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Tiger
28th February 2009, 10:12 PM
My lathe, a WL-18 which is the same as the MC-900 lathes becomes very noisy when the speed is set to 7 or above which translates to about 1400 rpm or above. It makes a knocking sound which gets very loud and annoying. Both the motor pulley and headstock pulley are well lubricated and I have tightened the pulley setscrews as far as they will go. I can't feel any play in the spindle but that appears to be where the noise is coming from. What do you think the problem might be here?

RETIRED
28th February 2009, 10:13 PM
Probably a bearing by the sound of it.

Tiger
28th February 2009, 10:44 PM
Thanks, , if it's the bearing why doesn't it affect the lower speeds.

If it is the bearing is there any test I can use to confirm that and how difficult is to change the bearing on these type of lathe?

hughie
28th February 2009, 11:29 PM
Maybe bearings, the noise kicks in a particular rpm and or harmonics. Also over tightening the belts can produce noise ie clicking from the bearings, you should be able to deflect the belts around 12mm or 1/2" with reasonable pressure.

Gil Jones
1st March 2009, 07:12 AM
Try running the motor with the belt off or at least not turning the spindle. If it still makes the noise it could be the motor bearings or or something else in the motor.

Calm
1st March 2009, 07:45 AM
Has the noise always been there or has it just started?

Try it with nothing on the spindle - chucks can rattle.

I think it's a Hafco WL-18- they are quite simple to remove the shaft.
remove the cover, then the belt,

then the ciclip on the end of the shaft. - you need opening circlip plyers

loosen the grubscrew and slide the pulley off - you will need to unhook the Reeves pulley lever

There is another circlip before the bearing (the same as the first one) Mine then had 2 shims on it - watch they dont drop in the circlip groove and catch

then the shaft comes out towards the tailstock and one bearing will probably stay in the housing - it can now be knocked out.

Not that difficult for someone with mechanical aptitude.

Good luck

Cheers

Tiger
1st March 2009, 09:06 AM
Thanks for your input guys.

Have checked it without belt, definitely not the motor bearings, anyway the motor is almost brand new.

Belt is not tight, enough deflection there. Not the chuck, noise happens irrespective of whether chuck is attached or not.

Did notice that the 2nd pulley on the motor spindle seems to be running out of true. If that is the problem, how do you fix that? I have tightened the setscrews on it as far as they can go.

Calm, I didn't see any shims there, does it need shims?

Papa
1st March 2009, 09:26 AM
It sounds like a spindle bearing that may be dry. They start out making
a noise at one speed and get worse.

I would pull the spindle in order not to damage the shaft if the bearing should
freeze!

oldiephred
1st March 2009, 09:52 AM
I suggest that a "knocking" sound is quite unlikely to be caused by a bearing. I would expect a bearing to create a growling sound and should not be speed dependent. I would suspect the belt. the belt could have a small bad spot on it and this results in it "slapping" at certain speeds. Belts can be out of balance just like a wheel and the frequency of the sound can be related to the rotational speed of the belt. IMHO
Good luck.

OGYT
1st March 2009, 02:04 PM
My Reeves drive on Old Griz did that. It was a fast knock and didn't sound like a bearing, to me. I finally discovered it was coming from the Reeves drive, and after a very good cleaning and lube, it stopped. I took the set screws that I could get to out, put lock tite on them, and put 'em back in.
Don't know exactly what it was, but it stopped.
Just a suggestion.

RETIRED
1st March 2009, 04:30 PM
Ask DJ if a bearing knocks.:whistling:

thefixer
1st March 2009, 05:49 PM
With my MC1100 the knocking sound only occurs at full speed and it is the spring at very top of the headstock hitting on the cast iron casing. I jammed a piece of foam rubber in there and it solved the problem

Cheers
Shorty

DJ’s Timber
1st March 2009, 06:25 PM
Ask DJ if a bearing knocks.:whistling:

Hmm that reminds me, still haven't put the new bearings in yet :roll:

And to answer the question, yes bearings do make a knocking noise, particularly in the higher RPM range

NeilS
3rd March 2009, 06:56 PM
One secondhand lathe I bought knocked at higher speeds.

It was the belt that was too long (knocking against the housing) and there was not enough adjustment left to tension it further.

I assumed that the belt had stretched with prior use so replaced it with a new one of the identified size. The problem persisted.

Turned out that the belt on the lathe when I acquired it had been incorrectly fitted with too long a belt all along.

Unlikely to be a problem for others, but mentioned just in case.

Neil

Papa
3rd March 2009, 07:36 PM
And to answer the question, yes bearings do make a knocking noise, particularly in the higher RPM range

After 50+ years of tinkering and buying used stuff, I have learned that bearings are like
women, they can do about anything they want and we have to listen to it or replace
them, and sooner or later the new ones will start it all over again!