[SDesigns]

Hi, I have seen a post here months ago, about how to grease the spindle bearings on an SX3, but cannot seem to find it now.

My spindle is rather noisy, and I would like to try and grease the bearings in the hope that the DB count will come down dramatically.

Can anyone explain how to do this?
Is this a 2 hour job, or a two week job?
Is the quill spring tricky?

[neilw20]

There are 2 spindle bearings AND a separate bearing assembly supporting the top pulley which has radial loads on it from the belt. It is much more likely to be from where the noise emanates.

There has been a thread somewhere where the whole assembly has been rebuilt to have 2 bearings. Attached are the drawings, which I have no idea of how sound the design is, but might help.

My spindle has done close to 2000 hours, and most noise I had was from the belt not running in the center of the pulley.
Careful shimming of the motor bracket will solve this.
I have never dismantled the spindle. Only the pulley assembly, which drives the spline.

When lightly loaded extra noise can come from the spline rattling, particularly if the too in the spindle is heavy, acting like a flywheel.

[SDesigns]

Hi Neil,

It's a whining sound, much like my kids, only more irritating.

If it is simply a shimming issue, it's easy to sort out.

"a separate bearing assembly supporting the top pulley"
Is this a sealed bearing, and is it easy enough to replace?
Does the quill have to be removed?

[neilw20]

The bearing assembly unbolts from the top.
Try running with the lid off and see that the belt is tracking OK.

BUT !!!
Be very careful with the display wiring and limit switch wiring etc.
One short to ground and POOF!!! Bye Bye motor controller and more.

IMPORTANT

Remove the power first!!!

Put the quill all the way down, engaged with hand wheel, before removing the front panel so the DTI does not dameg the push button PCB assembly.

[SDesigns]

Thanks Neil,

I'll give it a try.
How tight should the belt be? Mine has a bit of "flop" to it.

I dont remember seing any wiring under the spindle pulley cover, but will take care.

Do the bearings in the top bearing assembly need to be pressed out? do you have the bearing size?

Have you got a diagram illustrating this Neil?
I seem to remember that you have a few different ones.

after 2000 hours of use, how noisy is your spindle?

[neilw20]

About the same as when I started. Just noisy. But it is just a combination of all the noises, the belt, the spline(mostly) and the echo chamber.
If you load up the spindle the noise decreases a bit.
Once you unbolt it it is fairly easy to see how it goes together.
Not sure whether it can be dismantled without damaging the bearing.
No way to push it out properly, I think.

[SDesigns]

Thanks Neil, I'll give it go later today.

[Journey_Man]

Here is the Link to the Spindle Mod by Old Megawatts..

http://www.cnczone.com/forums/syil_p...ification.html

[SDesigns]

I took it apart on Friday afternoon to get a feel for what i'm in for.

The top pulley bearing is running smooth, and with this removed, I can feel that the other three are the cause of my problems.

How do I remove the quill?
I removed the depth guage and found the rotational stop pin. Now ...... how do I remove the spring without causing injury, and how do I remove the horizontal shaft?
Will the quill then "drop" out?

[neilw20]

This should help..

[SDesigns]

Thanks Neil.

I have the manual that came with the machine, but it doesn't show clearly how the spring is attached. Once removed, how do I tension it again?
Is this done by simply turning the cover?

[neilw20]

I guess so. Never pulled mine apart.

[SDesigns]

The bearings should be delivered this afternoon.
I must still make a tool to get the nuts off the spindle.
Thereafter, i'll let you know how how it works out.

Hold thumbs .....

[neilw20]

Hold thumbs? We call that crossing fingers.

[SDesigns]

Okay .... so I managed to get the quill out without any difficulty.

Now comes the hard work. How do I get the spindle shaft out of the quill? I have hit it with a rubber mallet a few times, but it doesn't seem to have budged. Any advice?

[neilw20]

Rubber mallet will absorb most of the hit.
You need someone, who is game enough, to hold the quill with some leather gloves while you strike firmly with a copper hammer.
The force will react against the mass of the housing.
If it does not move then it really needs clamping (without crushing) and pressing out.
The poor design does not lend itself to ease of dismantling.
The force used dismantling it will no doubt leave the bearings in a noisier state than when you started.
Because it has a hole through it you should be able to use a bolt or threaded rod to press it back together, with suitably made tubular spacers to ensure that no axial load is placed on the new bearings (through their balls).

Anyone else who has pulled one apart??? I am sure there are some experienced CNCers there. Hello.....????

Just my comments and MHO.

[SDesigns]

...... I didn't want to clamp it.
I'll just keep trying with the hammer. I dont have a copper one, but will use a block of wood and a regular hammer.

I like your idea about the threaded rod fro re-assembly.

[neilw20]

Hardwood, not too thick, and hit the end grain (preferably), with a BIG hammer.
It is all about transferring the energy to the place(s) required.

Make sure there is a soft landing surface as sometimes it might exit like a bullet.

[SDesigns]

Thanks for the tip Neil.
I'll let you know how it works out.

[SDesigns]

It came out easily. [relatively]
I placed a hard wooden block on the floor, turned the quill upsidedown, and knocked it firmly on the wood a few times.

Right ..... now that that is done, how do I get the old bearings out?
I'm going to cheat here, and send it to a mate down the road....

Watch this space.....