Author Topic: Magneto Earthing Brush and Contact Surface  (Read 3086 times)

Offline RichardL

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Re: Magneto Earthing Brush and Contact Surface
« Reply #15 on: 09.09. 2020 12:13 »
Juslian,

Thanks, so much. Very enlightening to know the sit inside the wall thickness.

Richard L.

I may have jumped the gun in considering the equivalence of the pins on Julian's steel earthing cylinder with those on the brass version. In the latter, the pins Groily mentioned appear to be the small ones holding a brass cap on the brass contact cylinder (where my left index finger is pointing). Those pins appear to be about 0.050" from the surface, still OK, I believe, but something to watch.

Richard L.


Offline RichardL

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Re: Magneto Earthing Brush and Contact Surface
« Reply #16 on: 18.10. 2020 21:47 »
OK,  finally able to report back on this. Since turning seemed the best answer, as validated by Mr. G. ("Mr. Bill"? Oh, no!), I set about trying to figure out the best way to do it with limited skill and machinery. First problem was protecting the drive-end threads while chucked-up in my drill press (aka, poor man's lathe). After a bunch of head scratching and searching my garage, stumbled on my drawer full of electrolytic capacitors. Aha! Aluminum body of the cap would serve as a sacrificial sleeve. (When finished, there was a very minor impression on the peaks of the thread due to the chuck jaws, but of no concern to me.) Next, how to stabilize the points end without the benefit of a live center. Solution, small 1/4"-drive socket attached to a breaker bar in a vise clamped to the drill-press table. I was a bit surprised how stable this turned out (and turned).

With the "lathe" set up, it was a straightforward process of using ever-finer files as the cutting tools. Actually, worked my way up through four coursenesses before settling on the main meat remover. Turned out there was no real threat of breaking through to the dowel pins. I'd show the photo, but it's basically the same as the one I previously posted.

The first photo shows the sacrificial thread protector before trimming to length. Second photo shows the "dead" center in the vise. Third photo shows the rig ready to spin. Fourth photo shows the main cutting file and the dimple after the test attack. Fifth photo shows the result after a final run of 600-grit paper. Sixth photo shows a small amount of chamfering at the points end due to the dead center. No problem fitting the brass points plate. (In retrospect, was that chamfer there before I started?)

I have a video of the armature spinning, which I might post to YouTube. If interested, watch this space.

Apologies if I'm irrationally satisfied with myself for getting this sucessfully done.


Richard L.

Online berger

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Re: Magneto Earthing Brush and Contact Surface
« Reply #17 on: 19.10. 2020 00:11 »
don't worry about the points end Richard you got a result by using the tools available , I say gooood lad *beer*

Offline RichardL

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Re: Magneto Earthing Brush and Contact Surface
« Reply #18 on: 19.10. 2020 01:50 »
Thanks, Bergs.

Offline RichardL

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Re: Magneto Earthing Brush and Contact Surface
« Reply #19 on: 19.10. 2020 02:48 »
Just re-read most of this thread and realize that, basically, everyone recommended turning, not just G. Everyone, you were right.

Richard L.

Online groily

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Re: Magneto Earthing Brush and Contact Surface
« Reply #20 on: 19.10. 2020 08:20 »
Really neat job Richard! Resourceful as ever.
Why not invest just a few Budweiser and Rye vouchers in getting hold of a small lathe though - you'd love it, especially now that the DIY & Teach Yourself shop you were using has closed down?
Life has many milestones, and for me Getting a Lathe was right up there. Of course, I'd like a bigger better one, and I'd like all sorts of extra refinements, but a basic one (as long as it has screw-cutting and backgear) covers 90% of anything we ever need. Over there, you guys can pick up elderly but decent South Bends and similar for sensible $$$, and the investment is repaid very quickly. Not to mention the huge saving in time when it comes to not needing to order up and wait for things one can make for oneself - often out of better materials as well.
Occupational Therapy for the middle-aged, that's what they are! Much better than basket-weaving  . . .
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Re: Magneto Earthing Brush and Contact Surface
« Reply #21 on: 19.10. 2020 08:34 »
Totaly agree Groily.  Richard you are in a country that simply oozes machine tools of every kind. Ive had a Boxford AUD ( South Bend 9A clone ) for 30 years & wish I'd got it 15 years earlier.

Online Black Sheep

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Re: Magneto Earthing Brush and Contact Surface
« Reply #22 on: 19.10. 2020 19:18 »
Have been doing things to magnetos... My brass contacts were missing the little pip that the retaining arm locates on.These things as we know are like hen's teeth and the after market ones don't fit. In a moment of inspiration, I snipped the end off a plastic syringe and tried that. Not perfect but it seems to do the trick. Sorted, hopefully.     
2 twins, 2 singles, lots of sheep

Offline muskrat

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Re: Magneto Earthing Brush and Contact Surface
« Reply #23 on: 19.10. 2020 20:26 »
G'day Richard.
Well done mate. Necessity is the mother of invention.
I have done similar many times, but yesterday I picked up my new lathe. *woo*
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Offline chaterlea25

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Re: Magneto Earthing Brush and Contact Surface
« Reply #24 on: 19.10. 2020 20:51 »
Hi All,
Well done Richard, reminds me of times past when I was latheless  *eek*
For the last number of years I have had a second lathe, but a couple of months ago a gear failed in the apron gearbox of the Colchester, Of course when I dismantled the gearbox a myriad of other issues came to light
I now have all the bits to rebuild it just not finding the time. I have to plan the sequences of work a lot more carefully when down to one machine
I really miss not being able to do a quick job when there's a half done piece in the running lathes chuck
Am I just "lathe selfish" *conf2* *conf2*

John

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1963 RGS (ongoing)

Offline RDfella

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Re: Magneto Earthing Brush and Contact Surface
« Reply #25 on: 19.10. 2020 21:30 »
Never been a fan of Colchester. OK when new, but seemed to deteriorate fairly quickly. Now, if it was DS&G or Holbrook ......
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Offline chaterlea25

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Re: Magneto Earthing Brush and Contact Surface
« Reply #26 on: 19.10. 2020 23:50 »
Hi RD,
Yes they be would be nice to have one but the weight of either would test my workshop foundations  *eek*

John

1961 Super Rocket
1963 RGS (ongoing)

Offline Tomcat

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Re: Magneto Earthing Brush and Contact Surface
« Reply #27 on: 20.10. 2020 07:42 »
I bought a small chinese lathe 15 years ago after wanting one forever and can't believe how handy they are. First job was making a mandrel to press in gearbox bushes and since then I enjoy making special tools and parts.
1959 Super Rocket, 1990 NX650

Offline RichardL

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Re: Magneto Earthing Brush and Contact Surface
« Reply #28 on: 20.10. 2020 12:40 »
Having paid the appropriate import license fee for the use of the word, I'm quite chuffed that folks I respect appreciate my hobbyist effort to overcome my shop shortcomings. Thank you.

Not sure in what price range you guys are seeing the abundance of used lathes in the US, but, on eBay, the pickings are not that great. Yes, there is the occasional bargain, but the seller has moved it 2000 miles away just to thwart me. Otherwise, it'll be a giant, greasy old Leblond or Warner Swasey born during WWII and requiring me to buy a new house with twice the garage space in which it might sit. That cost might just overcome the bargain for the lathe.

Richard L.

Offline RDfella

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Re: Magneto Earthing Brush and Contact Surface
« Reply #29 on: 20.10. 2020 13:35 »
This one should do it (no, it's not mine) ....
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.