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Hitachi Seiki cnc lathe turret procedure

surfit

Plastic
Joined
Apr 23, 2008
Location
ventura ca usa
I have a Hitachi Seiki CS 25 lathe the turret got bumped and is about 1/4" out of alignment does anyone have an alignment procedure?
Thanks,
 
ok here goes

Look at the face of your turret.
You will see about 6 or 8 bolts.

DO NOT REMOVE these completely...
Just loosen them about 1-2 full turns...

Throw in some sort of pointy, accuratly ground material in the chuck , then index up a center drill on the turret... Get those 2 points about .03-.04 apart from each other...

Once ALL the bolts are loose, You take a light rubber mallet And (((GENTLY)))
tap one of the tool holders in the diraction you need to for the turret to get back to center...

You will tap it a few times and you will see it move ever so slightly...

Get it as close as you can to perfect with your eyes... Then throw in a dial indicator to check it...

Remember once you are done... DO NOT tighten each bolt all the way...
Tighten each bolt only half way in sequence... Then tighten them all the way...

If you use the mallet and the turret does not move... You will probably need to extract the ground tappered allignment pin first... Its ussually in between two of the bolts... just slightly smaller hole...

What we did was ... On both our Hitachi's We removed those allignment pins completely... and never put them back in...

REASON...

If you have a major crash... that pin can get bent... And then your REALLY SCREWED!!!

Better to take it out and have the turret move a little bit when you have a small crash, or alot if you have a larger crash VS small crashed not moving the turret at all, but large crashes bending the pin...

Good luck... but this is easy, so you wont need any
 
Thank you Solar71 I followed your proceedure and it worked pretty good :cheers: but I got within .100" and it won't move any more. :angry: I found three places where it looked like pins had been removed and I don't see any other places for pin's. Any ideas on how to get it to move more? :confused:
 
you might need to loosen the bolts more...
If the pins are already removed ( thats a good thing )
You should be abble to spin the turret as much as you like...

try loosening the bolts a bit more... then try again...

Exactly how OFF was the turret to beggin with ?

I wonder if maybe you were tapping with the mallet, but went in the wrong direction...
on second thought, with the bolts loose the turret should move independantly, so direction shouldnt be a problem... hmmm

damn i wish i could help you more, but ive never had the turret start moving then get stuck.
 
Solar has some good points but indicating in the drill/ boring bar holders will only get you close because on most machines you can check several different holders and get a different reading on each, the final test is to mount a .0005 test indicator to where it can check the flat area inside the rectangular pocket where O.D. tools mount, run the turret up and down in X and make sure your within .0005 TIR. As far as the turret being stuck .100 out then look inside at where the tapered pins were located with a flashlight, if the holes are pretty much lined up then the "Bump" was more of a CRASH and the the internal Curvic coupling may have slipped and that requires the turret to come off to realign.
 
I found three places where it looked like pins had been removed and I don't see any other places for pin's. Any ideas on how to get it to move more? :confused:


If the pins weren't installed and it was wrecked, the head could have slipped far enough that the bolts "bottomed" on their sides, against their holes, bending them. Also, a bad wreck can slip both coupling halves, so you can't obtain enough adjustment on the turret head alone, as the rear coupling has also slipped. Those pins are supposed to absorb the energy of a wreck, and bend, or more precisely, displace the centerlines (think of a partial shearing). I know many on this site like to leave the pins out, but when they get damaged, they're taking up energy instead of it being transferred to more expensive parts.


Make sure you check the toolpost for squareness on the cross-slide and correct it BEFORE you try aligning the head. Otherwise, you can get a boring bar holder on center at the front, but it won't be at the rear, since the bore won't be parallel to the spindle.
 
Wouldn't the first step be checking the headstock for square???? That's where I always start. If you Bumped(crashed) hard enough to knock the turret out of alignment, odds are the headstock is off too.

Also, if this is a slant bed machine, there is no point in aligning the turret to an unsquare headstock. That could be the reason you can't get the turret to move far enough to line up with the spindle.
 








 
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