Thread: Oil seal groove

Originally Posted by philmc

Shaft diameter is 88.25mm.

No wonder its cutting in, with that additional compression of the seal.

If you ground that land down to 88, would the groove clean up?

I’d think you could have 3mm of that seal exposed, just put some gasket goo on the seal OD when you install it.

Phil.

Hi Guys,
Knowing almost nothing about these things. Is it possible that that groove is infact the only area that was ever finished to size?

Also, whats the price of failure? i.e. how much oil is behind this seal to run over the table over night.

Stuart

Those bearing would run on grease Stuart.... Will mine does and it is a similar design.....The seal gets very hot on it as well...

Hi RC,

Now I am confused

Originally Posted by philmc

It normally runs hot anyway as both bearings are in an oil bath.

My mill runs oil on the spindle bearings, but I wouldn't call it an oil bath. Its more "pour it in at the top and tomorrow morning it will be on the table. Maybe its just got some felt in there to slow the oil down?* I know you are recommended to run for extended periods with the head over 45Deg. I have no idea what sort of sealing there is. I'll go see if I can see anything.

Stuart

(I haven't been inside the head of my mill but have been on the only other Bridgeport clone I have had much to do with and it was also oil but its been to long to remember the finer details. This is not to say a Novar is a bridgport)

Originally Posted by Stustoys

Hi RC,

Now I am confused

Actually I am the one that is confused..... I thought it was a DM45 mill, but it isn't...

I was just reading another thread about a DM45 and got confused with this one...

I have no idea what a Novar mill looks like inside...

Like this. Universal, twin spindle, three motors, separate powered overarm, and feeds all axes.

Holds about 6 litres in the oil bath for the vert head.

Originally Posted by Stustoys

Hi Guys,
Knowing almost nothing about these things. Is it possible that that groove is infact the only area that was ever finished to size?

That's what I am thinking. The seal is for a shaft of 88mm.

Nev

Originally Posted by Machtool

No wonder its cutting in, with that additional compression of the seal.

If you ground that land down to 88, would the groove clean up?

I’d think you could have 3mm of that seal exposed, just put some gasket goo on the seal OD when you install it.

Phil.

Hi Phil,
If ground would just about clean up, but would be on the low side for the seal tolerances (87.86mm). Groove is only 0.19 deep and smooth, am I worrying about nothing? Most seals shaft diameter tolerances seem to be +/-0.1mm, but SKF's are +0/-0.20mm, from what I have found on the web.
Cheers Phil Mc.

Originally Posted by philmc

Groove is only 0.19 deep and smooth, am I worrying about nothing?

Truth be known, you could probably just reinstall a seal and see how it goes. That groove has probably worn concentric. Its external, if you were to make up a sleeve to push a new seal in, you could change it yearly, when the oil loss gets too bad. With a decent set of seal picks, you should be able to pull a used seal out in place.

Even if you change the brand of seal, you might find the lip runs on a different position of the journal anyway.

Regards Phil.

As per usual for this foroum you should wait untill you have at least 30 replies,then ask the question again.
In between time you should pull the susspect piece apart untill you get to the stage that you have to wait for another 20+ replies,disregard most of what is relayed here as most will be guesses.
Follow your own decision hopefully it will be ok.
Totally disregard anything that might possably be quick and easy.
Wait another few weeks or months and ask again or ask other question in regards to problems with the fix and start all again,easy.

Should we totally disregard post 26 on account of how long it takes to work out the spelling mistakes.
As usual pipeclay I say this 'tongue in cheek' and will apologise in advance

Phil