Motor Power/RPM Tests
 

Here are the RPM tests I've been promising, along with an updated Power Usage test. Keep in mind these are just the motors that I have...I don't own a store (that's Tiny's gig) so if you don't see a motor tested here it's because I don't have it.

Motors tested
Tomy: 1.0, 1.6, 2.2 and 2.6
ZipZaps: Stock, Performance, Turbo, and Racing
Bit Char-gmotors: 2.6, 3.0, 3.2 and 3.8
TinyRC: 3.8, R-spec and Formula34

Testing environment
For the RPM tests:
I used a Tachometer that Wild03 (Forum Member) made. All props and credit for that belongs to him. you can build one as well, check out his site:
http://www.geocities.com/wdiaz03/tachcometer.html

Instead of putting the mouse encoder wheel (from the site above) directly on the Motor...I took apart a 12:1 Axle and attached the encoder to the Axle. The reason for doing this was because my first batch of tests had erroneous results at higher than 22,000rpm. Using the axle with the 12:1 gearing brings down the initial readings and results in better numbers.

Once mounted to the car, the car was charged to full, run for a short time and then the tests were done at ~1.34v

For the Power Usage tests:
The Motors were mounted in a clip from a work badge (looks like a big alligator clip) with a ground wire run through touching the barrel when mounted. To provide the power, the ground wire was run to one side of a battery (a fully charged, 160mAH NiMH Bit battery) and the negative was run through my Digital Multimeter (in series, to get readings) and then to the metal piece on the motor endbell to close the circuit and get the motor running.

In previous tests the PCB was in the middle and any limitation of the PCB would taint the results. This time the tests are done straight from the power source.

I tested for no load against the motor and 'stalled' (the motor shaft was forcefully held not to spin).



Results:

All results (in the Power Usage tests) are in MilliAmps (mA)

http://tinyrc.com/lincoln/Images/Mis...MotorTests.gif

* Indicates I had more than 1 of that Motor and the number listed is the average of all the tests for those motors.


Final Thoughts
In the RPM department, for the most part the motors perform to what they're rated. The higher RPM motors come in a little under their rating though, but not by much.

As far as the Current usage tests, there's 2 things these numbers tell you; motor efficiency (runtime) and how much juice it'll demand to spin the wheels.

The numbers under no load gives you an idea of the effiency of the Motor, the lower the number the less power it demands and therefore longer runtimes. Take the Tomy 2.2 vs the 2.6, even though the 2.6 is a higher RPM motor it uses less power when running and will last considerably longer than the 2.2!

The stalled numbers (I believe, not positive on this yet) indicates how much the motor will demand for power to spin the wheels. The higher the number, the more "pull" it has...I'll have more concrete info when I do the 'hill climb' tests. I'm especially interested in that Bit Char-Gmotor 3.0, at no load it's pulling A LOT of juice!

My next batch of tests will be to see how steep an incline the motors can handle, this will compliment the power usage tests and give us a better picture of Torque.

would it be possible to do this somehow but with the same load the car puts on it? so we can get a better understanding bcuz the rpm with no load doesn tell us enough

Cool. Let me be the first to say thanks for the effort!

Thank you! good stuff you got there. Makes me think...i wonder if there is a good way to measure the torque? I'm thinking like one of them stationary bikes, turn up the levels of resistance till the motor can't turn anymore...:D

anyways, thats really cool!

EDIT: hehehehe i just re-read your post and saw the part about torque...man am i dumb or what? :D

Audi-TT,
Yes, it would be great to do such tests...But that would probably require building a dynamometer (and all that would entail) to test these little 'toys', well I just don't know if I'm THAT crazy yet.

While the RPM with no load alone doesn't give you much...You CAN match it up with my other tests (like the battery tests and the Motor Power Usage tests) and all together some things about the motors start to show.

cool info man, thanx a lot

does the power usage when it is stalled have anythjing to do with how much the torque the motor would have? im just wondering

thanx again

Nice work!
 

Thanks for the info! You should move your own thread to Bit Science!

It is my belief that the stalled current indicates how much juice the motor demands before giving up...So in essence yes, I think that equates to torque.

I'll be more sure when I do the incline tests.

Any chance of including bitmod1 3.0, 3.2, 3.5 motors?
How about Perfection 3.0, 3.8?
DKS rotors, etc.?
It'd be great to have a complete table of the most popular motors.

Any news about that micro-b dyno thing, perhaps for some real torque numbers?

Excellent work so far. Looking forward to incline tests.

I've merged the Power Usage and RPM test threads. So if things seem a little out of place, that's way.

Figured this is the best way to keep everything together.

actofgod,

I will try contacting the retailers for those motors and see if they want to send me any motors to test.

As usual us aussies are just too good!
 

DYNO project.

Used it on the weekend, check it here.

http://www.ausmicro.com/link.asp?TOPIC_ID=527

ph2t.

maybe you could test a dual and tri cell setup to prove whether a motor's speed is doubled and tripled by double and tripling the voltage. if the law of diminishing returns apply here, then it'll quiet those people who say their tri cell 3.0 runs at 9.0 or something along those lines

can you try that with a perfection 3.8
and compaire

he can only test what he has so if u want him to test the perfection 3.8, u betta donate one to him then :D

Update:

I just received the 'Darkside rotor' 3.4 motor from DriftKingShop. I'll hopefully have some results on this motor soon.

I'll also be getting the 'Phast Motor' from RCMod soon as well.

The Multi-Cell tests is a definite must-do, good call TypeZer0.

Maybe you can add an efficiency column to the chart with the RATIO of the MAX current to MIN current. This could be really useful for multi-cell bits, I believe, because more efficient motors perform better with multiple cells. In this case, the 2.6 rules!

If a motor is doing NO work, than 100% of the power is converted to heat. This can explain why motors get so warm under no load. I think the maximum heat produced is I^2*R,
where R is the armature resistance and I is the NO LOAD current. Since the current is directly proportional the the voltage, a more efficient motor can run at a higher voltage before overheating.

This is good because the frequency (rpm) is directly proportional to the voltage. Please don't bite my head off if that's not what the tests say... that's just what my physics text book says!

By the way, your idea that current = torque is verified in my physics book too. ;)

and could you give us info on the r-spec v2 and mabey hardwired motors?

Hard-wired motors should work exactly the same. Sometimes the contact between the motor and the motor clip isn't very good (high resistance), so hard-wiring is juts a way to ensure that you don't have this problem. This is one of those mods where I gotta say... Don't fix it if it ain't broke.

(And of course, if it is broke... ya know)

umm thats kinda funny how the formula 34 out preforms r-spec and it has more torqe but the r-spec has a new version and its cheaper so i think ill buy another r-spec

Hey Namuna, did you test out the new NOS Express for ZIP ZAPS?

For the folks that keep asking if I've tested a certain motor or request that I do...As I've said in the beginning, I've test ONLY the motors that I have and anything after that are Motors sent to me by a Retailer/Manufacturer for testing.

At this point I've got PLENTY enough motors and have NO incentive to spend my own money to buy anymore.

If there's a motor I haven't tested and you want to see results on (like the Perfection 3.8 or ZZ NOS Express) I'd suggest maybe contacting the manufacturer or reseller and pointing them my way to send 'test' motors for me to get results on.

Update:

- Received the 'Darkside Rotor 3.4' from DriftKingShop.
- Should soon be receiving the 'Phast' motor from RCMod soon
- Ordered an 'Angle Finder' for precise measurment when I do the incline tests.

hey you edited the formula 34 rpm >:(

I notice that the lower rated motors work better in my dual and triple cells. Is there any particular reason for this? Also, while we're on the subject, what's the best motor for dual cell rides ? I currently am using the zz red 2.1 in my mult-cell cars. BTW. I've said this before, but those tests are awsome.......JD

I too am currently running a 2.1 in my daul ZZ, i tried a TRC 2.8... but that things got sooo much torque that it would just fishtail like mad! So I've found the 2.1 to be my best choice right now too.

And yeah Namuna's the man when it comes to all this techno gobbly-gook, he brings the info you didn't even know you wanted to know! :D

Nope, I haven't touched the numbers.

I'm also using a 2.1 motor in my hybrid dual cell MS Pro/Zip Zap. I tried faster motors, but had problems. The boosted speed would be very fast with the faster motor, but the unboosted speed would be slower than the 2.1. It's as if the motors display different properties with different voltages run through them.

the formula 34 rpm was higher than the r-spec before so if you didnt tiny did cause he didnt want that to get out

Results of the r-spec may have changed with the replacement of the original by V2.0... just a guess *shrug*

the formula 34 had about 300 rpm over the r-spec beforce and in lowered 2000 rpm

The Formula34 is a 34,000rpm motor...The R-Spec was never quoted an RPM, but I tested it to be 36,000+

There's NO MISTAKE, there's NO CHANGES.

Let's just get a couple of things straight about information I post.

1. I NEVER falsify, nor allow the falsification of any of my findings.

2. The results I find are the results I give, any deviation of that (like rounding off or allowance of errors) is and will ALWAYS be given and upfront. You're NOT going to find little details that blur the facts omitted.

3. Mistakes WILL happen, though I try my BEST to get all the facts right (like the whole STUPID name changes and confusion with the colors of the ZipZaps motors). If I make a mistake, I own up to it and fix it.

im just saying when i first saw the chart i could have swore the formula 34 rpm was 300rpm higher than r-spec

are we every going to see the results for phast motor or did u not get it yet????????????????

Hi Namuna, just wondering if you got my e-mail with the permanent magnet DC motor equations? I hope it is helpful in your motor testing if you did not already have/know this stuff. I think it is great what you are doing. If the armature resistance, torque constant and no-load rated speed can be found for each motor it will go a long way to determining which motor is truly the "best". :)

Ahhh, leave it to BabyKiller to keep me on my toes.

Unfortunately I won't be able to put it to the test until early next week (just had my wedding last weekend and am going away this weekend for a pseudo-honeymoon).

Don't worry, I know we're all anxious (especially you BabyKiller
;) ) to see the results. I'll get on it ASAP when I get back.

Gamma Burst, I replied to your email. Check it out.

Edit: I actually haven't received the PHAST motor, yet anyway. What I do have to be tested are:

- 3.4 Darkside Rotor from DriftKingShop
- 4.0 from Gizmo Guru (in UK)
- A whole bunch of Motor from Extreme Micros

congradulations
on getting married

yeah congratulations namuna! btw i am most interested in 2 and 3 cell zip tests. i want to find out exactly how much more power multiple cells give. this will help a guy i know who is making a zipzap speed calculator, hopefully battery voltage can become one of those factors:D i'd like to know how much of a difference there is between 3 normal batteries and 3 layman's cells...

Lord Nick and flatlander, ditto.....congrats on the wedding namuna

thats a big decision lets hope she is the one congrates