Clicking from Super 7 headstock.

[Glyn DaviesParticipant @glyndavies49417]

[Glyn DaviesParticipant @glyndavies49417]

I've been trying to adjust the headstock on my Myford Super 7 to eliminate a clicking noise when it is running. The click seems to be once per rev and it is definitely the headstock, not the motor or countershaft. I have adjusted the bearings and set the end float on the cone pulley to a minimum (book says .005&quot, but it still clicks. I can't feel any play in the cone pulley bearing.

My questions are – do they all do it and has anyone had it and cured it?

Thanks

[roy entwistleParticipant @royentwistle24699]

Mine doesn't It's not the lever for freeing the bull wheel is it ?

Roy

[speelwerkParticipant @speelwerk]

Check if you still hear it when you turn the spindle by hand. Niko.

[RobboParticipant @robbo]

Not something simple like the spindle locking bolt sticking out a bit and catching?

[Chris TriceParticipant @christrice43267]

It’s almost certainly the little locking lever that locks and unlocks the bull wheel. More of a tick than a click. Easy to test for too.

[Glyn DaviesParticipant @glyndavies49417]

Thanks for the replies. It's something to do with the engagement of the bull wheel to the cone pulley set. It's slightly quieter with the chuck fitted and disappears altogether when I grasp the chuck to put some load on. Of the two recesses in the cone pulley set for the rotating half moon pin, one is a tighter fit than the other, and the noise is less when in the latter.

[Chris TriceParticipant @christrice43267]

The lever is lightly sprung so it stays in position when switched. If badly worn or something is amiss, centrifugal force thows it outward slightly just enough to impact other parts. It’ll be worse at higher speeds.

[Glyn DaviesParticipant @glyndavies49417]

There is no trace of play in the half moon lever. I think it must be that the rotation of the mandrel is not uniform throughout a revolution so that the spindle accelerates and decelerates. This causes the half moon pin to slop back and forth in its recess in the cone pulley enough to make a clonk. I'm thinking that the drive belt might be the culprit.

[NobbyParticipant @nobby]

Hi
I had the same problem . I made a lever with a small grub screw to lock against the gear
Nobby

[KMPParticipant @kmp]

Hi Otley,

From my experience it is as you suggest caused by a variable stiffness in the standard drive belt so that the spindle accelerates and decelerates a small amount but enough to clatter within the half moon cutout. While I stopped it temporarily by shimming the pin, the problem on my S7 was completely cured by a change to a T-Link type belt. A new standard belt from Myford (original company) made no difference at all. I might have done something similar to Nobby if I had thought of it. I found that not all Link types belts are equal but the more expensive T-Link worked for me and is still working after a number of years use.

Regards Keith

[Chris TriceParticipant @christrice43267]

If you want to discount the lever hitting anything, wrap a length of tape around it holding it in position and then run the lathe. How much clearance must there be to generate a click in the pin due to acceleration and deceleration? You could try putting a blob of grease in the hole to act as a cushion just to see if the click disappears or is reduced.

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