ES DIY Motor Challenge

[jscoot]

Good catch,
I forgot the temp monitering in that post.
I originaly thought measuring at set times of duration will be nessisary also.
I am more concerned with the durability of the drive components than smoking a test motor.

I suppose if a motor is clearly under stress attempting to make the touque ratings of the challange, it will be considerd a "fail"
then any measurments performed using what ever standards we determine (I perfer a standardize procedure to elliminate as much speculation as possible) will allow us to gage the motors against each other.

Certainly all the dyno prmeters need to be discussed.
A thought would be is to add 4 mn loads in levels of three (4/8/12 nm) by adjusting the motor throttle for each load to reach a total of 12 mn. At each 3 levels take a wattage and rpm reading and a freespin (no load) reading at the same rpm as the three loaded readings. ? By stage two you will know by the wattage increase that some motors will not handle stage 3 for too long. In those cases just get the figure in and shut it down before the smoke. 4.8/12 Nm...

 

[Miles]

As we are testing for specific torque, only 3 kg motors would be required to output 12Nm.

First weigh the motor, then calculate the amount of continuous torque required to meet the challenge.....

 

[jscoot]

As we are testing for specific torque, only 3 kg motors would be required to output 12Nm.

First weigh the motor, then calculate the amount of continuous torque required to meet the challenge.....

Yes then test it in Thrids ?

 

[Miles]

Maybe run tests for 80%, 90% then 100% of required output?

 

[jscoot]

Maybe run tests for 80%, 90% then 100% of required output?

33 66 and 100% would show which motors do well at lower power levels.
Is the limit 1000 watts

 

[Miles]

Maybe run tests for 80%, 90% then 100% of required output?

33 66 and 100% would show which motors do well at lower power levels.

It might be interesting to test for efficiency at lower levels - though it's not a requirement.

I guess it depends how much time Todd is prepared to spend.....

 

[Thud]

I like the asending scale aproach.

I also think 80,90,100% would be good for the challange, given that the power requirments to make these steps are exponential.
(seat of the pants feeling-nothing empirical to that)
Measuring wattage(or amperage x time) is more a measure of efficancys, nessisary for total compairisons.
I see no benifit in setting preliminary restraints.
any thoughts there?
My only issue is staying within the limits of the test equipment.

edit: regarding my time, I will clamp the motors to the required touque out puts & see if we need to continue. once we have 2 motors competeing for a kudo, we will get into the finite analisis of "the most tourqe per kg" & then the efficancys of said motors at = input levels.
I am not going to worry about it too much. There is a zero backlog for testing yet
Looks like e-noobs motor may be here befor the dyno is actualy finished.
oops, I ment to say Dynomometer (ahh so satisfying)

 

[Miles]

My only issue is staying within the limits of the test equipment.

The dyno would need to be able to handle up to 12Nm.

It's not necessary to test for maximum torque output.

 

[jscoot]

What do you think about the idea of a competition for the diy motor builders on ES?

What would be a suitable goal to work towards?

4Nm of continuous rated torque per kg of motor weight - passive cooling only - for a motor weighing under 3 kg?

........................................................................................................................................................

Edit

Goal:

- Over 4Nm continuous torque per kg of motor weight.

Rules:

- Less than 3kg in weight.

- No energy input other than that to the motor itself.

- Capable of practical use on an electric bike.

If efficiency is not involved you can buy off the shelf motors to meet your goal. I now wonder what the great accomplishment would be for all the money spent ? Would rewinding this motor be in the Spirit of the rules ? It would make a nice ebike motor if rewound and vented if you didnt mind the low efficiency. This motor under 2kg is rated at 13.9 nm as it is.

 

[Miles]

Randy,

Please could you explain how you can achieve the specified continuous torque output without involving efficiency...?

For goodness sake.......... 1970 oz-in is the stall torque for the S28-150

Feel free to enter one, though

 

[jscoot]

Randy,

Please could you explain how you can achieve the specified continuous torque output without involving efficiency...?

For goodness sake.......... 1970 oz-in is the stall torque for the S28-150

Feel free to enter one, though

What I ment is highest eficiency FIGURES on the dyno tests not being the goal.

 

[Miles]

Why does the efficiency of a motor matter?

 

[Thud]

Jscoot,
Again, I am totaly baffeled to your point of discusion. This thread is: ES DIY motor challange.

There is no debate regarding economics, virtues,efficancys, politics, color, or any other tangent......just a few guys who want to build a motor to see if it can be done, to some parameters set origianly by Miles. ( with very few adjustment)

I thought we were now defining the actual testing procedure for the DIY guys to see whats what.

I apreciate your concern regarding the above issues, they are all viable points of conversation.

Just not in this thread.

I am not the forum police by any measure. You just come off as argumentitive at times.
I hope I am mis-interpreting these inputs
Jscoot wrote:

If efficiency is not involved you can buy off the shelf motors to meet your goal. (not DIY) I now wonder what the great accomplishment would be for all the money spent ? ( who is spending vast amounts of money? I suspect there are larger budgets than mine but who cares?) Would rewinding this motor be in the Spirit of the rules ? (I will say yes, not because I think re-winding a comercial high powerd motor is a DIY project, I just want to see as many participants as we can gather) It would make a nice ebike motor if rewound and vented if you didnt mind the low efficiency. This motor under 2kg is rated at 13.9 nm as it is.

whoa! Miles posted as i am spell chacking!!! FOILED AGAIN!

Miles wrote:

Why does the efficiency of a motor matter?

I will add: to the parameters of this challenge.

Back on topic:
Motor testing procedure summery:
senario 1 ("kill em all" mentality)
1) run motor at no load-establish base amp draw & rpm.
2) crush it on the dyno to see if it will meet the base parameter of Nm/weight
3) see if it survives 30 min. at the challenge parameters.
4) extingish all fires & ventilate the room

senario 2 ("scientific" mentality)
1) run motor at no load-establish base amp draw & rpm.
2) load motor to 80% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp
3) load motor to 90% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp (assuming it survived #2)
4) load motor to 100% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp(assuming it survived #3)

senario 3 ("everybodys in love" mentality) (AKA T-Ball/jr soccer that doesn't keep score)
1) run motor at no load-establish base amp draw & rpm.
2) load the motor some how & compliment its craftsmanship.
3) carfully repackage the motor & ship it back with a big "Participant" kudo.

once we have 2 motors that meet the t/w requirments we will compair efficancys....till we have 2 spinning motors I am not fretting any details of competition....er challange........
..........Dynomometer!

 

[Miles]

Yes, that's fine.

Please start a thread on the dynomomometer

 

[Thud]

Is that a vote for one of the senario's? :lol:
or all of them in that sequence?
(I'll wager you enjoy saying "Dynomometer" as much as I do!)

 

[TylerDurden]

'Jscoot' (Randy Draper) has been banned on this board twice previously, as 'ebikemaui' and 'bobdiode'; for precisely the same disruptive activity. Clearly, he can not take a hint.

 

[Miles]

Is that a vote for one of the senario's? :lol:
or all of them in that sequence?

I vote for scenario 2 but, subject to participant waiver, to carry on increasing the load by 5% increments, after the target figure has been met, until the motor smokes.......

 

[bigmoose]

Scenario 1 for screening. ...perhaps with thermal monitoring/cutoff.

Scenario 2 with serial number #2 of the winner before it goes into production!

... perhaps consider that submitted motors should come with a controller from the inventor? Also I like your standardization of test voltages.

 

[Miles]

... perhaps consider that submitted motors should come with a controller from the inventor?

There's a lot to be said for this...

How about using a bench supply instead of batteries? It would allow more flexibility with regard to voltages.

 

[enoob]

jscoot this is actually a thank you.

I thank you for reminding me why i like this forum so much . You remind me to appreciate the the people who know how to contribute in a constructive manner. Although some of your points have a certain validity your delivery makes those around you work to maintain a constructive flow .

And to those spending their time to further develop the conditions under which this challenge is administrated i again thank you .

I am under no allusion that my entry will be a high water mark so to speak and i actually hope to see video of it smoking a silent death thereby establishing its peak.

I am not concerned about the overall efficiency of my entry , not the challenge as i recall. and unless im wrong efficiency will come with improvement once the design proves itself on the bench and the bike.

Now im gonna head up to whistler today and demand that they alter the conditions of the downhill ski race coming up . i wish to compete and my fat lazy "rear end" is just to old to do the circuit at full length . you think they will shorten it up a tad for me?

 

[Thud]

There is some value added input,
Thanks guys,
Miles, I will let you be the ultimate vote on the final test parameters, it is your challange after all.

I will nutshell it for those skimming the chaff in this thread:
(my 1st choice for voltage is 36-It is just so attainable by the masses)

senario 2 ("scientific" mentality)
1) run motor at no load-establish base amp draw & rpm.
2) load motor to 80% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp
3) load motor to 90% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp (assuming it survived #2)
4) load motor to 100% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp(assuming it survived #3)

After all that data is assembled a winner will obviouse (although specultive, as end users will have variying criteria as to what represents a winning combination) :x
MIles wrote:

to carry on increasing the load by 5% increments, after the target figure has been met, until the motor smokes.......

I love this idea....so you tube a'licious!

Bigmoosewrote:

... perhaps consider that submitted motors should come with a controller from the inventor?

I like the idea but am not totaly comfortable being responceable for electronical (new word) devices under these extream conditions. I don't really plan on running my controllers past the manfactures recomendations. A power supply would be ideal, again not on my agenda.
I am not opposed to shipping the Dynomometer(there! got it in another post!) to someone with better testing equipment on the ellectrical side. (I am the most dangerous guy on this forum when it comes to electrical applications! :lol: )
If a senario presents the need for a tie-breaking run off,
I propose a duel at dawn. pistols at 20 paces
(its the only gentlmanly way to settle this)

 

[John in CR]

For ages I've been wanting to build a wheel motor, so the total weight would include the original swing arm to which the stator is attached along with the original weight of the wheel. It's not realistic to bring the entire assembly in under the 3kg limit, but I think it's very possible for a high torque wheel motor to come in within the rules if only the incremental weight is considered the motor weight.

 

[enoob]

For ages I've been wanting to build a wheel motor, so the total weight would include the original swing arm to which the stator is attached along with the original weight of the wheel. It's not realistic to bring the entire assembly in under the 3kg limit, but I think it's very possible for a high torque wheel motor to come in within the rules if only the incremental weight is considered the motor weight.

im assuming the motor itself would be something that one could incorporate into a build on a bike with similar geometry ? if so i would love to see it in the challenge.

If the assembly as you mention is more for ease of setting up for testing ie: testers wont have to buy a suitable bike and build a wheel, then i think its more than reasonable.

 

[jscoot]

There is some value added input,
Thanks guys,
Miles, I will let you be the ultimate vote on the final test parameters, it is your challange after all.

I will nutshell it for those skimming the chaff in this thread:
(my 1st choice for voltage is 36-It is just so attainable by the masses)

senario 2 ("scientific" mentality)
1) run motor at no load-establish base amp draw & rpm.
2) load motor to 80% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp
3) load motor to 90% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp (assuming it survived #2)
4) load motor to 100% of chalenge for 30 min & measure the dynamics rpm/amp draw/temp(assuming it survived #3)

After all that data is assembled a winner will obviouse (although specultive, as end users will have variying criteria as to what represents a winning combination) :x
MIles wrote:

to carry on increasing the load by 5% increments, after the target figure has been met, until the motor smokes.......

I love this idea....so you tube a'licious!

Bigmoosewrote:

... perhaps consider that submitted motors should come with a controller from the inventor?

I like the idea but am not totaly comfortable being responceable for electronical (new word) devices under these extream conditions. I don't really plan on running my controllers past the manfactures recomendations. A power supply would be ideal, again not on my agenda.
I am not opposed to shipping the Dynomometer(there! got it in another post!) to someone with better testing equipment on the ellectrical side. (I am the most dangerous guy on this forum when it comes to electrical applications! :lol: )
If a senario presents the need for a tie-breaking run off,
I propose a duel at dawn. pistols at 20 paces
(its the only gentlmanly way to settle this)

I would think that the motor would be supplied with the builders controller, throttle and fuse with the power leads marked in red and black.?
Also for running some motors for 30 minutes in still air I would like to run a fan on the shaft and run it at 66 volts.

 

[jscoot]

For ages I've been wanting to build a wheel motor, so the total weight would include the original swing arm to which the stator is attached along with the original weight of the wheel. It's not realistic to bring the entire assembly in under the 3kg limit, but I think it's very possible for a high torque wheel motor to come in within the rules if only the incremental weight is considered the motor weight.

im assuming the motor itself would be something that one could incorporate into a build on a bike with similar geometry ? if so i would love to see it in the challenge.

If the assembly as you mention is more for ease of setting up for testing ie: testers wont have to buy a suitable bike and build a wheel, then i think its more than reasonable.

to old to do the circuit at full length . you think they will shorten it up a tad for me?