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CNC Lathe To Do

This page is my running To Do list of tasks to finish the project.

Phase 1: Minimum Necessary to Run Under CNC

Assumptions: No control panel, coolant, or spindle control. Driver enclosure connectors all installed so no further machine work is needed on the enclosure in later stages.

Design & Research Tasks
Home and Limit Switches: Decide how to mount the Z-axis switches.
 
Purchase and Procurement
 
 
Driver Enclosure
 

Finish rear panel connections:

        Mic connector for coolant controls (installed now, wired later)

        Mic connector for spindle controls (installed now, wired later)

        Mic connector for Limit Switch (installed now, wired later)

        Mic connector for spindle sync sensor (installed now, wired later)

Stronger bracketry for control panel connector. Better bezel as well.

Finish relay delay system for DC supply and switched AC receptacle.

 
Enclosure Rack and Control Panel/Screen/Keyboard System
    Drill rack mount ears for rack bolts
    Photograph the rack for the web site
 
Testing and Operation
Clear area to make room for Lathe electronics rack
Assemble the enclosures in the workshop.
Configure Mach 3 Turn
Test the motors and limit switches before installing in the lathe
 
Lathe Mechanicals
Make Z-Axis Step Motor Mount: Needs an M6 bolt and trial fit
Mount steppers with cabling to X-Axis and Z-Axis Mounts
Mount home/limit switches on X-Axis and Z-Axis
Install Igus chain for Z-axis cabling
 
Final Lathe Testing and Configuration
 
Fire it up and try some turning and facing operations
Design and execute an accuracy measurement regime. Tune up the lathe to improve the accuracy as well as possible.
 
 

Phase 2: Add Control Panel

Design & Research Tasks
 
Purchase and Procurement
Knobs for Pots: Or make some?
 
Construction Tasks
    Fabricate back cover from sheet metal.
    Mount 5K Pots to Control Panel
    Find and attach some knobs to the pots
    Wire Panel
    Wire GRex to DB-25 printer connector
    Attach Panel to Rack Framework Below Monitor
 
 

 

Phase 3: Add Spindle Control

Design & Research Tasks
Where to mount motor speed controller? Behind control panel? Behind lathe?

Spindle Circuitry incl. Load Meter

    What to do about analog isolation for GRex on spindle speed control? Status of Hohman board?

    Experiment with the load meter to see how well it works for the lathe. Will be mounting in the motor electronics box.

Going to need a box for motor electronics and coolant relays. What connections will that box need from the driver electronics chassis?

- Analog output controlling speed. Will go to a Hohman board in the motor electronics chassis.

- Spindle on/off

- Spindle reverse

- Power for motor controller to come from a switched AC receptacle on the driver chassis. Power to be switched along with stepper DC power for E-Stop.

 
Purchase and Procurement
Mechanical Relay for Coolant, Because it's going into the same box as the spindle relays.
 
 
 

 

Phase 4: Add Spindle Sync Sensor for Threading

Design & Research Tasks
Wait for GRex firmware upgrade and subsequent Mach 3 update to support threading with GRex.
Spindle Encoder. GRex requires an encoder for threading on the spindle. Need to decide what encoder and how to mount it to the spindle.
Noise Suppression: Insulated metal flex conduit from VFD to motor, grounded. Shielded cabling into VFD. Ferrite cores as needed.
 
Purchase
Appropriate encoder or sync sensor
 
Construction Tasks
Install sensor and cable back to the driver enclosure
 
 
 
 
 
 

 

Phase 5: Add Coolant Control

Design & Research Tasks
 
 
Construction Tasks
Start out with an air jet or fog buster type coolant system
Build an enclosure and move up to flood cooling if desired.
 
 
 
 
 
 

Phase 6: Ballscrews

Design & Research Tasks
Consider mounting X-axis ballscrew on the rear of the machine. This can be set to preserve manual operation if desired.
Going to have to think hard about the Z-axis ballscrew. There's almost no room for a conventional approach. Suggestion is to attach the ballnut to the rear of the slide so that we only need to find clearance for the nose of the ballscrew under the slide. This could also be done in the front if desired. If it is desirable to preserve manual operation, engineering this ballscrew to work like a taper attachment seems ideal.
 
Construction Tasks
 
 
 
 

Other Embellishments

Design & Research Tasks
 
Construction Tasks
PC Front Panel Power & Disk LEDs: Purchase 5V units and wire them up to the mobo
Add filter pad to fan and orient for positive pressure in case.
Plug original HD mounting holes by making a name plate and mounting w/ socket heads.
Play around with making an optical limit and see how well it works. If it's repeatability is better than the roller switches, make a second one and replace the mechanical limits with optical switches.
Custom engraved and CNC front panels for both enclosures.
Collet closer
Gang tooling

 

 

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