CNC Machine Build
From Payne.org Wiki
This page summarizes my notes on building a CNC machine.
I've built the FLA100-00 2'x3' machine described here. I like the design because it's modularized to 80/20 aluminum T-channel extrusions. I think the design is a very good value for the price -- it's a "real machine".
I built the machine exactly as shown in the plans, though I added a t-slot later (see below).
- Amazon (80/20 extrusions, stock lengths)
- CNC Router Parts (steppers, drivers, linear carriages, misc. hardware)
- Fine Line Automation (rails, misc. hardware)
- MSC Supply (misc. hardware)
- Automation4Less (80/20 extrusions, cut to length)
- Linux CNC (control software)
Both Ahren (CNC Router parts) and Nate (Fine Line Automation) have been super responsive and helpful.
Initial build pictures, with a small temporary table installed:
After getting confused about my Z-axis reference and cutting a slot in the table, I implemented the emergency stop switch:
The mount was fabricated (on the machine!) out of 0.221" plexi. I got the switch on eBay: $10 new.
This is currently connected to the DISABLE/E-STOP input (position 10) on the Gecko G540 driver. Alternatively, it could be connected to one of the G540 input pins and configured as the ESTOP input to EMC2.
T-Slot Table Top
After I got the basic machine up and running, I built a T-slot top. I used Incra 48" T-Track spaced on 6" centers. The substrate is 3/4" plywood with a 1/2" MDF top layer, screwed down (easily replaced after wear or gouging).
The table is attached to the aluminum extrusion with 6 recessed button head cap screws, and 5/16" T-slot nuts. It slides in and out from either end.
If I were doing it again, I'd consider:
- Shorter 36" T-track (the working area of the machine)
- The Kreg track, which is slightly thinner and has countersunk holes. The Incra track screws are not countersunk, and the screw heads catch a lot of sawdust and debris.
- Planking the entire deck with 48" 3075 extrusions. Eight sections needed: about $240 total.
- When using the 5-start ACME nuts from CNC Router parts, make sure you get the recommended leadscrew from McMaster-Carr
- The PB-0001 fastener bundle from Fine Line Automation is missing two 5/16-18 3/4" SHCS (for attaching the cross-gantry motor mounting plate). The screws are also missing from the CAD drawings (as of Oct-2009)
- Use the latest plans from Fine Line Automation's Web site, which include PDF drawings of how to cut and drill the 80/20 extrusions. The plan .ZIP on the CNC Router Parts site is one rev old.
- The MSC part numbers in the Excel spread sheet files for Powertrain components, Force Transfer are incorrect. Also, the LoveJoy motor coupling scheme has been superseded by the zero-backlash coupler from CNC Router parts.