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Dual Spindles vs. Dual Lathes

GiroDyno

Cast Iron
Joined
Apr 19, 2021
Location
PNW
First off, thanks to everyone for the help contributed so far. I've had a few (maybe dumb) questions and gotten some good feedback.

We make a line of 6061 parts 7-11" diameter, .5-3" tall, imagine the classic flying saucer with a raised center.
90% of the work is done in the lathes, we load stock to do a face and OD turn so we have a clean reference, flip part and do backside rough and finish, flip part again and do frontside rough and finish. After that we finish with a mill op to put in a bolt circle, serial # and cut a profile around the outside edge.

We have two Haas (SL30, ST25) machines running this right now and have maxed out our capacity so we are trying to add some automation to this process. First thing we have been looking into are DS lathes that can handle the part flips for us, maybe even the milling op. Potential issues we've noted are the turret slide colliding with the part in the sub, the price, and the learning curve. Add a robot loader to that and we should be able to double our capacity and then some.

An alternative would be to get two lathes and a robot split between them. Its cheaper than one DS, machines are familiar (except the robot), and we have redundancy in equipment. Downsides are the floorspace, probably going to overload the mill. (We don't need a tailstock so if anyone has a recommendation for a chucker style machine would love to hear that as well.)

What are some other factors not considered above?
Anybody gone through a similar experience and have some thoughts on their decision making process?

Looking forward to some input.
 
What kind of quantities are you talking? You might consider a gantry loader rather than a robot. Much easier to integrate.
 
We do about 75/day, ideally that number would be closer to 200. Gantry loaders looked interesting but information was not as easy to come across, Fanuc OTOH was happy enough to answer my robot emails.
 
The dual spindle sounds obvious but there are some considerations, for example Doosan told us we could not fit a 10" chuck on the sub. Mori was in yesterday and had similar concerns as well, which is what brought up the idea of two single spindle machines. I like that the dual spindle handles all the flips and reduces the need for, or the amount of work a robot (or gantry) loader would have to do.

What brands have a chucker style lathe w/a 10" chuck and 30(ish) HP? That would mitigate the floor space issue. Then there is the issue two machines would be running potentially different parts with different cycle times that don't jive which complicates loading with a single 'bot :crazy:
 
We have a Mori NZX. It is a dual spindle, y-axis live tooling machine, but both spindles are the same and have 8 inch chucks mounted. I believe 10 inch chucks are an option. Maybe you can pair that with a gantry. The NZX is a lighter duty version of their workhorse NLX.
 
Ther are a group of two spindle machines with an integrated gantry. Fuji, Okuma and we sell versions of a Takisawa that does this in high volume jobs just like this. Turn one side and then the gantry loads the other spindle after a turn around station. This is used in thousands of automotive applications. Link below to video
takisawa TT-2600G - Bing video
 
We have a Mori NZX. It is a dual spindle, y-axis live tooling machine, but both spindles are the same and have 8 inch chucks mounted. I believe 10 inch chucks are an option. Maybe you can pair that with a gantry. The NZX is a lighter duty version of their workhorse NLX.

We've got the NZX2000s with metric 10" equivalent chucks and the gantry loaders. If you can setup a way to hold the parts with the gantry while chucking them on either spindle you could definitely make it work. What's the max weight of your blanks?
 
We've got the NZX2000s with metric 10" equivalent chucks and the gantry loaders. If you can setup a way to hold the parts with the gantry while chucking them on either spindle you could definitely make it work. What's the max weight of your blanks?

Our largest blank is 11x2.75" and 25lbs.

It is also conceivable that this cell would be dedicated to just crank out our top sellers which would drop it down to 9x3.5" and 22lbs. Just that size accounts for probably 1/3 of our production volume, and would mean we never really have to switch out work holding or tools, just go-go-go.
 
We've got the NZX2000s with metric 10" equivalent chucks and the gantry loaders. If you can setup a way to hold the parts with the gantry while chucking them on either spindle you could definitely make it work. What's the max weight of your blanks?

I think Mori makes a gantry with a capacity to hold his blanks.
 
NLX or NZX sounds like it fits the bill pretty perfectly tbh.

Will these machines only ever see this line of parts or do you foresee new styles of parts in your future, especially with the potential growth this would offer? Worth considering, if you add some mix to the business then you will want a machine cell that can handle some change. Additionally this sounds like a full on production setup so you definitely want a machine that can handle that, so I would steer clear of Haas for this application.

Does Mazak offer dual spindles that can handle this? I know their Quick Turn line is great but not sure if they are big enough
 
Ther are a group of two spindle machines with an integrated gantry. Fuji, Okuma and we sell versions of a Takisawa that does this in high volume jobs just like this. Turn one side and then the gantry loads the other spindle after a turn around station. This is used in thousands of automotive applications. Link below to video
takisawa TT-2600G - Bing video

That looks like just the ticket!
I figured those machines were all custom built, had no idea that was something more or less off the shelf. Can't imagine they come cheap, any idea what the pricetag is on one of those bad mama jamas?
 
Will these machines only ever see this line of parts or do you foresee new styles of parts in your future, especially with the potential growth this would offer? Worth considering, if you add some mix to the business then you will want a machine cell that can handle some change. Additionally this sounds like a full on production setup so you definitely want a machine that can handle that, so I would steer clear of Haas for this application.

We do make new parts, but they're all just different flavors of the same thing. We dream of the day when we get to make anything else...
Hopefully we get this cell running and then we can do special projects on the original machines, but in all likelihood I think they will probably run these parts until the day they die.
 
If you are going to use a turn around station, one set of jaws will have to be able to hold the blank and the machined side. Probably not an issue, but a consideration.
 
We have steps in the jaws to hold the full size blank and the backside drum that gets machined in our jaws, don't see why the loader couldn't manage that as well... There are a bunch of brands/sizes to accommodate but because we design the parts we managed to put standard sizes features in for chucking.
 
Before going too crazy with the automation, make sure you have chip control down pat. A large aluminum birds nest will stop a $500K, gantry-loaded, twin-turret lathe dead in its tracks, just as quickly as it would on on a $70K Haas.
 
That looks like just the ticket!
I figured those machines were all custom built, had no idea that was something more or less off the shelf. Can't imagine they come cheap, any idea what the pricetag is on one of those bad mama jamas?

I have a TCN2600 Tak...single spindle with gantry loader and flip over device. No live tooling. It’s been making parts every day for years. We’ve been very happy with it. Load up the blanks and come back in 6 hours. $175k but that was 3-4 years ago. Good luck!
 








 
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