I have exhausted everything I can think of to the point of ultimate frustration so I am seeking you sage advice…
My Machine:
24x48" cut area
84oz Nema 17s all axis
400w Brushless spindle 12500 rpm
Interface is Raspberry Pi 3 with Protoneer Raspberry Pi CNC Hat and Pololu A4988 drivers
I use BCNC as my gcode sender
All Models and CAM generated in Autodesk Fusion 360
The machine is totally in square and the longer tube runs are center supported. I am using 23.5mm parts and 3/4" 23.5mm emt conduit.
Everything was working perfect. I ran numerous test jobs above the work surface without the spindle engaged. I even did a relief of my logo with only about a 1/16" depth running at 12-16mm in mdf.
When I cut plywood the first time set way conservative feeds at 5mm and 3mm plunge using the 1/8" diameter 2 flute Kyocera endmill from drillman. It plunged two holes and the third it seemed to grab the side wall, spun it self around, necessitating a mash of the emergency button. This has happened twice now and not in the same hole. The first time things were slightly loose on the rail carriages so i tightened them up…smooth as silk. I also noticed the center assembly was rocking slightly which seems to be why it is moving slightly off course on the plunge. The only solution that tightened it up was increasing tension on the long middle bolt in the center assembly. The problem is, if you crank the tension on this at all, it causes the leadscrew to bind!
Here is a vid of the movement:
Please help! Any insight you have would be welcome…