Myford BackGear Lever

[Martin KyteParticipant @martinkyte99762]

Hi Chaps

I have an annoying issue with my Myford Super7. When running at high speed the cetrifugal force on the lever of the BackGear key causes it to rotate and foul on the headstock casting. Has anyone done a modification to solve this.? The only hing I can come up with so far is a spring detent which would be quite involved, probably why Myfords never bothered in the first place.

Thanks in anticipation.

Martin

[Martin KyteParticipant @martinkyte99762]

[Roderick JenkinsParticipant @roderickjenkins93242]

I didn't come across this problem until I was running at 3000 rpm with my VFD and the lever broke off. I don't have a solution though. I don't intend to run at that speed again!

Rod

[KWILParticipant @kwil]

As I recall there is a small spring and ball in that back gear key assembly to allow a detent action. Never had this problem at high speed.

Just looked at the Parts Breakdown in the Manual and it shows the above items.

Edited By KWIL on 25/07/2013 14:41:27

[RobboParticipant @robbo]

Martin,

As Kwil says, there is a detent in the form of a spring and ball inside the key assembly.

I know because I took one off a damaged bullwheel and of course the spring shot the ball across the room! Had to buy a pack of 10 to get a replacement, so if you need a ball?? message me.

Phil

[BazyleParticipant @bazyle]

Seems possible that
a) the spring deteriorates with age,
b) the dimple the ball sets into needs deepening,
c) the mechanism gets gunged up with old oil & dirt so doesn't work so well.

[Martin KyteParticipant @martinkyte99762]

Hi Chaps

Had a quick look at my spare bull wheel and you are correct of course re the assembly. I am not entirely sure the spring and ball detent is fitted on my lathe. Could be that when I bought a new bull wheel and lever Myfords didn't supply the spring and balls so I didn't fit them. When I get time I will strip the mandrel and find out.

Thanks for the responses.

regards Martin

[RobboParticipant @robbo]

Martin,

A word to the wise. When you dismantle the key assy., don't try and twist the handle out, it breaks easily. It's on a slight taper, so needs to be driven out from the reverse side. Guess how I know this!!

If you eventually need a ball and spring, get in touch.

Phil

[Martin KyteParticipant @martinkyte99762]

Thanks for all the offers, I'm OK for parts but I'm impressed with the level of support.

regards Martin

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