Author Topic: Tool tip radius  (Read 7798 times)

0 Members and 1 Guest are viewing this topic.

Offline rnr107

  • Active Member
  • Posts: 10
    • View Profile
Tool tip radius
« on: March 30, 2012, 08:40:14 AM »
Hi all,
I am experimenting with LT on a Boxford 125TCL.
I get a preaty good finish but got a little problem with the dimensions...
For some reason if I create a tool in LT with a 0.4mm tip radius, the Gcode output from LT leave an 0.8mm extra of material (0.4 radius)
If I create a tool with a 0.1mm tip radius it leaces an 0.15...mm extra ??

I am trying to turn a part with a finish radius of 12mm and get a 12.4mm with a rough + fine pass with a stock clearance of "0".  Any ideas ?
Am I doing something wrong?

Ta,
Laurent
« Last Edit: March 30, 2012, 08:55:55 AM by rnr107 »

Offline RICH

  • Global Moderator
  • *
  • Posts: 7,300
    • View Profile
Re: Tool tip radius
« Reply #1 on: March 30, 2012, 05:48:34 PM »
Can you post the code for the one that is leaving .8mm extra material?
Also post the dxf file.
When you define the tool number in LT is that  tool number also defined in Mach's tool table?
(See page 19 in the manual)
RICH

Offline rnr107

  • Active Member
  • Posts: 10
    • View Profile
Re: Tool tip radius
« Reply #2 on: March 31, 2012, 03:00:06 AM »
Hi Rich,
I don't have any tools define in Mach3 yet. I just had a look at the Gcode and Mach3 is following it to the letter.
But LT for some reason leaves an extra 0.8mm extra in the code. If youu look at the Z0.0000 you will see that X never go bellow 12.4000
where the profile is only 12.0000.
I will have a look at P19.

Ta,
Laurent

Offline RICH

  • Global Moderator
  • *
  • Posts: 7,300
    • View Profile
Re: Tool tip radius
« Reply #3 on: March 31, 2012, 06:34:42 AM »
Laurent,
Have a look at Appendix "B" in the manual. Move the profile appropriately to 0,0 as you are drawing in the wrong quadrant for LT.
Note the pathing is wrong as compared to the drawing.So more than just leaving extra material. ;)
RICH
« Last Edit: March 31, 2012, 06:45:22 AM by RICH »

Offline rnr107

  • Active Member
  • Posts: 10
    • View Profile
Re: Tool tip radius
« Reply #4 on: April 02, 2012, 02:57:50 AM »
Hi Rich,
I changed the Quadran, But no difference... :-(

See files attached...

Laurent

Offline RICH

  • Global Moderator
  • *
  • Posts: 7,300
    • View Profile
Re: Tool tip radius
« Reply #5 on: April 02, 2012, 06:21:14 AM »
A few comments:
- The diamond tool can't cut the ball on the back side as defined. It will gouge. LC adjusts the pathing accordingly to avoid the gouging.
- You are only doing finishing cuts. A combination of rough and finish cuts should be done.
- You will need to use a combination of different tools to cut that profile.  A button with a radius no larger that the smallest profile radius will work
  or a point tool with side radius's larger than the largest radius on the profile will work also.
- The clearance from the profile shown in your pic would be .4 since it using the tip radius to pre-compensate the code.
   Zoom in and place the tool on the path closest to the profile and you will see that the controlled point / tip center lies on the path and that the cutting edge
   is on the profile.

Example below ......all in the manual....have a read
RICH

« Last Edit: April 02, 2012, 06:37:14 AM by RICH »

Offline rnr107

  • Active Member
  • Posts: 10
    • View Profile
Re: Tool tip radius
« Reply #6 on: April 02, 2012, 10:07:57 AM »
Hi Rich,
This tool path I posted was not the real thing... It was just to show you what I meant.
In reallity I have 3 path.
1- roughing with a right hand tool.
2- fine with the right hand tool.
3- fine with the left hand tool.

This conbination sut the profile properly... But at the end I get a diameter of 12.8mm instead of 12.0mm.

If the tool tip is pre-compensated, How do I setup the "0" on Mach3 at the start?
I mean right now to set the tool to 0 coordinate I move the X axe down until the tip touches the top of the billet and set the DRO in Mach3 to the radius of the billet.
Are u saying I should substract 0.4mm ?   Is there any way to cancel the compensation? (I tryed with and without the tick in the "use tip center" it doesn't make any difference)

Ta,
Laurent

Offline RICH

  • Global Moderator
  • *
  • Posts: 7,300
    • View Profile
Re: Tool tip radius
« Reply #7 on: April 02, 2012, 05:21:24 PM »
Laurent,
Post the LT generated code from your  reply #6. Real thing please....... :)

Quote
How do I setup

Have a read of Appendix "F" in the LT Manual.

RICH

Offline rnr107

  • Active Member
  • Posts: 10
    • View Profile
Re: Tool tip radius
« Reply #8 on: April 03, 2012, 02:54:03 AM »
Hi Rich,
Here is the code...  :-)
I must had an old version of the manual, it did not have the F section...
Will have a read.  :-)

Laurent

Offline RICH

  • Global Moderator
  • *
  • Posts: 7,300
    • View Profile
Re: Tool tip radius
« Reply #9 on: April 03, 2012, 06:42:28 AM »
What version of LT are you using? It should be the one noted in the manual on page 6 of 50.

Are you using the dxf file that you posted in reply #2?
If not please post the dxf file you used for reply #8.

RICH