Knocking sound coming from headstock on PM1127

MSD0

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I’m getting a knocking sound from the gearbox on my PM1127 when the power feed is engaged. The sound and vibration sounds like either a tooth has broken off or something has come loose and is catching on a gear. Has anyone opened up the gearbox before and if so, is it as simple as removing the front panel?
 
I am not familiar with your particular lathe but I can't see it being any more difficult than that. Bear in mind it is probably full of oil which will need to be drained first unless you want a big mess!
 
I am not familiar with your particular lathe but I can't see it being any more difficult than that. Bear in mind it is probably full of oil which will need to be drained first unless you want a big mess!
Yeah, I was planning on draining it first (which already makes a mess). While I have it taken apart, I might add a drain valve with a hose fitting to make oil changes easier.
 
Bummer! I haven't had mine open, but please update us with what you find out.

I like the idea of a drain valve and fitting. Trying to get something under there to catch the oil is a bit annoying.
 
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Bummer! I haven't had mine open, but please update us with what you find out.

I like the idea of a drain valve and fitting. Trying to get something under there to catch the oil is a bit annoying.
Didn’t find anything broken, but there was a large burr and lots of grit on the bottom. Was kind of surprised at the size of the gears. Much smaller than expected.
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Does your machine have a feed rod clutch? I remember seeing a YouTube video of a PM1127 that had a clunking sound while making a cut. There was also a slight hesitation of the carriage during the cut when the clutch slipped intermittently. Unfortunately, I do not remember which video. There are 4 ball bearings, springs and set screws on the right. The left side has 4 radial grooves that capture the ball bearings. If there is a crash or some binding in the feed rod, the clutch will slip making a clunking sound. Also, I believe the clutch can be used in conjunction with the carriage stop.

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Does your machine have a feed rod clutch? I remember seeing a YouTube video of a PM1127 that had a clunking sound while making a cut. There was also a slight hesitation of the carriage during the cut when the clutch slipped intermittently. Unfortunately, I do not remember which video. There are 4 ball bearings, springs and set screws on the right. The left side has 4 radial grooves that capture the ball bearings. If there is a crash or some binding in the feed rod, the clutch will slip making a clunking sound. Also, I believe the clutch can be used in conjunction with the carriage stop.

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I have the older version without the clutch (I think it just has a sheer pin). After putting it back together, I noticed that I was getting a lot of vibration from the belt at certain rpms, so I’m now thinking it might be the change gears that are making the noise.
 
So after cleaning everything up and getting it put back together, I found that the set screw on the motor pulley was loose. I was already getting some vibration from the belt, so I think the noise was a combination of the loose pulley, vibration from the belt, and excess backlash in the change gears. I spent some time getting the gear mesh dialed in and replaced the original belt with a link belt and it’s running like new.
 
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