Easiest to convert alternators?

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hallkbrdz   100 W

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Easiest to convert alternators?

Post by hallkbrdz » May 29 2021 10:15am

A video sparked my interest in converting an alternator into a PM 3-phase motor. My son-in-law had a Ford Freestar that I obtained the alternator from, but that Motorcraft part has been a PITA to disassemble. Separating the cases was near impossible, and I resorted to using the gear puller on the wide case, pulling the stator wires from the diode board in the process (sort of nice!). While the one in the video popped off easy with a screwdriver, I'm still fighting to get the rotor conduction ring off this one, and have ordered a small two-arm puller just for that.

Given that - what fairly modern alternators that I could find in fair numbers at say, LKQ, that are good candidates for easy disassembly and conversion to 1.5ish kW motors.

Cheers

monette999   1 W

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Re: Easiest to convert alternators?

Post by monette999 » May 29 2021 10:45am

I am using a Valeo 180A,
but a PM Rotor is an expensive modifications. Is it worth to spend that money.

Sensor System is mandator for a project that request high torque @ start.
Let me participate how you do it.

Have fun.
BobImageImageImage

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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » May 29 2021 11:08am

Nice.

Yes, I think a PM rotor is well worth it. The magnet is only about $40 plus shipping, and it saves the weight and complexity of an additional battery. This will be for karting (kid kart), so weight is important. I'll need to build at least 3 so they can race competitively in their own class.

monette999   1 W

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Re: Easiest to convert alternators?

Post by monette999 » May 29 2021 2:10pm

What magnet did you choose?

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j bjork   100 kW

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Re: Easiest to convert alternators?

Post by j bjork » May 29 2021 2:17pm

I would also be interested to know what magnet you found.

I looked in my thread, but it dosent seem like I mentioned what magnets I found or what they cost.
But I think it was at least double of the one you found :wink:

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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » May 29 2021 4:23pm

It's all apart now - except for the core. This nut on the shaft is the last thing in the way, and it won't budge with a drift. Such fun. :D
IMG_20210529_160456 (Medium).jpg
IMG_20210529_160456 (Medium).jpg (230.8 KiB) Viewed 381 times
The magnet I plan on getting is this one - although I will need to measure the shaft to be sure before ordering. This is the size the video I referenced used.

https://www.magnet4sale.com/n45-3od-x-3 ... ng-magnet/

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spinningmagnets   100 GW

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Re: Easiest to convert alternators?

Post by spinningmagnets » May 29 2021 6:00pm

There's a chance it may be left-handed threads. I don't know...

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fechter   100 GW

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Re: Easiest to convert alternators?

Post by fechter » May 30 2021 12:14am

hallkbrdz wrote:
May 29 2021 4:23pm
It's all apart now - except for the core. This nut on the shaft is the last thing in the way, and it won't budge with a drift. Such fun. :D

The magnet I plan on getting is this one - although I will need to measure the shaft to be sure before ordering. This is the size the video I referenced used.

https://www.magnet4sale.com/n45-3od-x-3 ... ng-magnet/
If the shaft is magnetic, it will shunt a lot of the flux away from the teeth. You may need to make a new shaft from something non-magnetic.
"One test is worth a thousand opinions"

monette999   1 W

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Re: Easiest to convert alternators?

Post by monette999 » May 30 2021 1:08am


[/quote]
If the shaft is magnetic, it will shunt a lot of the flux away from the teeth. You may need to make a new shaft from something non-magnetic.[/quote]

Hello
Interessant

Do you have evidence for this statement!

I think the magnet can be chosen after you took the clawpole Eddy Current Rotor apart.

This is still an expensive magnet.
And you need three of them for your family.
IF you are spending $55 for the magnet (shipped) and $25 for an used alternator and then $15 for a sensor system and you want 1.5kw,
Are you sure you are on the wright path. The PM Rotor is great but you have everything on the Rotor to create a nice magnet field.

I stepped away from that approach as long nobody is prooving that I can use cheap FE Magnet to make an Rotor.

Greeting
Bob

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fechter   100 GW

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Re: Easiest to convert alternators?

Post by fechter » May 31 2021 11:12am

monette999 wrote:
May 30 2021 1:08am
If the shaft is magnetic, it will shunt a lot of the flux away from the teeth. You may need to make a new shaft from something non-magnetic.[/quote]

Hello
Interessant

Do you have evidence for this statement!
[/quote]

Many years ago I built a PM rotor to use as a hydroelectric generator. I was using a large doughnut shaped ferrite magnet from a loudspeaker. With the original steel shaft, it was useless. Once I replaced the shaft with one made from stainless steel, it worked quite well. The flux will follow the path of least resistance. In the original alternator, there is an energized coil around the shaft, so the steel shaft helps in that case, but with a permanent magnet, the shaft "short circuits" the flux.
"One test is worth a thousand opinions"

monette999   1 W

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Re: Easiest to convert alternators?

Post by monette999 » May 31 2021 12:01pm

Hi Fechter but in this post the starter want to use an axial magnetized round magnet, and then an non magnetic shaft will not work well.

So we have to stay of the subject.

Greeting
Bob

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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » May 31 2021 6:33pm

spinningmagnets wrote:
May 29 2021 6:00pm
There's a chance it may be left-handed threads. I don't know...
I tried both directions, but it was my mistake. While the other end looks (and felt) like it is welded, it is not. It was either going to break the gear puller of come apart, but with some hammering with the air tool on full reverse at 120 PSI, it finally let go. :)
IMG_20210531_185501 (Medium).jpg
IMG_20210531_185501 (Medium).jpg (258.12 KiB) Viewed 267 times
I'll need to strip them down, get it milled, add the magnet, and add hall sensors. But it's a proven to work design so the only question is will it be a good fit for purpose compared to iffy Chinese motors in the power range. At least with this I know the windings are heavy enough to take abuse.
fechter wrote:
May 30 2021 12:14am
If the shaft is magnetic, it will shunt a lot of the flux away from the teeth. You may need to make a new shaft from something non-magnetic.
As Bob pointed out, this is not an issue due to the way the teeth influence the flux.

Thanks,
Bryan

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Re: Easiest to convert alternators?

Post by monette999 » Jun 10 2021 8:34am

Show us your magnet and Sensor System please

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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » Jun 11 2021 9:50am

The magnet portion is relatively straight forward. I just need to get some clamps and a plastic or wood sleeve to lower the magnet onto one of the rotors.

The hall sensors... not so much. I'll upload photos later today showing why, but in a nutshell - a 4+mm wide sensor doesn't fit in a < 3mm wide slot. 6G slots are closer than 3G slots.

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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » Jun 11 2021 5:24pm

As pictured on the bottom, the Ford 6G alternator I have slots are narrower (< 3mm) than the 3G slots (4+ mm) shown on top, so the hall sensors will not fit between the iron.

A suggestion was made to use a small grinding tool to remove some of the iron in the center and then epoxy the sensor there. So far that seems the most sensible solution.
Motocraft 3G vs 6G.jpg
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hallkbrdz   100 W

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Re: Easiest to convert alternators?

Post by hallkbrdz » Jun 11 2021 5:30pm

Oh, and the milled down rotor. Now to gently place a magnet onto it...
IMG_20210609_161732_617.jpg
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enrengineering   10 mW

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Re: Easiest to convert alternators?

Post by enrengineering » Jun 13 2021 2:16pm

That's definetely nice to see!
If you need any help feel free to ask, I've successfully converted to alternators into motors. Recently I fixed the first I've ever converted (the sensor setup was messed) and it's installed on a go kart (here is the video: https://youtu.be/93eG9ZT8RY8)
Also I made another one with a VESC, I took all the rotor and axle dimensions, machined a custom shaft and a 3d printed PETG rotor to hold 12 10x10x40mm magnets, and runs like a charm (full conversion video: https://youtu.be/IsX3zHV-hZs)
Regards.
Henry.

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