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Bacon slicer advice needed
#21
Highly likely the motor has been tampered with in 90 years-  it looks very new - I expect you have cleaned it within an inch of its life but possibly when last overhauled some time back  it was incorrectly assembled and when it didn't work properly  it was put to one side.

The commutator cover is not correct, it should have a 'clip on' cover with the body clips held under the terminal from memory. as shown in R's pictures

I suspect you will have to strip and check  the internal connections.
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#22
Thanks Tony,

What are the chances of finding one
Of those clip covers I wonder?

I’ll dissemble the end plate today and report back

Regards

Bill G
Based near the Scottish Border,
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#23
(08-05-2019, 07:35 PM)AllAlloyCup Wrote: Thanks a lot Dennis for the time given to
write this note and explain how motor normally works.

I peered into the commutator end of the motor
and it all looks remarkably untouched, except
The two clamping screws which can be adjusted at the end of the casing.
I may try and move these, a simple screwdriver job to see it makes a difference
if the brushes touch differently spaced commutator segments.

The internal brush leads are relatively short so not easily
modified, plus I’d have to completely disassemble the whole motor
to see where connections go to the motor body.

Will let you know how I get on, thanks again for
everyone’s help with this daft problem.

Regards

Bill G

Moving the brushes just a little will not help.  But if they can be moved 180 degrees....i.e. to the opposite side to where they are then that will send the electric round the other way in the rotor coils and reverse the motor direction.
Moving the brushes a little is to enable the brushes to be changing from one commutator segment to another at the point where the voltage at each is the same so no spark occurs.......another thing to think of when setting up.  Move brushes a little till no sparking.

Dennis
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#24
I H
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I’ve pulled the end plate off the starter motor this morning and note

1. The end plate can only go on one way due to the stud connection hole and a notch in the end cover which lines up with a mark on the main casing.

2. Note that the brush gear can be partly rotated and clamped by two screws accessible from outside the end cover.

3. The flat screw that attached one brush to the casing was loose, not tightened up.

4. The brushes are brand new, indicating that someone, not me has been inside the motor. A tiny bit of wear is showing compatible with the few times I’ve run it backwards.

5. The lead clamped to the casing looks wrong, facing the wrong way? So will try to turn it round and see if it can reach to the other brush holder.

6. Will also check if the flying lead from the field coils can reach the other brush

If 5 and 6 check out I’ll reassemble and try putting power on it and seeing what difference the adjustable ring plate makes , which by the way carries both brushes in a fixed relationship to each other



Here goes! 
If 5 &6 don’t check out , a rethink is required?

Regards

Bill G

On close examination the earthing lead cannot be turned round as it 
would foul one of the long securing bolts.

But I’ve realised though that I can turn the brush mounting plate 180 degrees 
and that looks to suit the earthing lead so now will go out to the garage
And check the flying coil lead can reach the other brush.

I’ve a feeling this will solve the puzzle!!

Update coming soon!

Regards

Bill G
Based near the Scottish Border,
Reply
#25
Sure enough the 180 degree rotation of the brush base plate
has solved the problem. Not much sparking at the commentator 
either.

The pinion gear dutifully progresses along the spiral
Cut shaft towards the ring gear on the flywheel when power is
applied.

I’ll also try and make sure the small spring loaded pin
, which stops the pinion going awol is working before
Finally fitting onto the crankcase.

This is all good news as once the starter is installed I can finalise
the flooring, the petrol tank, petrol line, and under dash wiring.

Many thanks to all who contributed to this thread, adding a little to
The community Database that A7 Friends Forum represents.

Now to try and sort out the Dynamo!!

Regards

Bill G
Based near the Scottish Border,
Reply
#26
Glad to hear that has solved the mystery.
The spring loaded pin should drop into a groove in the shaft when the pinion is fully retracted.
Jim
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#27
Thanks Jim

Your advice is always appreciated and always right as well!!

Hope your engine assembly is going OK

Let me know if you need a hand with anything.

We cured the stiffness in the gearbox by moving one
Shaft further in by 1mm with a brass drift.

The friction was between the end of the shaft
and a boss on the cover plate

Hope to see you soon


Kind regards

Bill G
Based near the Scottish Border,
Reply
#28
Good to hear success.....always a great satisfaction to solve a problem.
Dynamo is exactly same as motor except instead of putting electric through the rotating windings and they move you move the windings mechanically so they pass through the field magnetic force and electric is induced in the winding and fed out of the brushes to the contact breaker/regulator to feed the battery/rest of the car electrics.

Dennis
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#29
Thanks a lot Dennis for taking the time
To help me solve one of the last problems
Encountered before starting this engine for the
first time in probably 50+ years

Kind regards

Bills
aka AllAlloyCup
Based near the Scottish Border,
Reply
#30
This reminds me of our second RN 40 years ago, the starter wasn't connected as the cable wouldn't reach the oversize battery behind the passenger seat but it started easily on the handle. I eventually bought a battery which would fit it's box and connected up the starter, this operated well but the engine wouldn't start then I spotted the fan was rotating the wrong way. So I fitted a spare starter and that cured the problem. Some time later I was at John Platts and asked about a 3 speed starter motor, sorry we haven't got one but we a 4 speed starter motor which goes the wrong way which would do was the reply. I bought it swapped the casings with their field coils and bendix drives over and I now had two motors which went the correct way and sold the 4 speed one.
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