Close

X Axis

A project log for CNC Plasma Table

Plasma Cutter + CNC Table + Auto Load/Unload = Tool to build other projects faster

willbadenwillbaden 07/28/2016 at 11:210 Comments

The X Axis linear guides started life as an industrial printer. The rails sat on what is now the top of the printer chassis.

The picture shows the original belt drive. It used a DC motor like many other printers and moved the plastic print head mounted to plastic bearings. This allowed some movement in directions that were more than my liking. So at the very least, the carriage bearings were needing an upgrade.

The rail design was changed by moving the back linear guide down in front of the chassis. The guide had to be cut down. The material was not hardened (which means wear will play into bearing contact at some point) so a horizontal band saw cut off the excess.

To hold the rail in its new place, some mounts were made from aluminum. The rail already had some holes drilled and tapped from the original configuration, so they were utilized.

Before the rail could be mounted, the X axis carriage needed to be built. Along with this the new bearings. Using more bearings from copy machines, they were attached to some peaked blocks that would allow the bearings to form a v. Many linear guide configurations have used similar v designs.

The X carriage forms a box that surrounds the printer chassis. It is made from 4 aluminum plates and will allow for the x and z motor assembly mounting.

There are four bearing blocks that are used in this axis. 2 are fixed at the top as can be seen by the screw heads. 2 are floating along the bottom. IE, they are adjustable front to back and top to bottom. This allows fine tuning of the bearing to rail clearance.

The rail was then ready to be mounted. Installing all four bearing blocks (the bottom two in the middle of adjustment travel) the rail was clamped to the chassis. A 6" micrometer was used to measure the distance between the rails.

The final assembly included some spacers between the x carriage and bearing blocks that the above picture does not show. The spacers were added due to maximum micrometer size for measurement between the rails. But the idea is there on how the rails were clamped for installation. Below is the picture of the mounted rail.

This configuration did not allow for a consistent distance between the rails that was satisfactory. So the linear mounts had the holes slotted to allow for adjustment. Jack screw blocks were also made that attached below the linear mounts. I couldn't find pictures, if there is interest, I will try to get them posted.

The X axis motor assembly using the same motor/pulley configuration as the Y axis.

The big difference is placing another bearing surface to ride on the printer chassis. Since there is a lot of weight on the side of the motor and the x axis box carriage is springy, some method needed to contain the movement.

The fourth wheel that is opposite the drive pulley is the bearing. this rides on the printer chassis. It is aluminum on aluminum, so at some point, galling will show up. Using a plastic bearing might come into play in the future.

The belt clamps were mounted to either side of travel. The adjustable belt clamp did not see as much tilt as the Y axis. Attributed to moving the screw holes closer to the belt.

Discussions