Re: Loose alternator rotor centre.

[Mike Farmer]

 

Thanks for the replies.

So I am in a nothing to lose situ, So I think shall strip mine into "scrap" parts and check.

Before I go there would someone answer following, Working outward from the Hex bar centre. Are the "square" bits fixed in any way..
Continuing outward how are the magnetic shoes attached. Are they simply held in place by the cover or are they fixed in place then the cover mounted around them.

What are the magnetic shoes made of.

Ultimately if I can fix the various bits in place do I really need the cover. I cant see why I should.

In the end it may be an exercise in futility, but I guess as stated nothing to lose.

Mike

[Mike Farmer]

 

I have decided to give the "strip and weld" idea a go. Lots of things that I dont know about this lump of electrics. Wont be just yet but I'll keep you all up to speed. Boring bit by boring bit. A point comes immediately to mind. I doubt my efforts will be 100% balanced. What guesses about imbalance on such a short moment. I would have thought negligable---however.

Mike

[Bess]

Hi Mike,
            I considered welding the components, but after researching magnet welding changed my mind, its worth a quick google.

Here's where I bought my new rotor: https://www.feked.com/alternator-rotor-magnet-genuine-lucas-rm20-rotor-lu-54202299.html

Best wishes...

[Mike Farmer]

 

Hi Bess. Thanks for that.

I agree that it will be "a challenge". I have been giving this more than its fair share of thought and shall experiment with a different idea first. If you wish to get rid of your old one I would be interested cos I dont wish to remove mine at the moment. I'm more interested in keping it all in one piece to get the registration done.

I am thinking more in the Silver Solder route. Yes I saw that one at FEKED.

Mike

[Bess]

Hi Mike,
            You are quite welcome to a rotor, they are nearly 1kg in weight. Do you want me to parcel it up and send it?

Best wishes...

[Mike Farmer]

 

Hi Bess.

Yes please. Let me know postage and I'll send it to you.

Question are they solid Zinc other than the obvious innards.

Mike

[Bess]

Hi Mike,
            They are zinc wrapped, you can take your pick.

Best wishes...

[Mike Farmer]

 

Hi Bess.

Thanks again. Either is good so I'll take the lighter one if thats OK by you. I'll PM my address

Mike

[Bess]

Hi Mike,
            Its in the post £3.49, can you put the money in an air ambulance charity box?

Regards...

[Mike Farmer]

 

Hi Bess.

Thanks again. Yes to the Air Ambulance. Easy for me a friend is a fund raiser for them

Mike

[Mike Farmer]

 

Hi Bess.

The rotor was delivered this morning. Thanks.

I've done a bit of mejurin and the loose centre boss does not run true at 90^ to the perifery but it's only 0015"at most, so I guess thats wear. Impossible to tell how many times it has "shuttled" to and fro.. Anyway thats just a comment.

My thoughts are this can be done more simply than welding so I have another idea I'll try first.

I'll keep you up to speed here.

Thanks agen

Mike

[Bess]

Hi Mike,
            Good to hear its arrived safely. The history of that rotor is that I bought an engine bottom end and the owner thought the main bearing/bush had issues. On strip down it was the rotor keyway which was oversized. On reflection I wondered if the rotor wear was the cause of the keyway distortion.

Hope you find use for the rotor and maybe come away with a fix.

Best wishes...

[Mike Farmer]

 

Hi Gents.

As promised I would keep you psides with my efforts to tighten an A65 alternator. My first intention was to strip it and weld. That was a serious over kill.

The progress has really been mush better than expected and really relatively simple.

Hoefully my pics should be self explanatory but I shall enlarge on it should it be necessary.

I would point out that at this stage i Have only taken out any shuttle movement. It should cure any rotational move ment if not I have a couple of thoughts on that.

Mike

[Mike Farmer]

 

Hope this is a better image

Mike

[Mike Farmer]

 

Hi Again.

Julian sent me a knackered and stripped rotor to play with. Photo should be attached That I shall deal with in due course. I am attaching the pics.

Having also carried out various checks I have come up with( bear in mind I am only a user not in any field an expert) what I consider to be probabilities.

1. Assuming the front sprocket is fully "home" Once the Alternator centre boss is in place and torqued up it cannot possibly move laterally on the shaft.

2. Internally the alternator components are not fixed it place but only held by the magnets and the zinc??? casing.

3. Rotary movement between the magnets/casing is impossible-for the square magnets to
move on a square base it would need to increase the diameter of the whole item.

4. The only possible area of movement is the magnets sliding sideways, that is possible. They could also twist an extremely small amount probably no more than 001".

5. My thoughts are--Possibly the only part/s that is moving is the skirts of the casing.

6. Any rotational movement must be the boss on the shaft, likely as a result of inacurate broaching of the keyway.

7. Repairs? forget welding. If you use an electrical method you risk murdering the magnets. If you use a torch you risk melting the whole issue. So I would suggest the method of repair I have used in previous post is probably the only viable.

8. There are several ways of achieving that repair. At a later date I shall consider putting a plate on back and front and bolting it through with something like 3mm bolts/screws. Providing available clearance between alternator and front sprocket.

As you will see from pics the "shoes" are not solid but consist of about20 "blades" held by a cetral long rivet. The rotor that is already stripped I am going to attempt to weld/braze together and use without a casing(luck requested). Not for a while---busy.

So thats it in a nut shell. Phew Any Q's just ask

Mike