Sand bag damping of sheet metal is not new. Using sand bags to dampen down structures is not new, not even to this blog. Previously I used sand bags to dampen the column of the Sieg SX2.7. They added a very small, but still significant level of damping.
The trouble with large thin sheets of material is it is hard to get enough fixing points. In a manual milling machine I would get around this by just machining one part at a time. Then I could clamp it down and hence make it very stiff.
However, with a CNC machine a great feature is being able to fit a large sheet on the table and hence machine lots of parts. You can then walk away and get on with another job.
This tiny Genmitsu 3018-pro cnc is small, is not that stiff and not that heavy. Hence it is already at a disadvantage. However, the following video shows the impact of adding bags of sand onto the table.
Hopefully this demonstrates just how well sand bag damping sheet metal really works.
I have used cloth bags filled with sand, but you could just as easily use thick plastic bags of sand. Double bagging the sand will help give a level of protection from spilling.
Kant Twist Clamp
The first Kant Twist Clamp, maybe a few more are needed to give me a set. With the arms being machined on the Genmitsu 3018-pro then these are not too bad to make. This initial set of parts that you are seeing as a completed clamp were my first proper cnc parts.
Sieg SX2.7 Milling Machine
Finally got tired of the Amadeal XJ12-300 milling machine and upgraded to a Sieg SX2.7 Milling Machine. I had to split the machine into 2 parts to move it from the drive to the workshop. Even so it still hurt, total weight of the mill is around 95kg.