Time for a dedicated thread as the machine is becoming a reality now.
Early threads with some discussion here- http://bbs.homeshopmachinist.net/sho...ghlight=gilman
and here- http://bbs.homeshopmachinist.net/sho...lding+machines
So basically I'm building a small horizontal boring mill/lathe.
The bed and base is a high end Gilman box way slide. .ooo5" accuracy over 3 feet. Meehanite iron base with hardened and ground rails. Scraped bearing surfaces and anti friction coating on the gibs.
The 2 columns are from a Sieg mini mill. The spindle is from a Sieg mini mill retrofitted with better bearings.
The z-axis for the horizontal spindle is 16tpi acme with a delrin nut. A gas strut will be used for counterbalance.
.2 pitch ball screws are used on the long and cross feed axis with dual preloaded nuts. 269oz steppers on each axis. The cross feed has been tested at a smooth reliable 200IPM and I have not yet fully tested the long axis as I just finished it today.
The cross feed table is mounted to a doweled sub plate so it can be easily removed for parts that might need to be mounted directly to the table.
The z axis is manual for now.
The spindle will be indexed with a proximity sensor and this info sent to mach 3. This will enable the machine to cut any pitch thread.
The spindle transmission is a 3 speed planetary drive with reductions of 72:1-40:1- and 13.5:1 and features a detent torque sensing clutch. A direct drive mode with slight reduction is also available by swapping the belts around.
Spindle speeds of around 20-3000+. A dc 5000 rpm motor and a Minarik DC drive will be used.
The boring bar in the pictures is there for scale. It is 1" diameter by 13" long.
The end support column can either be stationary and locked to the bed or towed with a strap by the main table.
The end column uses a rack and pinion for it's z-axis with fine feed. Heights will setup equally with a height gage.
The end column still needs to be finished.
A sliding support for the spindle will be built to give the headstock better rigidity.
I plan on adding another stepper to allow indexing the spindle and a small grinding/milling head to be used on the cross feed table.
Once finished I'll paint and pretty up the machine.
long axis ball screw with soft limit-
cross feed table-