smokeing lathe

[brickyParticipant @bricky]

Drilling a hole for a 2mm tap in the lathe I ran the lathe at 2000 rpm which drilled a dream until Isaw smoke around the change wheel cover.The smell was of an electrical fault but the motor was cold also the wiring.The tufnol tumbler reverse gears were warm and as I had still got the traverse on I wondered if they were overheating and could have been the cause of the smoke any ideas please.

Frank

[SteviegtrParticipant @steviegtr]

Burning Tufnol does smell like electrical burning.

Steve.

[brickyParticipant @bricky]

That’s  a reasureing start thanks for your reply.

Frank

[bernard towersParticipant @bernardtowers37738]

if they were only warm they would not be smoking, try running it with the cover off you will have a better view

 

[DC31kParticipant @dc31k]

If your lathe is smoking, buy it some nicotine gum.

Have a think about the relationship between spindle speed and motor speed. It might help to diagnose things if you could say what that is: does the lathe have a variable speed DC motor or a fixed speed AC motor where spindle speed is changed via belts of gears?

Perhaps mention the model of lathe as that will narrow the possiblities considerably.

[SillyOldDufferModerator @sillyoldduffer]

Maybe the change gears are too tightly engaged?  I guess tufnol wouldn’t like that.  I set my steel gears 2 thicknesses of A4 sheet apart.

Dave

[brickyParticipant @bricky]

It’s an AC motor on a large bore S7 Myford with belt change .

Frank

[MichaelRParticipant @michaelr]

Are the belts slipping ?

[Dave HalfordParticipant @davehalford22513]

In which case is a belt rubbing otherwise there’s not much left in a Myford to let the smoke out.

[brickyParticipant @bricky]

The belts are not slipping or rubbing .I will try running on the fastest speed and make sure the tumble gears are not engaged this time and see if I still get smoke.I hope it’s not the motor.Thanks for to all for the advice.

Frank

[Grindstone CowboyParticipant @grindstonecowboy]

The S7 has a clutch, doesn’t it? Is that maybe slipping?

Rob

[Charles LamontParticipant @charleslamont71117]

The clutch is bronze on iron. No smoke or smell, but squealing on engagement in top speeds if you don’t oil it.

The tumbler gears should be fine at 2000 rpm. If they are getting at all hot, let alone hot enough to smell, you have a problem somewhere.

[HopperParticipant @hopper]

Sounds like the change gears to me. Tufnol will smell like that. Check the temperature of the iron gears as well, and check you can fit a strip of paper between all mating gear teeth for clearance. If they bind they can get hot at high rpm.

And check the temperature of your left hand headstock bearing assembly too. It’s OK for the bearing housing to be warm but not too hot to hold your hand on. Needs bearing adjustment or lubrication if too hot.

[brickyParticipant @bricky]

Thanks to all who replied ,I checked all of the above suggestions and as the tuffnol gears smell strongly of burning electronics I decided to run the lathe at the 2100 speed and see if the motor wasn’t smoking.It was definately the tumbler gears,possibly too much oil on the change gears .It gave me a fright but all is now well.

Frank

[HopperParticipant @hopper]

Try using motorcycle spray can chain lube on the gears instead of oil. Use the Teflon street formula, not the messy graphite off-road formula. Sticks to the gears and doesn’t fling everywhere like oil.

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