[B_Bueno]

I am doing maint. on my 4020 and will be checking the play in the axis. I might encounter the need to adjust the gibbs.
I would apreciate any advice or input with correct procedures involving this.
Thank you

[FanucIssues]

I will see if I can get time to get the fadal disc out, and see if I can get some instructions for you.

[cadman]

You will need a very long hex key to reach the adjustment screw. Take a 2-3 foot rod and mill the flats on one end for the screw, then mill a couple flats on the other end so you can turn it with a wrench of your choice. Reaching the adjustment screw is a mild pain in the ass and you will thank yourself for making a cheap adjustment tool.

[B_Bueno]

Thank you both,
I look foward to more info when you get the disc Fanuc.
Cad, I have no idea where the screw would be.

[FanucIssues]

For one thing, be sure to watch the x, and y load when you dial the table back and forth, at a one rotation of the dial a sec (Roughly). If the load is nice and smooth then the ball screw nut should be ok, but if is high at one end lower in the middle then high at the other end, then crack the ball screw nut loose, half a turn, and then dial it from one side to the other then back, but on the way back snug the bolts back up, doing that a little turn each tim, until the nuts are tight. I've found that this helps on a lathe too.

[B_Bueno]

Fanuc,
Do you have any literature you possibly e-mail me?
Thank you

[cadman]

Thank you both,
I look foward to more info when you get the disc Fanuc.
Cad, I have no idea where the screw would be.

http://www.fadal.com/index.php?id=3626&L=0%23Top

You can download service manuals here. When you do a gibb adjustment on the Fadal you will want to check out the table straps and also adjust the backlash.

[B_Bueno]

Thank you for the direction Cadman

[FanucIssues]

I don't know if you had gotten that adjusted yet, but here are the instructions I found. Hope it helps, I remember it not making sence reading it, but when I spent some quality time with our Fadal, it made a little bit of sence.


There are two gibs at the front of the table and from 4 to 6 Gib/Strap
assemblies on the underside of the table (depending on the VMC model, see
Figure 6-1). The following procedure covers adjustment of the front table gibs. There are two front gibs, one on the left and one on the right. This adjustment procedure is applicable for all VMC models.

1) Center the table at the X-axis cold start position. Attach a magnetic base
and an indicator just below the gib, as shown in Figure 6-7. Adjust and set
at a zero reading.
2) Place a pry bar between the front table gib/strap assembly and the saddle.
3) With the pry bar, move the table forward so the solid rear way of the table is
against the saddle.
4) Zero the indicator.
5) Place the pry bar between the rear table gib/strap assembly and the
saddle.
6) Gently pry the table the opposite way.
7) The indicator reading is the adjustment that needs to be made. A properly
adjusted set of gibs will have a front to back motion of .0003”.
8) If the gib needs adjusting, there is a gib adjuster screw located at the end
of the gib. Turning this screw clockwise will loosen the gib and turning it
counter clockwise will tighten the gib.
9) Repeat the above steps until a .0003” indicator motion is achieved. Then,
perform the procedure over again for the gib at the opposite end.
After both gibs have been completely adjusted, run the table to its extremes at
the plus and minus ends and then return the table back to center. Then, repeat
the above gib adjustment procedure for verification.
When adjusting gibs with shim stock, use extreme care to prevent ripping the
shim and leaving pieces of it between the gib and way surfaces.
There are gib/strap assemblies on the underside of the table at the front and
rear. Depending on the model of VMC there will be from one to three gib/strap
assemblies at the front and at the rear.


Adjust the gib/strap assembly as follows:
1) Jog the table in the X-axis to clear the cold start indicator.
2) Loosen the three hex head bolts. The slot for the bolt is tapered. When the
gib is moved, the head of the bolt may bind. Verify that the bolt is loosened
enough to allow the gib to slide from left to right.
3) Slide the gib to the right to loosen the gib. The gib must be loosened first
before it can be tightened. To move the gib, use an open end wrench or a
hex head and tap with a mallet.
4) To adjust, slide the gib to the left (operator orientation is facing the strap)
until it contacts the underside of the saddle. Use finger pressure to push
the gib.
5) Verify that each of the three hex head bolts are not caught in the tapered
slot. If the bolts are binding on the slot, loosen and re-adjust the bolts.
6) Tighten the three hex head bolts.
7) Repeat the above steps for the opposite table gib/strap assembly.
There are two gibs to the right of the center base rail and two gib/strap
assemblies on the underside of the saddle. The following procedure covers
adjustment of the center saddle gibs only. The following adjustments apply to
all VMC models. It may be necessary to remove the rear Y-axis tray to adjust
the saddle gibs.


1) Center the saddle to the Y-axis cold start position. Attach the magnetic
base and indicator to the saddle. Position the indicator as shown in Figure
6-8. Set the indicator to zero.
Figure 6-7 Position Indicator
2) Standard machines: Place a pry bar between the right saddle gib/strap
assembly and the base.
2) Performance Models: Place a pry bar between the X axis ballscrew mount
and the table.
3) With the pry bar, move the saddle so the solid way of the saddle makes
contact with the center base rail.
4) Zero the indicator.
5) Standard machines: Place the pry bar between the left saddle gib/strap
assembly and base.
5) Performance models: Place the pry bar between the other side of the X axis
ballscrew mount of the table.
6) Gently pry the saddle the opposite way.
7) The indicator reading specifies the amount that the gib should be adjusted.
A properly adjusted set of gibs will have a side to side motion of .0003”.
8) If the gibs need adjusting, there is a gib adjuster screw located at the end
of each gib. Turning this screw clockwise will loosen the gib and counter
clockwise will tighten the gib.
9) Repeat the above steps, until .0003” indicator motion is achieved, then
adjust the gib at the opposite side.
After the gib adjustments are complete, run the saddle to its extremes at the
plus and minus end and then back to center again. Then, repeat the above gib adjustment procedure for verification.
When adjusting gibs with shim stock, use extreme care to prevent ripping the
shim and leaving pieces of it between the gib and way surfaces.
There is one gib/strap assembly on the left side of the saddle and one on the
right. Each gib/strap assembly has two gibs that require adjustment. Adjust the
saddle gib/strap assembly as follows:
1) Loosen both the front and back gibs on the strap by turning the gib adjuster screw clockwise.
2) Insert a .001" shim about three to four inches between the gib and the
way. Place shims in both the front and rear at the same tim e.
3) Tighten the gib to pinch the shim between the gib and way by turning the
gib adjuster screw counter clockwise. Tighten the screw enough to prevent
the shim from moving.
4) Slowly turn the gib adjuster screw clockwise while pulling on the shim.
WARNING
Shim stock is very sharp!
5) When the shim starts pulling out, stop turning the gib adjuster screw and
remove the shim completely.
6) Turn the gib adjuster screw 3/4 turn counter-clockwise.
7) Repeat the above steps for the front, rear, left, and right gibs.
!