[FTC]: Custom Material and Wiring Questions

[electron]

Hello all!
While reading the TechnoGuard's Engineering Notebook (Thank you so much for opening that up, btw!), I noticed the use of what looks like stock aluminum C-Channel for angled bar. You can see what I mean here, and here.
Is that really some sort of stock channel/angle bar? Can I just grab some at the home depot down the road, and (most importantly), is it legal to use in FTC?

I noticed too that they used Kydex extensively, and I'm wondering if anyone has a good supplier that they would recommend.

And one more quick question I have is this:
I noticed that they extensively used custom sensors. Does anyone have a good guide for wiring the protoboard?

Thanks for you help, everyone!

[Andrew Remmers]

You can use Aluminum U(C) Channel, L Bar, and I think Square (been a while since I have read the rules)

I however don't thing you can get this from your local Home Depot or Lowes (Doesn't show up on the website) However Im pretty sure you could get it from an Ace Hardware or something like that.

You can get Kydex from Mcmaster.com as well.

- Andrew

[electron]

Originally Posted by Joyride_67_1902

You can use Aluminum U(C) Channel, L Bar, and I think Square (been a while since I have read the rules)

You can get Kydex from Mcmaster.com as well.

Andrew, thank you very much, I (finally) found the page in the manual that allows for Aluminum channel (page 28). I'll look around for suppliers of the aluminum materials, and I found the kydex on mcmaster carr.
Thanks!

[Al Skierkiewicz]

Joe,
Check your manual for allowed sensors as well. I read it as NXT or Lego sensors only.

[Billfred]

Originally Posted by Joyride_67_1902

I however don't thing you can get this from your local Home Depot or Lowes (Doesn't show up on the website)

Probably 98.2815% of the aluminum on our FRC robot's arm tower this year was sourced from Lowe's. Home Depot also carries a selection, though I'm not as familiar with its precise offerings.

[electron]

Originally Posted by Al Skierkiewicz

Joe,
Check your manual for allowed sensors as well. I read it as NXT or Lego sensors only.

Mr. Skierkiewicz, on page 29-30, rule d (especially d.5) allows for custom circuits to be used, as long as they fit within some specific guidelines, but thank you for you word of caution.

Also see the Inspection list:

No electrical components have been nodified from their original state except the HiTechnic Prototype Board.

[ryanftc2827]

I would highly recommend kydex to all teams, great plastic. Heat forms very well and is very durable. We used it all over our robot for most everything.

[NalaTI]

Originally Posted by electron

Hello all!
While reading the TechnoGuard's Engineering Notebook (Thank you so much for opening that up, btw!),

You're welcome!

Originally Posted by electron

I noticed the use of what looks like stock aluminum C-Channel for angled bar. You can see what I mean here, and here.
Is that really some sort of stock channel/angle bar? Can I just grab some at the home depot down the road, and (most importantly), is it legal to use in FTC?

We did use channel at first because of size, (it's slightly smaller than the Tetrix channel). But then ended up using the square stuff for structural strength instead (which is what's in the pictures) -- you can find it at McMaster (http://www.mcmaster.com/#aluminum/=cra6bh)

Originally Posted by electron

I noticed too that they used Kydex extensively, and I'm wondering if anyone has a good supplier that they would recommend.

Interstate Plastics (http://www.interstateplastics.com)

We used all four plastics BTW. On the final robot, the upper shields were ABS, the lower ones were Kydex, the Hand (and lots of other small pieces) were PETG, the paddles and a few other clear pieces that needed to be strong were Polycarb. We used thin Kydex as covers for parts of the hand as well...

Originally Posted by electron

And one more quick question I have is this:
I noticed that they extensively used custom sensors. Does anyone have a good guide for wiring the protoboard?

On the prototype board we used three potentiometers, 4 switches, and a hall effect sensor. They show how to wire all of these to the prototype board in the Experimentor's Kit manual (http://www.hitechnic.com/downloadnew.php?category=19).

As an aside, on the prototype board, once we figured out how to use this, it became a nice thing, but for most teams, it's not needed. We waited to tackle it until their third year, and partly used it so Gavin (our programmer) would have something new to learn! We also re-built at least four extension boards. If you are going to look into using this, definitely consider getting the prototyping sensor kit. Being able to build it without solder first was a great tool.

We also used four other sensors (two gyroscopes, an accelerometer, and the I/R Seeker) all with the sensor multiplexer (which we used last year).

[Al Skierkiewicz]

Joe,
I read R5 as only NXT or RCX sensors may be used. Specifically b.4, b.7, d.4 and d.8. The Q&A did allow the use of reed switches with some very specific limitations. That is all that I was able to see.

[electron]

Originally Posted by Al Skierkiewicz

I read R5 as only NXT or RCX sensors may be used. Specifically b.4, b.7, d.4 and d.8. The Q&A did allow the use of reed switches with some very specific limitations. That is all that I was able to see.

Mr. Skierkiewicz, I was under the impression that certain custom sensors (eg, potentiometers, some limit switches, and some reed contacts) are considered "modifications", "additional circuits", or "sensors" connected to the prototype board. (see all rules in d. pages 29 to 30).
Also, see post #28 on the GOI Q&A Electrical page here.

[Al Skierkiewicz]

Joe,
R5 d really doesn't allow even the micro switches so the Q&A for reed and microswitch is a waiver made by the GDC. Note that the inspection checklist does not have a spot for these devices. Also if you search you will find that toggle switches also were deemed legal in January after many regional events had already taken place. As you are not modifying any FTC or NXT parts these are not considered legal modifications to use such parts. I did not find any reference to the use of pots, have you? Although I have been a lead inspector for FTC, I do not have any additional input to the GDC for FTC. A strict reading of the rules, in my mind, prevents the use of these devices. That does not mean, however, that I think they should be banned. I personally would like to see the rules in this area opened to the same use as in FRC. All of the stated devices are legal in FRC and encouraged. The real issue is the ability for a team to correctly use these items with the interface tools allowed and prevent damage to the NXT.

[electron]

Originally Posted by Al Skierkiewicz

Joe,
[snip].
That does not mean, however, that I think they should be banned. I personally would like to see the rules in this area opened to the same use as in FRC. All of the stated devices are legal in FRC and encouraged. The real issue is the ability for a team to correctly use these items with the interface tools allowed and prevent damage to the NXT.

I could not agree more! I used to be the electrical guy on Overdrive's FRC team, and I really miss the open-nes with which FIRST viewed COTs sensors in FRC.
Hopefully, they will address custom sensors more clearly in next year's manual