# Sieg SC-3 Lathe, Taper Bearing Fitment



## Ghosty (Oct 15, 2016)

Hi All,
Started with the replacement of the OEM bearings with taper bearings.
Removed the feed screw drive cover and the drive gearing.


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## Ghosty (Oct 15, 2016)

Checked positioning of drive gear.


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## Ghosty (Oct 15, 2016)

Removed chuck after indexing shaft to aid in reassembly


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## Ghosty (Oct 15, 2016)

Removed shield screw, so shield could be moved out of way of dust cover.


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## Ghosty (Oct 15, 2016)

Removed the dust cover, loosened motor mounts, removed belt, gears, spacer's and key, spacer's are plastic, will make new alloy ones


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## Ghosty (Oct 15, 2016)

Removed shaft and bearings. Had to go to a friends place to remove the bearing from the shaft in a press.


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## Ghosty (Oct 15, 2016)

Fitted the new outer bearing shells.


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## Ghosty (Oct 15, 2016)

Fitted bearing to shaft and refitted shaft.(Make shore that the dust cover is fitted to the shaft before fitting bearing) Only tighten just enough to seat the bearings. Re-fit front dust cover.


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## Ghosty (Oct 15, 2016)

Re-check position of the driven pulley.


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## Ghosty (Oct 15, 2016)

Re-assembled the shaft gears so I could make up the new spacers


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## Ghosty (Oct 15, 2016)

Machined the new spacers. The lathe is already running smother than with the old bearings, still have to re-centre the chuck.


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## Ghosty (Oct 15, 2016)

Re-assembled the drive with the new spacers, first spacer is only .5mm smaller dia than the dust cover. Set the preload and checked the machine operation. Very happy with it.


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## Ghosty (Oct 15, 2016)

Finished assembly of the feed screw gear system, I very seldom us this feature.


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## Ghosty (Oct 15, 2016)

Will spend tomorrow re-centring the chuck, and then testing it out as I have some brass bushes to make.

Cheers


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## oldboy (Oct 15, 2016)

Great write up.  Good job.  I done this ages ago, I have a Real Bull 7 X 14, the new bearings will make a big difference.

Barry.


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## Blogwitch (Oct 15, 2016)

G,

Very nicely done.

If you really want to improve your lathe, then have a look at fitting tapered gibs.

I brought back a mini lathe from the edge by uprating it and one of those mods was tapered gibs. It turned it from being bent like a banana to a very accurate precision lathe.

[ame]https://www.youtube.com/watch?v=YoxxeJ2aI2U[/ame]

[ame]https://www.youtube.com/watch?v=GnL3ipa7JO8[/ame]

Unfortunately, the site I refer you to has the same problem with some of my posts on here, the pictures are missing from when Photoshop lost all mine.


John


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## oldboy (Oct 15, 2016)

Hi John,

I have seen the article, "Fixing Darrens Lathe". It is a very a very good write up for the mini lathe's.  Am disappointed that the photos have disappeared.  Would it be possible to get a copy of them, as I know they are very informative?  My email is [email protected].  Scrollsawer61 is also my Skype name.

Thankyou,
Barry


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## oldboy (Oct 15, 2016)

Hi John,
Sorry for the second post.  I forgot to add that I am about to try and fit tapered gibs that why I was looking up you article.  I have only had my lathe and mill since retiring, so still learning everything.

Thanks again 
Barry.


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## Blogwitch (Oct 15, 2016)

Barry,

Email with 125 pictures sent. I do hope that you manage to get the job done, it really does make a massive difference to the lathe.
I have tapered gibs on both my lathe and mill, and once set correctly, they shouldn't need doing again unless you have to disturb them for some reason.

Chuck Fellows also did an article on fitting tapered gibs, I don't know if it was on here or on Madmodders, it was such a long time ago and as far as I can remember it was only a basic type of fitting not requiring as much machining, as I was putting the WHOLE lathe right at the time, so I was machining all sorts to get things square and level, putting things right as I went along.

John


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## Ghosty (Oct 16, 2016)

First test run, just to check finish

[ame]https://www.youtube.com/watch?v=Itbo4kEkvz0[/ame]


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## oldboy (Oct 16, 2016)

Looks like everything turned out fine.  Good job.

Barry


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## oldboy (Oct 16, 2016)

Thanks John for the photo's.  Yes I have seen the write up by Chuck.  Just got to get some more confidence and work out how to set up the mill for doing the tapers?

Barry.


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## oldboy (Oct 16, 2016)

Thought I had received the photo's but it wasn't them that appeared.  Thanks anyway.

Barry.


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## Blogwitch (Oct 16, 2016)

G, well done, isn't it mice when something goes right and turns out as good as you thought it would do.

Barry, the email I sent to you was returned to me as the attachment was too large, 6mb. It seems like the Antipodes has a limited download system.
 I will send you a link through Dropbox using the PM system, so read your messages.

The tapers are dead easy, just follow my pictures and text, once you have the first one cut, you use that to set up for cutting the second, that way they are both exactly the same. Use brass instead of ali bronze as I did, you will find it should last for many years.
BTW, Chucks version uses a better adjusting screw than mine, so maybe you can cobble a bit out of each post.

John


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## Blogwitch (Oct 19, 2016)

Barry,
Did you download the pictures from the link I sent to you?

I have a limited size I can hold on Dropbox, so if you have them, I can delete them and put something else in their place as I do have a couple of people waiting for bits to be sent.

John


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## oldboy (Oct 19, 2016)

Hi John,

Yes thank you very much, it is much appreciated.  Have not had much of a chance to properly go through them.  Grandparent duties taking up to much time.

Barry.


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## Ghosty (Nov 9, 2016)

Hi All,
New back plate, and 5" 3jaw chuck fitted and setup. Old one had damage in the scroll and would lock up every now and then. Mic is in 10,000"

Cheers
[ame]https://www.youtube.com/watch?v=6u5TPqtfoUY[/ame]


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## Blogwitch (Nov 9, 2016)

Just going back a bit to when you fitted the taper bearings.

I have not seen anyone going the other way and fitting solid phos bronze ones.

You may laugh and scoff at what looks like a step back in time, but when you see the results from plain bearings, you wouldn't.

I noticed straight away when I uprated my Atlas 10F to a Timken head from a plain bearing one. With plain bearings you could get finishes like they had been ground then chrome plated, they were fantastic, with the head with bearings, they come out like most machines nowadays, where you are chasing a better surface finish.

If ever I went to decorative work, the first thing I would do would be to pick up a mini lathe and fit solid bearings.

Not trying to deflect the post, just attempting to show people that sometimes we go backwards when going forwards.

John


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## goldstar31 (Nov 9, 2016)

Actually the bearings on my recently acquired but ancient little Myford ML10 are cast iron whilst the nose bearing on the Super7B is phosphor bronze.

Most of the answer lies in the relative bearing surface areas.  Oddly, it surprising but there are a lot of full size propeller stern tubes made from - lignum vitae.


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## Ghosty (Nov 9, 2016)

Blogwitch said:


> Just going back a bit to when you fitted the taper bearings.
> 
> I have not seen anyone going the other way and fitting solid phos bronze ones.
> 
> ...


I though about that, but would be really hard to machine the bearings when the lathe is in bits, you would also need to machine a new spindle. This lathe replaced an old Advance lathe built back in the 20's, had split cast iron bearings in the head, adjusted with a bolt, had a lead screw to move the carriage for and aft, this is what wore out and was going to cost in excess of $1000 to have a new lead screw and block nut made.

Cheers


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