Fadal 4020 head gib adjustments, any tips?

I have a fadal 4020 and seem to be getting more wandering lately with drilled holes. Always seems to drift off in same direction so looks like machine could be the problem. I put an indicator on the head and set tip on the Z ways while drilling and sure enough im getting like 3-4 thou movement while peck drilling. Looks like I need some adjustment for sure.

So I read manual and it suggests adjusting gibs until tight on a 0.001" feeler gage, then removing gage and tighten an extra quarter turn. Do I remove backlash and then tighten quarter turn? Or just 1/4 turn and thats it?

Anybody do this with an indicator instead? Maybe use prybar on spindle housing to rock the head and look for play? Or should I go buy the book? Any other advice or tips is appreciated. Thanks

I did it all With indicators shims just was difficult to set especially the top straps as the weight of the head always makes those tight.

I just put some wood on the table and jogged the head onto it and watched the indicator.

For the side gibs I just used a pry bar.

I made mine a bit tight and once I did I had a bit of stick slip but it hasn’t been an issue for me.

My y axis tram actually has the head leaned back a bit(.001” over 20” circle) instead of the normal droop down

Usually it’s the top 2 gibs set the head down on some wood to load it up adjust the gibs to a slight drag on wrench.
Don


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Thanks guys! I adjusted them a lot (several turns) and seems much better now. I used a prybar against an old toolholder to lift the head and used indicator as close as possible to gibs. Got it down to about a thou or maybe better now and it seems much better, could probably go tighter but little afraid of binding and damaging something. Machine used to make tiny thump when peck drilling before, thats gone now, and drilling much straighter. Amazing it milled as well as it did before with that much slop.

Do these adjustments tend to back off over time or is it likely that the slop is from wear? Nothing locking it in place. Seems like we are carefully adjusting it and then hoping for the best.

mmurray70 said:

Thanks guys! I adjusted them a lot (several turns) and seems much better now. I used a prybar against an old toolholder to lift the head and used indicator as close as possible to gibs. Got it down to about a thou or maybe better now and it seems much better, could probably go tighter but little afraid of binding and damaging something. Machine used to make tiny thump when peck drilling before, thats gone now, and drilling much straighter. Amazing it milled as well as it did before with that much slop.

Do these adjustments tend to back off over time or is it likely that the slop is from wear? Nothing locking it in place. Seems like we are carefully adjusting it and then hoping for the best.

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Well I don’t think anybody loosened them on purpose. I figured they just wore as time went on?

Mine are also bronze to me I would think turcite would have been better but oh well.

Glad you got it sorted.

Just thinking about all the moving back and forth, maybe screw might back off after a while? Maybe not?

Mine are turcite, machine is 1994

mmurray70 said:

Just thinking about all the moving back and forth, maybe screw might back off after a while? Maybe not?

Mine are turcite, machine is 1994

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Atleast on my machines the screws were decently tight in the gib.

Turcite gibs make a lot more sense to me

Be careful not to over tighten them, too tight will smoke the Z motor, been there done that..