2011 Lone Star Regional

[Pjohn1959]

Originally Posted by LightWaves1636

We use jags cause they're more powerful than using victors. The only weakness to jaguars are metal shavings have easier access getting in.

I think you might need to check your specs again. We get faster and higher responses with the Victors.

We also found them to be a lot less durable. We have had several fail due to stress, where we have experienced nothing like that with the Victors. They just work.

[Kevin Sevcik]

I'm calling BS on both sides here without some sort of verifiable data. First, the Jaguar isn't going to be terribly more "powerful" than the Victor. The FETS in the Jaguar have slightly lower on resistance, which means slightly lower power lost to heat, but it's pretty minimal and the Jag's current sense resistor probably makes the whole thing even.

Similarly, the Victor isn't going to have any quicker response than the Jaguar to a specified output voltage. They both use the same PWM rate, processing time is minimal, and I'm not going to get into whether the Jag's 15kHz chop rate would react any faster than the Victor's 120Hz chop, because you guys aren't capable of noticing that difference.

And both speed controllers are just as easy to drop metal shavings in. In case you didn't notice, the FETs on the Victor are right under that fan. The leads are exposed and just waiting for a chance aluminum shard to vaporize them.

There's only a few actual differences between the two:
1. The Victor is smaller, lighter, and more expensive.
2. The Jaguar has a more linear response curve. Meaning 20% input actually gives you 20% output. The Victors ramp up the output rather quicker than the input and then level off, so 20% input gives you something like 30% output. This may account for Paul's "quicker response".
3. The Jaguars have built in voltage rate control, which prevents you from rapidly switching between positive and negative outputs. The Grey Jaguar was likely to blow a FET driver under these conditions, which is apparently what gave the entire line a bad rep for reliability.
4. The Grey Jaguars had captive screws that were never meant to be fully removed. They left metal shavings inside the case if you DID force them to unscrew, which added to the number of failures. Which is rather more operator error than lack of robustness. Black Jaguars have fully removable screws.
5. The Jaguars have current and temperature limiting features which kick in to protect the speed controller from damage under high load conditions. The Victors will let you beat them till the breaker or the Victor blows.

And that's it until you get into the laundry list of features the Jag has that the Victor doesn't. So as far as I'm concerned the robustness of the Black Jaguar is still in the proving stage but looking good and there's little performance difference between the two aside from the linearity of the output. I think anything else is hearsay and confirmation bias unless someone's got some actual test data to back it up.

[lynca]

THank you TI & IFI for providing options for controlling motors in FIRST. Maybe one day we will have more motor control options and more things to debate...

Getting back on topic to the people Thank Yous !

Huge thank you to Lucia , LSR was so smooth and really fast. We were out of awards at 4:30 this year !

Volunteers :
Craig for scorekeeping, J. Rogers the FTA, Kris the "MC" , Lyndon "Mr. Inspection" (notice how all of these great volunteers are NASA/Robonauts!) , and Kevin for picking up the slack , you guys are awesome year in year out and LSR would not be the same without you.

Thank you 3103/57 for setting up the rookie workshop in week 1. That made a huge difference for a handful of rookies.

Thank you to 441/2276/624/3335 for helping out with the Houston scrimmage this year ! Maybe next year we will get a few more teams

Big congrats to student leader Victor and team 441 , you amaze me every year and I wish you the best of luck in college.

118/1477/1801, great alliance and best of luck at Champs

2936 & 3320 , Miracles & DiscoZillas has a nice ring!

624/57 - leopards and green capes just works ! Hopefully it will be a recurring trend !

Last but not least !
1429 1429 1429 .... Woodie flowers, chairman's , website , qualified for VEX worlds, BEST nationals, FIRST Championship , ,....
All this success is going to dry up your piggy bank

[LightWaves1636]

oops, I meant versatile not powerful, sorry haven't gotten time to wind down from Lone Star still...

[I-DOG]

Congrats to 1477, 118 and 1801 for their 2011 lonestar win!

Thanks 57 and 1817 for the great run our alliance had with one another!

Awesome job 2936 and 2587! You guys sure gave the number 1 seed alliance a run for their money!

Thank you gatorzillas for combining forces with some of the 624 members in order to help out 3758.

And why is their never an archive for Lonestar's matches?

[RoboCat2005]

Thank you to team 57 and their 2 mentors who helped out 2969 with our drive train issues. It was a big help and the kids really appreciated it. Ended up being something as simple as doubled up omni wheels that was causing the issue.

Thank you again

FRC team 2969 Sam Houston High School - Hurricane Robotics

[MrHance]

Originally Posted by Kevin Sevcik

I'm calling BS on both sides here without some sort of verifiable data. First, the Jaguar isn't going to be terribly more "powerful" than the Victor. The FETS in the Jaguar have slightly lower on resistance, which means slightly lower power lost to heat, but it's pretty minimal and the Jag's current sense resistor probably makes the whole thing even.

Similarly, the Victor isn't going to have any quicker response than the Jaguar to a specified output voltage. They both use the same PWM rate, processing time is minimal, and I'm not going to get into whether the Jag's 15kHz chop rate would react any faster than the Victor's 120Hz chop, because you guys aren't capable of noticing that difference.

And both speed controllers are just as easy to drop metal shavings in. In case you didn't notice, the FETs on the Victor are right under that fan. The leads are exposed and just waiting for a chance aluminum shard to vaporize them.

There's only a few actual differences between the two:
1. The Victor is smaller, lighter, and more expensive.
2. The Jaguar has a more linear response curve. Meaning 20% input actually gives you 20% output. The Victors ramp up the output rather quicker than the input and then level off, so 20% input gives you something like 30% output. This may account for Paul's "quicker response".
3. The Jaguars have built in voltage rate control, which prevents you from rapidly switching between positive and negative outputs. The Grey Jaguar was likely to blow a FET driver under these conditions, which is apparently what gave the entire line a bad rep for reliability.
4. The Grey Jaguars had captive screws that were never meant to be fully removed. They left metal shavings inside the case if you DID force them to unscrew, which added to the number of failures. Which is rather more operator error than lack of robustness. Black Jaguars have fully removable screws.
5. The Jaguars have current and temperature limiting features which kick in to protect the speed controller from damage under high load conditions. The Victors will let you beat them till the breaker or the Victor blows.

And that's it until you get into the laundry list of features the Jag has that the Victor doesn't. So as far as I'm concerned the robustness of the Black Jaguar is still in the proving stage but looking good and there's little performance difference between the two aside from the linearity of the output. I think anything else is hearsay and confirmation bias unless someone's got some actual test data to back it up.

Based on the above information, I also believe it depends on the application of the device. It would be interesting to see if a team or a group of teams would test the JAGs and Victors under similar conditions and collect data to be posted on CD as a white paper for all to reference for future use. Let's not favor on device over another unless it can be backed up with data. This is how engineers determine which device should be use over another, not by individual gut feeling. This could cause issue as was seen in the past without data to back up claims of problems. Think about it.