Graziano 12S Headstock Lubrication System

ACHiPo

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I thought I'd post things as I learn them on the Graziano 12S. This topic is on the headstock lubrication system. It took me a long time looking through the manual, brochure, and web posts to figure it out so thought I'd share.

From all the research I've done, oil flow in the headstock is critical to the performance and longevity of the spindle and headstock gears. There are several posts and even warnings in the nearly illegible manual about the importance of motor phasing so the oil pump spins in the correct direction. As I result I've been pretty paranoid about not messing something up with these critical parts.

The 12S headstock contains the back-gear, lead-screw/carriage drive rotation direction, and thread selection. These gears and bearings are lubricated with ISO 46 hydraulic fluid, recirculated by a mechanical pump driven from the main drive shaft from the transmission. From the pump, the oil travels in a copper tube to the headstock control panel, where it flows through a brass filter element, then into a sight glass with a plastic turbine wheel. From the sight glass the oil flows to a manifold for distribution to the critical areas.

The photo below shows the headstock with the cover removed. The oil pump is highlighted with the light blue arrow. The filter and flow indicator is highlighted with the green arrow, and the manifold has the dark blue arrow.
12s headstock lubrication.jpg
 
Very cool @ACHiPo !!!

i would consider placing a rare earth magnet on the exterior of the sump near the bottom in an inconspicuous place.

the magnet will attract any iron/steel particulates to keep them from recirculating and prematurely wearing your headstock
 
Very cool @ACHiPo !!!

i would consider placing a rare earth magnet on the exterior of the sump near the bottom in an inconspicuous place.

the magnet will attract any iron/steel particulates to keep them from recirculating and prematurely wearing your headstock
Mike,
That's a great idea. I have magnetic oil pan plugs for my car--I wonder if I can find one with the right threads as it would be a good location. Short of that I can just put some magnets along the base.

Here's what came out of the filter. It's sure a good thing there IS a filter!
Evan
IMG_0330.JPG
 
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How is all that stuff getting into the headstock oil supply? If it isn't coming from the outside, I shudder to think where else it might be coming from ...
 
How is all that stuff getting into the headstock oil supply? If it isn't coming from the outside, I shudder to think where else it might be coming from ...
Mike,
It's likely coming from the gears. Hopefully not the bearings (motion seems smooth and tight so I don't think it's bearings, but I will continue to investigate).
Evan
 
It may be that all of that was from when it was first built. If you flush everything out and change the filter and it still looks like that in a few months then I would be very worried. On the other hand, if the filter is clean in a few months then you're probably okay.
 
I pulled the drip tray so I can inspect a bit better. There's definitely wear on the gear teeth, but nothing that looks particularly nasty. I'm going to drain the oil this coming week and do a closer inspection when it's dry. I also plan to do some magnet fishing. Depending on what all I pull out, I may flush with mineral spirits (other suggestions on what to use?)
IMG_0347 (Large).JPG
IMG_0339 (Large).JPG

The oil pump goes into the top of the flow indicator (shown with a orange arrow below), surrounding the filter, then exits the filter in the back, bottom, and top (shown with green arrows below). The back and top exits flow in parallel to the manifold block, which spray oil onto the spindle bearings.
Graz 12s oil filter.jpg

Here are a couple pictures of reassembly of the filter and flow indicator. Not terribly easy to access--would not be surprised if this is the first time the filter has been removed and cleaned.
IMG_0341 (Large).JPG
IMG_0342 (Large).JPG
IMG_0343 (Large).JPG
IMG_0344 (Large).JPGIMG_0345 (Large).JPGIMG_0346 (Large).JPGOil flow indicator.jpg
 
I drained the headstock. What a mess. The drain plug did not unscrew from the pipe, but the pipe unscrewed from the casting. I was able to route most of it to the drain pan, but a lot more than I would have liked ran down the side of the machine, over the sheaves, motor, etc. Ick. Glad I have some PIG oil mats, but it's still pretty messy.

There are a few metal flakes in the bottom of the headstock, but a lot fewer than in the filter, so that's good news I think. There is also a thin layer of sludge, which I assume is steel powder.

I rinsed out the headstock with mineral spirits. Not a great idea, as they reacted with the oil to make small flecks of white waxy stuff. So I wiped as much as I could of that off everything, and flushed a couple times with denatured alcohol.

While I had the tray out I disassembled the oil distribution system and blew it out with compressed air. Everything seemed to flow ok and the oil indicator spun in the right direction.

I'm letting it sit overnight for the alcohol to evaporate. I think my next step will be to fill it partially with ISO46, and manually pump it around, then drain and fill.
 
Oil change is complete except for the apron. The headstock took a little over 1.5 gal of Shell Tellus ISO 46, which is more than estimated based on the manual's requirement of 4.7 kg. The feed box took right at 1.45 gal which is what was estimated based on the manual. The gearbox took less than a gallon of Mobil DTE 26 (~3.2L) compared to the 1.1g/4L estimated from the manual.

The oil pump only pumps when the spindle is spinning, and it pumps when the spindle is spinning in forward or reverse. The oil flow indicator spins when the spindle turns in either direction. It took a couple minutes for the oil indicator to begin spinning after buttoning the headstock back up. I'm glad I generously squirted oil on everything with a syringe before starting it. (This wasn't clear in the manual, and I came across one post that talked about somebody trashing the spindle bearings because he started up the lathe in reverse.) Once the pump was primed, the oil flow indicator spins within a few seconds of starting the spindle.
 
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