As the header states I am drilling through 12 mm of Acrylic and want to do so without melt. The holes are 2 - 3 mm dia. Just looking at different options to get the job done as effectively as possible.
Michael
Printable View
As the header states I am drilling through 12 mm of Acrylic and want to do so without melt. The holes are 2 - 3 mm dia. Just looking at different options to get the job done as effectively as possible.
Michael
A while ago I had to drill lots of 3mm holes through 12mm Nylon, so a similar situation. The problem is since the thermal conductivity of plastics is much lower than metals, most of the heat generated transfers into the drill - so the drill will soon overheat, causing the plastic to melt and ultimately break the drill. I did it by peck drilling using something close to the recommended feed-rate by G-wizard. The problem when peck drilling with a small peck depth (e.g 3mm) a significant amount of time is wasted by the drill retracting fully out of the hole which isn't required for this. So instead I substituted the drill commands for code to only retract by a small amount - for instance keep doing 3mm down, 1mm back up, 3mm down, 1mm back.. etc until the full depth is reached.
Clearly it's not worth altering the code for only a few holes or only one part, but it can save a lot of time otherwise.
What I've found when working with acrylic is that there's two types ....cast acrylic (which doesn't melt easily) & extruded acrylic (which is twatful for melting & gumming up the drill/end mill)...so my first top tip would be to make sure you buy only cast acrylic for using with CNC/drilling etc.
If you still end up with melting using cast acrylic, the only other thing I could suggest is to first drill with say a 2.8mm drill (and due it to doing all the work, may result in some melting of the acylic), then take out the final 0.2mm by using a 3mm bit ...because it's not having to do much work you can therefore descend quickly & stop any melting (kind of like a final pass)