Open Source Electric Supercharger

[Ingen]

Originally Posted by neutron256

I'm curious what sources for motors everyone has found. Like many of us I've been looking at motors on HobbyKing.com, but haven't found much else.

I'm also curious if anyone else is activly working on the hardware at this point.

Digikey has some More than I'm linking, but the one I'm linking is the beefy one I found with a quick search. I have zero idea what the RPM requirement is for the compressor though

http://www.digikey.com/product-detai...002-ND/2466699

[Toma]

Originally Posted by Ingen

Digikey has some More than I'm linking, but the one I'm linking is the beefy one I found with a quick search. I have zero idea what the RPM requirement is for the compressor though

http://www.digikey.com/product-detai...002-ND/2466699

Depends on the size/design of the compressor. 30,000 to 60,000 would get you in the ballpark

[neutron256]

Originally Posted by Ingen

Digikey has some More than I'm linking, but the one I'm linking is the beefy one I found with a quick search. I have zero idea what the RPM requirement is for the compressor though

http://www.digikey.com/product-detai...002-ND/2466699

We're probably looking at 35K minimum unless you use a really large compressor like ones used for some diesel engines. So very few motors are going to cut it. The one you linked to is not going to be up to the task. Digikey has a really nice paramater search, but their motors top out at 16364 RPM and that is a tiny little motor.

It's easy to find compressor maps online which will give you an idea of what sort of RPM you'll need for a given compressor. Keep in mind that we're only going to be shooting for the extreme low end of the map for any given compressor.

Another issue will be mating the motor shaft to the compressor wheel so shaft diameter needs to be a consideration. I think TD05/06 wheels are 6.5mm shaft diameter.

[mid_life_crisis]

Originally Posted by neutron256

Another issue will be mating the motor shaft to the compressor wheel so shaft diameter needs to be a consideration. I think TD05/06 wheels are 6.5mm shaft diameter.

I was wondering about this myself. Also curious about sealing the assembly properly. There is normally a center section with bearings that separates the driving from the driven side. Doing it this way there is no seal behind the compressor wheel so that will have to be figured out.
Another problem is the environment. You need a motor capable of working/surviving in the environment under the hood of a car. Temperature extremes, moisture, I question whether an R/C motor would be up to the task. Even if it has the power, they are used in pretty controlled conditions (you don't fly an expensive heli in the rain, do you?) so might not do well under a hood.

[neutron256]

Originally Posted by mid_life_crisis

I was wondering about this myself. Also curious about sealing the assembly properly. There is normally a center section with bearings that separates the driving from the driven side. Doing it this way there is no seal behind the compressor wheel so that will have to be figured out.
Another problem is the environment. You need a motor capable of working/surviving in the environment under the hood of a car. Temperature extremes, moisture, I question whether an R/C motor would be up to the task. Even if it has the power, they are used in pretty controlled conditions (you don't fly an expensive heli in the rain, do you?) so might not do well under a hood.

All thoughts I've had as well. I'm not that worried about sealing the compressor. I think this will mostly be taken care of by making sure there are tight tollerences and possibably adding a bearing on the shaft where it passes through the backplate.

Although our engine bays are pretty good at keeping weather out it is still a concern. I probably won't be leaving this installed in the winter here in Minnesota.

Another possibility is to go with sealed water cooled RC motors which would fix most or all of these problems. It does add complexity to the system though which I don't like.

[mid_life_crisis]

Originally Posted by neutron256

All thoughts I've had as well. I'm not that worried about sealing the compressor. I think this will mostly be taken care of by making sure there are tight tollerences and possibly adding a bearing on the shaft where it passes through the backplate.

I considered the bearing idea and then realized that this thing will be spinning at 35,000 or possibly even more rpm. What bearing type are you thinking of? The possibility exists that the end of the motor could be sealed to the back of the mounting plate, assuming that end of the motor is sealed. Problem solved. If that end of the motor is sealed by design.

Another possibility is to go with sealed water cooled RC motors which would fix most or all of these problems. It does add complexity to the system though which I don't like.

I agree. Water cooled electric motors would be completely against best KISS principles.

[neutron256]

Originally Posted by mid_life_crisis

I considered the bearing idea and then realized that this thing will be spinning at 35,000 or possibly even more rpm. What bearing type are you thinking of? The possibility exists that the end of the motor could be sealed to the back of the mounting plate, assuming that end of the motor is sealed. Problem solved. If that end of the motor is sealed by design.

You can get sealed ABEC-1's rated for over 60K RPM for around $20


I agree. Water cooled electric motors would be completely against best KISS principles.

I just took a serious look at water cooled motors oh hobbyking.com I think I may have my motor.

Kv: 3180rpm/v
Diameter: 36mm
Length: 60mm
Shaft diameter: 5mm
Max voltage: 18V
Max current: 94A
Idle current: 2.7A
Weight: 280g

Thats a max 57240 RPM! That would do very nicely.

[200hp/tonne]

Originally Posted by neutron256

Are you talking about driving the system directly off the alternator? Isn't that sort of missing the point? The idea, at least to me is to act more like a hybrid slowly charging the battery during normal driving and then draining the battery for a quick burst of power.

alternator - battery - motor
Isn't the slow charging during driving taken from the alternator and ultimately from the engine?
I just meant for the alternator to have a high capacity to charge the battery much faster (only Lead acid battery though) and have juice left over to drive the SC when need be.
Unless you have a braking regenerative system, there is no hybrid functionality, is there?

[solma]

Here some BL motor with, I think with higher power. Price wise, it seem good.

http://goldenmotorcz.en.made-in-chin...catalog-1.html

Looking more closely,max rpm might not be there.

[Toma]

Originally Posted by neutron256

I just took a serious look at water cooled motors oh hobbyking.com I think I may have my motor.

Kv: 3180rpm/v
Diameter: 36mm
Length: 60mm
Shaft diameter: 5mm
Max voltage: 18V
Max current: 94A
Idle current: 2.7A
Weight: 280g

Thats a max 57240 RPM! That would do very nicely.

That's just a hair over 2 hp. Not enough.

[neutron256]

Originally Posted by 200hp/tonne

alternator - battery - motor
Isn't the slow charging during driving taken from the alternator and ultimately from the engine?
I just meant for the alternator to have a high capacity to charge the battery much faster (only Lead acid battery though) and have juice left over to drive the SC when need be.
Unless you have a braking regenerative system, there is no hybrid functionality, is there?

I think I see what you're getting at. And I'm sure having a larger alternator wouldn't hurt, but keep in mind SLA's are limited on how fast they can charge (too fast = kaboom) and if you're ever driving the compressor directly off the alternator you would probably be a net loss in overall power due to the extra load the alternator would create.

When I use the term hybrid I don't mean in the Prius sense. I'm talking in more general terms of storing energy up in the battery during a low demand time, and then using it to get an extra boost of power at a high demand time. No efficency gain, just changing how/when the power is used.

[neutron256]

Originally Posted by Toma

That's just a hair over 2 hp. Not enough.

How are you calculating the required power?

[solma]

It a paper on what you want to do, atleast in the supercharger.

http://www.movingmagnet.com/medias/d.../m12-12-16.pdf

[ptuning]

Originally Posted by neutron256

How are you calculating the required power?

18v*94a = 1,692 watts/746 watts = 2.27 hp