[aarongough]

Got to the shop only for a little while this evening. Did some prep work for the next pieces.

The 2 inner elements of the labyrinth seal will be going between the frontmost bearing and the shoulder on the spindle, this means that if they're not parallel then they will cause the all the pressure to hit the bearings unevenly, which I am pretty sure is not a good thing

So the faces of the parts need to be parallel, to very close tolerances. One part resembles a washer and should be relatively easy, if I had a surface grinder I would use that to grind it to thickness, but lacking the grinder I will be doing it on the lathe instead.

With this in mind I took a DTI to my chuck to see what the front face looked like. Bear in mind this is a new lathe and I'm dialling it in as I go.

The front face of the chuck was out by almost 0.003", which is obviously not great. I took the chuck off the backplate, cleaned up the back face of the chuck with a stone (it had many dings in it), removed the backplate from the spindle, stoned the back face of the backplate, reinstalled it and took a skim cut over the chuck mating surface and the registration boss.

I then re-fitted the chuck. There was only 0.0005" variation left in the front face of the chuck now after I bumped the chuck body concentric. I took a very light skim cut on the face of the chuck to get it dialled in. After the cut I read only tiny amounts of surface noise when using my 0.0005" DTI.

I still don't have the machining plan for the labyrinth parts worked out, but at least now I have a good base to work from! I'll probably have to repeat the process with the faceplate and 4-jaw for the lathe as they all seem a little sloppy.

[aarongough]

Hey all.
Bad news unfortunately...

My *new* lathe is really not up to the sort of quality that I had expected when I bought it. I haven't been able to find something better as a replacement either, which means that I am probably going to be sinking the money I had intended to go into the 5C spindle build into fixing up this lathe that I just bought.

I intend to come back to the 5C spindle build as it's a project that still has a lot to teach me, I just think the timeline may be a fair bit longer now.

I really appreciate all the help you guys have given me so far! It won't be in vain, I will be back. It's just a matter of time!

Best regards,
Aaron

[Bob La Londe]

Have you made any progress on the 5C build? Any new and innovative thoughts?

[aarongough]

Have you made any progress on the 5C build? Any new and innovative thoughts?

Unfortunately not much progress no. I discontinued the product I was building the lathe for, so I didn't have much motivation to finish it. It also turns out that the 'large' lathe that I bought needs a bit of work before it's up to the task of doing any high-precision work.

I do have all the parts for the 5C headstock though, including the bearings and a 6x6x6" block of aluminum for the headstock block. Hopefully some day I will get to finish it.

Sorry for the disappointment...

[Bob La Londe]

I had been considering a similar build and was following yours. Particularly the stuff about labyrinth seals. Hope you get inspired for it again someday. I have a mini lathe and slightly larger mini lathe and the hardware to convert one of them to CNC, but I was thinking your approach had the potential to be so much better in that everything would be built with CNC in mind.

[sandric]

Any luck with that?

[ngr1]

Hello, I am embarking upon the same project and have all of the raw materials I need.

The bearings I am going with are below and the configuration can be seen in the attached drawing.

6209ZZE Nachi Bearing Shielded C3 Japan 45x85x19
https://www.vxb.com/6209ZZE-Nachi-Be...-p/kit9569.htm

The spindle housing will be cut from 12L14 or CD1144 as recommended here.

I have two questions that I hope I can get some feedback on.

1) Is a spacer needed between the two front bearings? I assumed yes in order to set a pre-load when tightening the lock nut on the tail end of the 5C spindle.
2) Is a spacer needed between the 2nd bearing in the front and rear bearing? I do not think so as the outer races of the bearing have a shoulder machined into the housing to support them but I could be wrong.

Any help would be appreciated... thx.

[ngr1]

Drawing.

[mactec54]

Hello, I am embarking upon the same project and have all of the raw materials I need.

The bearings I am going with are below and the configuration can be seen in the attached drawing.

6209ZZE Nachi Bearing Shielded C3 Japan 45x85x19
https://www.vxb.com/6209ZZE-Nachi-Be...-p/kit9569.htm

The spindle housing will be cut from 12L14 or CD1144 as recommended here.

I have two questions that I hope I can get some feedback on.

1) Is a spacer needed between the two front bearings? I assumed yes in order to set a pre-load when tightening the lock nut on the tail end of the 5C spindle.
2) Is a spacer needed between the 2nd bearing in the front and rear bearing? I do not think so as the outer races of the bearing have a shoulder machined into the housing to support them but I could be wrong.

Any help would be appreciated... thx.

If the Bearings are not a matched pair, then you would have to have a shim, of some kind, to preload the bearings, you will have to measure the Bearings to get the correct preload, the bearings you have posted are not suitable for a spindle like this, normally you would have AC bearing in the front, and a radial ball at the rear, if you use these, which you can, don't buy ZZ you will need RS, The ZZ is just a shielded bearing, the RS are a sealed bearing

[ngr1]

Thanks Mactec54, just what I thought about the spacer. The ratings for the bearings seemed good in all directions and for a hobby application I think I will give it a try.

Will post an update when it is done.

[ngr1]

Parts are now machined and everything is designed to be a press or interference fit. The ID of the bearings is exactly the OD of the spindle which is 45 mm so I am hoping I can get some advice about the order of assembly and how to use heat and cold to get this assembly together.

I have come up with two options, any advice would be appreciated.


Option 1:

1) heat housing to the point where any water evaporates immediately
2) freeze bearings
3 press front (with spacer) and rear bearings into housing.
4) heat the housing again with the bearings inside.
5) freeze spindle
6) slide the frozen spindle into the bearings.

Option 2:

1) heat front bearings only
2) freeze spindle
3 press front bearing onto spindle with spacer
4) freeze spindle with front bearings
5) heat up housing
6) Press spindle into housing with front bearings.
7) freeze rear bearing.
8) heat housing with spindle and front bearings
9) press rear bearing onto spindle and housing.

[DSpeck]

We've been doing a bunch of stuff at work with bearings, lately. From this experience, I can tell you that the option 2 is your better choice. Also, your bearings should be a tight fit on the moving element (the spindle), and a loose, almost sliding fit into the housing. This is because if you press from both the outside and the inside of the bearing, all the space is taken up, and you will be too tight on the bearing balls. Thiat will lead to noise and premature wear on the bearings. Step 7 and 8 in option 2 are a no-no, as the bearing would end up too tight on the spindle and damage will occur. Just press it in as evenly as possible, with a thin coating of oil to help it into place. Heating and freezing in the order you have them in those steps are the opposite of what you want to do.

If you can heat up the housing, make sure it is hot enough the bearings slide in easily, so they have little to no stress on them. Cool it down from the outside fairly quickly, so the bearings are not overheated from the transmitted heat, as that can ruin the grease in the bearings (guess how we found that out...).

Hope this helps (and isn't too late).