O/T Lathe Spindle Directions

[dan m]

We just purchased a new Mori Lathe. What I am wondering is what is the difference of setting the machine up with left hand tools verses right hand tools? I realize that right hand tool runs the spindle in the normal direction and left hand tools is spindle reverse. The operator would like this machine setup with left hand tools because it’s easier to see the inserts. I have to believe there is a reason slant bed machines are designed to use right hand tools I just don’t know what the reason might be. If anyone could shed some light on this subject I would appreciate it.

 

Thanks

Dan

[crazy^millman]

Well dave i think it will be up to what makes him comfortable need to have more thought. I have done both and have had good results. The only place it will give you trouble is threading and if you are going in one direction for threading then it will make it more productive for parts and if you want to keep wear and tear down then you would want the tools facing the same direction. If you are changing spindle direction 5 times in a program and it take 3 sec to do this then over 1000 parts you have added 4 hours to the job. Having the tools left hand will throw chips at the door where as right handed tool will throw chips into the chip pan. If doing your tools left hand alot then it will fill up the back of the machine quicker and if you have a auto tailstock will make keeping it clean fun. The other side is that if you do a lot of back cutting the you will want both. I use to make crank shafts on mine using left and right faced right handed. Then another thing is if you do alot of turning down of nuts or parts you want to thread on a mandel then you will want to use left handed tools so they will screw on and not back off when turing them. My point to all of this he wants to be able to see the inserts maybe he needs to put some more thought into than that.

 

Crazy Millman

 

PS Crazy Millman is a Much Crazier as a Crazy Latheman.

 

[ 09-11-2003, 12:18 AM: Message edited by: Millman^crazy ]

[Jack Mitchell]

Actually, I believe the predominant slantbed style of Cnc lathes revolves around gravity.

It seems that gravity adds to the rigidity of the turret when the natural weight tends to fall forward. (less chatter etc!).

 

To take advantage the tools would face away from the operator - this makes changing inserts a little more difficult.

 

Another consideration is to purchase some lefts and some right hand tool holders in order to avoid spindle stopping and reversing - Sandvik makes the sweetest tools and propietary mounting systems , but this is my personal opinion.

 

 

Regards, Jack

[dan m]

thanks for the responses. they make sense to me. I was wondering if there would be any ill affect on the machine like putting more presure on the ways or anything in the turret. But it don't sound like there is. So if the is what the operator wants thats what i will give him. Cycle time and changing spindle directions is not a problem.

 

Thanks Again,

Dan

[Rick Damiani]

I always thought it was for better chip evacuation, actually. With the insert facing down, the chips will tend to fall away from the part, rather than collecting on the top of the holder and/or wrapping around the stock.

 

Seems like a lot of trouble to avoid turning the turret 90 degrees to index the insert. I'm with Millman here - this might be something that needs a bit more thought.

[Brendan P]

I have heard great discussion on this topic before in another forum.

At my place we use left hand tools and run in M04.

(insert facing up as you say)

I'm not saying that it is the right way or wrong way.

We have never seemed to have any problems.

 

Andrew gets pretty deep into things.

He may be able to shed some light on the subject.

 

[ 09-11-2003, 06:54 AM: Message edited by: BUCKET HEAD ]

[chris m]

Our Hardinges require left-hand tools, we run right hand on all of our other machines. Rick is right about chip flow being better with right-hand tools, in my opinion. However, it is nice to be able to see the cutting edge when you look in the window. Easier to touch off, too, if you don't have a touch-setter. Just remember to set the tools up right in your MC files, the back of the insert doesn't cut very well.

 

Yes, Brendan, I speak from experience.

 

C

[crazy^millman]

Well Chris that is not as bad as one of the jobs I set-up for a guy. I was doing long parts so I have three programs looped together. The frist one would face it off center drill it. The secone would bring the tool down and you would pull the part to that then it would clear the talistock and bring out the tail stock and then start turing the shaft from there. Well I was teaching a guy who didnt want to listen to me and he borke an insert. He then hits reset in the middle of program two and changeds the insert. We then hits cycle start wit hthe machine at full rapid. I after remvoing the buired tool out of the Riten high speed center and a day later was able to get the machine running again. Amazing what 55 deg insert will do to a center when it hits at 1118in min rapid.

 

Crazy Millman

 

If anyone that has ran a lathe has not ran the spindle backwards at least once on a tool I would be very suprised.

[McRae]

With a Y-Axis machine like the Integrex - Go Left... This way you gain the added rigidity of the machine ball screw to push against.

 

With the Mori SL7 that I ran, alos had fewer chatter issues with the Lefties. Made some home made front/back facing holdere in an inverted U shape and found that the Lefties (Insert Facing Operator) gave fewer problems.

 

My interpretation of the mechanics is to when ever possible - machine into the mass of the machine, Righties tend to pull against the turret and all the othere mechanical fasteners.

 

Answer to you question in my experience is - User Preference. Did Mori officially suggest anything?

[chris m]

quote:

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My interpretation of the mechanics is to when ever possible - machine into the mass of the machine

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You'd think so, but I'm sure that Sandvik, KM, and the others will tell you that they sell a lot more right hand tools. Like I said, we use right hand on 15 of our 17 turrets and the only reason we use lefts on the Hardinges is because the manufacturer says so. I personally like the left hand tools from a setup / operate standpoint but we have run the rights for many years doing some pretty aggressive turning with no probs at all. My biggest suggestion is to make all of your machines the same, at least as much as possible, to keep interchangeability.

 

C

 

[ 09-11-2003, 12:05 PM: Message edited by: chris m ]

[McRae]

Chris,

 

I agree - when I was CTE for a Sandvik Distrib, we sold right handed tools 10:1 for lefties...

 

Legacy from the manual machines I think, if you revolve the system around, you will see that on a manual machine, the tool is a rightie so you can see the insert...

[crazy^millman]

Andrew I think it is right cause you are cutting toward you and to the ckuck majority of the time.

 

Crazy Millman

[McRae]

Millman,

 

You are correct based on a constant spindle rotation direction. With the CNC and an enclosed machine, this isn't such an issue and as I say, my preference is to turn the spindle into the ways of the machine. With a slant bed construction, this happens to be clockwise with a left ahnded tool - making the insert visible to the operator. On an old manual machine, the spindle would be turning counter clockwise with the right handed tool closest to the machinist - insert is visible.

 

The old turning shops had a thousand turning holders - 90 percent of which are for tuning toward the chuck and they would have stuck them into their recently aquired CNC machines as they would have been at the time and voila - a president has been set and no one has asked why for the last 30 years - "we have just always ordered right handed tools, thats why! you young ignorant little piece of crap..."

 

Again, I say that it is preference based not emperical evidence - Hardinge has made that assertion because they likly have the data.

 

My MBB (Master Black Belt and Mentor) says

"If you don't have DATA, you're just someone else with an opinion."

[PE @ IHS]

Left hand tools and right hand tools work with the spindle spinning in the same direction. The only time you would need to reverse the spindle is if you purposely put a holder in backwards (and shim it accordingly to keep the tool on center).

 

 

Left hand tools are used for turning AWAY from the chuck, right hand tools are used to turn TOWARD the chuck. The spindle doesn't reverse.

[dan m]

Thanks again for all the replies. Andrews reasoning for why we still use right-handed tools makes a lot of sense. Sounds to me like we will try left handed tools on this one. Thanks again for all your input.

[chris m]

quote:

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Left hand tools and right hand tools work with the spindle spinning in the same direction

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I guess I'd better take the M04 out of about 500 programs for my Hardinges then...

 

To turn toward the chuck with left hand tools the insert is facing 'up' thereby necessitating [sp?] the spindle to run opposite of a right hand tool of the same type which has the insert facing 'down'

 

Flipping either tool over will allow 'reverse' turning, as stated

 

C

 

[ 09-12-2003, 07:19 AM: Message edited by: chris m ]

[McRae]

quote:

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The only time you would need to reverse the spindle is if you purposely put a holder in backwards (and shim it accordingly to keep the tool on center).

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This is exactly the point. Invert the holder, put the wedge clamp in the other set of holes in the turret (Gee, I always wondered why those were there...) and you will achieve greatness.

[chris m]

Easy, Andrew

 

You guys have been getting along soooo well....

 

C

[Grant]

I have to laugh at this topic, as this was a great issue for us in the last 3 years. The debate was so strong here that we actually went to Mori for the answer. We run Mori's pretty much through the shop. We dealt directly with the "man in Japan", there take was VERY non-committal, the only issue they did mention was that in the result of a crash (who has them? ) the machine would be better served running M04 with left hand tools. BTW, we have set our newer machines up to be left-handers. Andrew, our Sandvik man says the same heaps more rights to left, Sorry 90% of the world is wrong!!

[resjun]

im a lefty on our mazak quick turn 300 see thing alot better sandvick guy look at me kinda funny at me when i ask for left hand tools i guess it's a production thing and drilling thing to have a right hand tool to have the spindle running the same way. mind you i alway's do thing different

[crazy^millman]

Well Andrew it is funny how people with idea they firmly beleive in that them to the point to be insulting of someone. I will gladly admit I was not around when the lathes were invented and neither were you. The idea of an opionion is to have one no matter right or wrong you are atleast making an attempt to have a concious thought. With that said I also ask that you fully understand what someone says as a commnet and not a critic of what you have said. I fully support it is a matter of choice but you might think about a more postive apporach in your comments.

 

quote:

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"we have just always ordered right handed tools, thats why! you young ignorant little piece of crap..."

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quote:

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"If you don't have DATA, you're just someone else with an opinion."

---

quote:

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This is exactly the point. Invert the holder, put the wedge clamp in the other set of holes in the turret (Gee, I always wondered why those were there...) and you will achieve greatness.

---

Crazy Millman wondering till the next post.

 

PS: Resjun If I was running a higher than normal production run on the Mazak lathe I would set the change turret varaible to the closest position have all of my tools ganged on one side of the turret all facing the same turning direction. I could cut off any where from 30 seconds to 1 full minute off per part and when running 10,000 parts I liked the $10,000 profit since we got a $1 a minute. But hey that is just me.

 

[ 09-14-2003, 11:47 PM: Message edited by: Millman^Crazy ]

[chris m]

quote:

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you might think about a more positive approach in your comments

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You ain't been around long, fella; for Andrew those comments aren't negative

 

Of course, most of the really good ones got edited out after further contemplation

 

C

[Brendan P]

quote:

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(Gee, I always wondered why those were there...)

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While we are on the subject....

I have actually seen grown men (with many years of experience) putting the "wedge" in the wrong way,and not even know that it made a difference.

Man this used to pi$$ me off!

[Philcott]

Millman,

 

quote:

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Well Andrew it is funny how people with idea they firmly beleive in that them to the point to be insulting of someone.

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Sorry man. I just can't make this one out. What were you trying to say?

 

Phil

[Jack Mitchell]

Millman,

 

Please forgive my noticing, but I do believe that perhaps you’re a little upset with some Andrews’s comments.

 

“A president has been set and no one has asked why for the last 30 years - "we have just always ordered right handed tools, that’s why! You young ignorant little piece of crap..."

 

This is merely an example of the hierarchy determining that a programmer/operator suggests that perhaps we are doing things backwards. – Of course this would go over like a lead balloon. With a 10:1 ratio of right hand tools to left, speaks volumes about his statement; which is to say, that there is a ten percent chance that a lathe turret in North America is actually tooled to take advantage of a slant bed style an it’s inherent rigidity. - scary stuff indeed!

 

I know that Andrew is currently in Texas for this week (something about demonstrating a paddle wheel set-up along the Rio Grand for corporate consideration)

 

I also just noticed that you're moving into senior membership with your next post - congrats.

 

 

Regards, Jack