I’ve bought a 7R [ Myford, not AJS ]

[Michael GilliganParticipant @michaelgilligan61133]

… In the immortal words of Rolf Harris:

"Can you see what it is yet ?"

MichaelG.

[CotswoldsPhilParticipant @cotswoldsphil]

Looks a bit like a woodruff key to me. The pull on the preset loading collar is going to a bit lob-sided, I fear, and not like that intended by Myford.

CotswoldsPhil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by CotswoldsPhil on 18/09/2014 08:53:45:

Looks a bit like a woodruff key to me.

.

Right-in-One, Phil

… it's actually about 90% of a Woodruff Key

… one end is missing; but I don't want to contemplate how that might have happened.

Interesting times ahead, I fear.

MichaelG.

[Douglas JohnstonParticipant @douglasjohnston98463]

Another way of preventing screws from working loose, while retaining the ability to adjust them, is to put a dab of low strength adhesive on the thread before fitting. After curing, the screw can be moved but retains a tight fit and will not vibrate loose. I use bearing strength loctite and this works well on gib screw threads. Don't be tempted to use high strength retainer like loctite 603 or you will never get the screw to move.

Doug

[Howard LewisParticipant @howardlewis46836]

If a woodruff key is no longer available, you can always make one, with minimal "hand crafting".

With a piece of round bar (silver steel?) of the correct diameter, part off to the correct width (thickness), and hacksaw/file a flat until the key is the correct depth.

(Alternatively, if you know what the correct depth is, make the flat before parting off.

Deburr, and voila!

At least, that's how my son in law's circular saw was repaired when he sheared the key on the spindle.

Howard

[TrevorhParticipant @trevorh]

Are you sure its not a standard parrallel key the shaft doesn't look deep enough for it to be a woodruff key?

as you know woodruff keys are semi circular and are usually twice as deep as they are wide, the length being what ever it needs to be

cheers

[CotswoldsPhilParticipant @cotswoldsphil]

It's a woodruff key, Myford part no 700002 (there are two of them on the spindle) that has obviously been displaced when the headstock rear gear/collar was installed, at some earlier time. The perpetrator must have thought it lost, so made a replacement as Michael describes. I can see exactly how this might have happened, although the tumbler gears being misaligned with the headstock driver gear should have raised an alarm when everything was refitted.

Myford's instructions are quite specific about ensuring an even load on the inner races of the annular contact bearings (you can just make out some identification on the inner race in the photo) by only loosening the screwed adjusting collar's locking screw by just enough to allow it to be turned by hand. As shown, when reassembled, the force applied to the inner race through the misplaced woodruff key would not be as Myford intended.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Phil

That's saved me the bother of explaining.

MichaelG.

[CotswoldsPhilParticipant @cotswoldsphil]

Michael, my pleasure, all learned when I changed the bearings on my Super 7 a couple of weeks ago.

Cotswoldsphil

[Author]

Posts