02-06-2020, 10:36 PM
Well, spent another few hours on this today but not sure it's made much difference.
Earlier today I spoke to a possible repairer who suggested I make sure there was no lateral movement of the armature in it's bearings which might allow it to contact the field coils so once again I stripped it all down and this time also took out the ball race at the pinion end but it all looked OK.
Whilst it was in pieces I again checked for continuity of the field coils and that there was no short to earth and it looks fine.
The armature windings are actually strips of solid copper which I believe is called a bar armature. The construction is so solid it seems extremely unlikely there could be a break in these and, in any case it all seems to check out OK.
I then cleaned up the terminals which connect to the brushes and also cleaned the faces between the central motor casing and the ends just in case this was creating high resistance in the earth side.
When I reassembled the brushes I did notice that although the earth brush seemed to mate well with the commutator the live brush was only touching over a relatively small part of it's surface so I used some abrasive paper between the brush and commutator to bed this in which I hoped would be the answer.
Finally I again thoroughly cleaned the Bendix assembly and re-assembled everything.
Laying on the floor and connected to the battery with jump leads it spins up well but doesn't have the violent acceleration others have mentioned.
I think all I can now do it to try to bend the pinion clip so that it barely holds the pinion and then mount it back on the engine to see if it will engage and if it has the power to turn the engine over.
If that fails I'll have to accept defeat and take it to a specialist.
Earlier today I spoke to a possible repairer who suggested I make sure there was no lateral movement of the armature in it's bearings which might allow it to contact the field coils so once again I stripped it all down and this time also took out the ball race at the pinion end but it all looked OK.
Whilst it was in pieces I again checked for continuity of the field coils and that there was no short to earth and it looks fine.
The armature windings are actually strips of solid copper which I believe is called a bar armature. The construction is so solid it seems extremely unlikely there could be a break in these and, in any case it all seems to check out OK.
I then cleaned up the terminals which connect to the brushes and also cleaned the faces between the central motor casing and the ends just in case this was creating high resistance in the earth side.
When I reassembled the brushes I did notice that although the earth brush seemed to mate well with the commutator the live brush was only touching over a relatively small part of it's surface so I used some abrasive paper between the brush and commutator to bed this in which I hoped would be the answer.
Finally I again thoroughly cleaned the Bendix assembly and re-assembled everything.
Laying on the floor and connected to the battery with jump leads it spins up well but doesn't have the violent acceleration others have mentioned.
I think all I can now do it to try to bend the pinion clip so that it barely holds the pinion and then mount it back on the engine to see if it will engage and if it has the power to turn the engine over.
If that fails I'll have to accept defeat and take it to a specialist.