Build Thread- microCarve A4/Gecko G540

[saundby]

I used GCode to get the design.

Full account on my blog:
An Infinite Number of Cats on Keyboards: First Attempt at Engraving an IC with my CNC

[Fish4Fun]

Saundby,

I too am a recent, proud A4 owner! (Pictures of my build are on pg 57 of John's thread: http://www.cnczone.com/forums/diy-cn...achine-57.html ). After an extended bout with Win7 & Mach3, I finally have everything running to my satisfaction (switched to WinXP, lol). Tuesday I actually used my A4 to make a part for my "minnow tank" (I own a fishing tackle store), and it turned out perfectly!

I have some V-bits on order, and hope to do some PCB work when they arrive. I noticed your IC engraving, and was curious if you have done/plan to do any PCB work? I have read a ton, and am currently planning on starting with Eagle & pcb-gcode.ulp . I am more familiar with Altium's products (and quite honestly find Eagle very clumsy in comparison), but the cnc support for the Eagle appears to be first rate and "easy". My first PCB attempt is going to be an LED board to replace the "circle line" fluorescent bulb in my desk magnifying glass, LOL.

I did not notice any limit switches on your A4; I assume you have given them some thought? I initially thought, "limit switches are for people who are too cautious." Of course, after a couple of crashes I am now "one of those people who wants some safety features." LMAO. I will post something about them in John's thread, he likely already knows the best answer...

Another thing that I dismissed out of hand prior to actually using my A4 was a "dust cabinet". After my first "practice cut session" (a "sample" file from V-Carve of a Marlin), I quickly realized the value of an enclosure and set off building one. That took a couple of days, but was WELL WORTH the effort! (My A4 currently resides in my "game room", a 900sqft finished room with hardwood floors, big screen TV and a pool table. Took 2 hours to cut the marlin, 4 hours to clean up the mess!) The noise difference is amazing as well. I built "panels" from 3/4" x 1" strips covered with 1/8in luan and filled with 3/4in foam. It is basically a 34 inch cube with a "45" cut out for a view window/access panel. I can now run my spindle day or night w/o disturbing my bride :-) (much, LOL).

My build uses a G540 & Keling steppers (the ones recommended for the G540), Bosch Colt for a spindle, with the K2CNC mount John reccomends, a solara power supply (48V 12A I found on ebay for $28 including shipping!) a think&tink set of collets for the Colt, a couple hundred carbide bits & drills from various ebay vendors and my cabinet. I need to add a 12V/5V PSU, spindle relay, limit switches, vacuum relay, "cooling hoses" to direct air flow from the vacuum to the steppers, G540 & tool tip and more in-cabinet lighting (I currently have three "LED Pucks" but plan to replace them with some brighter LEDs & a uController based dimmer).

And finally, have you looked @ the Arduino based controller? It sounds like it would be right up your alley. I plan on getting an Arduino and playing with it. I am very familiar with AVR assembler language/programming (though I am woefully ignorant of "C") and am hoping that the new 2560 based Arduino might be able to handle a 4th axis, even though it should have plenty of memory resources, it may not be fast enough to crunch the numbers, but I figure I can worry about that when I get a 4th axis, LOL. (I am probably the only person on earth who finds assembly language easier than C! I really need to dedicate some time to learning C.)

I hope it doesn't appear that I am attempting to hijack your thread, I just had several thoughts in response to your build that are closely related to me and my build. Thanks for posting your build log, I hope we can compare notes on our A4s!

Fish

[saundby]

Yup, I'm planning all pretty much the same things you are. I'll be upgrading and improving my setup in between spates of actually using it.

Limit switches will probably come pretty soon. I'll be opening up my controller/power supply case to punch through some holes for connectors, I'll probably put in connectors for both limit switches and a spindle motor relay.

I've also been planning an enclosure since before the A4 arrived. It's too big for a 1.1 meter equipment rack I've got, but I want to build something similar that's sized right for the A4. I'll be using homosote board and plexiglas to trap sound and dust, there'll be a vacuum in the bottom (with its own noise damping) to help with dust control. I've been moving my paper drawings to CAD, I'll probably post them when I'm getting close to building. That may not be till the end of summer, but I'll probably get the frame built, at least. I need to get my CNC off my workbench!

I'll be doing PCBs at some point as well. I've been trying to turn up my supply of FR4 between other jobs, once I find some I'll probably do a little one-sided board for a simple AVR circuit just as a test of concept. I'm getting pretty good at levelling my work and all, I feel pretty confident I can manage it. The big question will be what I do the PCB designs in, and what CAM package I'll use to generate gcode. For the first board I'm expecting to code it by hand. PCB geometry is a lot simpler than the decorative woodwork I've been working on this past week or so.

Sorry to hear you've had some crashes with your CNC! I've managed to avoid it, so far (knock on wood). I've gotten pretty good at using the software limits in EMC2, though. I started out re-running the setup program for each job, setting the axis movement limits on a job-by-job basis to keep me from hitting the ends of the rails. Now I've got two setups I use regularly, that I've gotten used to. One has the origin at the lower left corner of the table, the other has the origin at the center of travel. Between the two I can pretty well set up my work and not end up with crashes. Before I run each program, I manually command the head to move close to the limits, check that there's room, then move it to those limits manually a bit at a time. If necessary I change my zeros. It's a bit time-consuming, but it prevents crashes.

Putting in the limit switches will let me be a _little_ more cavalier about my setup, but on the other hand I don't want a job ruined by hitting a limit switch, either. So I'll probably keep being pretty cagey before I click the "run" button. As it is, I've settled into a few standard ways of setting up the job on the table, which makes things go more easily.

On Arduinos, yeah, they look pretty cool. I've been working with "bare metal" AVRs since they first came out (lessee, the AT90S1200, IIRC), so I haven't had a project to use an Arduino on yet. I'll probably pick one up to play with for the heck of it sometime. Right now I've got a few other projects to finish first--like an 8085 based computer (I need to at least finish a releasable version of a basic OS for it) and an 1802-based computer called the "Membership Card", a close relative of the COSMAC Elf computer. I probably only need a solid day's work to finish that up, I'm doing up a sort of "steampunk" case for it, which is nearly complete. Compared to that, the electronic part will be a breeze.

[saundby]

I've posted instructions on assembling the microCarve A4 itself on my website. I've also posted my design for a simple spindle mount for the Harbor Freight #44914 router (or equivalent, they have sold others with the same mold line). Both are in the new CNC wing of my website:

saundby.com: CNC Machining

Any corrections or other feedback appreciated.