Vertical Turning: Myths vs. Reality
Jury Sollenberger 05.13.2015
Vertical turning may be most misunderstood and under-applied technology available in manufacturing today. The myth associated with vertical turning is that it is only applicable to large heavy parts. However, vertical turning brings as many advantages for small parts manufacturing as it does for large, heavy parts.
Target applications for vertical turning are the obvious heavy, hard-to-load workpieces requiring a crane or automation, or nonconforming part shapes that need to be fixtured as opposed to traditional centralizing chucking. Additionally, fragile work pieces requiring low clamping pressures to prevent distortion also benefit from the vertical turning process. Let us not forget all the challenging parts out there with interrupted cuts and unbalanced work pieces. Therefore, if you stop for a minute and think about the applications I just outlined, the only popular turning applications I did not mention are those requiring a tailstock.
Taking Advantage of Gravity
So now that we have the gears turning, you may be asking yourself “what advantages does vertical turning provide that allows so many applications to benefit from it?” Before we get into the specifics, take a minute and think about how parts move through your shop. If you’re processing chucker parts, I’d guess that nearly 100% of these parts move through your shop on a pallet lying flat, and we do this because it’s the most stable way. What makes this the best way to move and store your parts? Gravity.
Well, gravity is the number one, largest contributor to the vertical turning process. Gravity is a constant, providing a positive downward force on the workpiece, assisting the workholding. This assists those heavy machining applications by providing additional stability especially on those delicate parts that like to resemble eggs or potato chips after machining. Minimal clamp force can be applied to these types of parts and gravity keeps the part in the chuck. I have actually machined parts and removed them from the chuck without even opening the chuck after machining. Try that on your horizontal spindle lathe – I bet you dig the part out of the chip conveyor.
The Advantages of Additional Support
Having the spindle vertical, as opposed to horizontal, allows the spindle to be supported 360°, eliminating spindle droop and increasing the maximum weight allowable on the spindle. The additional support also dissipates the cutting forces created by heavy and or interrupted cutting. Eliminating spindle droop also allows capabilities for achieving better part flatness and perpendicularity accuracies.
The vertical lathe also provides a distinct ergonomic advantage by facilitating part loading. I’ve witnessed operators performing some very unsafe acts by actually placing one foot into a horizontal lathe to hold a workpiece in place on locators while closing the chuck. With the vertical lathe, an operator can simply place the part into the chuck, just like they place it onto a pallet, and close the chuck while gravity does its job.
I visit shops on a weekly basis and I repeatedly hear from customers that they’re challenged with a lack of floor space. Brick and mortar is expensive. Many shops simply do not have the luxury of being able to add on to their facility, and they need to utilize every square foot available. I also see literally hundreds of horizontal lathes running chucker work and the tailstock is never used. Many machines may go their entire life and never have tailstock used. This creates another huge advantage of the vertical lathe as it normally consumes one-half of the footprint of a horizontal lathe. And more times than not, the footprint of a twin spindle vertical lathe is still either less than or equal to a horizontal lathe.
Vertical Lathe Lineup
I hope everyone caught the twin spindle comment, as Okuma provides vertical lathes from a 12-inch chuck to a 40-inch chuck in both single and twin spindle configurations. The twin spindle allows for simultaneous processing of first and second operations, further adding to the advantages. Okuma provides vertical lathes with complete multitasking capabilities, including full five-axis. The entire vertical lathe lineup is also available with the power of the OSP control, or even the FANUC control if preferred.
When you’re looking for your next turning center, I hope you consider the advantages and profitability that vertical turning can bring to your business. If you’d like help evaluating your options, please contact us, or your local distributor.
Jury Sollenberger is Senior Regional Sales Manager, Okuma America Corporation.