Author Topic: Dynamo question  (Read 1284 times)

Offline Housewiz

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Dynamo question
« on: 21.10. 2012 15:07 »
My '58 SR came with several extra dynamos and the motor is missing it's own dynamo.  I pulled the two right side covers off and found the dynamo chain is missing.  All the spare dynamos have gears on their ends, not sprockets.  My spare parts manual has photos of sprockets and a chain.  What motors do you guys think all those geared dynamos match up with?

I also pulled the magneto which is missing it's end cover and the small inspection(?) cover.  Saw mention on the Forum of a mag rebuild kit - would anyone have contact info or a web link for it?

I've decided there should be a new name coined for the mag part #67-1259 ("long nut").  Took me 5 minutes to return it home!!!!

Steve

Offline iansoady

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Re: Dynamo question
« Reply #1 on: 21.10. 2012 15:13 »
Geared dynamos are generally from magdynos but the guts are identical.
Ian.
1962 Golden Flash (arrived)
1955 Velo Viper/Venom (departed)
2004 Triumph Tiger 955i (staying)

Offline Housewiz

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Re: Dynamo question
« Reply #2 on: 21.10. 2012 15:25 »
Thanks Ian for the quick reply.

So if the guts are the same, would that mean the physical dimensions of the geared dynamo casing would bolt up to my engine case?  What the heck did the dynamo gear engage with - the large sprocket is a few inches away?  And also could the gear be removed from the shaft and a sprocket be installed and aligned with the large diameter sprocket?

The term magdynamo is new to me - was there a part that served both purposes? 

Thanks,

Steve

Online groily

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Re: Dynamo question
« Reply #3 on: 21.10. 2012 16:31 »
Not quite or necessarily identical unfortunately. Gear driven E3Ls are as likely to come off things like AMC, Norton twins etc as from magdynos (which are just mags with a dynamo piggy-backed on top of them and driven off the magneto's drive). The armature shaft on gear driven jobs is different as there are keyways for woodruff keys, a tapped and threaded hole for securing same with an axial setscrew, and no taper + external thread for the sprocket or pulley as used on As. Plus the bearing and oil seal retainer on the drive end varies quite a bit between marques and models. The bodies are interchangeable and the brushes end is pretty much universal subject to variations in end-cover used, but the spindles and drive end arrangements do vary, to the point of non-interchangeability. Beesa-type shafts are longer too - which is why you have the visible non-connect you mention steve. It's a pain  . . .
Bill

Offline wilko

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Re: Dynamo question
« Reply #4 on: 21.10. 2012 22:24 »
A10 dynamos seem to be quite common on ebay. It must have a tapered shaft.

Offline duTch

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Re: Dynamo question
« Reply #5 on: 22.10. 2012 20:51 »

 could be wrong, but I think the Triumph T110 had a gear drive dyno from the exhaust Cam. ?
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online trevinoz

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Re: Dynamo question
« Reply #6 on: 22.10. 2012 21:29 »
Steve,
             Post the dynamo model numbers and I will identify what they are or more precisely, what they were originally.
Pictures would help.
Model numbers are stamped in the body, starting with 200.
Date is also stamped.
Trev.

Online Triton Thrasher

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Re: Dynamo question
« Reply #7 on: 22.10. 2012 22:02 »

 could be wrong, but I think the Triumph T110 had a gear drive dyno from the exhaust Cam. ?

It has. Parallel shaft, two key ways, pinion held on by a screw into internal thread in the armature.

Offline Housewiz

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Re: Dynamo question
« Reply #8 on: 23.10. 2012 18:37 »
Just read two road tests on the SR and in the descriptions, one describes a gear-driven dynamo and the other describes a sprocket-driven dynamo.  Unfortunately the years of the test bikes were not listed - mine has the sprocket-driven.  Did see in one photo of a large gear behind a the large sprocket - man, there seems to be so many combinations of evolutionary parts I can't keep track of it all.  Challenging for a rookie trying to restore this thing.

Thanks guys for any enlightenment you wish to share.

Steve

Online chaterlea25

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Re: Dynamo question
« Reply #9 on: 23.10. 2012 20:58 »
Hi Steve,
Just goes to show, dont believe all you read!!!!!
All A7 and 10's had chain driven dynamo's
HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline duTch

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Re: Dynamo question
« Reply #10 on: 25.10. 2012 09:52 »

 I'm fairly keen to see the photo...?

Quote
Did see in one photo of a large gear behind a the large sprocket - man,
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia