Z access retraction problem.

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MAX THE MILLER
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Posts: 144
Joined: Tue 23 Aug , 2011 18:25 pm
Hardware/Software: Denford Triac PC. VR Milling 5.51.0.616

Z access retraction problem.

Post by MAX THE MILLER » Tue 07 Jan , 2014 19:42 pm

Triac PC manufactured 1998. Upgraded to USB with BI00434Y NES003-501 (RACK) card.
VR MILLING V5.54. Machine selected Triac VME. Speed pot boxes ticked. ATC box unticked.

VR Milling used to import a DXF file and produce an FNC file. The aim is to drill four 6mm holes in a square formation.
Retract height specified as 40mm in order to miss work holding clamps. No tool offset used, but work offsets are set correctly.

Part program started. Machine travels to MACHINE POSITION X0 Y0 Z-25, stops and prompts for manual tool change. Tool changed and program restarted. Machine performs rapid XY travel to first hole position, but Z remains at -25 which would result in a collision between the drill bit and a clamp, so emergency stop button pressed.

Clamp repositioned and part program run again. Machine reaches position of first hole and the Z axis RETRACTS to PROGRAM position Z40. All holes drilled correctly with 40mm retraction after each hole is drilled.

As a work round I entered a new G0 Z40 instruction after the tool change. Should VR Milling do this when the FNC file is generated?

Looking at Triac VME machine parameter "tool change", this gives X=0, Y=0 and Z=-25, which fits the machine's behaviour. Could I change the Z value to 0 in the machine parameter file?

Looking at Triac machine parameter "tool change" this gives X=0, Y=0 and Z=0. However if I select Triac as the machine, the X axis tries to home the wrong way, ie into the table.

Any advice would be much appreciated.

fnc file follows.

Thanks, Max.


(**** Denford DXF Importer ****
(Source File: C:\Documents and Settings\name deleted\Desktop\LADDERPLATES\LADDER PLATES.DXF
G21
G90
(Denford Default Post Processor
(G Code created by - DXF Wizard
(Date: 05/01/2014
(Time: 17:17:40
[BILLET X150.000 Y150.000 Z21.000
[EDGEMOVE X127.000 Y279.400 Z0.000
G91 G28 X0 Y0 Z0 M05
M05
G90 M6 T0202
M03 S1185
(Drill Cut - Tool 2 - 6.000mm Diameter. Description: Twist Drill 6mm
G0 X135.000Y15.000
G0 Z40.000
G1 Z-7.000 F150
G0 Z40.000
G0 X15.000Y15.000
G1 Z-7.000 F150
G0 Z40.000
G0 Y135.000
G1 Z-7.000 F150
G0 Z40.000
G0 X135.000
G1 Z-7.000 F150
G0 Z40.000
G00 Z40.000
G91 G28 X0 Y0 Z0 M05
G90
M30

Martin
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Re: Z access retraction problem.

Post by Martin » Tue 07 Jan , 2014 23:42 pm

The Z -25 is set as the toolchange position for the ATC. If you don't have a ATC then you can change the values to what you want.

The older Triacs datum in a different way to the newer ones & run a different mint file so needs to be set as Triac VME.

MAX THE MILLER
CNC Expert
CNC Expert
Posts: 144
Joined: Tue 23 Aug , 2011 18:25 pm
Hardware/Software: Denford Triac PC. VR Milling 5.51.0.616

Re: Z access retraction problem.

Post by MAX THE MILLER » Wed 08 Jan , 2014 22:58 pm

Thanks for that. I've set Z to 0 in the tool change parameters and it all now works OK.

When I have the machine parameters window open and press F1, I get this message:-

"The fields in this option should only be edited by your CNC machine Technician or Supervisor. Please refer to the separate parameter helpfile distributed on the VR CNC Milling CD-ROM for further information".

I've been unable to find this help file on my CD-ROM. What's the file name?

Thanks.

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