Sheet hold-down

[Gdeaver]

It's pricey but Misumi sells 250 mm T-slot that can be mounted on a extrusion frame. This allows t nut clamps to be moved all around. I used a good dense MDF board leveled. I drill 4 holes in the corner of the AL plate. The Al plate is screwed down onto a good flat piece of 1/2" plywood into the MDF. Has worked very well so far but is not Ideal. Had problems with double sided tape building up and gooing the mill. Also interfered with chip ejection on the last cut thew pass. We have an X-carve stock, no stiffing mods. When the part allows , we use a 1/4" 2 flute 45 degree helix ticn coated end mill designed for AL. We get clean cuts on 6061 at 15 IPM and .01 DOC. Can go faster but cuts are not as clean. For small precise cuts have been using a 3 flute 45 helix .125 end mill at 10 IPM and .003 DOC. This may seem slow compared to those with real router tables but, we only have 700$ in this. It's been cutting all week. With some mods the capability can be increased. It's been a learning experience. We have had some friction stir welding experiences in the beginning. For next year with some mods it will be better. Software also is important. Next year we intend to master HMS Express to give better tool path planning.
Last night we cut some 7075 AL and my what a difference. It cuts so much better than the gooey 6061.
So far the X-Carve while not pro grade has been of great value to our build season.