CIM Motor Sacrifice
 

I was wondering how many people are thinking of sacrificing their CIM motors to use on their ball shooter or something else and just have 2 CIM's on the drivetrain.

Re: CIM Motor Sacrifice
 

Thinking about it? Definitely. Cims would be really helpful for a powerful shooting mechanism. We are of course wondering if we can run the robot over the barrier and the ramps fast enough with only two CIMS powering the wheels.

Re: CIM Motor Sacrifice
 

You can add an FP motors as the 3rd/4th drive motors.

Though for a shooter, is the CIM really that much better then a FP motor?

Re: CIM Motor Sacrifice
 

Stall Torque: 2.42 N-m, or 343.4 oz-in

vs

Max torque (stall): 450 mNm (63.4 oz-in)


I believe quite a difference

Re: CIM Motor Sacrifice
 

Apples and Oranges. It's all about power not just torque.

Re: CIM Motor Sacrifice
 

FP motors actually seem to be a bit better than CIMs.

In any case, using only 2 CIMs for drive will halve the power of your robot. Replacing 2 with FP motors will help, but you'll get weird, unequal forces that are really only good for a basic 4wd robot. Using 2 FP motors for a shooter and 4 CIMs for the drive keeps the drive consistent in terms of power and allows you to use different types of drive, especially omni/mecanum, which are practically impossible if you're using motors with different torque and speeds.

Re: CIM Motor Sacrifice
 

Not to be rude, but there's some faulty logic and a heck of a false-statement if I've ever seen one.

Re: CIM Motor Sacrifice
 

Would you guys mind clarifying your choices? My team has been looking into motors to serve a pitching machine styled launch system and I was originally thinking that we would start with the motor with the highest rpm... and hadn't even considered using Cims here. What should we be looking for in relative motor torque vs rpm? Thanks!

Re: CIM Motor Sacrifice
 

I'm coming from a team that has only ever used mecanum while I've been on it, so I'm probably exaggerating by a lot. But my omni/mecanum statement still stands.

Re: CIM Motor Sacrifice
 

Fair enough. I see your point now.

Re: CIM Motor Sacrifice
 

Back to OP, this year we are placing a BB 775 with a CIMulator gearbox in places where a CIM would be normally used.
You could do this on your drivetrain or anywhere else really. If you are going to build a ball pitcher, I would use the 775s and keep the more powerful CIMs for drive.

Re: CIM Motor Sacrifice
 

This is EXACTLY what I would do.:)

Re: CIM Motor Sacrifice
 

If we go with the shooter, probably what we would do.
Use the FP/775 and leave the CIMS in drive.

Re: CIM Motor Sacrifice
 

In general I think you will see a lot of 775 based shooters. This years motor allowance gives a lot of variability of what you can and cannot do, you can go 775 cimulators for the drive or the shooter/ vice versa.

Re: CIM Motor Sacrifice
 

We have faaaaaaaaaaaaaar more motor power than we ever had available in the past this year. If you you can't figure out how to use the 22 available motor to make all you mechanisms and drive work then I would love to know what you're planning. We may not have the mini-bike motors we had during 2006 but we have far more power available with the replacements.

Re: CIM Motor Sacrifice
 

We might try the cimulator for launch, and then change over to an FP set once BaneBots breaks my heart all over again.

I gave my bot to you, BaneBots, and then you just short it all away? *tears*

Re: CIM Motor Sacrifice
 

Assuming the shooter in a given robot is higher than the drive train motors (likely) I think that using the 775s to shoot is a good choice because they weigh about 2lbs less than a CIM. Keeping weight low in the robot will be very important for balancing and going over the barrier.

We're planning on having our shooter at the top of the robot, so keeping 4lbs at the bottom will help make the robot more stable while only sacrificing a little bit of shooting power.

Re: CIM Motor Sacrifice
 

Wait, when was it decided that 775's are better than FP's?

Re: CIM Motor Sacrifice
 

Our plan is to put 4 CIMs in the drive-train. With single motor drive and trying to balance, especially attempting to push other robots on the ramp (single person controlling the balance instead of 2 or even 3. This is accomplished by a low level of stall by the other balancing robot against your robot, and then back-driving or sliding the other robot to control the balance.) would be all but impossible without either 2 speed gearboxes or a 4 CIM drive. I would recommend the CIM SIM from andymark as an alternative power method for flywheels, belts, conveyors, and other high power systems. A pair of 500 series motors will actually perform better than a single CIM in most cases, and with the gearbox is comparable on weight. I try to avoid the RS-775, because they don't offer the same benefit/weight as the other motors, designed properly, the fragility of some of the 500 series motors wont be a problem, and there are more gearbox options which allows for the possibility of keeping it lighter with more power.

Re: CIM Motor Sacrifice
 

I'll be honest. I'm more worried about battery power droop than our motors. I believe you will see a lot of robots resetting 1.2 way through the match because they are running so many motors.

Just my 2 cents

Re: CIM Motor Sacrifice
 

Completely agree with you. I've been waiting for them to do this for a few years because it makes sense to give more than we can use and force tradeoffs.

Re: CIM Motor Sacrifice
 

For your consideration... our prototype shooter managed to score fairly consistently from the key last night running off two cordless drills (which are closer to 550's than CIM's). With the plethora of motors this year, you could easily stick 4 BB motors on the shooter (and have enough motors for everything else you want to do), and get 1000W of power out of them for shooting. That's more power than two CIM's!

Re: CIM Motor Sacrifice
 

How far did it shoot? If two CIMS can accuratly shoot a ball farther than 4 BB's, there is an advantage right there.

Re: CIM Motor Sacrifice
 

With the two drills, it was making it from the key into the top basket with about a 45 degree angle. As far as baskets go, that's probably about the furthest I'd realistically plan for on the field (which won't stop us from trying for further, of course!), if only due to the protection available there.

Note that we didn't use actual KoP motors, we didn't spend any time figuring out proper gear ratios or speed... this was just a prototype. I would imagine that 4 similar BB motors, properly geared, would be able to clear half court pretty easily based on what we saw last night, if that's what you're going for. Once you get it past half court, is there much of a benefit to shooting further?

Re: CIM Motor Sacrifice
 

this can be avoided by gearing smaller motors thats what were doing for right now at least

Re: CIM Motor Sacrifice
 

What does the pronoun "this" refer to ?

Re: CIM Motor Sacrifice
 

I think this thread needs some numbers to justify the motor comparisons going on. As stated above, power is what matters, because you can gear all the motors to the same speed, and if they have the same power, the torque will be more or less the same (ignoring some inefficiencies).

The CIM has a max power of about 337W.
The FP-2011 has a max power of about 289W.
The RS775-18V (powered at 12V) has a max power of about 266W.

So they are somewhat close, with CIM beating FP beating RS775. Since the CIM is so much larger, most people will agree that it's the motor to put in the drivetrain since it will take continuous duty all day (relatively speaking). The FPs and RS775s will be more sensitive to overheating and would be better suited to intermittent duty, i.e. a shooter (even if the wheels are always spinning, they are only loaded down when you shoot, which will be relatively infrequent).

We also have a much larger limit on quantity in past years. Even with 4 CIMs in the drivetrain, you can have another 2 FPs and 4 RS775s, besides all the other motors at our disposal. So you can make up for another 4 or 5 CIMs in power, but of course your battery will start complaining before long.

We are foreseeing something like 4 CIM drive, 2 FP shooter, and various smaller motors for collection and loading, based on our testing so far.

Re: CIM Motor Sacrifice
 

I have heard no mention about the wide array of automotive motors available to teams this year. If power is a concern, there are some very powerful Denso motors used in seats that would be legal for use.

Re: CIM Motor Sacrifice
 

Do you have power specs for them? Historically the seat motors have not been very powerful (they have been KOP in past years).

Re: CIM Motor Sacrifice
 

How are you defining power? Check out the official specs for this year's motors:
http://www.usfirst.org/sites/default...torInfo2.2.pdf

The normal Denso motors we've gotten the past few years can provide a lot of torque (which is NOT equivalent to power!), true... but they're so slow, the overall power output is really low. Likewise, the third one listed on the sheet might be faster, but doesn't provide near as much speed or torque as other motors listed (like the FP or the 775's).

Re: CIM Motor Sacrifice
 

Count me in for using a FP or 775 in the shooter. They'll be lighter for a nearly equivalent level of power, and you can leave your CIMs on your drivetrain. We'll probably lean to the RS775-18, since running an 18V motor at 12V gives you a little more margin for overheating, and (I think) the slightly heavier motor will give you a higher effective inertia, when it's all said and done.

Re: CIM Motor Sacrifice
 

A word of warning, that plagued many teams last year (but not ours, at all) is that the 775s can develop case shorts and cause all sorts of nasty issues.

Neither of our 775s caused an issues, and I think its because they were both electrically insulated from the chassis. This year we will be mounting them on wood or lexan panels to keep them isolated.

Then again, I might be totally off in this evaluation.

Re: CIM Motor Sacrifice
 

I still have memories of the guys up the road from us using a FP to power their 2008 shooter with a FP and a "gigantic" Zalman copper heatsink on it so it didn't melt down.

As an offseason project we had some students build an AIM High style shooter using two CIMs and AM hubs to direct mount wheels, not only did it sound like a death trap spooling up but it was really heavy. They never got around to building a version only using one CIM.

I'd still have reservations with putting one of those way up "high" on a robot.

Re: CIM Motor Sacrifice
 

When you guys are referring to the Fisher Price motors, which motor are you referring to because there are a couple different FP motors.

Re: CIM Motor Sacrifice
 

I listed specs for the 2011 FP (289W), and since we all get 2 of those in the kit and they are more powerful than the 2010 and prior ones, we would plan to use those.

Re: CIM Motor Sacrifice
 

In some cases I saw, the short was transmitted through the gears/sprockets as well. Don't rely only on the mounting material to keep you safe, and come with a backup plan if you run into problems!

Re: CIM Motor Sacrifice
 

FP-2011? Did you mean the Fisher Price 00801-0673 ? As of this writing, the 0673 is listed in the Game Manual Chapter 04 Paragraph 4.1.8, and in the USFIRST 2012 FRC motor spec chart, but it's not listed in the 2012 Kit of Parts Checklist.

Re: CIM Motor Sacrifice
 

That last post was a mess, let's try to get this straight.

We got 2 00968-9013 motors in the kit. These are NOT listed on FIRST's spec sheet, but there is a 9012. Upon looking at them in person they looked like the 2011 motors (and that made sense that they would give us recent ones) but this is incorrect.

Last year's motor was listed as the 00801-0673 in the 2011 KoP, and is now listed on FIRST's spec sheet as "Gearbox: 112:1 Reduction". These specs match the motor we used in 2011.

The 2010 and prior motor is listed as a -9015 motor in all the KoP checklists, but on FIRST's spec sheet is the "Motor from the 2011 KoP"

There is additionally a 00968-2719 on the spec sheet listed as the "Motor from the 2010 KoP".

So lots of confusion. This should maybe move to the motor specs thread.

Edit:
FIRST provided motor specs here
Past years' KoP lists here
This year's KoP list here

Re: CIM Motor Sacrifice
 

In the real world of FIRST you will probably find that the FP motor of the past few years if roughly equal to 1/2 of a CIM... (roughly... and I mean in practice and not just theoretically) 2 FP motors weigh less than a CIM.

In this game the shooter may be located high on your robot so make sure you consider the weight distribution carefully... going over the "bumps" is going to present difficulties and a low CG will really help you not tip over...

Remember you can double up 2 FP in a transmission by using a CIMULATOR
so in effect you have the power of a CIM in a smaller and lighter package...
You could also use a 775 cimulator to do the same thing with those motors..

Up to about 2-3 years ago the FP motors we used had little ( if any ) thermal protection and they were notorious for burning out...in the past few years they have added thermal protection which really helps their longevity and usefulness.

I am not sure about the new 500 size Andy Mark motor... yet

Also don't discount the BaneBot 550's ... they also have plenty of power (more than the FP in wattage...) but they have no thermal protection.
We used them very successfully on our lift last year...

They are rather unforgiving though...

You don't need the CIM to throw the balls unless you really want to use it..
You have plenty of other options...

Do some prototyping and see what you can find out!!

Re: CIM Motor Sacrifice
 

I see no real need to use CIM motors for shooting purposes when they're are other motors that can be used to do the same job. As 1708 doesn't have the option because we use 2 speeds which use up all four of our aloud CIMs. Banebot, Fisher Price, and Drill motors seems to work just fine.

Re: CIM Motor Sacrifice
 

Not more than the FP 00801-0673

Re: CIM Motor Sacrifice
 

Does anyone have specs for this motor? Google returns no hits.


It was listed in Paragraph 4.1.8 of the Game Manual as a 2012 legal motor, but Team Update 1 removed it and replaced it with FP9013. Last I checked, FP2719 is still listed on the USFIRST spec chart, and FP9013 is not.

Re: CIM Motor Sacrifice
 

during the Breakaway challenge my team used 3 omni-wheels spaced out in an equilateral triangle, all wheels faced different directions, and we could go in any direction by varying the power to each. at full power, only two wheels were in a direction capeable of pulling us foreward, but since the wheels were angled, we could only get the square root of two (1.4) CIM's worth of power out of two CIM motors

our robot was very slow and couldn't push anyone around

now, i know there are other forces in play and you will have more force than our robot, but keep in mind that with only two CIMs you will probably not push a robot with 4 CIMs

Re: CIM Motor Sacrifice
 

Hi, my teams plan right now for our ball launcher is to mount one or two of the Bane Bot RS-775-18V (at 12V) motors to CIMulators, and then into a CIMple box; which will then drive two 8" 2011 KoP wheels via chain or belt. However, we have no experiance with these motors and gear box. Do you think that this is a viable/reliable option?
Also, I see that some people have used the Fisher Price motors to drive ball launchers like this. How are these motors attached? Is there a COTS gear box, or do you have to custom make one?
Thanks.

Re: CIM Motor Sacrifice
 

First off I refuse to sacrifice a CIM to the robot gods this year...


Now onto the more serious part of my post...

You can stick a FP motor in a banebots P60 gearbox or in a cheap Harbor Fright 18v drill gearbox (or most other 18v 900rpm single speed drills for that matter)

Re: CIM Motor Sacrifice
 

Where can you purchase a CIMulator gearbox? Banebots has something called a cimulator, but it says it only mounts to one RS775.

Re: CIM Motor Sacrifice
 

We were discussing that today as well. We're gonna probably be doing what it seems everyone else has been saying: try out the FP motors with CIM gearboxes. The build crew pointed out that for the shooter you don't really need the CIM's torque, more just their speed, so the FP be ok.

Re: CIM Motor Sacrifice
 

AM Planetary Gearbox (am-0002)

Re: CIM Motor Sacrifice
 

Check AndyMark for the Cim-Sim gearbox, $89 each. I also found an adapter to adapt the 8mm keyed output shaft to a 1/2" hex for $10.

http://www.andymark.com/product-p/am-0932.htm

http://www.andymark.com/product-p/am-0588.htm

Hope this helps.

Re: CIM Motor Sacrifice
 

This is why Fisher Price gearboxes are so awesome. It is a plastic case with plastic gears and it already has both 500 AND 700 size motor compatible mounting holes. The downside is that you have to find the pinion or take the pinion provided on the FP in the KOP and bore it out to fit the 775. Also, the output could be an issue. That being said, it worked brilliantly on our 2011 robot.

Re: CIM Motor Sacrifice
 

PROTIP: I didn't see anything in the Robot Rules about springs. So a spring powered mechanism may eliminate the need for a motor.

Re: CIM Motor Sacrifice
 

Well, I'm not building a robot this year, but in 2006 one FP worked okay.

http://www.youtube.com/watch?v=jggKd...fOxsD6WqKj3HO_

Looking back, our original intent was to have a second FP on the other side of the turret, so the shooter would run off 2 FP's. This would have been good as far as getting our shot rate up, but would have also meant that we would have violated the maximum ball velocity rule that was in place that year... we weren't sufficiently skilled at sensors and software at that point to have a constant-speed closed-loop feedback system on the shooter motor(s).

While the full pan/tilt turret looks really good, and we could hit from half court, and this became our #1 demo robot for years, we got whupped by teams with simpler mechanisms who could aim and shoot more balls from closer range.... and that was with a much larger target to aim at.

I don't know how much more energy the larger balls this year will require, but I suspect 2 CIMs will have more than enough energy to hit the target from wherever you choose to shoot.

Jason

Re: CIM Motor Sacrifice
 

That seems like a lot of gears to go through between your motor(s) and your shooter; you'll loose a lot of efficiency that way. You may want to just skip the CIMple box and go directly from CIMilator to shooter. My team tested direct-driving CIMs on our prototype shooter and it worked great.

As for the Fisher Price gearbox, the AndyMark planetary gearbox (am-0002) is really easy and works well. It's just like a CIMulator from BaneBots, although we've never used a BB CIMulator on one of our 'bots.

Re: CIM Motor Sacrifice
 

Do you plan on doubling up on that set up? As in 2 or 4 motors driving 4 wheels? If you only have 2 wheels, there won't be enough points of contact to ensure a consistent shot, unless you guide the ball to the same spot each time.

Also, going from a CIMulator to a CIMple box seems like a lot of work. You can change the gear ratio of a gearbox to better match your needs. However, I doubt you'll need to do that since the CIMulator is designed to give similar performance to a CIM. A standard CIM has plenty of speed and torque to launch a ball.

Re: CIM Motor Sacrifice
 

As a 500 series motor, a fisher price (or 2) should fit nicely into a CIMulator, which are nice because they are cheap.

Off of a banebots or fisher price (at about 16000 rpm) you will want something in the ballpark of a 7:1 reduction from motor to 4" wheel. For an 8" wheel, 14:1, and the extrapolation is easy.

Re: CIM Motor Sacrifice
 

The only reason that we wanted the CIMple box is to combine two motors and have one output shaft (if needed). We plan on testing our prototype shooter today with a CIM (maybe 2) through the CIMple box. Is there a simpler way to do this?
As for the amount of wheels, will will find out today in our test.

Re: CIM Motor Sacrifice
 

We're using Nanotube transmissions/drives so we're using CIMs for our shooter. I would rather have to step the motors down than get into a match and our shooter need some extra juice or burn out because we skimped on the motors. Just one person's opinion...worth a warm bucket of spit! :eek:

Re: CIM Motor Sacrifice
 

What is possible with a 2-FP shooter from 2006. Six (6) balls air-born at the same time. Needless to say we are building another 5-roller shooter. No need to sacrifice CIMs for it IMO.

Re: CIM Motor Sacrifice
 

Did you actually get 2 9013's in the Kit, or are you simply referring to the fact that the KoP lists 2 9013 motors?

http://www.chiefdelphi.com/forums/sh...41#post1104041

Re: CIM Motor Sacrifice
 

I only briefly looked at the FPs in the kit in person, and later looked at the Checklist, which is where I originally got the 9013. Today I looked through our motor stash, we have a heck of a lot of 9015s, as expected, one 00673 from last year, and two rather old looking 9012s, probably from 2007? (our rookie year) I didn't get around to looking at what the number on the new ones was (they were hidden in a kit box somewhere and there were more pressing things at hand), so I will likely check that out tomorrow.

Edit: checked the 2007 KoP checklist (hadn't done that yet) and there were two 9012s (with gearboxes) in the 2007 kit (according to that document).

Re: CIM Motor Sacrifice
 

And that's with the older, less powerful (if the specs out there right are to be trusted) FP. With 2 of last year's, the 00673, you are much closer to CIM performance. 289W vs only 172W (approx).

Re: CIM Motor Sacrifice
 

That sounds about right. Though the FP specs seem to change every darn year... including one year where they gave us 6V FP motors :ahh:

Re: CIM Motor Sacrifice
 

Have any teams used two RS-550s in a CIM-U-LATOR in place of a CIM? If so, what were your results?

I've seen a lot of posts in this thread with grievances towards the RS-775 (and case shorts), so I'm wondering about experiences with the RS-550s, if anyone can share.

Re: CIM Motor Sacrifice
 

Today we tested an RS 775 into a CIMulator with a 10 to 42 sprocket reduction (#25 chain) to 8 inch wheels. Gear ratio of 11.3, calculated free speed at tip of wheel of 40 ft/s. The wheels didn't appear to spin down very noticably on shooting the ball, but we don't know yet exactly what the exit velocity was or where we are for making some of the shots we need (top goal from key, half court, etc.). We are sticking with the FP/775 substitution plan, and at worst might need 4 of such motors. Hoping for only needing 2. It's too important to keep our CIMs in the drivetrain.

Re: CIM Motor Sacrifice
 

My team is looking into motors for a launching device and you seem to know what you're talking about. Now for the amateur question: what is the BB 775 motor and the CIMulator? Where might I find specs on it or at least somewhere to buy it?

Re: CIM Motor Sacrifice
 

Based on all the contributions you've given to this post thus far, I don't doubt this estimation, but where are you getting these ratios? Is it just based on experience with the FP's or did you do some calculations to figure it out, and if so could you share? 'preciate it!

Can I just point out real quick that your robot BROKE the match that we were supposed to be allied with you!! :ahh: Yes I'm still bitter about that, you had an AMAZING robot that year! Haha can't wait to see what you guys put out this year!

Re: CIM Motor Sacrifice
 

BB775 is a BaneBots M7-RS775-18 Motor. Specs can be found here.

CIMulator is a gearbox that will mount 1 or 2 BB 775s and give you an output shaft and output mounting holes of a CIM motor (Basically it allows you to fit BB775s where you'd use a CIM motor). Specs can be found here.

Re: CIM Motor Sacrifice
 

Those are the specs at 18 volts.

The 12 volt specs are here.

Or you can go here.

Re: CIM Motor Sacrifice
 

I just looked at that link and I think you are slightly mistaken. It appears that there are 2 different cimulators from BB, one for RS-775s and one for RS-550s. Only the one for the 550 says it can accomodate 2 motors, the RS-775 cimulator can only accomdate 1 motor. Is this correct?

Also, when people talk of using the 775s for shooting, should I assume you mean the RS-775-18v?

Pardon my ignorance, but I was wondering what is meant by the numbers before the motors. I know it has something to do with size or power, but I don't know much more than that. Could someone give me a brief explanation?

Thank you.

Re: CIM Motor Sacrifice
 

Your assumption about the gearboxes is correct. I was just looking at our cimulators for 775s today noting how they only take one, likely because the motor is just too big to fit two with that shaft separation.

We would certainly use the 18V motors since they are less likely to fry due to the higher volt rating. I haven't actually looked at the specs for the 12V, but I imagine they can't be much better than the 18V at 12 volts.

The 550 or 775 business (or 00673, 9015, 9012 if you're talking about the FPs) is for the most part just a part number. The first digit implies something about the size, as the 550s are 500 series motors, a common DC motor size (the FPs are as well, and will mount in many of the same places as the 550). The 775 is a bit bigger and more powerful, as the bigger number implies, but there is no overarching protocol of any sort determining these numbers (that I'm aware of....)

Re: CIM Motor Sacrifice
 

After testing our prototype shooter, powered by a single CIM, we decided to make a change. The CIM was more than sufficient for our plans, but we believe they are better suited for our drive train.

Based on the results of our testing, we made the following adjustments:
The single 340Watt CIM, driving 8" wheels, reduced 1.8:1 with chain sprockets will be replaced by 2 250Watt RS550s attached to a 5:1 reduction CIM-Sim from AndyMark. The output will either be direct driving the shooting wheels or go through a 1:1.8 chain sprocket increase. Either way will work out, but the 1:1.8 increase should have the motors running at about 50% power.

We plan on using and encoder and PID loop to maintain the desired RPM. Running the motors at 50% power will allow us plenty of overhead to control RPM during shots and when the battery starts to fade near the end of a match.

Re: CIM Motor Sacrifice
 

In our testing, the 550 appears more than enough to handle our 12" shooting wheels.
This is exactly our plan as well. We went with custom machined shooting wheels so we can move all the mass to the very lip of them to get the most bang for the buck. Two 550s geared down seems more than enough all told.

-Mike

Re: CIM Motor Sacrifice
 

What do you mean by 50% "power" in this context?

Re: CIM Motor Sacrifice
 

Ah, I see I was a little more vague than I intended to be.

Our intent is to run the motors as close to (Max No Load RPM/2), technically at or near the motors maximum power point. So, my statement was termed incorrectly. I should have simply said 50% of max RPM.

Thanks for calling me on this. Clarifying this point does make a HUGE difference.

Re: CIM Motor Sacrifice
 

OK thanks, I'm with you now.

See my earlier post in another thread on this same design question.

Re: CIM Motor Sacrifice
 

My team is using two CIM motors to power our robot. Last year we used two motor two power and it worked fine. We had a six wheel drive. The two center wheels had the power and the four outer wheels were "omni" wheels just for support. As for a shooter we are going to use the other two CIM motors

Re: CIM Motor Sacrifice
 

Just a word of caution if you plan on using the same drive train this year, climbing the ramp will be difficult at best.

Re: CIM Motor Sacrifice
 

Not a rhetorical question: have you ever driven a 4-cim robot?

Re: CIM Motor Sacrifice
 

FP motors are better, because you can achieve a higher speed (roughly 19,000rpm) if i am not mistaken. And if you were to create a fly wheel launcher you could overcome the lack of torque a FP provides. Also once you are up to speed you only require minimal current to sustain the launcher. But dont go quoting me i could be wrong. Feedback?

Also the only problem I can see is connection between motor and wheel, direct drive would be best.

Re: CIM Motor Sacrifice
 

Just saying we tested a fisher price to day and to keep two 8inch wheels spinning on a 4:1 reduction drew about 9amps. And it did get kind of warm.

Re: CIM Motor Sacrifice
 

We're going to be CIM-SIM-ing our lift with the Fisher Price motors and we'll be CIMULATOR-ing the launcher with two RS-775s. I heard good things about BaneBots this year and we want to keep all 4 drive CIMS.

If the BaneBot motors become the bane of my existence again, we may go to a hooded one wheel with a CIM-SIM and change our conveyor to a window motor.

Here's to hoping we can pull off "7" CIMs on our robot, in addition to a pneumatics set.

We're going to weigh our bot week 4 and it's going to be 200 pounds and I will die.

Re: CIM Motor Sacrifice
 

I think you need to rethink this. Is an FP at, say, 12:1 better than a CIM at 3:1 (assuming an FP spins 4 times faster than a CIM)? It is better than an RS 775 geared to the same speed, by a torque comparison, but this is not because its ungeared free speed is higher.

Up to efficiency losses, motor power is pretty much all that matters.

Re: CIM Motor Sacrifice
 

piggybacking on the above..

@Ludicium, read this:
http://www.chiefdelphi.com/forums/sh...7&postcount=34

Re: CIM Motor Sacrifice
 

Careful.... The RS-775 is rated at 18v. At 12v, it is less powerful than the RS-550, making the RS-550 the highest power output available after a CIM to FIRST teams. We chose it last year to raise our boom (at significant mechanical disadvantage) and it really packs a wallop.

Also, remember the FP motors have integral worm gears that can't be legally removed. So while the FP motor specs are pretty good, the worm drive makes it unsuitable for anything other than low-speed, torquey applications.

Re: CIM Motor Sacrifice
 

Not true.

The RS-775-18 running at 12 volts is more powerful than the RS-550 also running at 12 volts.

Re: CIM Motor Sacrifice
 

Also not true.

The FP does not and has never (as far as I know) come with a worm drive, you are thinking of one of the various Window motors from this or previous kits.

Re: CIM Motor Sacrifice
 

Came to post exactly this.

Re: CIM Motor Sacrifice
 

WRT the FP motor, you're correct, thats my mistake!

@Ether

Perhaps I am wrong (and there's always an opportunity to learn) but we went through the specs last year and we were unable to find anything that showed that the 18V version running at 2/3 the nominal voltage performed better than the RS-550 at nominal.

Re: CIM Motor Sacrifice
 

Keep the CIMs on the wheels. Put a CIM-SIM for your launcher. Especially for maneuvering onto the bridges at the end, you will not want two motor tank drive, seeing as the bridges are flush to the wall.

Re: CIM Motor Sacrifice
 

The data on this page shows the 18V version specs at 12V (although you are right ... it doesn't specifically say it).

Re: CIM Motor Sacrifice
 

Here's the specs for the 775-18 operating at 12 volts:

M7-RS775-18-AT12V.pdf

Re: CIM Motor Sacrifice
 

We are considering this

AM Planetary with 2011 Fisher Price KOP Motor Installed (am-0822)

Performance Data:
Input voltage: 12 volts
Stall Torque: 1.4 ft-lb
Free speed: 5500 rpm
http://www.andymark.com/product-p/am-0822.htm

Specs are really close to a regular CIM motor

Re: CIM Motor Sacrifice
 

this is a great idea. hopefully it will keep our weight and power consumption down.

Re: CIM Motor Sacrifice
 

Some numbers to consider:

CIM stalled at 60* amps generates ~325 watts of waste heat

775-18 stalled at 60* amps generates ~500 watts of waste heat.

Has anyone run a test to see how long a 775-18 can be stalled at 60 amps before it smokes?

EDIT: see this post: http://www.chiefdelphi.com/forums/sh...&postcount=237


*per the datasheet, 40 amp MX5 can sustain 60 amp for up to 47 seconds

Re: CIM Motor Sacrifice
 

Our team believes that four CIM's is essential for our drive train. We need our most powerful motors to get over the bump. We'll be using some other motor for our shooter. Perhaps a bane bots or fisher price.