Hello Guest it is June 14, 2021, 12:57:57 AM

Author Topic: Re building an Okuma LS-N  (Read 5157 times)

0 Members and 1 Guest are viewing this topic.

Re building an Okuma LS-N
« on: April 16, 2007, 03:19:08 AM »

I have an Okuma LS-N, which I will try and rebuild to run from Mach3.

The lathe is fully functional except that I get a DIFF error on the drives. This is due to the absolute encoders, which have been turned out. Okuma personnel are not interested to help me out.

I have a few questions, and hoping someone will be willing to help me.

Drives: My lathe has working servo drives, and according to the documentation these drive take an analog voltage then provide a rpm to satisfy. My question will ordinary PWM (Mach3) satisfy, if I run the PWM signal through a DA converter? I don't really need the Tacho on the servo's. I know I will have to replace the absolute encoders with incremental ones.

Relays: I have 2 turrets on my lathe, they are operated via relays. My plan is to use an IO card I have to provide these signals. I've read the Mach docs and it seems possible.

Spindle: I have a 12 speed automatic gearbox, which determine the speed selection as well, also relay driven. Will convert same as above.

If anyone who has experience is willing to help me, I greatly appreciate it. My lathe is not operational, and I do need to get it to a functional stage ASAP to make some living.

Greatly appreciate any pointers and help.


Ruan Basson
South Africa

Offline Chaoticone

  • *
  •  5,626 5,626
  • Precision Chaos
    • View Profile
Re: Re building an Okuma LS-N
« Reply #1 on: April 16, 2007, 09:41:25 AM »
Ruan, I will help all I can which will be limited at best. What series controller does it have? Do you have and manuals for it? If not, I may be able to find some. Can you post some pictures of your machine? I have a great intrest in knowing all of the details to make this work as well.

;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!


Re: Re building an Okuma LS-N
« Reply #2 on: April 16, 2007, 12:26:06 PM »
I am doing a lathe retro at the moment, it has a rear turret and front toolpost which are hydraulically operated through relays. Also it has a 24 speed spindle (actually only 16 as some are duplicated) which is worked by electromagnetic clutches. I have used a PLC to control all of this and it works great, maybe you could do the same.
 The problem I am having is I got the lathe through my friend and he got it for the drives and control. This is where I am hitting a problem as the motors are huge and I am having trouble getting drives (reasonablyl priced ones as I am on a budget) that can handle the current these motors demand. You are in a better situation as you have the drives and should be able to use a couple of Pixie or Rutex boards that convert the Step/dir to analogue.
 Would like to see pics as well.
Re: Re building an Okuma LS-N
« Reply #3 on: April 16, 2007, 02:23:41 PM »

Thanks for the replies.

For starters, I do have manuals (electrical diagrams as well), the controller is an OSP 2200 . Pictures I'll take some tommorrow and post tommorow night. I have a complete control set, but some of the connectors at the cards has been pulled out (the pins), I can't find any pin out diagram to check if everything is OK. With my multimeter I can't really trace sensible connections to the panel. But with the exception of MDI everything als seems to be OK.

Numerous people said if I do get problems with any of the cards, I will have trouble. So, I thought a modern PC will probably cope better than a 70's odd control with the huge 16K memory!

For the two servo motors, the Z axes runs a 1.5 Kw ad the X axes a 750 W motor.

The lathe is an excellent condition (except paint), there is absolutely no play on any of the leadscrews and she is very solid. I could not find indication anywhere of wear on any component.

For the drives, I saw this link on CNCZONE alot of potensial


Think is that I do need this lathe in operation, and by money saved by using Mach3, I can rather spent on really good encoders and a nice panel, maybe.

I'm also on a very tight budget.

Will post you guys the pics tommorrow.

Thanx again
Re: Re building an Okuma LS-N
« Reply #4 on: April 16, 2007, 09:43:06 PM »
You are not going to like the lathe and I think you should give it to me :)

I like Okuma's :)

Fixing problems one post at a time ;)