Re: No Discount on Jaguar Controllers
 

Here is the link to the Microluminary page listing stock, This also reflects the Digikey stock numbers. Unfortunately
no one checked my time table prior to scheduling production. And just as unfortunately this is all coming out of my pocket. (Rookie team = ^<$0)

I agree with Bob Steel's comment and would add that Micro Luminary has done a great job in getting FRC teams a improve motor controller at a improved price.
A really neat addition would be to involve teams that have experienced failures in the process of determining what caused the failures and testing improved versions on the platform where the failure occurred.

Re: No Discount on Jaguar Controllers
 

Scott,

We're happy to hear that you're still on the team! We look forward to working with Lum...Texas Instruments!

Re: No Discount on Jaguar Controllers
 

We also had a Jag failure after a hard side hit, going into the second match of quarterfinals. Caused a domino effect of problems and we lost the round. We are reluctant to buy an old version at a high price now, but we need it for low speed control on our current project. We will welcome any revisions that improve the robustness of these units.

Re: No Discount on Jaguar Controllers
 

Hello again,

I absolutely love the passion on Chief Delphi. As most the mentors know, as long as passion is directed, patient, controlled, and utilized for the betterment of the whole, that passion will make you very successful in whatever it is you are passionate about.

Just in case you missed my posts last season, we did not ignore the fact that teams were reporting failures on Chief Delphi - hence, my repeated (almost annoying) failure updates and requests for teams to send us failed units (on our dime), shipping next day replacements, following up personally with teams that were reporting a failure on Chief Delphi but did not turn in units for FA, and sending out a Luminary Micro engineer to most every regional event (and championships) to personally check on teams, gather experience, and perform on-the-spot RMAs - most of the time, regardless of how the unit failed. I, like a lot of people, was expecting the failure rate to be horrid based on the posts I was seeing on Chief Delphi. When all was said and done, we published a report the week before Championships in order to convey our findings. (here is that thread again for your reference - with Jaguar FA report). Summary/Conclusion:

• 131 of the 136 returned units are legitimate failures.
• The total validated failure rate for MDL-BDC is 1.4% of all units sold.
• The most common issue reported was a loss of control in the forward direction (representing over 40% of all specific failure reports).
• Failure analysis of all units concluded that over 70% of units returned for examination exhibited a failure of the U6 and/or U7 gate driver, sometimes in addition to other components.
• The probable cause of the gate driver(s) failure can be attributed to a variety of factors, including inadvertent misuse (such as temporarily mis-wiring the MDL-BDC Jaguar unit or accidental swarf causing a short) and potential ESD vulnerability of the MDL-BDC design.

Some notables not included in the report was our own personal visual check on which teams were using Jaguars on their robot. Over 80% of teams across all regional and championship events were using either ALL Jaguars or were using a hybrid of Victor/Jaguar. This is important because it lessens the argument that our numbers were extremely skewed because "most teams didn't use their Jags". (not true, actually)

At Championships (even after submitting the report), we set up both in the pits and on the mezzanine to gather more data and more failed Jags to see if failures were consistent with what we were seeing. I brought over 100 replacement Jaguars in case there was a chance that our data was bad. (I really DO want you to be successful and I want to position you for the best chance at success - which are facts that one can sometimes lose when one experiences a failure). We did replace some more units, but several teams admitted that units being returned were due to their own fault. No problem - this was championships, so if I am at Champs and you experience a Jag failure - I am going to make sure you are equipped to compete.

All told - post champs, our failure rate was much less than 2% - which includes several misused Jaguars that we replaced onsite at Regional and Chmpionship events.

So, if right about now you are thinking that I am defending rather than learning, you'd be wrong. :cool: As an engineer myself (yeah, imagine that - an engineer and a collegiate linebacker... and unless you are incredibly talented to make lots of money in sports, trust Dean - I am much happier/successful as a engineer than an aging, injured pro athlete - I digress)... as an engineer myself, we have taken all of our learnings and applied them to Black Jaguar. We've bumped suspect components (and replaced with TI Analog!), we've redesigned to improve ESD, we've changed CMs, we've added some new features that *might* be incorporated in FRC :yikes:, and we've finally taken your advice that you didn't like our Pantone corporate grey color - and rebranded/shot with TI Black and Red (like I had a choice...). To specifically address that sw question I saw, we even added a way to use Black Jag to update firmware on Black and Grey Jags. So, even though I am personally glad that the failure rate seemed higher than it really was, the entire "Luminary Micro" team made a commitment to FIRST to improve the design - based on all the great feedback, returned units, and design recommendations that we received from the FRC network of engineers.

Looking forward to another successful FRC season, and I'll be about to keep you informed.

Regards,
Scott

Re: No Discount on Jaguar Controllers
 

Scott,

First, thank you.

Second, just to put some perspective on these numbers, what is the industry standard for part failure? I know manufacturing can sometimes expect up to 25% of a part to be out of tolerance but I don't have much experience in production of electronics so I have no clue here.

Now, my disclaimer. 397 did not use Jaguars this year so I can't comment on their reliability.

Once again, thank you for supporting your product, I hope you are enjoying your induction into FIRST. You will never get out again :)

Re: No Discount on Jaguar Controllers
 

I am sure someone else knows better than me on this forum, but I often hear customers state 3-5% is standard/acceptable. Of course, it is acceptable to me, too, until I am the one that experiences the failure. This is why we are endeavoring to make Jaguar even better.

Dr. Ian Thomas (retired) in the University of Texas at Austin Electrical Engineering dept always had a famous quote when his class wondered why a surprise question popped up on the test that a good majority of the class would probably panic with or choke on. Students would file up at his desk during the exam to inquire 1:1 about it, and his constant, steadfast response to each panicked student was: "Don't look at me like that. You... were... WARNED!" Call me crazy, but I loved that class, and I love FIRST, even though in both cases, "I... was... WARNED!" :)

Re: No Discount on Jaguar Controllers
 

Scott,
Thank you for the detailed explanation.

TI is a great company, with great products, and they stand behind their stuff with massive resources. As a paying customer for most of my career, no, they're not the least expensive. But they're the best.

Re: No Discount on Jaguar Controllers
 

These 141s have been working for almost 40 years....great stuff indeed

Re: No Discount on Jaguar Controllers
 

Scott,

Thanks for all your input on this subject.

I wonder if you can shed any light on the discrepancy with the in stock vs. backorder issue at Digi-Key. This link http://www.luminarymicro.com/compone...14/return,522/ shows that according to Luminary, Digi-Key has 4100 units in stock. Yet with my recent order, Digi-Key says that it is back-ordered, that their scheduled recieve date was 11/5/09, and that they hope to get some soon. Their sales reps can only say what they see on their computer, but it seems that someone's computer is wrong. Any idea what the real inventory situation is? Will units that are ordered now be the same as 2009 units?

Re: No Discount on Jaguar Controllers
 

Is the new Jag still in the same form factor i.e. huge? That was reason enough to keep using the Victors.

Re: No Discount on Jaguar Controllers
 

Just to report on my own question.....Digi-Key reports that they have recieved some Jags and our order is shipping. Don't know how many they have. I assume these are 2009 units since the black jags are still in beta.

Re: No Discount on Jaguar Controllers
 

Scott, AKA UTlinebacker
First it is note worthy that at my work place one of our most respected engineers played Football for WSU. Instead of pursuing a career in sports he is a civil engineer with his PE... Who happens to be overseeing the construction of two of the worlds largest reinforced concrete water reservoirs.

Thanks for the details I had overlooked the failure report. Out teams only Jag failure was from human error. V+ and V- reversed. This blew copper all over the board and one way or another took out the 5v regulator and U6. the FETs appear to have survived just fine . The Victor that suffered the same fate in 08 didn't fare as well, It lost 6/12ths of its FETs.
In my experience human error is one of the most common reasons for failure. Usually we (our team) does a lot of color coding and labeling to try to prevent errors from "heat of the moment" maintenance. In this case the coach didn't have someone else check his work prior to power up.
The Red and Black screws for V+ and V- are a good example of simple things that can be done to help prevent errors. Taking this one step farther; No matter what color the package is the raised lettering can be difficult to read when put in a robot. We use a paint pen smeared across the jumper labels to highlight the lettering. I could really dig some more TI red on the raised lettering!
Finally for our team the Jag linearity improves drivability and that trumps all other considerations such as: form factor, cost and even reliability.
And by the way we really appreciated the Luminary Micro guy coming to Portland last year.:)
Thanks