Myford Super 7 Headstock bearings

[Adam HarrisParticipant @adamharris13683]

Can anyone please tell me how tight the two adjustment rings either side of the rear headstock bearing should be? Should the C Spanner be pulled as hard as is pretty much possible to tighten them both as far as they will go, or less hard, and if less hard, how much of a turn (1/4? 1/2? ) should the C spanner be backed off from fully tight. I realise they need to be tightened up together in a balanced gradual way in order not to interfere with the alignment of the shaft, but there is nothing in the manual about how tight they should be set….Many thanks for any help. Adam

Edited By Adam Harris on 27/02/2014 21:53:52

[Adam HarrisParticipant @adamharris13683]

Recommended tightness of Adjustment Rings

[Michael GilliganParticipant @michaelgilligan61133]

Adam,

No personal experience of the Super 7, but

There's a copy of the manual here

… might be of some help.

MichaelG.

[KMPParticipant @kmp]

Adam

Myford produced a Service Call Sheet which detailed the replacement of the spindle drive belt including the adjustment of the main spindle bearing. I'm not sure if the new Myford company still have them they were a couple of pounds if my memory is correct.

Basically you adjust the inside collar until you feel some drag on the spindle taper bearing and then tighten the outside collar until it locks and then give it a "sharp wrap" with a mallet. Yes it is that technical. From memory it takes a few attemps to get it just right. One must back off the adjustment collars and tap the spindle to release and start again should the spindle tighten as you lock the collars up. Run the machine to ensure that the front bearing is not heating up.

Hope this helps a little.

Keith

[Adam HarrisParticipant @adamharris13683]

Thanks Michael – already have the manual but no mention of tightness required. Adam

[Adam HarrisParticipant @adamharris13683]

Hi Keith, fantastic info – many thanks indeed. Will do this. So the effect is that the adjuster rings end up being pretty darn tight?

[KMPParticipant @kmp]

Adam

Send me a message with your e-mail and I will send you a present in PDF format.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Adam Harris on 27/02/2014 22:20:18:

Thanks Michael – already have the manual but no mention of tightness required. Adam

.

Sorry, Adam … obviously tired, I missed that bit in your first post.

MichaelG.

[KMPParticipant @kmp]

Sorry Adam, forgot to answer your question. No not that tight really when they are locked together with a steady pull which overcomes the drag on the locking collar you will feel the bearings come together having taken up all the free play in the bearings. A sharp wrap with the mallet will tighten a further 1 – 2 serrations on the C rings. Don't do what I did once and break the C spanner.

Keith

[Adam HarrisParticipant @adamharris13683]

Ha Ha – thanks for that tip. OK I will take only a moderately firm approach! Adam

[speelwerkParticipant @speelwerk]

When you think you have the correct setting, mark the placing of the outside collar on the headstock casting, if you have to make further adjustments you have a reference point. Niko.

[Adam HarrisParticipant @adamharris13683]

Hi Niko, very good advice thank you. Best wishes,

Adam

[NobbyParticipant @nobby]

Hi Adam & Guys
Move the bearings and spindle back until the spindle cone contacts the tapered bush and will not rotate ie to a
condition of no clearance. Clearance can now be set by moving the spindle forward from this "solid "
position by a 1/4"rotation ) ie 15 degrees
Nobby

[Adam HarrisParticipant @adamharris13683]

Hi Nobby, many thanks. Adam

[Martin KyteParticipant @martinkyte99762]

This is the Myford protocol

1. Power Down

2. Remove all belt tension.

3. Remove Chuck

4. Rotate RH collar one complete turn. (top towards you).

5. Rotate LH collar one complete turn. (top towards you).

Spindle should be completely free of front bush.

6.Loosen allen screw on collar at end of spindle.

7. Using the Allen key tighten collar as tight at it will go by hand.

Inner tapered roller races are now locked together with correct pre-load.

8. Back off LH collar one complete turn + a bit (top away from you)

9. Rocking the spindle by holding the spindle nose tighten the RH collar by hand (top away from you).

10. When you feel resistance to movement stop.

11. Collar should be just tight enough that spindle can just be moved by hand holding the nose.

12. Do up the LH collar by hand (top towards you).

You should still feel resistance when turning the spindle by the nose.

13. With the crescent wrench on the LH collar tap the end smartly with a 12oz hammer.

The spindle should move forwards by a couple of tenths and be completely free running.

14. With the lathe running slowly (lowest direct speed) put the oil gun in the front oil cup and pump until oil issues from the front bearing.

regards Martin

[Adam HarrisParticipant @adamharris13683]

Many thanks Martin for these clear instructions. Very much appreciated! Best regards,

Adam

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