Internal machining. Error messages.

[MAX THE MILLER]

I've been experimenting with internal machining on a Mirac and have produced the attached .LCM file.

When I try to generate Gcode I get the errors below which I do not understand.

(Drilling)
Cannot Process: Drill:8 diam:6.00 is less than current internal diam:11.11
Cannot Process: Drill:4 diam:10.00 is less than current internal diam:11.11

(Internal Roughing)
Cannot Process: Current internal diam:11.11 is less than min. tool diam:12.00

There is no internal diameter of 11.11mm and I don't see how it matters in any case when drilling.

I can understand the Internal Roughing problem as the boring tool is specified as 12mm and in order to start boring it would need to make a cut of 1mm in order to enter a 10mm drilled hole and that's with zero clearance on the back edge of the tool. There's still a reference to an internal diameter of 11.11mm though.

Would appreciate any advice. Thanks, Max.

EDIT. Can't upload .lcm file so renamed as .txt

[Mitch]

Hi Max,

it looks like it must be related to some settings you have made within Quickturn2D Design. i have opened and simulated your drawing without errors on a standard installation of QuickTurn. i suggest you make a fresh install of the software.

did the machine manage to complete the centre drill operation?

Thanks

[MAX THE MILLER]

Thanks for the explanation.

The problem is down to my defining a centre drill as having a major diameter of 7/16", 0.4375" or 11.113mm.

This looks perfectly legitimate to me. QT2DD seems to be working on the major diameter rather than the minor diameter, hence the error.

MAX

[MAX THE MILLER]

I managed to get rid of the drilling errors by fitting a 6mm centre drill in place of the 11.1mm diameter one fitted and editing the tooling file accordingly. I believe Miracs came with 5mm centre drills? I had use a 6mm one as the only spare DB25 holders I have for use with my ATC have 6mm bores.

The error relating to needing a minimum tool diameter of 12mm seems to be explained in this thread:-

https://www.denfordata.com/bb/viewtopic ... ter#p25125

This suggests that the hole needs to be pre-drilled to a minimum diameter of 14mm. This seems odd as my boring tool will easily enter a 12mm hole and is specified as such. It has an 8mm dia shank.