Hello cnczone!
My name's Hank, and I've been lurking around these forums (learning and admiring) for about a year now. My friend and I are both architecture graduate students, and we've decided to move forward with an ambitious build. We've built a handful of commissioned furniture using large 4/5 axis machines at a shop that we had a connection to. Our "friend discount" has slowly disappeared, and we've decided to take the next step in our venture by bringing the machinery in-house. We'd like to begin building by December, giving us a little time to work out some bugs in the design.
The design is currently on it's second draft; revisions were made after meeting with and consulting "lunchtrayrider" who coincidently has his machine located a few blocks from my house (thanks aaron!)
I've attached a few images of the structure, but if you have sketchup on your computer, I can email you the 12.0MP file so you can wander around the drawing yourself!
A few key notes:
Table
- The table structure is 8" hot-rolled steel channel.
- Corners are braced with 1.5" slices of 4x4 steel bar-stock cut diagonally.
- Table is squared using cables tensioned diagonally between the braces.
- X-axis rails are .25 x 1.5 cold rolled steel (adjustable)
- The 49x97 MDF substrate is supported by interlocked 3/4"plywood.
Gantry
- The gantry structure is a combination of aluminum channel and aluminum tubing
- The ganry has 3 height settings, increasing rigidity and reducing distance from bearing to bit when cutting ply.
- Height settings offer 3", 7", 10" of clearance between top of substrate and lowest point on gantry
- Y-axis rails are .25 x 2 cold rolled steel (adjustable)
Z-axis
- The Z-axis structure is a combination of cold-rolled steel, aluminum tubing, and machined aluminum plate
- The Z-axis is centered on the gantry limiting any torque from moment stresses
- The Z-axis has a range of motion that allows a 1" bit to reach the substrate from full gantry height, and allow a 2" bit to raise high enough to clear the lowest point on the gantry. 10"+ of travel
- The router drawn is a Milwaukee 5625 3.5HP router to demonstrate the capability to upgrade. I plan on starting with a Hitachi M12VC.
Drive System
- Linear carriages and countless other parts will be sourced from cncrouterparts.com (what an incredible resource!)
- The X and Y axes will be driven by rack and pinion system. I'll be using all of the parts from Ahren's NEMA 23 R&P system, except I'll be using a custom aluminum plate to suit my needs.
- The Z axis will be driven by a 5-start ACME screw.
- I am planning on using Ahren's 4-axis complete electronics kit, but am a little concerned it may be underpowered. I'll be starting a seperate thread to discuss motors and electronics, and would rather focus on structure in this thread.
- The motors drawn are NEMA 34, to demonstrate the capability to upgrade.
Because of the scale of our projects, anything less than a 4'x8' cutting area will handicap our design. (Luckily we have a full stall in a large 2-car garage to work with). As drawn, the cutting area is 49.5" x 99" (from bit-center, allowing 1/4" clearance from any "hard stop").
All metal will sourced from discount steel, convieniently located a mile from home.
Current budget is 3000-4000. The most recent estimate, including all structural material (including cutting, but not machining or drilling), all electronics (assuming Ahren's 4-axis package), and the Hitachi router is $2300. This leaves a small cushion for some machining (most of which will be done taking advantage of Harvards waterjet/milling machines).
So, I guess that's enough info for one post! I know a lot of you wandering the forums have years of experience and a number of builds under your belt, and I'd love to hear your thoughts on the direction I'm headed! Thanks!
Hank