http://picasaweb.google.com/nghs1771/Building#5434011624392842818
They’re so cute 
Pic link is broken for me 
So did you guys buy the black jags?
what is gthe difference between the black ones and the gray ones?
I believe you have to have one of the black jaguars to use CAN.
-RC
We bought the black jaguars for 2 reasons.
1 You have to have a black jag to start the can bus.
2 we needed to buy 4 more jaguars this year and decided that for only 7 more dollars apiece we could have 4 jaguars that worked better, looked cooler, and could run a can bus.
If we break any of our gray jags this year we will be replacing them with black ones.
Here is the link in case you cant see the picture
http://picasaweb.google.com/nghs1771/Building#5434011624392842818
ahhhh…there’s that pesky picture. When you use the img tags, you need to make sure your image link ends with .jpg, or else we might not be able to see it.
I see. Thanks for the advice
Interesting little connectors on the wires, what are those? They seem like they would be very helpful in keeping the control panel all nice and neat.
-Tanner
They look like the power connectors commonly used on RC cars. Might also look into the smaller sizes of Anderson Powerpole connectors, they don’t have the exposed contacts.
I would not recommend using a connector such as that on both the input and output side of a Jaguar, or any speed controller. You add resistance and another point of failure. Run all wiring directly from the PD board to the Jaguar, then from the Jaguar directly to the motor. If the motor has built in leads, crimp on a quick connect there and only there. The only exception is if a large portion of your robot must be removable, then having mass quick-connects or a terminal block there would help. It isn’t that hard to screw in a fork terminal, so having those connectors provides no advantage. If you plan on re-using the Jaguars from year to year, you can always unscrew the fork terminals and pull it out, it’s not that hard.
It isn’t clear to me if the Black jaguars are actually a better product, but after the problems last year my team is only buying Victors. We will use the Jaguars that come in the kit, but no more. All Jaguars can handle CAN, so having more than 1 Serial-CAN Black Jaguar isn’t helpful. The do look nicer, but when they’re buried in the chassis, do looks really count?
The connectors in the picture are ‘Deans Connectors’. They’re used in RC cars. We used them all through last year and had no problems with them. Dean’s Connectors are about 1/3 the size of the power pole connectors and have a higher current rating. IRC the Dean’s Connectors were rated to 80A, whereas the power poles are rated to 30A.
Those are Deans Ultra Plug Connectors http://www.wsdeans.com/
They offer a lower resistance and in turn are capable of handling higher current than most quick disconnects of their size, which is why many people in the competitive RC Model market use them. I’ve used them on 395 machines in the past without any problems.
Super clean setup, quick interchangeability if something needs to get replaced, higher current capability across the connector. Nice job!
*Sorry about the delayed post got distracted by a work call and Jon Jack beat me to the punch and did it better.
I don’t know for sure why the black jaguars are better, but our programming mentor said that they are. Something about handling 24 volts instead of 12.
Also, we have never had a jaguar fail.
We have had experience with powerpoles melting. We switched to the Deans connectors because a) we got them donated, b) they rely on solder instead of crimping, c) they handle higher current and offer lower resistance, and d) they are easier to work with
I know Deans connectors are popular in the RC hobby, but I’m not a fan of them. Here’s my reasons:
1 - As far as I know, they are not recognized as an industrial connector outside of the hobby market
2 - The require both a male and a female side
3 - The male side has exposed contacts, that can easily be shorted
4 - The attachment points for the wires provide no mechanical connection other than soldering, and are very close together. There is no housing, and thus, heat shrink, which can easily be punctured from a sharp solder blob, is all that’s keeping you from a short.
5 - They cannot be combined into a larger connector block
6 - As far as I know, there is no positive locking mechanism. It is a friction fit.
As for current ratings, I speculate the Anderson PowerPole contacts can handle a lot more current than they are rated for.
I’m very interested to know what you did to melt a powerpole. On dozens I’ve installed, I have never had this happen, and never heard of it before.
There are also Power Pole’s rated for 45 amps, and larger Power Poles connectors for 50, 175, and 350 amps. We use some for our robot batteries. (the 50 amp kind, actually) We have also used simple quick-connects in many places and screw-terminal blocks when a large number of connections are necessary, without any problems. There are power poles to handle more then 30 amps.
Guys,
I would need to see the actual tested ratings for these connectors. None appeared in the link above. Although the 35 amp Power Poles would seem a bad choice remember the Power Poles are rated for continuous duty at that current. Have you noticed that the battery is only a 50 amp Power Pole? The two minute (say up to ten minute) rating for these connectors far exceeds the failure point of 35 amps continuous. In case you haven’t tried, Power poles are easy to solder but if you use the West Mountain crimper, with #10 wire your connector resistance is already very low. If you solder, it is almost the same resistance as a wire. A bad crimp on any connector (or a solder job that only covers part of the wire) will get hot under load. Inspectors need to have numbers. You may have been able to get away with them in the past but if they are under rated, then you will need to change.
As stated earlier, I recommend using the least number of connections you can. We use Power Poles on motors (and in special applications) only to allow their rapid removal. Everything else is point to point.
For reference…
CIM Stall Current is 129 amps
Fisher Price Stall Current is 70 amps
Battery (charged) is capable of over 600 amps.
Al,
For reference, I find that quite often, published specs are misleading, and in some cases outright wrong. I did a great deal of research with the CIM motor over the last year (not FIRST related). While the data around the higher efficiency end of the curve is reasonably accurate, as you get farther from that point, it goes off into the weeds. Using accurate instrumentation, I measured the current at several different operating speeds and loads. I was using a 95 AH AGM 12V battery with an internal resistance much lower than the FIRST batteries. I don’t remember exactly how high the current got at its highest, but it was very near 30 Amps, no more than 35. That was when the motor was nearly stalled. At stall, the draw dropped to less than 30 amps. Not sure why the data sheet says what it does, but the CIM doesn’t draw 129 amps.
Based on that, and the fact that Fisher Price toy cars (the main use of the FP motors) are wired with ~14 gauge wire, I don’t believe the 70 amp rating on them. I know my kids were able to stall the motors out on the jeep they drove around, and no wires smoked.
I find this very hard to believe. We have known and trusted and designed to these specs for 9 years now. For the CIM to stall at less than 40 Amps, would mean its peak power is significantly less than published, yet our robots seem to perform to expectations every time.
To be honest, I’ve never run one through any sort of current measuring device, but I certainly have tripped 40 Amp breakers with them. I know some teams have done current monitoring (and if I recall, some sort of FIRST-sponsored program at IRI 2008?). Do any teams have any current draw data they’d like to share?
As I said, in the range where a motor is used, the specs are fairly accurate. You don’t USE a motor at stall. It doesn’t do much. I am offering the results of a scientific experiment, you can choose to do with that data what you like. I can say, with absolute certainty, that a CIM motor will never draw 129 amps, or even 50 amps.
I’m not discrediting your test, as I have done none of my own. I’m more just intrigued by your findings. If your results are correct, it could really change the way many teams design things in the future. So you are saying that your data shows the motor is highly non-linear, deviating from the theoretical model of a permanent-magnet DC motor? Interesting. Do you have some experimental curves produced from the test?
Has anyone else ever put one on a testing rig?