Big problems with cutting HDPE can you help?

Hi All,

I have had an ordeal today cutting 2d profiles out of a sheet of (15mm thick) 8 x 4 HDPE using a multicam flat bed cnc router.

first I rough cut the shapes out using an end mill, this step is fine. I then remove the waste and here is where the problem starts.

I need to add a radius to the top and bottom edge simultaneously and im attempting to do this using a vortex two flute upcut eased edge profile spiral. Part # 3650

No matter how many times i adjust the depth of cut I can only seem to get a radius on one edge, even then the varying thickness's in the material mean that the edge is not constant and does not go around the entire perimeter.

Has anyone experienced this? and how did you overcome it? Can you suggest a tool more suitable to the task?

Thanks!!

Did you ever get to the bottom of this Nathan ?

yes,

I purchased a speacial tool from Trend, and made a jig out of 25mm mdf to allow the router bit to cut both the top and bottom edges at the same time. it took a lot of time to get it right but the customer was happy in the end.

also ive been using 10mm diameter neoprene to seal the jigs off. Does anyone have an alternative to this as it it quite expensive.