red/black)...They seem very nice...look like mini battery connectors and easier than two quick disconnects terminals. Where did you get those?

Those are Anderson Power Pole connectors in the 15/45 Ampere size as shown here. You can get them through several distributors. A low cost crimping tool for their terminals is available at West Mountain Radio.

Good luck this season.

[Darkswordsmith]

I'm still not sure whether we can use the negative stud in power distribution. Can anyone give a definite answer?

[Jeremytice]

That electrical layout looks very nice you guys. Great job!

[Al Skierkiewicz]

Richard,
Looks really cool, nice job! I would eliminate the ground stud and return the negative leads directly to the distro block. You save some weight in #6 and crimp on connectors and lower the series resistance, not to mention a single point failure if the stud hardware loosens.
How do you like the crimper and the Power Poles so far? We add a touch of solder to the connector just to be sure, before assembly. They crimp on the #12 Chalupa leads OK as well, but again a touch of solder just to be sure.

[Richard Wallace]

Thanks, Al.

We will probably lose the stud when we compact the layout somewhat -- right now the footprint is still too large. I agree the stud takes up valuable space and is an extra failure point.

Also, I am not sure that the stud is a COTS component. It was in an old (2003? '04?) KoP but I don't think it was custom made for FIRST. Anyway I would need to get a part number and price to show for material cost analysis if we want to use it on the robot.

[Al Skierkiewicz]

Richard,
It seems to me that they were available from Terminal Supply that year.