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Ah Yes, It has begun...

posted Jan 12, 2012, 11:34 PM by Christopher Robinson   [ updated Jan 13, 2012, 1:13 AM ]
1.13.12 (Wicked early in the morning)

I was awoken bright and very early at 11:30 AM this fine, rainy morning. Bondo the dog barked as I hurriedly tried to find pants.  I ran out to catch the Fed Ex driver just as she was finishing the "We were here, you were not" sticky note. (I found the pants by the way.) "Is it heavy?" I ask. "Christ, yes", says the lady that couldn't be a day younger than 55. She enters the truck, the garage door in the back rolls upward and there, there I see it. More friggin' packaging tape than I have ever seen in the total of my 34 years on this planet. I swear to God, there was no box, no crate... there were only linear bearings, ball-screws, 2 pieces of styrofoam and miles and miles of yellow packaging tape. I signed the TriCorder thing and ran into my shop with package perched on my right shoulder.

So I'm gunna build me a CNC machine.
(and I hope the thing will 3D print as well)

Over the last month or so, I have been reading a bunch of blogs and forums, watching a lot of YouTube and ordering parts. Today, as the story is told, the linear bearings and ball screws showed up. I have had the motors for a week or so, and have successfully gotten them to talk to software via both a parallel board and an Arduino, however, I have been stuck there waiting for these glides. Without actual parts in my hands, I could do nothing more that sketch. Now that they are here, I can officially start this project.

My plans are to document this build as completely and carefully as I can. When doing research, I found a few things that really rang true: Information about doing this kind of thing is incomplete and scattered. Although I could find walk-through's, and some fairly complete, I could not find a truly well documented start-to-finish post about building one of these units. I mean, I want to see someone build one of these and on step 4, post a video of, "Man, I sure screwed this step up! --Ok folk, here's the thing that didn't work..." --And this is what I intend to do. Also, I am building CNC which will also print, something I can find very little information on. I would assume others would like to do this, hopefully they can glean something from my stuff. 

Also, please note: There is going to be one underlying assumption that everyone who watches this build should know. I assume, rather I stress, actually I demand that people use the Google. One aspect of any project you are new to, is when you simply don't know what search terms to use to find what you want. I.e. I didn't know what "linear bearings" were called and a bunch of googling for "glides" and "slides" and "heavy duty" got me nowhere. In my posts and videos, I may "shorthand" some things and when doing so, I will try to furnish you with nice, solid search terms to use. In exchange, please use them! I love, no, adore questions, but when one is simply asking me to google something for them... Uhh, yeah -No.

Can we get started already, Chris?
Ok, first post. 
What are we building?
Where did all the stuff come from and what did it cost?

I am building a CNC machine that will also 3D print. Overall dimensions of the work area are roughly 24" x  30" x  10". 
  • Able to mill materials including (hopefully) light metals
  • Mill and drill PBC's (Circuit boards)
  • Print 3D objects
The stuff we gunna use:
  • Steel frame of 16g square tube. 1x1 box, 1x1.5 rect, 1.5x1.5 angle, 4x2 C-channel, various barstock
  • MDF deck
  • Slides are fully-supported linear bearings at 300mm, 700mm, 800mm
  • Ball screws of matched length
  • (3) 425 oz/in NEMA 23 stepper motors with controllers and power supply
  • Parallel port breakout board
  • Arduino(s)
  • Limit switches and other electronic whosa-wudgets
  • Porter-Cable 690 router body 
The stuff we's all worried about an' stuff:
  • Obviously, rigidity is by far the #1 issue with this type of build. I've seen it a million times in forum posts etc. I have the advantage that I      A) spent the money to get nice slides and B) I can weld and I am doing this out of steel. This brings me to worry #2...
  • I am worried about over-building this thing. I tend to do this in general, and having no point-of-reference with a project like this, I will err on the side of too heavy, but wicked stiff.
  • I wonder if I should have gotten the next-size-up on the motors or if the 425 oz'ers are going to be ok.
  • Because this unit is going to use ball screws (not belts) for travel, it may be too slow for printing
  • Last worry: I have no idea what the hell I am doing and have never done this before.
I have been a metalworker as a hobby for quite a long time and I can weld real good (not "really well" mind you, but "real good"). In addition, I was a Trim Carpenter, cabinet guy and Cabinetmaker for more than a decade. The bottom line is that although I don't have everything I would truly want on a build like this, I am blessed with (and worked my butt off to obtain (over many years)) a gosh-darn-good set of tools. That said, I would assume that about 95% of this build will be done with a grinder and a welder only.

  • Lincoln MIG welder
  • 14" chop saw
  • Grinders
  • Big drill press
  • A "full shop worth" of woodworking tools 
  • Bunch O' clamps (God Himself doesn't own enough clamps...  You can NEVER have too many clamps)
  • Yadda yadda... bunch of stuff.
Where did it come from?
The vast majority of everything came from good ol' Ebay. The two biggies were the linear bearings kit and the stepper motors. The links below will probably be dead soon but you simply need to search for "linear bearing ballscrew" or "NEMA 23" on Ebay and you will find all you need.

 Linear Bearings, trucks (sliders), ballscrews,  ends for the ballscrews, flex couplersCame as one kit on Ebay
 300mm for the Z axis.
700mm for the X axis.
800mm for the Y axis.
 (3) NEMA 23 425 oz/in steppers, "black box" controllers, pwr, PCB Came as one kit on Ebay
 This is NOT the crappy "all-in-one" board/motors combo for 150 bucks --Don't buy those. $370
 Steel     Local Supplier Assorted box tube, rect tube and flatstock   $220
 Hardware  (Nuts/ bolts) Albany County Fastener
(This is the best place, hands down, to buy nuts and bolts --one of the best co's I have ever done business with)
I splurged and bought all allen-key and stainless. $52
 Consumables     Local Supplier Argon/Co2, Mig wire, grinding wheels $70
 Endmills              Not purchased yet 
 3D Print stuff  To be covered later 
 Miscellaneous    $100

In the following posts, hopefully the next one, we are gunna start cuttin' metal and stickin' it together.