cuttouts without tabs

[argreen]

The project was to cut out of 3/8 in plywood 120 panels for our local 3rd graders to paint on. The project required 6 - 4ft x 4ft sheets each cutting being 2 sheets stacked and screwed to a waste sheet. A ¼ in down cutting mill bit would be used. Each cutout had 4 tabs the same thickness as the sheet. That was the plan but with revisions to get a maximum number the final cut file had unknowingly dropped the tabs. The setup required removing the side mounted dust collector so I would hand vacuum during the cutting.
When the cutting started I didn’t pay much attention until the first pieces was about half way done when I realized there were no tabs. Expecting the worse nothing happened! The packed sawdust from the down spiral was keeping the pieces in their place. All the other cuts turned out the same way. I ended up not having to cut out and clean up 480 tabs. Hope this helps someone with the same sort of project.

[plcamp]

Downcut bits have always been a good choice for not using tabs, however some caution must still be exercised as the possibility of the cutter kicking out the part still exists. Another option would be to use a compression bit. These are great for plywood as they cut in opposite directions at the same time helping to reduce splintering at the top and bottom surface.

[TReischl]

Sometimes it works, sometimes it doesn't.

Occasionally I will cut thru when I did not intend to. It always surprises me how durable the bits are, I have never snapped a bit off when the part got loose.

Some of this is a function of the size of bit being used. Small bits, like .125, do not seem to cause flinging. But when it comes to the bigger ones, like .500 the event can be quite amazing.