Re: 2012 motors?
 

Seconded

Re: 2012 motors?
 

For those of you contemplating this for the future, please see the rules about modifying the motors.

The rookie team who lightened the CIMs drilled 3/16" holes in the side of motor case without knowing what was happening inside. It didn't take long for the motor to self destruct and that is where I was consulted. It took a look inside to explain that ceramic magnets shatter when machined and that those fragments are still magnetic. Several of the larger chunks, eventually were caught up in the armature until they jammed the armature against the remaining magnet assy. The team wanted to know how to drill holes without shattering the magnets. During the course of the discussion, one of the students had an "OH ****!" moment when he realized why they kept breaking off the drill bits while working. (some broken drill bits were still projecting from the case where they had broken off.) For those of you reading this and wondering to yourselves, drilling or modifying the magnet structure reduces the available power while disturbing the magnetic fields and filling the motor with shavings that have a mind of their own. I will get at least a couple questions related to this subject every year. DON'T DO IT!

On a related note, we will get a few Q&A's every year asking if it is legal to drill holes in the pneumatic storage tanks to lighten them. The answer is the same, the rules do not allow modifying these parts.

I know it sounds weird, but this is one of the reasons I like inspecting. It allows the opportunity to interface with students and impart some knowledge that they will need in the future. An exercise like this is something they will never forget. The hard part is supplying the knowledge without shattering self esteem. I hope all inspectors do that. I am very proud of the work we have done thus far.

Re: 2012 motors?
 

I believe we had a talk about that particular modification at Waterloo a few years ago (probably 2008).

If I'm recalling the event correctly, an inspector noticed that the robot was employing those modified motors on late Thursday afternoon. In a situation like that one, the rule interpretation was pretty clear-cut: the motor had been machined to change the size of the device, so as to fit somewhere it ordinarily wouldn't have. (These weren't modifications to the mounting points, instead, they involved roughly machining away a strip about a millimetre deep from the side of the case, away from any location used for mounting the motor. It was definitely more than just the paint, but not enough to weaken the motor in any significant way.)

The robot certainly would have missed (or been rendered impotent during) a few matches, while corrective modifications were in progress. I believe the robot's configuration was such that any resolution would have required disassembly of two gearboxes buried within the robot to get the motors out. There may have also been a motor-to-motor clearance issue that prevented two full-sized motors from being mounted side-by-side, so the robot might have had to make do with 2 CIMs instead of 4. And even then, it was possible that minor structural changes would have been necessary to achieve the required clearance with the frame. (Feel free to correct me on details.)

Given the relative infeasibility of modifying the robot to achieve full compliance versus the competitive advantage gained by employing this illegal design, we chose to allow the robot to compete as-is. I believe we suggested that 1075 to use their remaining time to prepare whatever was necessary to make the robot compliant in time for the Championship, if they intended to appear there (they didn't attend that year).

So for everyone's future reference (presuming the specifications don't change), CIMs are a maximum of Ø2.536 in. Plan accordingly, and avoid resorting to illegal modifications!

Re: 2012 motors?
 

Yes Tristan, you and I did discuss it, and it would have been most likely Waterloo 2007 or 8.

The way those drive units were assembled, changing it would have necessitated remanufacturing all of the pillowblocks supporting the shafts between the two side plates of the drive units, never mind the time-intensive task of disassembling and reassembling them, a multi-hour task (which is why we had brought assembled spares, also modified in the same way). The modification involved grinding away that ~0.036" difference, and as Tristan said, didn't appreciably change the performance or structural integrity of the motor, however was undeniably against the rules.

In addition, as I recall, it would have required 4 unmodified CIMs, which we didn't have.

Everybody makes screwups: we re-built the units over the summer, and used them at an offseason, before tossing the design altogether due to belt-reliability issues.

Re: 2012 motors?
 

i say go big, i totally like the turbines tho. my team will likely use 4 single motor gearboxes, as we like mechanum, we've started to use nanos, but the cimple boxes look weak to me. i dislike plastic in parts that need strength, thick aluminum, steel, or, my personal favorite, cast iron.

Re: 2012 motors?
 

Jet engines, anyone? You get a lot more power and speed......with a small touch of fire hazard.

Re: 2012 motors?
 

http://www.jetcatusa.com/index.html

I don't suppose any of these will be in the kit?

Re: 2012 motors?
 

I see they have a turboprop now. That should be ideal for our purposes.

Re: 2012 motors?
 

Even in the model aviation community, planes with those get a special inspection, and most people are just fine with fuel of various types on model aircraft.

So first fuel needs to be allowed. Then you need to put in heat shields around the arena...

...and then you get to figure out how to use the engines.

Re: 2012 motors?
 

You could make a pretty amazing parade robot with that turboprop version. Getting FIRST to OK fire on a comp robot might be tricky though.

Re: 2012 motors?
 

I am surprised that no one is considering the BOM and costs. Remember, no single piece greater than $400?

Re: 2012 motors?
 

There are components in the KoP that break that rule. If the motors are provided, or donated, then we're clear for takeoff.