Lathe Spindle Direction Wrong

[Paul Nelson]

I am mounting a left hand tool in a rear turret 2 axes lathe. I need the spindle to run in reverse (M04) or CCW as viewed from the headstock end. (this is the standard is it not?) The only way I can get it to work is to say I have a right hand tool. If I specify the correct left hand tool I have to choose Mastercams CW (in setup tool) which appears to be viewed from the tailstock end. The orientation of the tool looks correct in Mastercam but outputs an M03 instead of a M04.

Am I doing something wrong? I am about to change my posts to output the opposite spindle direction.

Thank you in advance.

[Andy]

You are using lathe8??

I had trouble with this ccw/cw in ver7. Single spindle!! But ver8 cured the problem in tool setup.

So I dont know about 2 spindles but your post should be adjusted to the tool setup so you will get a consistent result as you are about to do.

Look for more answers here from others.

Andy

[Paul Nelson]

Thanks for your reply Andy. Yes, I am using version 8.1.1. and single spindle/turret regular lathe. It appears a tweak to the post is the solution although I hate to have M04 output when CW is selected in tool setup.

[cam-eleon]

Looks like as a std(gotta start somewhere) Mastercam has decided that lathe tools should run upside down in the positive side of the centerline. Therefore RH tools and CCW rot(as viewed looking into the spindle from the tailstock) is OK. If you want CW rot then a left hand tool and the reversal of the turret clamping block is req. I make this upside down/CCW my std and if another lathe in the shop is different then I let the post handle the change in direction. The tool designation is another story.

I tend to look at spindle rotation as "normal" direction and "reverse". I then let the post handle what code goes with what direction.

[ 10-23-2001: Message edited by: cam-eleon ]

[Andy]

Just to define terminology:

1. M4 Is cw viewing chuck from tailstock.

2. A left hand OD turning tool is a tool that turns the backside of the stock(opposite side from where we are watching with the spindle to our left)and turns from right to left. Insert is on the top of the tool holder. Tool is not upside down.

This LH RH tool terminology can be real confusing especially on the backside of the work. I always remember it from the manual lathe: tool on my side, turning OD right to left is a RIGHT HAND tool.

Someone decided that 100? years ago.

 

Anyway I get m4 in my post for this set up and it is consistent with the tool setup page.

On the tool setup page I choose:

1 Vertical tool (and insert facing me or up)

2 Reverse tool NOT checked.

3 Top turret

4 Clockwise Spindle

5 Left active spindle

So the pictures fit the actual machine.

Do you choose these and get m3??

Also check Job SU/Turret-Spindle settings?

I dont usually check these cause it always works right.

In version7 this stuff never worked right.

Andy

[ 10-23-2001: Message edited by: Andy ]

[ 10-23-2001: Message edited by: Andy ]

[ 10-23-2001: Message edited by: Andy ]

[Paul Nelson]

Thanks Andy,

I agree with all of your statements although it is my belief that when determining cw and ccw on a lathe the standard (not Mastercam's) is that you view it from the headstock. It bothers me that in Mastercam Lathe you drill a hole with ccw and Mastercam Mill you drill a hole with cw! And yes, I determine left and right hand tools by the way they sit on a regular conventional lathe. I also prefer forward and reverse (or M3 M4) terminology as opposed to the confusing cw ccw.

I checked all my settings and they were the same as you described ( the list of 5) To be certain I was using a left hand tool which I believe you were using too. (you described it at the top of your post) I also checked the Job su/turret - spindle setting and they were ok.

All of this produced a M3. Interestingly enough the mpfan post produced M14 (close enough to M4 for me)

So, I tweaked the posts. Here are the three changes I made:

sm04 M03 # Spindle reverse

sm03 M04 # Spindle forward

#if opcode = 104, pswtchspin #Reverse spindle direction

I commented out the last line so when the opcode was threading, the spindle would not reverse.

For better of for worse, thats what I did. Works ok but I would not doubt there is some consequence lurking in the background.

I still don't know why it happened. If anyone does, please let me know.

Thank you for your assistance.

Paul

[Andy]

Paul,

I seem to remember 2 years ago making the same change to the post. So far no bad consequences.

It is an interesting question about how to view the cw ccw diriction of drills etc.

For example, if you view a drill in the drill press as cw rotation, ie looking down from above the drill (Better use a RH drill), and as your drilling the hole the the drill stops turning and the stock starts turning and you still get chips, then the stock is turning CCW.

But maybe someone can tell us why any particular convection was chosen. I cant remember what convention I have always used in the manual lathe, if any. Only when I back that tap out I better REVERSE it. I dont think I ever thought CW or CCW. Forward and reverse maybe. The concept became more important in the cnc for me when the tools were cutting on the backside. But drilling was still the same. So now I must THINK about rotation, more aspirin please. Lets see, I am cutting an internal LH thread with a bar that has a rh insert but is upside down cutting on the close side of the bore.........????

What a puzzle!

Andy