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+--- Thread: At last working dynamo (/showthread.php?tid=6893)
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At last working dynamo - Tiger - 24-11-2021
After spending a lot of time trying to get my original Dynamo to charge and possibly failing.
I purchased another unit and last night managed to get it working.
The one on the car is still not showing any charge but I can install the replacement unit.
The replacement unit has end float of about 1/16” I guess
Is it necessary to reduce this before fitting??
I am reluctant to strip the working unit and wonder whether I could insert a packing washer near the large drive spiral??
Regards
Tim
RE: At last working dynamo - Stuart Giles - 24-11-2021
The ball race bearing in the drive end controls the endfloat on A7 dynamos, so there should be none or a tiny amount if the bearing isn't totally knackered/loose on the armature spindle/loose in its housing. I would definitely want to sort this if it were mine. Even if the endfloat didn't get worse in use, the amount already there will cause ignition timing scatter.
RE: At last working dynamo - Bob Culver - 24-11-2021
There is nothing complex, esp the last 35m type but keep an exact diag of what was where. However often spacers, washers etc missing and the Woodrow dwg despite caption is of the 35A model. Diags 35M have been published here, last by Dave Mann about 7 May. Beware the key does not damage the plain outer bearing.
If the main drive gear has to be held in a vice use soft wood clamps.
RE: At last working dynamo - Dave Mann - 24-11-2021
Photo 14 Dynamo drive end bearing.jpg (Size: 37.65 KB / Downloads: 400)
That situation can arise if the washers each side of the bearing are missing or the spacer is worn down.
RE: At last working dynamo - Tiger - 29-11-2021
After stripping my Dynamo .
It looks to have professionally built with a armature rewind.
However I can’t see why there is too much end float.
I am wondering whether the spacer fitted next to the large bevel is short.
Asking a lot here would anyone know the length ??
Tim
RE: At last working dynamo - Dave Mann - 29-11-2021
As I've got a few spacers all of different lengths and all showing signs of being worn down I usually make them sized to suit the job.
RE: At last working dynamo - Tiger - 29-11-2021
Thanks Dave
The spacer fitted is OD 18.3 mm
Length 13.5 mm
Shaft Dia 15mm
If you could help with a longer spacer that would be great.
I estimate a length of 21 mm would be needed
I am happy to shorten a spacer .
Regards
Tim
RE: At last working dynamo - Dave Mann - 07-12-2021
Hi I have 6 old spacers ranging from 12.38 to 13.9 mm you are welcome to, 21 mm seems somewhat long is there something else missing.
RE: At last working dynamo - Tiger - 07-12-2021
Thanks for your reply.
I can’t see anything missing after studying your diagram.
What do you think of adding an extra collar to the existing spacer ?
RE: At last working dynamo - Steve Bryant - 07-12-2021
Hi all. I hope you are coping ok with your winter weather.
Since this topic is about working Dynamos, I would like to ask those of you in the know about the best way to repair the rear end frame damage where the bearing is normally pressed in. The casting looks like cast iron.
If I can't find a way to repair the damage, I'll need to find a good serviceable replacement for the end frame. I'm not sure but according to the Woodrow I am missing the large thin steel washer which appears to go under the brush holders. I'm also missing the oil slinger at the front. All part of the legacy of the previous owner's servicing I'm guessing.
Cheers,
Stephen