How to guarantee the quality of the first part using a bar that has not been properly prepared beforehand !

When loading a new bar into the spindle, the bar feeder usually offers two alternatives with respect to the distance of feed in the chuck. Bar feeding at cutting level. Bar feeding against the bar stop.
Swiss type machine high precision turning numerically controlled machine cam machine tools single spindles monospindles multiple spindles multispindles high precision parts lathes NC numerically controlled multi-spindles lathe multispindles machining
0

Tips and Tricks

How to guarantee the quality of the
first part using a bar that has not
been properly prepared beforehand !
Technology
•  PNC
•  TB-DECO
•  Software Hotline
•  Tips and Tricks

When loading a new bar into the spindle, the bar feeder usually offers two alternatives with respect to the distance of feed in the chuck :

  • Bar feeding at cutting level
  • Bar feeding against the bar stop.
This choice of options is governed by bar preparation and the types of parts being executed ; each of these alternatives has its advantages and disadvantages (see table below).

Not properly prepared barNot properly prepared bar


Bar feeding at cutting level  
Advantages Disadvantages
Prevents execution of an initial, non-compliant part where the bars have not been prepared Loos of production of one part in the first lathe
  Risk of tool breakage

Bar feeding against the bar stop		  
Advantages Disadvantages
No production loss in the first lathe First part does not comply in the case of non-prepared bars
  Risk of tool breakage


Position the tool at the rear part
face level (cut) 		Program a cutting (or facing) movement

Not properly prepared bar
Position the tool normally for the operation
provided at station 1 		Program normally the operation
provided at station 1


The tip we are proposing today is a third alternative, which avoids tool breakage and the execution of an initial, non-compliant part owing to poor bar preparation. This is achieved by using a tool in position 1, which is capable of carrying out both the operation required and part cropping.

With the TB-DECO, we shall program the facing in the operation boxes before the green flag and normal machining in the boxes that follow (see illustration). With respect to the bar feeder variables, it will be necessary to program the bar feed distance, so as to stop the bar a little further than the cut. This means that when the machine resumes production with a new bar, the tool in position 1 will start by cropping the front of the bar, thereby providing us with a prepared surface to machine the first part in a proper and sure manner.

Important :
The operations programmed before the green flag, for purposes of facing the new bar are executed each time AUTO mode starts up, provided a RESET has been executed beforehand.

This tip can only be used provided the following two conditions are met.
  • MULTIDECO machine with a cross slide in position 1:
          MULTIDECO 20/6
          MULTIDECO 20/6b
          MULTIDECO 32/6i

  • Tool on support 11, which is capable of executing the necessary operations in the program loop and in the operations preceding the green flag (a special tool can be provided).


THINK PARTS THINK TORNOS

Home   Company   Applications   Products    Technology   Investor   News    Contacts    Download   Site Map  
privacy    -    copyright-disclaimer © 1997 - 2008   -   Tornos   -   eMail:
ascl.com
 
 Think Parts Think TORNOS
 Tornos
Think Parts Think TORNOS
 TORNOS SA
Rue Industrielle 111
CH-2740 Moutier
Switzerland
 Tel.: +41 (0)32 494-4444
Fax: +41 (0)32 494-4903
www.tornos.com
 Tornos
ENGLISH
FRANÇAIS
DEUTSCH