Thread: Al960

I appear to have a very noisy bearing. At this stage I suspect its in the lower gearbox...the ones that drive the lead screw etc and not the headstock. Has any pulled one apart?

Hi there,

If it has the norton style gearbox then yes I have. Before you start taking it apart, have you isolated that gearbox from headstock and see if the noise is still there or not? This can be done by removing the last change gear. You can then run the headstock in all it's 9 speeds and see if the noise persists.

If you are sure it's the gearbox, do you regularly oil the lube points? If yours is the same as mine then there are 3. 2 on the side where the leadscrew come out and one on the opposite side where the last gear rotates on the shaft. If you haven't oiled them in a while then give that a go.

If it still persists then removal of the gearbox is relatively straight forward. Disconnect the leadscrew (by drifting out the shear pin) and the shaft for the motor direction control shaft. Then, from memory there are two bolts on the RHS just below where the gap bed is and one or two on the LHS where the quick change gearbox is. I think it is also located on a couple of dowel pins or similar, so it will need to be pulled straight out horizontally and perpendicular to the bed.

Most of the running gear in this are just shafts running through the ci body as a bush. The gears that turn on the shaft have bronze bushes and the leadscrew has a couple of thrust bearings. Not alot to go wrong.

Good luck!

Simon

Originally Posted by simonl

Hi there,

Before you start taking it apart, have you isolated that gearbox from headstock and see if the noise is still there or not? This can be done by removing the last change gear. You can then run the headstock in all it's 9 speeds and see if the noise persists.

I wanted to do that after I had finished turning my part.

Then when I remembered to do what I was going to do after I had finished my part eg about 1.5 hrs later the noise had disappeared....so I had a beer instead.

When it happened I was running at 650 rpm...it was very noisy so I dropped the speed to 420 and it almost disappeared. I did get a chance to stick a screwdriver on it when it was there and I reckon (by the sound in the stethoscope) it has to be in the lower box

Thanks Simon.. I am about to go down to shed and have a play to see if I can reinvent it!

If it's any consolation, mine is (and always has been) noisy at that speed as well. Has yours suddenly got louder?

If you want to do a comparison before tearing into your machine you are welcome to drop in and listen to mine at the same speed if that helps.

I've not found any oiling points for the QCGB, there's just the total-loss tray which oils the gears and the centre bearing - the plug near the lead screw.

This guy https://www.youtube.com/user/JBFromOZ/videos has a series of videos showing a rebuild of an AL960B which may help - episode 12 has a few shots of the QCGB.


Rgds - Gavin

AL960

Check out “ JBfromoz” youtube video, he has rebuilt one of those this year, had the gearbox off and fettled the whole lathe making his own mods etc.

DD

Originally Posted by Gavin Newman

If it's any consolation, mine is (and always has been) noisy at that speed as well. Has yours suddenly got louder?

If you want to do a comparison before tearing into your machine you are welcome to drop in and listen to mine at the same speed if that helps.

I've not found any oiling points for the QCGB, there's just the total-loss tray which oils the gears and the centre bearing - the plug near the lead screw.

This guy https://www.youtube.com/user/JBFromOZ/videos has a series of videos showing a rebuild of an AL960B which may help - episode 12 has a few shots of the QCGB.


Rgds - Gavin

Yeah. mine became really noisy all of a sudden Gavin

I took the cover off the input shaft yesterday and packed a bit of grease into it. That has fixed it ..for now at least.

I will look at that video in minute as I will leave it as is for now till I have finished what I am doing and then attack it....i might as well replace all other bearings as well, as the way I see it the input shaft will be the last to come out.

I have been putting oil into that oil hole but from what I saw yesterday its a hit and miss affair as to what gets oil. The oil seems to spread out over this 6x2inch fine gauze of something and finds its way down into the lower gearbox which has a lot of grease on the gears as well. lol

One thing I did notice was a small tube which appears to come from the head stock or somewhere up in their down to one of what I think is a bearing or something??? Why ???

The bearing I packed grease into is not a sealed type.

Originally Posted by eskimo

One thing I did notice was a small tube which appears to come from the head stock or somewhere up in their down to one of what I think is a bearing or something??? Why ???.

In the QCGB? That's a feed from the QCGB oil supply tray that goes to lubricate a centre bearing in the QCGB - look at around the 3:15 mark in episode 12 of the series I referred to.

The oil tray is a total loss system - like a British motorcycle engine... - with a series of holes so the oil drips down onto each of the gears (more or less).

WRT the lubrication reservoir, I was not happy with the design of mine so I modified it. I forget exactly the details but when I pulled it apart I saw that unless the oil reservoir was completely full, not all the components got it's fair share of oil. So, I milled extra channels in the top and a couple of extra holes above key locations. I also added a felt sheet so that it would be more of a slow release drip feed over an extended period of time, rather than all the oil pouring down within a matter of minutes. I also measured how many pumps of oil for it to fill up, as once it's assembled you have no idea when to stop pumping oil in. I now know that 20 pumps fills it full and will slowly release oil over a day or so.

Edit: I also added a drip tray that fits under the QCGB so that it collects all the oil. I empty it from time to time and it stops the oil spreading over the chip tray and mixing with swarf etc.

Simon

Originally Posted by Gavin Newman

In the QCGB? That's a feed from the QCGB oil supply tray that goes to lubricate a centre bearing in the QCGB

yeah of course it is..what was i thinking???

maybe I should have had another beer..lol

Thanks Gavin and Simon.