Sieg SX2 mill

[Ghosty]

Machined the lip off the dust seals and installed the grease seals, then fitted to head, both upper and lower the same.

 

[oldboy]

Hi Ghosty,

Where in NSW are you. I am in Blacktown about 30km west of Sydney. Would love to have a talk about your mill and what you have done to it.

Thankyou.

Barry (Oldboy)

 

[Ghosty]

The rest is just reassembly of the machine, had to machine 1mm off the driven pulley to get the correct height. Done some machining of the removal too so it could be fitted into the machine for removal of the outer bearing shells. Now have almost a mirror finish, will have to keep messing around with the bearing pre-load, running a little hotter in the bearing areas.

 

[Ghosty]

Had the material all ready cut so I started machining up some more quick change tool holders, have been messing around with the bearing pre-load as well, I think I have it set about right now. No chatter at all, will have to wait and see now.
Hope this may have helped some one.

Cheers

 

[Blogwitch]

Very nice work G, nicely shown as well.

Unfortunately, there are a couple of problems when using tapered bearings with a preload.

The first and one that should always be followed is to allow the machine to warm up for about ten minutes before use, this is to allow the spindle to expand and reach it's working length by which time the preload should be almost non existent. I do this with my lathe, which has preloaded head bearings, before I start for the day. It might only be a couple of thou, but that could mean the difference between a failed job or not if working to tight tolerances.

The second is that if leaving the machine idle for any length of time, say over a month, you should release the preload to prevent the rollers in the bearings taking up a permanent place in the races causing 'brinelling' or make sure that the machine is run up regularly to ensure that the bearings are sitting in a slightly different position.

I had this very badly when I was restoring my previous lathe, an old Atlas 10F. I had bought a second hand Timken bearing head to replace the plain bearing one. Because the head hadn't had the preload removed before storage, it was like a heavy ratchet when it was turned, and I had to have the races reground to get indentations out of them. I should have fitted new bearings really, but the Atlas has specially ground shaped races and would have required a second mortgage to pay for them.

There is also the problem of the age old grease or oil syndrome. In a lathe, the bearings are horizontal and usually lubricated with oil, either from the gearbox or a drip feed from the top, I don't know how you can ensure an oil feed to a vertical setup like yours as grease isn't recommended as it can cause 'hydraulicing' on the rollers and cause pitting. My mill has oil cups for feeding both top and bottom bearings.

Even though I have had a long layoff from my workshop, I religiously go in there every week and lube up then run my two main machines for a time just to prevent problems occurring.

John

 

[Ghosty]

Thanks John, After doing this, I could retro fit an oil dripper, or oiling point to these machines, but the use of a light weight sticky grease and the weight put on the spindle, as these are only light weight machines, I will just have to see how much time I get out of it.

Cheers