laser cutting and cad advice

[the walrus]

Hi All.
Assistance needed from you laser cutting and cad experts.
I submitted some DXF laser cutting files to a well known company ,The files where taken directly from the cad drawn plan with no kerf correction applied.
And the returned cuts do not match the plan.
Previous cuts by a now defunked co fitted a treat with three test builds with no issues.
Is this a laser machine set up problem or other?
Your advise and help will be much appreciated,Thanks.
Cheers.
          John.

[Starduster]

I submitted some DXF laser cutting files to a well known company ,The files where taken directly from the cad drawn plan with no kerf correction applied.
And the returned cuts do not match the plan.

Hi John. When you say "cuts do not match the plan", can you be more specific? i.e. are the parts uniformly smaller?

I do a lot of CAD/Laser cutting and contrary to many others, I never adjust for kerf. And, I never have any issues. If you want, you can PM me and we can exchange emails. If you send me the original drawing and the .dxf files I can take a look to see if there are any problems.

[Arnold S]

If the parts are small then the kerf comp becomes obviously more significant, for larger parts the sort of distances (0.125mm typically) will just be acceptable.  The laser follows the path of the line, and the beam has a finite width, so it will always cut outer profiles small in inner ones large.

For a simple machine (and simple software) you have to do this Kerf comp manually by offsetting the lines.

More expensive machines and better software that I have used (to cut metals) have in built settings for the kerf comp, so you don’t have to do it manually.  I did a number of test cuts on various materials and thicknesses to establish the values for these and it became very reliable at the parts were pretty much spot on time after time.

My twopeneth worth!

Andrew

[the walrus]

Hi Starduster and Andrew.
                                   Thank you for helpfull replies. It seems the problem may have been solved. I am to receive fresh cuts so fingers crossed.
                                   Thanks again.
                                   Cheers.
                                             John.