Modern Machine Shop

JAN 2017

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

Issue link: https://mms.epubxp.com/i/765864

Contents of this Issue

Navigation

Page 114 of 148

BETTER PRODUCTION Shops Using Technology 112 MMS January 2017 mmsonline.com m a s s). T h e r e s u l t i s a s m o ot h e r m a c h i n i n g p r o c e s s w i t h l e s s v i b r a t i o n a n d a b e t t e r s u r f a c e f i n i s h q u a l i t y w h i l e u s i n g th e s a m e t o o l , m a c h i n e , p r o c e s s p a r a m e t e r s a n d fixturing technology. H e l l e r c o n d u c t e d a n e x t e n s i v e m i l l i n g applic ation stud y in titanium T i- 6A l-4V for a group of representatives from the aerospace industr y, the Technical University of Dor tmund and Technical University of Hamburg-Harburg. T h e s t u d y u s e d a f o u r- a x i s H e l l e r H 5 0 0 0 with a gear unit and HSK-A100 spindle, which y i e l d s t o r q u e s r a n g i n g t o 2. 2 9 0 N m , a n d dif ferent 25-mm-diameter end mills to mill full slots into a titanium plate. To simulate holder c o n d i t i o n s i n a e r o s p a c e a p p l i c a t i o n s , t h e to o l s we r e c l a m p e d i n to r e i n f o r c e d s h r i n k- fit chucks. At an a xial cutting depth of 0.5 to 1.0×D, the machining process was found to be ver y reliable, Mr. Kirsten says. However, af ter increasing to a full slotting depth of 2×D, the tool pulled out of the shrink-fit chuck, creating a slot closer to 2.5×D as it progressed through the par t. Toward the end of the slot, the tool finally broke due to increased cutting forces, he says. In this case, the clamping force of the chuck was the limiting factor, he explains. As soon as the a xial pressure and process-related vibra- t i o n s w e r e to o h i g h, t h e to o l m o v e d o u t o f the chuck and further into the workpiece. At the s a m e ti m e, th e c u t ti n g p re s s u re i n c re a s e d, the tool broke and the workpiece was damaged. Mr. Kirsten says that the reason for this pullout w a s t h a t t h e to o l s w e r e f o r c e d to n av i g a te towa rd th e s pindl e w h e n th e ho lding forc e s were exceeded. That is where the Haimer Safe-Lock system comes into play. In addition to frictional clamping forces, the system has the same helix pattern as the tool. Theoretically, even if the tool got loose while using Safe-Lock, it would be pulled into the holder through the helical drive keys and not into the par t—a move me nt that could e asily p r e v e n te d u s i n g l e n g t h p r e s e t t i n g s c r e w s, Mr. Kirsten says. To te s t th e S afe - Lo c k sys te m, th e H e l l e r technology developer repeated the trial, making some major changes. Haimer Safe-Lock grooves Questions? Automation Robots? Integration? Co-bots? Safety? Training? Plant Design? Performance Analysis? IIoT? With 25+ years experience in automation AMT is a one-stop solution for all your automation needs. Plan, Design, Test & Integrate – It's what we do. sales@appliedmfg.com www.appliedmfg.com

Articles in this issue

Links on this page

Archives of this issue

view archives of Modern Machine Shop - JAN 2017