this year we plan on using 4 small cims in our drive train and a FP cim for our arm. From my understanding its technically a FP motor so we can use a 30Amp breaker. But by looking at the torque curves of the motors using the 30 A fuse limits us to 140 oz-in of torque as opposed to 240 oz-in of torque with a 40A breaker. So we have been playing around with the 40 Amp maxi panel and we “reconfigured” it. So now we have one full fuse panel and a second one that only has one terminal. Does anyone know if we are allowed to make this modification?!
Unless something has changed, you MUST use the maxi block for all CIM motors.
i was looking at some threads from last yr and from what they said you could use the Big Cim on a 30A if you wanted. And in the wiring diagram they have the FP motors going to the 20/30 A panel. But regardless…we would rather use the 40A…does anyone know the rule about modifying the maxi block?
By “modifying”, do you mean something like “cutting in half”?
Ill have to check but I dont think you can modify any of the electronics.
if yoru farmilar with the block…one end is solid and the other ends and individual clips, we removed the big block and now have 2 individual clips…
I’ll go ahead and guarantee you that this will be illegal, even if it doesn’t appear to be now. The breaker panel is designed to be safe in its original configuration. cutting it in half will be viewed as rendering it unsafe, and the part will be declared illegal. FIRST is pretty serious about keeping teams from accidentally attempting arc welding with a poorly wired robot.
Even though it is a FP motor it is also concidered a CIM motor and therefore must use a 40AMP breaker.
Although there may be no rule specifying that you can’t modify the breakers it’s more than likely illegal.
Adam and Price,
A. He’s asking if he can modify the Maxi panel, not if he can protect a Bike Motor with a 30 A.
B. You’re wrong. You can protect a speed controller with whatever breaker you like, and you can then use that speed controller to power whatever motor you want.
<R97> Speed controllers may be protected by 20A, 30A, or 40A circuit breakers. Speed controllers may power motors or devices of any size.
Doesn’t get any clearer than that.
Thanks, Kevin; I agree that is perfectly clear.
Back to the original question:
<R46> prohibits “Fuse panels different from those provided in the Kit Of Parts.” Modifying the maxi block would render it different, so you can’t do that.
B. You’re wrong. You can protect a speed controller with whatever breaker you like, and you can then use that speed controller to power whatever motor you want.
Right…but you still cannot power any CIM motor through any thing less than a 40A Breaker…correct?
Read again. You can protect a speed controller with any breaker. Say 20A. You can then hook up whatever motor you like to this speed controller that’s protected with a 20A breaker. Even a CIM. This may not be intelligent in any given situation, but I’ve seen a lot of legal, unintelligent things on robots.
Richard,
Thanks, I figured there was a rule that applied directly, but couldn’t pick the right one out of so many options.
kb isn’t really clearly describing what’s being proposed.
If you look at the Maxi panel, the big brass pieces are attached to the plastic with little screws. We’re wondering if it would be legal to remove the unused brass, not cut, nodify or otherwise destroy the breaker panel. No parts will be damaged, and everything on there will be original, it would just be without a few pieces of brass. There’s no inherent reason why doing this would be unsafe, and we’re not doing anything that anyone with a phillips head screwdriver couldn’t do.
If it came with the brass, and you have you unscrew things to remove it, you’re modifying the part and it’s not the original anymore. I completely sympathize with the notion, and 57 is looking at powering some FP motors with 30A breakers just to avoid this same problem. It just doesn’t look legal from reading the rules this year and experience from years past. You’re more than welcome to ask on the Q&A, however.
yea we have not cut anything, merely reconfigured they set up that it was originally in. On one side there is a single input to come from the new dist block they gave us(the one that slides along that track), and on the other side there are 4 individual clips to hold the other end of the 40A breaker with 4 single outputs to go to each victor. We simply took off the single input block(which shorts together all 4 of the breakers) and using all the original hardware moved another single out put to the input side…
btw…you are allowed to use 30A on cims but depending using a smaller breaker will decrease the amount of torque you get out of motor.
Steve,
If I were your Robot Inspector, and I may be, I would render the modified Maxi block illegal. You may appeal my decision to the Lead Inspector, to FIRST, to the Supreme Court, but why take a chance. Make your weight savings in some other area.
Steven,
It was legal in the past to remove the unused portions of the Maxi Fuse block to save weight. This question has not been asked or answered this year to my knowledge. Keep checking the Q&A or make sure you post this question. In any case, the block must be protected with the clear plastic cover that shiped with the block for insulation purposes.
As many have pointed out, it is within the rules to use smaller breakers and smaller guage wire if a team chooses. The breakers are sized to appropriately protect the wire guage as specified. (for those of you who will look this up and find discrepancies, remember you can derate the safety margins since the wiring is in the open air and you only have a few minutes of “ON” time) So you can make the changes but WHY??? By moving to #12 wire from #10 and downsizing the breaker you provide a 50% increase in series resistance and further limit the power of the motor. By moving down to a 20 amp breaker and #14, you may have a hard time starting a motor under load. The FP and CIM motors are capable of 100 amp stall currents, all you will be doing is tripping the breakers which make them hot and cause them to trip more often. I can hear some of you saying ‘but I am designing the system to not stall the motors’. The definition of a stalled motor is one which is not turning, therefore every motor is in stall when it starts.
The buzzing you here is the breakers rapidly tripping and resetting.
yes thats exactly what we did was just remove the extra stuff were not using…thanks
kb,
I am not telling you this is OK for this year, just that is was legal in the past. The authorization must come from First. If they don’t pass on it neither will I as inspector.
understood, i will make sure that i ask on the Q and A