Sieg SX3 and Machine-DRO 3-Axis Kit

[JasonBModerator @jasonb]

As I have an X3 without the readout on the quill all my settings are done with the head and don't seem to suffer with judder or stickyness. Have not touched the gib in years but it's just a bit of trial and error to find the fine line between too tight and sloppy

[AdrianRParticipant @adrianr18614]

I don't have Jason's experience but yesterday I took a stab at adjusting my Z gib.

I first tried using a dti mounted on the top of the head to the column about 3" up. Using some wooden blocks and a leaver lifted the head via the quill. This resulted in about 10-20thou DTI reading and a sloping noise as the oil was forced in and out of the dovetail. Definitely proved I had a loose dovetail.

I tightened the gib about 4-6 turns before the noise stopped. I then tried raising and lowering the head. I found it got tight about 3" from the top of the column. When lowering the head from the top I could feel I was driving the head down. Then it went through a short distance of sticking/jumping and finally ran free. I used a very fine diamond hone on the column to smooth out the machining roughness to match how it had worn lower down. This improved it a little, but not much.

I then tried a second approach. I mounted the DTI under the head and measured the change in height when the head/gib was locked. I knew from past experience the head moved up a lot when locked, but after the above adjustment, I only saw 0.5thou movement. I loosened the gib till I was getting about 1 – 1.5thou over the normal working heights. After this, I found I could raise and lower the head all the way to the top without tightness or any juddering.

[Mike DonnerstagParticipant @mikedonnerstag]

I am still having issues with my Sieg SX3 Z-axis in spite of experimenting with the adjustment of the tapered gib. When moving the head with the handwheel, there is a mechanical judder that is shown on the following YouTube video:

The judder is worse when lowering the head, and only occurs when moving the handwheel slowly. As shown on the DRO, each 'judder' is about 0.05mm in travel.

Is this normal?

Mike

Edited By Mike Donnerstag on 07/01/2022 18:56:53

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