3-speed starter motor

[Tony Griffiths]

Might anyone have a brush end cover for a late-type 1929 to 1931 CAV starter (not the Bacon-slicer sort) - or a complete motor? We have rebuilt motor that that not only the wrong way, but is fitted with brush end cover that means it won't work on any Austin 7 - somebody must have had fun wrestling with this in the past!

[AustinWood]

I'm not sure what the problem is that you are describing. If it turns the wrong way then it could be that the internal connections to the brushes or the field windings (but not both) have been reversed. It's a long time since I've had a car with that starter (1966 probably) so my memory is shaky.

[Dave Mann]

The problem is someone has fitted a late forward mounted starter brush end on an early rear mounted starter so that the motor rotates the wrong way. Here's a photo of the two brush ends with the early 3 speed starter end on the left and the later 4 speed on the right      what Tony wants is one like that on the left.

[Dave Mann]

This is the third starter I've come across that rotates the wrong way, the first was a 3 speed on our second RN saloon, the second was a 4 speed bought from John Platts, I just swapped the bits over and sold the 4 speed so I know it is not an unusual problem.

[Howard Wright]

Hi All

Just for information if you have a dud 3 speed starter you can swap the end plates over to a four speed starter. You need to drill and tap the contact on the top of the starter. All described by Ray Moses on the Hereford club site. https://www.ha7c.co.uk/Technical/35%20Au...%20D18.pdf

Cheers

Howard

[Tony Griffiths]

Many thanks, everyone, for the advice......David will no doubt now set to work with renewed enthusiasm.

[Dave Mann]

Ah but this 3 speed starter has a 4 speed brush end cover, what we need is a 3 speed brush end cover.

[Dave Mann]

After studying the differences between a 3 speed and 4 speed brush end covers the brush end cover was turned through 90 degrees and it now runs the correct way.

[Tony Griffiths]

Dave was also rebuilding the dynamo from the prototype HRG (the restoration of which is nearly complete). It worked with a 'temporary' third brush but not the new one that we found. The solution? Motor the dynamo while pressing the brush down with a piece of wood - and it came to life. News to me - but not, perhaps, to the electrical experts on the forum....

[Dave Mann]

I've always known that you don't undercut starter commutators but never why, one of Tony's starters was seriously undercut such that skimming it didn't remove the undercutting and I tried it, the brush gear was like a catherine wheel with all the arcing. I dismantled it and seriously reduced the commutators life by skimming out the undercutting and retested it with no catherine wheel effects.