Mon
Feb
11
2008
CNC Machine Progress
My documentation pretty much reeks on this CNC machine, but I thought I would at least throw up what I have in terms of progress. This picture gives you a good idea of the table adjuster system. The entire table moves up and down on 4 THK linear bearings sliding on 1.25” hardened rods tapped on both ends.
Here is a top view of the table assembly prior to installation of the table top and the table adjustment ballscrew.
This is a picture of the gearbox and large spider coupling that drives the table ballscrew. The gearbox is a 60:1 ratio which is just about perfect. I can stand on the table as it moves up and down and yet the table moves at a decent speed.
Here you can see some of the machine work that went into making the adapter that mated the ball screw together with the table. It was quite the time sink. My dad polished it nicely on his lathe with some aluminum polish just for fun!
Here is the Y Axis Nema 23 mount to hold the stepper motors. I wish I could brag about machining that piece, but I just bought it off ebay for 10 bucks.
This photo shows the Z axis without the faceplate installed. You can see the positive and negative limit switches as well as the THK bearings which carry the load. The ballscrew is directly attached to the stepper motor above.
This is a detailed shot of the electronics. Pictured in the photo are four stepper drivers, a power supply for the logic, an optical isolated DB25 breakout board and a “charge pump” for the Mach 3 Software.
The power supply which drives the steppers is is housed in this box along with a 5th stepper motor driver. The laptop was designed to sit on top of this little computer arm support.
The X axis ballscrews were supported on each end with regular old roller skate bearings from KMart. They pretty much just float around in there. All the precision work is done on the other end.
Here is the X axis motor mounts. I had a lot of trouble eliminating slippage until I just bit the bullet and purchased some of those really nice spider couplings ($22 a piece. Owch!). Even though they are expensive, they really do the job well. Haven’t had one problem since!
Still got a long way to go, but here is what she looks like today after hours of use. Dusty and faithful!
