Razor E150 motor as alternator

[Rat]

So the title say enough about what I'm thinking about trying to do.
The motor in question is 24vDC but not brushless.

I've wound a piece of string to "pull start" the motor to see what type of unchecked voltage I can get off of it.

If I snap my fingers with the shaft between them I can get around 2v, yanking the "pull start" I got 36v but in any attempt to pull it harder and faster didn't yield any higher voltage.

The question is what would the max RPM be before I risc seizing the bearings or smoking the windings?
It does have a removable end for easy internal servicing.

I am looking at the possibility so that I may eventually run a billet flywheel assuming I can get one with a ring gear or mount a ring gear to one because under no circumstances will I not run without an electric start or the federal standard for road lights.

 

[Functional Artist]

Hey RLS UG
It should work, the really old cars had generators
...but, there must be a reason why no one uses them anymore
...& everyone went to alternators

Maybe Google it

 

[Rat]

Hey RLS UG
It should work, the really old cars had generators
...but, there must be a reason why no one uses them anymore
...& everyone went to alternators

EMF noise and RF interference are very large reasons why they stopped doing that, aside from advancements in technology opening new doors of possibility.

Maybe Google it

I did. I am NOT a f★cking invalid, I just can't find what info I am looking for in terms of max RPM.

I know it "will work" but I'm also aware that I would probably be wise to configure it with some sort of reduction since Im looking at 4500-5500 rpm range of the engine it would be hooked to (currently has a really tiny gear on a LH threaded shaft)
Im thinking a belt drive so that I can easily disengage it from the engine in the likely event I do lock it up or blow the brushes from too high of spindle speed.
I opened it up to check the internals and I'm not convinced I'll burn up the windings but thankfully the bearings are easily removed for replacement and the brushes look to be an easily obtained size.

 

[Functional Artist]

Your NOT gonna get many replies, with those kinda Asanine responses

I meant...maybe Google the motor specs (which will include the RPM specifications) for a Razor E150 (DUH!) ...nevermind...

 

[Rat]

Your NOT gonna get many replies, with those kinda Asanine responses

I meant...maybe Google the motor specs (which will include the RPM specifications) for a Razor E150 (DUH!) ...nevermind...

Again I did that...
And looked on ebay at the replacement motors on the random off chance I could get the specs that way.

Also the peak rpm it can make on a 24v power supply with a 150w rating is not the same as max rpm OR the overall speed rating before failure. I do know they can be over volted to 36v without frying the windings... they sell kits with replacement controller boxes and replacement full rang throttle controls for that.

It's like razor wants to act like it's some classified proprietary secret or something.

I was able to find the unloaded rpm, which is 3400 rpm, loaded is 2400... but this still doesn't quite tell me what I want to know.

I guess it's worth burning up a free motor to find out then

 

[Master Hack]

Hard to say max rpm, mechanically. The bearings in alot of ‘ lectric motors are ”rated for 20k rpm and run around 3600. Mechanical parts are good for what ya can throw at en. Electrically, probably has more to do with load than speed.
figger out what rpm yeilds max volts add a few hunderd and call that max.
then regulate it.

 

[Rat]

Hard to say max rpm, mechanically. The bearings in alot of ‘ lectric motors are ”rated for 20k rpm and run around 3600. Mechanical parts are good for what ya can throw at en. Electrically, probably has more to do with load than speed.
figger out what rpm yeilds max volts add a few hunderd and call that max.
then regulate it.

Well considering I got 36v at most likely under 1k with my pull string stunt it seems to me I could set it up 1:1 and be fine since the Tav2 doesn't let my 208 go over 5k for very long before it pulls the back rpm down to around 3800/4k so it should be fine with a 2" pulley and ran right off the shaft spacers behind the driver clutch assuming I've got the clearance.

IN THEORY I can swap one of my spacers for a pair of fender washers to act as pulley sheaves on either end of of the factory spacer (right around 1/4" not long enough with the 9t swap I did)

 

[Rat]

Ok so different same motor on hand (bigger)
BRUSHED
24vDC
2750 RPM
13.4A
250W

Help? This level of electrical is a smidge beyond my scope... In other words I know it can be done but I will most likely fry a few things before I nail it down and I'd rather not.

 

[Master Hack]

I love the smell of fried electric parts in morning! Smells like fried electric electric parts.

the theory is great, but for design considerations you need someone smarter than me!

l can give ya a couple of atta boy“s tho…

 

[Rat]

I love the smell of fried electric parts in morning! Smells like fried electric electric parts.

the theory is great, but for design considerations you need someone smarter than me!

l can give ya a couple of atta boy“s tho…

I do know that 36v overvolt kits exsist for them.

I don't have a way to clock the rpm, but I did get a 36v output reading at approximately 1000rpm given the "pull start" method I used to spin it on the bench, but I feel like I probably didn't even spin it that fast.