Motors: Past and Future
 

I was looking through some Chief Delphi threads for history on how the FRC technology has developed over the years and I noticed that the motors have not changed much in recent time.

How long has the CIM ben around?
I noticed that there was a Bosch drill motor from years ago, why did they discontinue it in FRC?
Do you think there is room for a new company to develop motors and improve upon what has already ben proven over the years?

Re: Motors: Past and Future
 

The CIM has been around since 2002, and four were first legal in 2005, making it practical for robots to use CIMs exclusively for drive motors.

I wasn't around then, but from what I hear drill motors stopped being used because they tended to blow up in situations where CIMs do not.

There's certainty not much that can be done to surpass the CIM for outright durability. Perhaps lighter or more efficient motors could be developed, but reliability under non-optimal conditions is what makes for a great FRC motor, and the CIMs are phenomenal at this.

Re: Motors: Past and Future
 

There's definitely room for more motors. I could see stepper motors coming in at some point.

Re: Motors: Past and Future
 

I don't really see stepper motors having a great place in FRC. Too many ways to lose counts.

Re: Motors: Past and Future
 

Just last season (2013) we added the BAG motor and MiniCIM which were huge improvements. I'm pretty sure we have all the motors we need now. I haven't see to many robots that use all of the 200+W motors that are legal (6 CIMs, 4 MiniCIMS, 4 BB775/550s). Unless they decide to change a lot of the rules to allow stepper motors or brushless motors, I'm pretty satisfied with the brushed motor options available to teams.

Re: Motors: Past and Future
 

There has certainly been plenty of new motors introduced over the years. The MiniCIM and BAG motor were introduced in 2013. The AndyMark motors were not much before that. The throttle motors have only been around since like 2010, iirc (but nobody uses those anyway). The 775 banebots motors have only been around since 2011 or 2012 (don't remember when they first introduced the 550, but it was around the same time I think). Not to mention several useful motors have been discontinued in the past decade, namely the globe and fisher price motors (not to mention the significant variations between different FP model numbers).

Very few motors are developed for FRC specifically (I think the two VexPro CIM variants being the only ones). More often, FRC-suppliers develop gearboxes to integrate with them (namely the CIM-size or 500 series motors). In some cases, namely with AndyMark, they are reatiled as gearmotors with these gearboxes affixed as a standard COTS item.

Honestly, if anything, I kinda yearn for the days of fewer high powered motors. The drivetrain arms race is getting ridiculous, and now you don't even have to sacrifice motors from elsewhere on your robot to compete. Scarcity isn't really a factor in designing with motors anymore. I'm not sure if that's a good thing or not, but my personal nostalgia biases me.

Re: Motors: Past and Future
 

Personally I wish the motor rules were:

6 - Cims
4 - MiniCims
Unlimited Bags!

No need for any new motors.

Re: Motors: Past and Future
 

I do like having 500 sized motors.

They're more power dense, which can be utilized if teams understand the failure mode from heat.

They're good for high bursts of power (like a 2013 shooter spinning up) with intermittent low load between.

Re: Motors: Past and Future
 

That would be pretty expensive for teams.

Re: Motors: Past and Future
 

As a mentor of a team that frequently uses the AM9015, PG-series, and window motors, I'm glad this isn't the case.

Re: Motors: Past and Future
 

Vs Buying 550's? Eh, I wouldn't mind the $15-20 dollar difference for a better motor. We use the 775's over the 550's currently so its not a big difference in what we spend currently.

Re: Motors: Past and Future
 

We're in the same boat, I'd be fine with just CIMs, MiniCIMs, BAGs, and 775s though most of the time we use 775s because we already used 4 MiniCIMs/Bags.

The 550s were useful in 2013 when we needed a lot of speed.

Re: Motors: Past and Future
 

Yes. The only thing that steers me away from BAGs is their relative price. That being said, my robot this year consisted of 5 CIMs and a 775.

Using 8 BAGs vs. 8 550s (4 competition bot + 4 practice bot) is a difference of $148.

Re: Motors: Past and Future
 

I'd like to see a motor that was a little more powerful than the 775 but packaged the same way, so that it could be used instead of the CIMs for drive. The reliability of the CIMs is great, but they're really heavy compared to a 775, and not that much more powerful.

Re: Motors: Past and Future
 

That's a fair comparison, we won't consider using the 550 over the 775 in the current motor allotment so for us its a $74 difference. Either way its just a personal preference, I tend to spend more :cool: .

Re: Motors: Past and Future
 

One crucial difference between a 775 and a CIM is how they're cooled. The 775s (along with 550s, AM9015s, FPs, Bosch drill motors, etc) are cooled via convection encouraged via the fan at the tail end of their shaft. That's why you don't want to stall these motors, since they need to be spinning at a relatively high speed to draw enough air to avoid overheating under load. The CIMs (along with MiniCIMs and BAG motors) are not cooled by fans, and instead rely on having a larger thermal mass to "absorb" the heat and prevent the motor from overheating. The heat is eventually dispersed via convection, conduction, and/or radiation away from the exposed surfaces of the motor (so having a larger surface area is important as well).

Since drivetrains often experience stall or near-stall conditions, it's important to have a motor that can survive stall or near-stall heating. Fan cooled motors are a poor choice for this (thus why so many Bosch drill motors failed back in the day). As a result, you need the additional mass to help these motors survive in a drivetrain. Of course, if you were to install some other cooling system this could be worked around, but I'd venture that the additional mass and space of the cooling system would outweigh the benefits.

I don't think you're going to get your wish.

Re: Motors: Past and Future
 

The only improvement I could scrounge up about the CIM that would be quite beneficial was improving the heat release (body conducted heat away from the brushes faster/possibly incorporated a better heat sink, to make the motor more than just a 10% On 90% Off, perhaps up to a 50/50 or continuous duty without aftermarket passive or active cooling

Re: Motors: Past and Future
 

My "dream" lineup for motors, current and past:

--CIMs (and variants--big, mini, bag), any combination but no more than 6 (Awright, quit complainin', 7).
--775s, 550s and the old FP motors (which were very similar), no more than 2 (maybe 4).
--Up to two Globe motors (need to specify allowed configurations, but those were very nice motors for light duty that was tough).
--Window and van door motors, no more than 4 total. For the right applications...
--Unlimited servos and VEX motors/servos (increase power on servos, though!)

--Additions: 2x brushless motors with speed controllers (restricted power/size, though, at least at first). The big thing here is that brushless motors are also known for not liking stalling, which would probably need to be pointed out to the teams.

Re: Motors: Past and Future
 

Sean has this exactly right. I am becoming more confident that he will be able to keep the Martian colony infrastructure operating smoothly, when the old timers of my generation are in our rocking chairs. :)

Just one point to add: power available from a motor falls off rapidly as the internal parts (i.e., brushes, armature windings, and magnets) get hot. This happens faster if the motor is smaller -- so even if a fan-cooled (e.g., 775) motor is nominally rated for more peak power than a totally enclosed non-ventilated (TENV) motor like a CIM, the TENV motor will deliver more power in all but the most intermittent of applications. Bottom line: stick to CIMs for your FRC drivetrain (duh).

Re: Motors: Past and Future
 

I wouldn't say that as a blanket statement. Teams have been using 775's/FP's in drives for a long time. In 2003 and past, several of the Einstein teams, like 111, used non CIM's in drive, as you could only have two that year. Pretty much every team with swerve did the same Plenty of teams have also ran 2 CIM + 1 775 drives, like 254 and 118, which are both very successful teams.

With the available current monitoring feature on next year's PDB, stalled motors can easily be detected. It is true that a 775 will burn up quickly when stalled at 12V, but it can last a significant amount of time at 6V.

A minicim weighs 1.5 lbs more than a 775, and is less powerful. Given 1.5 lbs, I could add a decent heatsink and fan to a 775 for roughly the same total cost, and have more power.

Also, a more powerful 775 would be really useful in climbers/hangars, where you (ideally) never stall.

Re: Motors: Past and Future
 

I like the way things are now. The only improvement I could see would be to use SSS-5940 10kw brushless motors in place of cims (they are the same size). :P
Oh, and raise the main breaker limit to like 600 amps.

Re: Motors: Past and Future
 

I'd love to see brushless motors.

Re: Motors: Past and Future
 

And you just beat me to saying it! Brushless motors are the next logical evolution... it is just a matter of getting the control circuitry down to a competitive price.

Jason

Re: Motors: Past and Future
 

Pretty sure that at some levels, it's down far enough. There's a reason electric R/C aircraft are becoming extremely common, and it isn't totally due to good batteries becoming more common/cheaper. The motors and ESCs also had to get cheaper. Admittedly, they don't often run on 12VDC, and typically have a "battery eliminator circuit" built in, but those can be worked around, right?

Re: Motors: Past and Future
 

I'd love to see some brushless motors as well.

I'm not allowed to give any details at all at this point, but I know of a pretty big company looking at donating some pretty good motors to the KOP and FIRST Choice for next season. Only time will tell how substantial the introduction of these motors will be in the field of FRC.

Re: Motors: Past and Future
 

ESCs (electronic speed controllers) for brushless motors do run on 12v actually, but it actually has to be 12v. Anything more than 12.6v and a little overhead should be avoided. This is because they are designed to be run on lipo battery packs. A 3-cell lipo has a normal voltage of 11.1v, but it's really 12.6v when charged. A lead acid battery like in FRC robots are 13.6v fully charged IIRC, which is a tad too high for a 3-cell ESC. It still might work, but you would have to check.
The voltage drop on the lead-acid battery over time might also be too much for ESCs.
ESCs are actually pretty cheap. Because they are often just SMD parts, I've noticed even cheap ones from places such as ebay work just fine due to the lack of manual work. If you wanted US-made ones though it could cost a bit more. They are usually cheaper than the controllers we use though.

Re: Motors: Past and Future
 

There are plenty of hobby grade ESC's for brushless motors that would work at 13+ V that FRC sees. I have way too many brushless RC cars, and I design brushless motors at a my day job (at a company that also makes the drives for them).

They really wouldn't be much better than brushed motors, just more efficient. Since most of those drives are sensorless in the affordable price points, teams would see issues with cogging as most wouldn't know how to properly size them.

Most of the lower cost controllers handle direction change awful as well, and would only be suitable for flywheels, etc...

The true benefit of brushless motors for FRC would be when we get current control, which is a higher price point controller. We could do some REALLY cool control stuff at that point though, very smooth motion.

If hobby grade brushless motors became available for FRC, it's unlikely we would use them (reliability, the potential cogging issue). I reserve the right to change my mind after testing though. If anything we'd reserve them for applications that never see high stall loads and we can take advantage of their high power and efficiency in the faster range.

Re: Motors: Past and Future
 

The reason I said it won't work is because of the wide range. Many ESCs have cell detection and cutoffs at certain points programmed in. Hardware wise it wouldn't be a problem, but the software on the ESC might cause problems.

Power density might also help. The SSS 5940, which I was looking at for a go kart, has exactly the same dimensions as a cim, but it has a peak rating of 10000 watts versus the cim's 1600. I'm not sure if that's just the motor specifically or a property of all brushless motors.
Well, it has a stall current of 180 amps, but a voltage capacity of around 60v.

What is cogging? I've never heard that term before.

Re: Motors: Past and Future
 

The same ESC's that have low voltage cuttoff that can't be turned off are usually also the ones that don't handle direction change nicely, so none of those would really be an option anyway.

That 10kw number is likely peak electrical, MOST cheaper brushless motors (RC grade stuff) is vastly overrated in power because they spec peak electrical power, and the motor would burn up at that operating point anyway. As you pointed out, this big power comes at higher voltage in most cases. You won't find an RC grade brushless motor at 12V pushing more than 1kw (if that) commonly.

If we were to go to brushless, I think the right move would be a custom controller adapted from industry to be cost effective, and possibly a modified RC brushless motor that is fully sensored. Industrial brushless motors are just too expensive for FRC currently.

Re: Motors: Past and Future
 

Did someone say Brushless RC motors and gokart, with 48v LiPo pack?

https://fbcdn-sphotos-e-a.akamaihd.n...304680_o.j pg

:cool:

Re: Motors: Past and Future
 

Wow, that's a nice gokart. Really simple design too.

Re: Motors: Past and Future
 

Sorry, I missed this.

In the RC community the word cogging is used, and it's a misnomer. It refers to a non-sensored motor being able to start due to the static load being too high. These ESCs generally chase through the phases and assume the motor starts then measure back EMF to com mutate after. If the motor was sensored and properly communicated through this time it'd be capable of starting.

The actually definition of cogging is the torque ripple from the specific arrangement of the magnets.

Re: Motors: Past and Future
 

Thanks!
If you want more information check out: http://www.instructables.com/id/Chib...iature-Electr/

Re: Motors: Past and Future
 

Going back into my mental archive, CIMs were first in the 2004 KOP. The 2003 KOP was the first "KITBOT" chassis with the large aluminum tubes and still had the drill motors because of the funky injection molded black plastic drill motor mount.

Re: Motors: Past and Future
 

CIMs were definitely in the 2003 KOP just not a part of the kit chassis design. We custom built a gearbox for the CIMs for our rear wheels and used the drill motors and the weird plastic right angle helical gearboxes for the front wheels.

I'm not sure about before 2003 since I wasn't on the team before then and they weren't on the previous year's robots my team had built.

Re: Motors: Past and Future
 

CIMs were on the 2003 KOP checklist but not the 2002 checklist

• 2002
• 2003

Re: Motors: Past and Future
 

Isn't the "Chiaphua motor" the CIM by a different name? I seem to recall seeing CIMs referred to by this name in a lot of older documents, like Dr. Joe's "Nothing but Dewalts" paper, for example.

Re: Motors: Past and Future
 

Yes, if I'm not mistaken CIM stands for Chiaphua Industrial Motor or something along those lines.

Here is the debate from 2003.

http://www.chiefdelphi.com/forums/sh...ad.php?t=21339

Anyone still calling them Atwood motors?

Re: Motors: Past and Future
 

I'd forgotten about that.
Here's the 2001 KOP checklist. Please check it, but I don't see the Chip listed.
2001

Re: Motors: Past and Future
 

Back in the day we called them "Chalupas". Please remember that these are designed as intermittent duty motors for lifting trailer tongues onto hitches. They are sealed to provide some weather proofing. The drill motors were discontinued because they were replaced with another design.
Magnets, Rich is a motor guy by day and my motor reference person. when he speaks, listen. I am thinking we ran two CIM and two FP motors on that drive system. They were obviously geared differently. At that time, both the drill and FP motors suffered from low RPM, high current designs. What complicated things, as the temperature began to rise, the fan actually fell off the shaft or simply melted. Then it was a simple matter of thermal runaway. For some reason, drill motors also had a nasty habit of emitting flame when they failed.

Re: Motors: Past and Future
 

So...flame is what makes motors work, right? Somewhat like how electronics work on magic smoke?

Re: Motors: Past and Future
 

Since they've been brought up, how well do brushless motors work at stall torques and low RPMs?

Re: Motors: Past and Future
 

RC brushless motors essentially won't work in this condition. Due to how they are commutated from a standstill their stall torque is very low.

Sensored industrial brushless motors work great.

Re: Motors: Past and Future
 

They do.

And there have been instances of lower cost, higher production quantity brushless permanent magnet motors -- their application in automobile power steering systems is a good example. That application first went to serial production more than fifteen years ago, and is now made by several of the world's most capable suppliers.

For many years I have thought that the FRC kit of parts is one of the best showcases for introducing new components with good potential to displace legacy technologies. Low cost brushless motors and their associated controllers have that potential.

----

@Michael: motors are electromechanical devices. Their proper operation requires containment of BOTH smoke and noise -- if either of these escapes the motor, bad things happen. ;)

Re: Motors: Past and Future
 

Have any of you used the snowblower motor this year? I saw that it was added, but I hadn't heard much about it.

Re: Motors: Past and Future
 

It's actually been around a couple years, but I have not used it.

Re: Motors: Past and Future
 

Oh I hadn't realized, I had just assumed it was new. My bad. Anyway has anyone found a good use for it on their robot?

Re: Motors: Past and Future
 

It seems that many teams chose other motors since only one snowblower motor was allowed. I did inspect some robots with the motor, but I would put it in the less than 5% range.

Re: Motors: Past and Future
 

Snow blower motors. We all should clearly absolutely totally use those.

Re: Motors: Past and Future
 

First Post
Ok, so I have gone through the search for over 20 mins and have also read last years rules and I cannot find where it prohibits using a DC/DC converter to raise the voltage to 18vdc to run a RS-775-18 at 18vdc. Wouldn't this be covered under custom circuits?

Whether or not that would be advisable is a different question.

Thanks in advance for your patience ;)

Re: Motors: Past and Future
 

I don't know why this would even matter.

The PDB will only supply 40A (at 12 volts) to a motor, or the individual breaker will reset.

That means that only 480 electrical watts can run through your motor anyways.

Stepping up the voltage to 18V drops your maximum amperage to just 26.6 amps.

I haven't looked at the specific motor torque/rpm/current curves, but barring inefficiency, they can only operate at the same maximum power

Re: Motors: Past and Future
 

It's also a pain to mount/interface with, even moreso than the window motor (actually, I've gotten a lot of mileage out of the window motors in my time in FRC).

Re: Motors: Past and Future
 

Raging,
R53
CUSTOM CIRCUITS shall not directly alter the power pathways between the ROBOT battery, PD Board, motor
controllers, relays, motors, or other elements of the ROBOT control system (items explicitly mentioned in R64). Custom
high impedance voltage monitoring or low impedance current monitoring circuitry connected to the ROBOT’S electrical
system is acceptable, if the effect on the ROBOT outputs is inconsequential.

Re: Motors: Past and Future
 

It matters a lot. See below.

The breaker doesn't reset instantaneously.


The power you are referring to above is the input electrical power.

Operating at higher voltage makes the motor much more efficient. The output shaft mechanical power at 18 volts and 26.6 amps is much greater than the power at 12 volts and 40 amps.

Re: Motors: Past and Future
 

But what is the efficiency of the DC-DC converter and at what cost, considering the high current draw?

Re: Motors: Past and Future
 

That's a separate question (but a good one).

There's also the question of motor speed. To get the higher output mechanical power, the motor would be operating at a higher speed, thus (potentially, depending on the application) requiring another stage of gear reduction with the attendant additional inefficiency.

But the point is, the RS-775-18 was designed for 18 volts, and it is far more efficient at that higher voltage.

Re: Motors: Past and Future
 

Ether
Thank you for that document. That is exactly why I was thinking about this. V=IxR. So if the voltage increases the amps go down. Less heat, more efficient and as shown more power. But from reading the rules a bit closer it appears it is a no no. Thanks for all of your help:)

Re: Motors: Past and Future
 

Here's a link to the app that created the output, in case you'd like to experiment with it.

Re: Motors: Past and Future
 

The number crunching began, and then I discovered that the 775-12 stalls at 30 Amps anyways, so a clear victory to the -18

I concur that there is plenty of leeway in the breakers before they pop.

Re: Motors: Past and Future
 

So why allow an 18v motor if we can't effectively use it???

Re: Motors: Past and Future
 

It can still support tons and tons of power. It has close to the capacity of a CIM even at 12v.

Re: Motors: Past and Future
 

Yeah, it's going to be pretty darn inefficient even if it were legal. You would have a real tough time finding a DC-DC converter that could boost from 8-13.5 V to 18 V with any respectable amount of current. You'd have to put several in parallel and you would have fun carrying that much current on a PCB. Even if you could find an adjustable boost converter capable of 5A, it would be at least $10/IC....and you'll need what? 8-10 of them?

Re: Motors: Past and Future
 

Rotary converter then rectify the output ;).

Re: Motors: Past and Future
 

$10 is waaaay too low an estimate. You want a 40 amp 12-18v converter. That will weigh several pounds and probably cost between $50 and $200 (I can't find one on ebay to get a closer estimate).
Making your own would just be a coupld $2 transistors rated for 60+ amps, a heatsink, and a large inductor. The inductor would be the hardest to source, as high-current high-inductance coils are expensive.
It wouldn't need to be adjustable as long as the motor controller can support the voltage, as you can place the controller after the boost converter.

Re: Motors: Past and Future
 

In some applications, this motor can actually deliver more output than a CIM. Motor performance decreases with increasing armature temperature, and in some operating conditions the CIM's armature temperature rises faster than the 775-18's. One example might be a continuously running intake.

Of course, a continuously running mechanism that is also likely to stall should be powered with a CIM rather than a 775-18.

Re: Motors: Past and Future
 

Ok
So I have read every word in the Motor section, power distribution and command and control, command & signals system from last years rules and NO where does it expressly prohibit an 18vdc motor being ran by 18vdc.

If someone can find any differently I would be surprised.

Here is the caveat that I feel would allow it.

4.8.10 R40
Any active electrical item not explicitly listed in R29 or R67 is considered a CUSTOM CIRCUIT. CUSTOM CIRCUITS
may not produce voltages exceeding 24V when referenced to the negative terminal of the battery.

Since R29 references the motors it does not apply to custom circuits. Also the speed controllers are rated up to 30vdc so they can handle 18vdc

Whether or not this is feasible/recommendable etc etc is a different question.

I am only after the legality of the question right now.

Re: Motors: Past and Future
 

Usual caveats about how rules can always change...

Re: Motors: Past and Future
 

Al already answered that. R53 bars custom circuits from altering power pathways between the PD board, speed controllers, and motors.

And yes, this booster IS a custom circuit. R29 is the motor list. R67 covers the Jaguar/control system interface. A voltage booster is not listed in either. You can also reference the definition of Custom Circuit--no voltage booster listed, therefore, it's a custom circuit. Because it's a custom circuit, it cannot alter the power pathways. I would consider boosting the voltage, either before or after the speed controller, to be an alteration of the power pathway, and thus illegal.

Re: Motors: Past and Future
 

Basically, unless a CUSTOM CIRCUIT is also a non-functional decoration, it can only be an input*.

*Under the 2014 rules.

Re: Motors: Past and Future
 

Hopefully things will change in 2015. Seems a shame to have the ability for an 18vdc motor and not use it to its full potential:(

Thanks for all of your help.

Cheers :D

Re: Motors: Past and Future
 

Going to 18V batteries for FRC seems like a good way to double the kinetic energy each robot could potentially bring to a collision. While there are quite a few teams already practicing robust design, the majority of FRC robots I inspected in 2014 would not be robust enough if they simply had 18V "dropped in" to replace the 12V batteries around which they were designed.

Back in 1996 we used to play with 12V drill batteries, two to a 'bot IIRC. The step up to the 12V sealed lead acid UPS/scooter batteries came a few years later. The average FRC robot today is much more powerful, and much more robust, compared with those early years.

Is the FRC ready for another step up in electrical storage?

Re: Motors: Past and Future
 

With 30 motors available*, I think they need a step up in electrical storage (and current capacity of the main breaker).

Get a battery company to donate enough 12V 25~30Ah LiFePO4 batteries for every team to have at least 4 and I don't think FIRST will have any choice but to change batteries**.

*2013 & 2014 rules.

**This applies to any electronic component you want to use. If enough is donated, the GDC will make it legal.

Re: Motors: Past and Future
 

I don't know why it's so important that we run the 18v motor at 18v. Even at 12v it's a very powerful, useful motor. We're not exactly wasting its potential - anything would be more powerful at a higher voltage...

Re: Motors: Past and Future
 

I don't think that's wise. Just because we have motors doesn't mean we have to use them. It's just nice that we have an array to choose from.
All that adding more motors will do increase the energy available to each bot, causing more damage and collisions and safety concerns. As it stands, we have enough motors to drive about as fast as a driver can handle. Main breaker blows are the exchange for that kind of speed. Making it bigger would make drivers drive more dangerously.

Re: Motors: Past and Future
 

to get the increased power associated with a higher-than-spec voltage, the motor must operate at a higher-than-spec speed.

the motor must be designed to operate at the higher voltage and speed.

the RS-775-18 is designed to operate at 18 volts, and the speeds associated with that higher voltage.

can the same be said for the 12V FRC motors? who knows.

Re: Motors: Past and Future
 

I don't.

But I strongly suspect that CIM motors, which are designed for 1000 hours mininum life when run at ~17% duty (3 minutes on CW 2 sec off 3 minutes on CCW 30 minutes off, repeating) with 64 oz-in load torque and 12V supply, would not survive that long if tested the same way at 18V supply. Maybe the reduced life would be sufficient for FRC application.

I wonder if CCL can be induced to provide life test data for the CIM at 18V?

Re: Motors: Past and Future
 

Not exactly, the motor series resistance doesn't change. Solving the above equation for increased V increases the current. You are thinking of transformer action where as the voltage is stepped up the current is decreased for a given power.

Re: Motors: Past and Future
 

Or perhaps he was thinking of the electrical power supplied to the motor input: P_in=V*I. For a given input power P_in, the motor current is inversely proportional to the applied voltage.

Re: Motors: Past and Future
 

I disagree.
Power management is a good exercise in proper engineering. Just because we have 30 motors available to us doesn't mean we should use 30 motors.

A limited supply of electrical energy forces teams to budget their available energy. Just another challenge.

DL

Re: Motors: Past and Future
 

I agree, the current battery is fine. We ran an 8 motor drive (6 CIM, 2 MiniCIM) and didn't have problems last year. Matches are less than 3 minutes, a single battery is more than enough to work with. You have to make good decisions about wiring and things but that's part of the competition. Also the 775-18 at 12V is a great motor (now that it doesn't case short as often) and we don't need to run it at 18V for it to be very useful. With the last two years allowing 6 CIMs, 4 MiniCIMs, and 4 BB775-18s I think teams have plenty of power to build just about any mechanism they need/want.

Re: Motors: Past and Future
 

Agreed. 6-CIM drives and the like are pushing the limits of what the current battery can do, and this adds depth to the engineering decisions that need to be made to field an effective robot. I think this is a good thing.

Re: Motors: Past and Future
 

But without a more capable battery, how can drives like this become possible? :D

Re: Motors: Past and Future
 

I'll still be able to out-push you with just 4 Cims :D