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This is Part 2 of a multi-part series. See also Part 1.

Synopsis

It has been about a week since the kit has arrived, and I have found time to begin assembly of my new micRo CNC milling machine. The kit I ordered did not include any fastener hardware (screws, nuts, bolts etc..). Nor was any hardware kit available upon purchase, though I bet they will change that. I took this as a mixed blessing and performed a preliminary “dry” assembly. As of the time of this writing, the kit has no formal instructions. I had to figure out the assembly pattern based on reference photos released on the site, and looking for key moments in videos released by Lumenlabs.

Leadscrew Lengths

This is proving to be a little more challenging than I had thought. Many of the components are pre-drilled and will only fit together a certain way. The portions which have ACME threads (the leadscrews) are obvious. Two of the 4 leadscrews, for example, are the same length (likely candidates for the X axis), but one is a little different by an inch. The last leadscrew is obviously Z (vertical) because it is very small. For now, I have placed the odd-man-out on the Y axis. 

Hardware Woes

I have begun looking for the hardware, and found most of it at local places around Seattle. I tried to visit the local places first, such as Hardwick’s, True Value Hardware, Stone Way Hardware, and finally Tacoma Screw. One of the harder to find screws is a 3mm cap screw, 45mm long for the Z axis motor mount. Tacoma Screw was able to supply a stainless steel 3mm by 40mm, but that last 5 mm makes all the difference. The 3mmx40mm worked for the Y axis, but not the Z axis motor controller. I believe Fastnel will have it in stock.

Another part which I thought would be difficult which was not included was the Z axis motor standoff. It turns out, it was a relatively common part from the plumbing section of a local hardware store. At 69 cents, one has to wonder why it wasn’t simply included in the kit. I guess it makes it more of an adventure!

Well I’m going to keep on keeping-on. Those looking to repeat my efforts should just buy the hardware kit!

Gallery (after the break)

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Finished micRo Desktop CNC Milling machine. (Photo by Lumenlab)

What is it?

Last week, my new desktop-scale CNC milling machine kit arrived! This is a fun new project which prospects both inherently as a technical electro-mechanical project but also what the machine itself can create. Much, much, larger scale versions of “robots” like this perform many of the industrial tasks, but at great expense. Lumenlab has designed this unit for cheap, desktop-enthusiast performance.

What do you get?

In a nutshell, the basic kit provides what you see:

1. series of plastic blocks (connectors and axis blocks)
2. linear bearings/rollers
3. stepper motors (4)
4. breakouts for the stepper motors for a parallel port
5. a series of leadscrews with ACME threads

Who makes this this?

First sprawled out on the table, minus the packing peanuts

You can watch the video blog Brainchild who is a bit of a mad scientist (and funny), but takes quality / projects like these seriously. The tooling required to produce these kits on a massive scale must have been a serious challenge, and I am thankful for the folks at Lumenlab’s late nights. It is a bit of an investment for a kit like this. The quality is foremost and shows even when so many people are whining for kits (we all get impatient after a few months). The lead time was long considering the but this unit is probably in the top 50 units shipped to customers. The waiting queue was considerable on a consumer scale, but compared with industrial tooling (or trying to make these kits by hand) it was amazingly fast. I also must mention that he tried VERY hard to keep most of the plastic suppliers in the US, and many of the US suppliers were very inconsiderate to the small scale he is operating (out of tolerance and warped parts for example). It might look easy and only a few bits of plastic, but the devil is in the detail.

Why am I working on a CNC mill?

At the end of October of 2008, I saw an interesting video posted at where a custom CNC machine drew a fun picture on a pumpkin. The milling machine shown in the video was huge, too big for my apartment! The precision and duplication of machined items on of a CNC mill makes it neat. It’s also just fun to mess around with Ubuntu and electronics sometimes.. :-)

So what can it make?

Well it can make a mess out of a pumpkin! Below is the pumpkin video:

This pumpkin is huge, so it is actually being hacked apart on a much larger machine (they call it a RoGR). The video shows what is possible though with CNC. The operator took a black and white photo of himself and created a grayscale bitmap. The theory is that lighter values in the grayscale bitmap will correspond to the deeper cuts. These deep cuts in turn will shine brighter when a light is placed in the pumpkin. You can read more about the pumpkin here.

Brainchild's Pumpkin Finished, after CNC carving (Photo by Lumenlab)

Here is a picture of it when a light is placed in the pumpkin.

This micRo kit is much smaller, but if one can control a machine on this desktop scale, any scale is possible. Hopefully I can get this kit up and running soon!

I’ll detail the electronic, mechanical, and software side of the construction of my micRo, as well as the objects I create with it.