CNC Machine Build

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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).

Suppliers:

Both Ahren (CNC Router parts) and Nate (Fine Line Automation) have been super responsive and helpful.

Here's my full bill of materials (BOM) and here are some CNC projects I've done.

Contents

Build Notes

Initial build pictures, with a small temporary table installed:

Overall view
Cross-gantry drive
Z-axis drive
Another overall view
Z-axis drive and router head
IMG 0990.jpg
Back of gantry
Rear view of gantry

Emergency Stop

After getting confused about my Z-axis reference and cutting a slot in the table, I implemented the emergency stop switch:

IMG 0993.jpg

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.

Basic construction
Finished view
In use

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.

Setup Probe

TBD

Errata

  • 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)

Plans:

  • 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.
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