The Guts ... Chasing Noises

[Logan Novice]

I'm chasing noises in my recently delivered 1127VF-LB. That required opening up the gearbox. The mystery noise does not originate therein; but I did see how the machine does its magic. Reminded me of a four speed tranny with wide gear spacing ....
Anyhow, long as I was in there, I took a pic to share with those who may wonder what's behind the cover. I was impressed with the cleanliness of the interior of the gearbox. Not a bit of swarf anywhere.
Going a bit deeper, I got inside the headstock. Found the source of the noise - bearing at the input side of the spindle shaft. But there's no decernable play and it runs true so I won't be premature in affecting a decision to replace it just yet. I did find that the speed control circuit board which is housed in the same area was contaminated with what appeared to be silver colored metal dust (perhaps the residue of a drilling operation) and because electronic circuits don't like that kind of stuff I did a compressed air cleanup.
UPDATE:
(For those who may need to remove and replace the gearbox cover for future maintenance)
Putting everything back in place requires a bit of adroit manipulation that would have been easier if I had four hands. Setting the feed direction, feed rate and feed/thread gears in their neutral positions and then "eyeballing" the alignment of the operating levers to mesh with the correct gear set worked best for me. I made a wooden block to just fit between the bottom of the gearbox and the tray and slipped it into place to support the cover whilst tipping the cover into place.

 

[7milesup]

Just an FYI. That board is the filter board I believe. It is where the speed sensor enters at the J2 position. The speed control board is mounted elsewhere, possibly immediately above the filter board.
Weird that there was metal dust on it. Cudos for catching that.

 

[graham-xrf]

The old trick of using a big screwdriver, and placing the tip against the side of the bearing housing, and gently pressing the handle end to the front small ear lobe to lightly close the ear? Maybe you used a stethoscope. Whatever - it lets you compare to other bearings.

It is quite possible for there to be contamination, or damage within the bearing, and still have the remainder of the races still run true - for a time. I know getting a bearing out, and precisely reassembling things can be awkward, especially if there is proper pre-load required, but if you know the noise is definitely coming from in there, the only sure way is to take it apart, and closely inspect.

 

[Nogoingback]

If this is a new lathe, it might be a good idea to call PM and discuss with them. Changing a bearing is a pain, but
if it has problems you'll probably wind up changing it in the end.

 

[pacifica]

Seems that geared head lathes are somewhat noisy, and it depends which gear combination you are using also.