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View Full Version : SX3 style mill -- z-axis gib adjustment



kayaker
11-02-2012, 09:04 AM
I am a beginner's beginner, so be gentle. I've had my new Grizzly G0619 for a couple of months now. The head seems to move up and down the column "extremely" freely to the point where it will almost move down on its own if you crank it down quickly. But to this point I have not taken a look at tightening the z-axis gib. However, yesterday I finished installing the z-axis DRO and now when I tighten down the head, I can see on the DRO that there is a lot of movement measured on the DRO display. I had the same issue on the X and Y axis, and snugging up the gibs a bit nearly eliminated the movement on the DRO reading when I lock them down now. I was hoping for the same effect on the z-axis. So here is the question. How do you adjust the gib on the z-axis of a G0619 (SX3)? The gib is bounded on the top and bottom by very large flat headed adjustment screws and I thought to would be a good idea to ask how they work before taking a chance at messing them up like I did with when I tried to remove the backlash from the x-axis. I would appreciate hearing about people's experience on this.

Thanks in advance.

uncle pete
11-02-2012, 11:47 AM
Going by your description those are the normal tapered gibs. One screw gets loosened and the other gets tightened so it move the gib inwards and tightening the clearances. Once your setting is correct the loose screw gets tightened against the gib and that locks the setting. DON'T try and get it too tight. It's better to have a slight clearance than an accelerated wear problem on the feed screw and nut. If your dovetails and gib are straight and with a high finish I'd expect you should be able to get fairly low backlash. If I recall your mill also has a spindle so normally the head is locked in the rough position and the fine setting is done with the spindle anyway. You should try and keep your spindle retracted into the head as much as possible, that helps a lot with rigidity.

Pete

kayaker
11-02-2012, 01:48 PM
Thanks uncle pete. I didn't understand that the gib was tapered, but that makes sense. I'll give it a go. Is it worth while to lower the head onto a block before making the adjustment so there is virtually no load on the gib to fight against?

dewat
11-02-2012, 03:04 PM
Kayaker,
You might want to join this Yahoo group, a lot of good info.

http://tech.groups.yahoo.com/group/X_Series_Mills/

.
Jim

kayaker
11-02-2012, 03:12 PM
Kayaker,
You might want to join this Yahoo group, a lot of good info.

http://tech.groups.yahoo.com/group/X_Series_Mills/

.
Jim

Thanks Jim, I'll give it a look.

uncle pete
11-02-2012, 04:57 PM
Jim,
Maybe for the initial adjustment that block would work ok. But those adjustments are a bit of trial and error anyway till you get everything as close as possible while still allowing smooth and free movement on your mills head. Depending on the pitch of those screws, it doesn't take much of a turn between the correct adjustment and far too tight.

Pete

oldtiffie
11-02-2012, 05:15 PM
Here is the mill.

http://www.grizzly.com/products/6-x-21-Mill-Drill/G0619

Here is the manual:

http://cdn0.grizzly.com/manuals/g0619_m.pdf

See page 27 for gib adjustments (all gibs).

kayaker
11-02-2012, 06:09 PM
Here is the mill.

http://www.grizzly.com/products/6-x-21-Mill-Drill/G0619

Here is the manual:

http://cdn0.grizzly.com/manuals/g0619_m.pdf

See page 27 for gib adjustments (all gibs).

Thanks [oldtiffie] for the smack in the back of the head. I went to that page for the x and y and somehow didn't even notice the z. Unbelievable!

Thanks again.

lugnut
11-02-2012, 08:22 PM
Oldtiffie beat me to it,, if all else fails, read the instructions. ;o)
Mel

velocette
11-04-2012, 09:29 PM
Can I add a small tip. Use "Cup Point" grub screws for gib adjustment and a "Ball Bearing" that is "Tapping Size" for the Gib Screw I.E 6 mm thread 5 mm ball bearing.

This is how it will be " < o > " on the screw end to gib.

I learned this from an old timer many years ago and now I am an old timer and still passing this on.

This will improve the "Feel" when adjusting


Eric

kayaker
11-05-2012, 07:39 AM
Can I add a small tip. Use "Cup Point" grub screws for gib adjustment and a "Ball Bearing" that is "Tapping Size" for the Gib Screw I.E 6 mm thread 5 mm ball bearing.

This is how it will be " < o > " on the screw end to gib.

I learned this from an old timer many years ago and now I am an old timer and still passing this on.

This will improve the "Feel" when adjusting


Eric

Hi Eric:

I like this, but as a beginner I need a little more detail. First, are you saying replace each of the 4 gib adjustment grub screws on each of the X and Y axis, or the lock-down bolt or both? Also, I don't understand the comment about a ball bearing this is tapping size.

Thanks in advance.