2006 Motor Specs

[Xufer]

Who knows where the 2005 motor specs can be found ? last year they were in the manual this year i dont see them there.

Thanks.

[ryan_f]

it was explained in the webcast. 36 teams are making the specs and will be publishing them

[Elgin Clock]

http://www.usfirst.org/robotics/2006...s.htm#Section5

Under



Other Important Documents 2006 FIRST Robotics Competition Specification Sheets

Originally Posted by ryan_f

it was explained in the webcast. 36 teams are making the specs and will be publishing them

edit: Yes, that is correct., but those will be "real world applications" for FIRST as opposed to the data shown in my link above which is directly from the manufacturers of said parts.

[Veselin Kolev]

Fairly accurate motor speeds: (no load)

CIM: 3590 rmp
Larger CIM: 2180 rpm
Fischer Price: 10,280 rpm

Found using a precision strobe light with adjustable ticks per minute. Accuracy is about +- 0.5% on the motor speeds.

Have fun, all.

[Joe Johnson]

Originally Posted by Veselin Kolev

...
Found using a precision strobe light with adjustable ticks per minute. Accuracy is about +- 0.5% on the motor speeds.
...

Typical tolerances on motors are +/-10-15% and that doesn't include variations due to voltage.

I have never designed a motor/gearbox application where the performance of the motor had to be within .5%, certainly never in FIRST...

For what it is worth.

Joe J.

[Veselin Kolev]

Originally Posted by Joe Johnson

Typical tolerances on motors are +/-10-15% and that doesn't include variations due to voltage.

I have never designed a motor/gearbox application where the performance of the motor had to be within .5%, certainly never in FIRST...

For what it is worth.

Joe J.

Joe, you are totally right.
However, what I mean is that the speed of the motors I got were measured to within 0.5% accuracy. There probably is a lot of fluctuation in the speeds of motors across the country, I was just letting people know that my equipment is quite precise.

Just to clarify

[Joe Johnson]

I have not had a chance to look at everything but from what I can tell so far these are the motors in order of wattage:

• 4 - Old CIM (340W)
• 2 - New CIM (270W)
• 2 - Fisher Price motors (170W)
• 1 - Bosch Motor (70W - based on old 12V specs of 35N-m stall & 75RPM Free)
• 2 - Globe Motors (50W)
• 2 - Denso Motors (25W)
• 1 - Mabuchi Motor (15W)

Am I missing any? I suppose there is the servos that are probably more powerful that 1W*, but they are harder to get continuous power out of since they don't automatically keep putting out work, they only do continous work if your program does some fancy footwork to keep the things moving (winding a mechanism or something I suppose is possible, but probably not worth the bother).

There is an very nice, rich set of motors for teams to pick from. Well done FIRST.

By the way, I am in the process of evaluation THESE MOTOR/GEARBOXES from BaneBots.com. For about $40 you can get gearboxes that the Fisher-Price and the Mabuchim motors will just bolt to. They come in a variety of ratios (5:1, 16:1, 20:1, 25:1, 64:1, 100:1, 256:1). The gearboxes have nice mounting points and long, easy to access (and support) D'ed shafts. And I just talked to them yesterday, they have 1000's in stock. Look for my recommendation or my non-recommendation early next week. I have no connection to these guys at all, I just found them on ebay a while back while looking for stuff for Robotic Amusements.

Joe J.



P.S. By the way, I have just found a table in this document that I believe is in error. It has the peak power of the FP motor over 300 Watts. This does not match the specs in the spec sheets or even the specs in the rest of the table in the same document. I believe my numbers are correct. Also, the Bosch and the Globe are listed as non-12V specs you have to scale the power ratings accordingly to get apples to apples comparisons.



*this message was written before I had corrected an error in converting g-cm's to N-m . I had the Mabuchi at 1W, when the motor is actually 15W or so. I have since went to the hitecrdc spec site for the 323HD servo. If I have not made another calc error, the servo motors are able to put out about .5W or so if you can load them at their 6V peak power point -- not exactly what you would call a real workhorse.

[Larry Barello]

Originally Posted by Joe Johnson

...
By the way, I am in the process of evaluation THESE MOTOR/GEARBOXES from BaneBots.com. For about $40 you can get gearboxes that the Fisher-Price and the Mabuchim motors will just bolt to. They come in a variety of ratios (5:1, 16:1, 20:1, 25:1, 64:1, 100:1, 256:1). The gearboxes have nice mounting points and long, easy to access (and support) D'ed shafts. And I just talked to them yesterday, they have 1000's in stock. Look for my recommendation or my non-recommendation early next week. I have no connection to these guys at all, I just found them on ebay a while back while looking for stuff for Robotic Amusements.

Joe, which of the 20:1 gearboxes would mate with the FP motor? Would I need to replace the pinion? Does Bane's pinion mate with the FP shaft?

Thanks!

[Joe Johnson]

Originally Posted by Larry Barello

Joe, which of the 20:1 gearboxes would mate with the FP motor? Would I need to replace the pinion? Does Bane's pinion mate with the FP shaft?

Thanks!

Go Here too see the answer

Good Luck,

Joe J.

[Schmitty!]

I measured the no-load speed and current of several of the motors we received in the 2006 KOP with an optical tachometer and Fluke DMM. I got the following results:
Small CIM #1 +12.00V: 5370 RPM 2.06Amps
Small CIM #1 -12.00V: 5412 RPM 2.00Amps

Small CIM #2 +12.00V: 5209 RPM 2.00Amps
Small CIM #2 -12.00V: 5374 RPM 2.13Amps

Large CIM #1 +12.00V: 2665 RPM 0.700Amps
Large CIM #1 -12.00V: 2738 RPM 0.790Amps

Large CIM #2 +12.00V: 2752 RPM 0.802Amps
Large CIM #2 -12.00V: 2686 RPM 0.690Amps

Fisher-Price #1 (without gearbox) +12.00V: 16224 RPM 1.06Amps
Fisher-Price #1 (without gearbox) -12.00V: 16579 RPM 1.03Amps

I am planning on grabbing the remaining no-load measurements tonight. So far the measurements I've taken fall in line with what I expected based on the datasheet values. I'm very happy to see that the Fisher-Price motor is a 12V motor!

Does anybody have a dynomometer test stand that can be used to capture the torque data? I can set up a test at stall to capture the stalled torque constant, but from previous experience it is more accurate to capture the torque constant while the motor is spinning under a known load. I don't have access to a dyno at my current job.

[Richard Wallace]

Originally Posted by Schmitty!

I measured the no-load speed and current of several of the motors we received in the 2006 KOP with an optical tachometer and Fluke DMM. I got the following results:
Small CIM #1 +12.00V: 5370 RPM 2.06Amps
Small CIM #1 -12.00V: 5412 RPM 2.00Amps

Small CIM #2 +12.00V: 5209 RPM 2.00Amps
Small CIM #2 -12.00V: 5374 RPM 2.13Amps

Large CIM #1 +12.00V: 2665 RPM 0.700Amps
Large CIM #1 -12.00V: 2738 RPM 0.790Amps

Large CIM #2 +12.00V: 2752 RPM 0.802Amps
Large CIM #2 -12.00V: 2686 RPM 0.690Amps

Fisher-Price #1 (without gearbox) +12.00V: 16224 RPM 1.06Amps
Fisher-Price #1 (without gearbox) -12.00V: 16579 RPM 1.03Amps

I am planning on grabbing the remaining no-load measurements tonight. So far the measurements I've taken fall in line with what I expected based on the datasheet values. I'm very happy to see that the Fisher-Price motor is a 12V motor!

Does anybody have a dynomometer test stand that can be used to capture the torque data? I can set up a test at stall to capture the stalled torque constant, but from previous experience it is more accurate to capture the torque constant while the motor is spinning under a known load. I don't have access to a dyno at my current job.

I have a Magtrol HD-715 dynamometer and Sorenson DCS 20-150 switchmode power supply in my day-job lab. I did a quick 12V test of the large CIM motor this morning. With the motor coupled to the dyno and no load (apart from dyno friction) applied the speed was 2710 RPM and the current was 1.5 Ampere. Peak efficiency was about 85% at 43 oz-in, 2470 RPM drawing 7.7 Ampere. Peak shaft power was about 218 Watts at 193 oz-in, 1530 RPM drawing 33.5 Ampere. The maximum steady load that I applied was 283 oz-in, 750 RPM drawing 51 Ampere. I did take the loading up to about 350 oz-in momentarily without stalling the motor, but did not leave it there long enough to record steady data.

[Spencer295]

Originally Posted by Richard

I have a Magtrol HD-715 dynamometer and Sorenson DCS 20-150 switchmode power supply in my day-job lab. I did a quick 12V test of the large CIM motor this morning. With the motor coupled to the dyno and no load (apart from dyno friction) applied the speed was 2710 RPM and the current was 1.5 Ampere. Peak efficiency was about 85% at 43 oz-in, 2470 RPM drawing 7.7 Ampere. Peak shaft power was about 218 Watts at 193 oz-in, 1530 RPM drawing 33.5 Ampere. The maximum steady load that I applied was 283 oz-in, 750 RPM drawing 51 Ampere. I did take the loading up to about 350 oz-in momentarily without stalling the motor, but did not leave it there long enough to record steady data.

Richard because your test results vary so drastically from the specs on previous posts on motor wattage, would you mind testing the old cim motors on your dyno so I can make an accurate comparison.

[Hutch]

Uhm, so I guess this begs the question, where are those 36 teams? It's been a week now and I haven't seen any specs posted by anyone except other people who decided to do it with the tools they have at work or whatever...

[Richard Wallace]

Originally Posted by Spencer295

Richard because your test results vary so drastically from the specs on previous posts on motor wattage, would you mind testing the old cim motors on your dyno so I can make an accurate comparison.

I don't have an old CIM motor available to test right now. Will try to get one later this week.

[Richard Wallace]

Originally Posted by Spencer295

Richard because your test results vary so drastically from the specs on previous posts on motor wattage, would you mind testing the old cim motors on your dyno so I can make an accurate comparison.

I finally got my hands on an old CIM motor, to measure speed and current vs. torque on my dynamometer. [N.B.: had to order some spares in case the team burns one up testing.]

Your suspicion that my measurements are low compared with published specs is correct: I measured peak power about 270 Watts (c.f. 337 published) at about 2700 RPM, drawing 50 Amperes.

There are several reasons my measurements might be low, but accurate dynamometer torque calibration is not one of them. The most likely (IMO) reasons are (1) I let the terminal voltage drop off at higher current draw due to lead resistance, about 5 ft. of 10 qmm (~7 AWG) for each lead from the supply terminals to the motor lead connection point, and (2) I let the motor get hot while taking readings. Imperfect shaft alignment and residual drag torque in the magnetic brake probably amount to about 25 Watts.

It has been my experience that the above loss mechanisms are also present, to about the same degree, in drivetrains that I have built for FRC robots.