View Full Version : Problem Okuma Lathe Turret Alignment

04-12-2008, 01:33 PM

I am trying to help the lathe guy at our shop.

We have an Okuma Captain L370 L/M. The problem we are having is that after a period of time, ( or maybe a crash or 2) the turret becomes misaligned slightly so that the tool is off center.

He told me that there are two taper pins that they install to realign it, and then they take them back out after the screws are tightened. This seems to be what the manual says to do, but it doesn't make sense to me. I think the pins should be left in.

Anybody know for sure?


04-12-2008, 03:25 PM
The taper pins should not be left in. If the machine is crashed hard enough with the pins in, they will bend and become damn near impossible to remove. It took a few days to get one out the last time one of our maintenance guys left them in and the machine was smashed fairly hard. Unless you want to spend a few days with a pry bar and slide hammer, I would take the pins out after the turret is tightened.


04-12-2008, 05:05 PM
Thanks for the reply.

Is it common to have to realign the turret very often?

04-15-2008, 12:25 AM
Usually only after a crash or a few weeks of heavy interrupted cutting.

04-27-2008, 08:07 AM
Maybe you are not tightening up the turret bolts enough after re-alignment, check the bolts tensile strength CR ( i.e. 9.0 or 12.0 stamped on the cap head) use a torque wrench in NM or lbs/ft to correct tension for the diameter and CR. Never leave the taper pins in, "OTI" was correct with his advise. The pins are only there to bring the turret back to spindle centre line after a crash etc;

05-01-2008, 11:55 PM
Any time a Machine is crashed It needs to be Dialed in !!!!

05-07-2008, 11:18 PM
I am with Tzollinger and Oti, but personally I dont use the pins I dont care where the turret is, I care where the tool is, so (depending on size) I either dial the tool holder in(bigger) or dial the tool tip itself in(smaller). Just my opinion

05-08-2008, 07:57 PM
do they come from the factory with the tapper pins in?

05-09-2008, 04:58 AM
Hey Guys,
I Run a LCS-25, LB250t, and a LB300MY.

On the LB250T we had a crash where it pulled the job out of the chuck. We were holding Dia. 210mm x 50mm Pieces of Black Bar with 5mm Deep soft jaws ":withstupi" DERR! This moved the turret a whopping 0.350 mm.

The boss bought these standard taper pins from an industrial store and left them in the turret after being told by the service engineer that they shouldn't be left in. "she'll be right, It'll make her more rigid" said "you know who". no more than 5 mins later after the techs left another part came out of the chuck, it took a day and a bit for the techs to remove the pins. The removal of the turret was the killer.

Why the machine crashed again? "you know who" said "we've been making them this way for 10 Years now without a problem. Why should we change the process now?"

$65.00 for taper pins.
$1500 (approx) service tech bill
Boss Saying "SHE'LL BE RIGHT" - PRICELESS!!!!!!!!!!!!

05-19-2008, 10:06 AM
I agree...take the pins out. I recently got a new gearbox in that had no holes for alignment pins so I machined them and only used the pins for a general ballpark alignment then pulled the pins and dialed it in to zero. I just started at this new facility and the older guys were flippin out cuz I pulled the pins out. The old gearbox had the pins still in and when it got crashed the pins didnt shear they just bent sideways so they were hell gettin em out. Like stated before just make sure you torque everything down properly and you'll be good to go.

06-12-2008, 04:35 PM
Im an okuma service tech take them out the bolts are strong enough to hold the turret the pins are for fast allighnment you only need them for riggity if you are cutting real hard metals.

06-17-2008, 11:51 AM
Im an okuma service tech take them out the bolts are strong enough to hold the turret the pins are for fast allighnment you only need them for riggity if you are cutting real hard metals.

Yeah.....What he said.....:)