Team Update #11

[Bill_B]

Originally Posted by Munter2081

Does anyone know what the value of the inductor is? I've only taken them apart after they burned up.

If you have taken apart a good motor and know the color bands please let us know, so I can put up a part number and a vendor so we can have spares.

We're up to 5 additional motors now for the one mini-bot.

This post has the only mention of inductance value that I remember seeing. It's a tiny part, so I expect a small current rating would apply based on its size. The thermal protector is rated at 2.5A. I'm off to search for an inductor with those specs.

Let's carry on further discussion in the topic above, OK?

Oh, and thanks to the GDC for injecting some rationality into the meeting of component fragility with somewhat freewheeling experimentation.

[Justin Montois]

Originally Posted by Bill_B

Let's carry on further discussion in the topic above, OK?

I understand your desire to keep the discussion in that thread, but due to the fact that this Update specifically says that you can replace the inductor, I feel more people will access the information in this thread.

Below are links that may be an identical part to the inductor that comes stock on the Tetrix motor.

Picture of the Inductor on the motor:
http://www.chiefdelphi.com/forums/sh...62&postcount=1

A PDF listing the specs, also in the upper left hand corner a picture that appears to show a similar inductor as the stock component:
http://www.bourns.com/data/global/pdfs/9310_series.pdf

And a link where you can but the above product:
http://www.mouser.com/ProductDetail/...7kb9bpww%3d%3d

At $0.86, if this is an identical part it sure beats the heck out of having to buy a brand new motor.

Can anyone confirm/deny this part as being identical?

[ratdude747]

4.4.1 Robot Wireless Control
 Robots may be operated via wireless control only on the competition fields and the
practice field with the FIRST supplied radio; and
 Teams are not allowed to set up their own 802.11a/b/g/n (2.4GHz or 5GHz) wireless
communication (access points or ad-hoc networks) in the venue

sounds like scouting may be more of a challenge this year...

[IndySam]

My first ever Q&A question was used for an update!

The 2011 Kit of Parts Checklist, Rev E has been updated to include VUVG-L10-B52-T-M7 as an alternate part number for the FESTO valves delivered in the Kit of Parts. There were two part numbers shipped for use in kitting and this revision allows teams to use either or both valves on the ROBOT.

[Akash Rastogi]

Originally Posted by ratdude747

4.4.1 Robot Wireless Control
 Robots may be operated via wireless control only on the competition fields and the
practice field with the FIRST supplied radio; and
 Teams are not allowed to set up their own 802.11a/b/g/n (2.4GHz or 5GHz) wireless
communication (access points or ad-hoc networks) in the venue

sounds like scouting may be more of a challenge this year...

This has been part of the rules since 09.....

[PaW]

Originally Posted by ratdude747
4.4.1 Robot Wireless Control
 Robots may be operated via wireless control only on the competition fields and the
practice field with the FIRST supplied radio; and
 Teams are not allowed to set up their own 802.11a/b/g/n (2.4GHz or 5GHz) wireless
communication (access points or ad-hoc networks) in the venue

sounds like scouting may be more of a challenge this year...

Originally Posted by Akash Rastogi

This has been part of the rules since 09.....

This is a good opportunity to remind students, mentors, parents, guests, etc. to disable the "hotspot" capability (and battery sucking feature) of the current generation of smartphones.

Each venue is different of course, so please make sure to check with your local director or coordinator. Some venues may have 'free wifi' in their concourse areas, and your scouting members might be able to set-up in those areas.

[Racer26]

The wifi (no team-setup 802.11a/b/g/n networks allowed) rule has always perplexed me. It actually has existed for as long as I can remember in FRC (yes, it PREDATES the cRIO and robot control systems running on 802.11n.)

The old IFI controls ran on 900MHz radio modems (they run an RS-422 Serial link over a radio connection).

The current cRIO+wifi controls run using 802.11n in the 5GHz band, everywhere except Israel, where 5GHz is a restricted military frequency, so they use 802.11n@2.4GHz.

The rule has always been in place with the intent of preventing robot interference, and it USED to outlaw ALL wireless communication devices in ANY band, except for cell phones IIRC. (this meant teams couldn't use walkie talkies or similar devices)

I've always found it silly for several reasons.

Cell phones regularly make use of the 900MHz frequency band, especially historically during the era of the IFI controls. If interference was such a problem, the literally hundreds of cell phones at an FRC event should have caused some robot weirdness. None occured, to my knowledge. Fast forward to today, and smartphones are now equipped with Wifi abilities, simultaneously operating in several frequency bands. You could never outlaw bringing your cellphone to an FRC event. It would be impossible to police.

Event venues, and indeed, even FRC events themselves, frequently have Wifi running at, or within range of FRC events. Additionally, the 2.4GHz, and 5GHz bands are unlicensed bands, usable by anyone for anything, anywhere in North America. Many FRC events have residential, commercial, industrial, or institutional lands within range. Interference in this band comes from all over the place, whether or not teams are wilfully adding to it or not.

The 802.11 standard (in all flavors) has proven itself to be fairly resilient to interference, otherwise you and all your neighbors couldn't run your wifi routers in such close proximity to one another without causing problems. Furthermore, since FRC is using the comparitively unused 802.11n @ 5GHz, any interference in the 2.4GHz or 900MHz bands would cause no problems at all.

If interference were a true problem for FRC bots (its not), FRC could apply to the FCC and CRTC to use the licensed 3GHz band. I know of at least one company that makes 802.11 compliant devices using that band. This solution would surely eliminate any interference concerns, however, it would potentially be problematic in that each team might have to apply for a license, unless FIRST could convince both CRTC and FCC to grant the program a blanket license.

[ratdude747]

Originally Posted by 1075guy

The wifi (no team-setup 802.11a/b/g/n networks allowed) rule has always perplexed me. It actually has existed for as long as I can remember in FRC (yes, it PREDATES the cRIO and robot control systems running on 802.11n.)

The old IFI controls ran on 900MHz radio modems (they run an RS-422 Serial link over a radio connection).

The current cRIO+wifi controls run using 802.11n in the 5GHz band, everywhere except Israel, where 5GHz is a restricted military frequency, so they use 802.11n@2.4GHz.

The rule has always been in place with the intent of preventing robot interference, and it USED to outlaw ALL wireless communication devices in ANY band, except for cell phones IIRC. (this meant teams couldn't use walkie talkies or similar devices)

I've always found it silly for several reasons.

Cell phones regularly make use of the 900MHz frequency band, especially historically during the era of the IFI controls. If interference was such a problem, the literally hundreds of cell phones at an FRC event should have caused some robot weirdness. None occured, to my knowledge. Fast forward to today, and smartphones are now equipped with Wifi abilities, simultaneously operating in several frequency bands. You could never outlaw bringing your cellphone to an FRC event. It would be impossible to police.

Event venues, and indeed, even FRC events themselves, frequently have Wifi running at, or within range of FRC events. Additionally, the 2.4GHz, and 5GHz bands are unlicensed bands, usable by anyone for anything, anywhere in North America. Many FRC events have residential, commercial, industrial, or institutional lands within range. Interference in this band comes from all over the place, whether or not teams are wilfully adding to it or not.

The 802.11 standard (in all flavors) has proven itself to be fairly resilient to interference, otherwise you and all your neighbors couldn't run your wifi routers in such close proximity to one another without causing problems. Furthermore, since FRC is using the comparitively unused 802.11n @ 5GHz, any interference in the 2.4GHz or 900MHz bands would cause no problems at all.

If interference were a true problem for FRC bots (its not), FRC could apply to the FCC and CRTC to use the licensed 3GHz band. I know of at least one company that makes 802.11 compliant devices using that band. This solution would surely eliminate any interference concerns, however, it would potentially be problematic in that each team might have to apply for a license, unless FIRST could convince both CRTC and FCC to grant the program a blanket license.

thats funny, i can always seem to remember teams having wireless networks set up for scouting... if the rule has existed that long, has it really been this poorly enforced?

[Racer26]

Originally Posted by ratdude747

thats funny, i can always seem to remember teams having wireless networks set up for scouting... if the rule has existed that long, has it really been this poorly enforced?

Prior to 2009 when the cRIO+wifi became the method of doing things, and there was 6 Wifi networks required to just run a match, it was just that poorly enforced.

2009-present, the FTAs have had spectrum analyzers and stuff hooked up, and can tell what Wifi is going on in the area. If teams set up their robot on wifi in the pits, the FTA will know about it.

[billbo911]

Originally Posted by Justin Montois

I understand your desire to keep the discussion in that thread, but due to the fact that this Update specifically says that you can replace the inductor, I feel more people will access the information in this thread.

Below are links that may be an identical part to the inductor that comes stock on the Tetrix motor.

Picture of the Inductor on the motor:
http://www.chiefdelphi.com/forums/sh...62&postcount=1

A PDF listing the specs, also in the upper left hand corner a picture that appears to show a similar inductor as the stock component:
http://www.bourns.com/data/global/pdfs/9310_series.pdf

And a link where you can but the above product:
http://www.mouser.com/ProductDetail/...7kb9bpww%3d%3d

At $0.86, if this is an identical part it sure beats the heck out of having to buy a brand new motor.

Can anyone confirm/deny this part as being identical?

I ordered 10 of the inductors listed on the Mouser site. They are the same value as the one in the motor, BUT, they are not an identical part. They appear to be a bit larger. I will have these with me in St. Louis if anyone needs one (or two). I believe they will be legal to use, but I will get approval first.
Here is a picture of what was delivered.