Programs not running smoothly

I am running a desktop CNC router, using HSMwork's with an EMC post processor. My current problem is that when linuxcnc runs the code it doesn't run a smooth continuous curve it breaks it up into small line segments and when I need the feed rate to run at 70ipm it will slows it down to 8ipm. In HSMworks I have told the code to run at a constant feedrate but the small line segments that are in there never seem to allow the machine to get up to speed because it effectively starts and stops at every small segment. I am not sure if I just need a post processor made for my machine or its something within linuxcnc. My current version is 2.6.4. Thanks

this can depend on how the arc's or circles are created in the cad system ,
iv'e found that before you cam the dxf , turn the line into a polyline ( keep a copy of the origional as well for easy editing later )
you should find this smooths the arc's.

What BigJohn is referring to is the path mode. You are probably using G61 and the machine is coming to a complete stop at the end of each line segment. You can change to G64 P0.05 if your machine units are mm or G64 P0.005 if your machine units are inches. This will smooth the path at the endpoints trying to keep the velocity up.

Also if you switch to 2.7 pre 7 then the trajectory planner is much better at keeping the velocity up.

Once you have completed that then you are at the mercy of the HSMWorks post processor determining if the section should be a line or an arc. It depends on the geometry.

Right after posting this I found the "important user concepts" that BigJohnT was referring me too and will try the G64 soon I get a chance, it does sound like my problem. As for the DXF file, I am making guitars for a company and they supply the CAD file. That being said I can almost say with 98% confidence that when they create a 3D model from a .dxf file they did not go through and make the lines a continuous curve before extruding the curve, but HSMworks has a "tolerance and smoothing" option that will allow the CAM software to overlook those tiny segments. I will give G64 a try and see if that helps and also upgrade to the newer version of linuxcnc.

Thanks,
TJ