DXF problems

[LS120]

i need help fixing a problem i'm having in mach3.

all the DXF files i load are too big for my table or are off set from the x0 & y0.

IE - y-59 x-25 ..

my table is in MM & is setup for x0 & y0, even if i set the X & Y to off set the -59 & -25 my table is not big enouth in the Y

my limits are Y570 & x1460

some are y640 but length is fine.. if i could change the X & Y temp to cut a DXF then set back to normal in Mach3

the other issue i have is a tryed upping the Feed rate & got upto 200 & snapped a 2mm 2flute bit.

I was trying to stop the MDF burning (4.75mm thick) have varied the speed from 3 - max (1 = 8000 max=20000 prm ) mini tool. have also run it at a feed of 30 & still burns.

any help out there ????

[ger21]

Open the .dxf files in a CAD program and scale/reposition them.

As for the burning. If the bits not dull, you need to either use a faster feedrate, or lower rpm.

[low_48]

I can't help with the DXF, but a couple ideas about the burning.
Are you cutting in one pass? Try two passes. You are probably not getting rid of the sawdust because flutes in that size of bit are really small. Try switching to an upcut spiral.

[Chrliev]

With tool burning issues, as stated previously limit the cut depth, use a carbide tool, make sure its spinning in the correct direction.

You might also try blowing high pressure compressed air directly into the cut, it will cool the tool and get the sawdust out of the cut channel.

[leaveme]

I was suffering of burning issue for some time.
In my case, it was because of low feed rate and higher spinddle RPM. It improved by a matched combination of feed rate and spinddle rpm.

Try spinddle RPM 7000-8000 (for mdf) and feedrate about 50-70.