Standing on Shoulders

Well, then… given my state of affairs as of late, I’m excited to share something more notable!

So, I designed my own parametric CNC mill. Straight from my imagination. Which is to say I absolutely could not come up with an industrial grade machine on the first round, especially on a shoestring budget. As far as my creations go, it’s about the most involved project I’ve undertaken on my own. It’s been alive for nearly a year, and despite a slow start, I’ve been getting ever more glitch free running hours out of it. 

I conglomerated a short list of project ideas a couple weeks ago, some that are essential and some just for kicks. I finally made it to an essential project: tightening up the play in the axis. I haven’t had a chance to do all the improvements I need to do, but this was a remarkable start! 

I clocked a good number of runtime hours in, feeling pretty stoked on the new mastery of shape that my machine empowered me with. Then, I thought I’d do something neat and cut out a perfect little pocket for a bearing to sit in. I barely set it in place before the obvious issue struck me down: the perfect circles I thought I cut were clearly perfect ovals. Observing the machine more closely, I finally saw all the little wiggles along the drive train.  The Z axis was easily secured with a couple washers, but the other two required more effort. Basically, the linear bearings were just all around sloppy. I shim-shiminy’d all the shims I had, but ultimately the failure was in the design. I skimped on the linear bearing brackets, opting for a mere one bracket per point of contact. It was a hundred dollar decision that cost me dearly in quality. Lesson learned! 

Moving on to the project at hand, I was really really tempted to clamp these pieces of HDPE to the mill for the heavy lifting and let my fingers work the magic on the keyboard. Circles being out of the question, all I really needed was good depth control and one firm axis. As I endeavored to get the two pieces positioned and imagining how the rest of the operation might go down, I got the feeling that maybe this wasn’t the best approach. 

Sitting against the wall, boxes piled on top and underneath, was my beloved Mark V. Most of my audience is wondering who Mark is, but I’m sure someone out there will read this and chuckle. It may seem peculiar that this antiquated old pile of metal has such value in my eyes, but I’m more connected to this thing than I care to discuss at the moment. Not this exact machine, but the Shop Smith in general. Much like the Volkswagen in its conception, this piece of Deutsch engineering was built with serviceability and ubiquity as focal points. Unlike Volkswagen, these folks stuck to their guns, but don’t let me get started on that rant! Since the Mark V’s debut in 1953, they have made very few but very thoughtful changes. My machine is a 70’s model, but absolutely any accessory ever made will fit without adaptation. I can still buy replacement belts, motors, quills, etcetera if it ever breaks. If I decide I have too much money one fairy tale day, I can upgrade the whole headstock. Ooh, digital rpm display! <Homer drool> 

I would say my CNC is standing on the shoulders of a giant. I’m sure the purists will tell me all about the lathe being king and what-not, but I have the capacity for a compact, light machine. I’m doing what I can with what I got! I also have to point out that, despite being an older model with fewer of the stabilizing revisions, I am fairly confident in the accuracy of cuts it can produce. So, with a sacrificial layer expertly mounted to the fence (eh hem) I started making shavings. 

Now, one aspect that dissuaded me from using the mill was thinking about all the passes I would have to make. It’s just plastic, so it should cut like butter, right? Well, sort of. It is high density plastic, so I couldn’t just hog off a quarter inch per pass. However, the Mark V has a 5/8 inch chuck as well as a 1/2 inch collet and I have a wider selection of bits to work with. A half inch end mill made for easy chewing of most of the block. From there, it took a couple of tedious hours to nibble the notches down using a cheap Dremel bit, but I really wanted that nice 1/8 inch bead profile to match the slot in the 80/20 extruded aluminum. 

Excellent! The gap in the notch is about 0.2mm, and will translate into less error than that at the bit. The notch that fastens to the other beam? Well…

…does it look accurate enough to you? 

At the end of it all, I did have to wonder if all the time I just spent on these things was worth it or if I should have just bought another set of brackets (maybe not 80/20 brand!) Considering my going rate and backlog of profitable work waiting to be done, these 4 brackets cost me at least a hund-o. I would have spent the same plus shipping on brackets, so I figure that it’s a wash as long as my parts don’t wear out too fast. 

As I went to mount them, I realized that I probably did better than just saving on shipping. I did spend a fair bit of time installing shims on the rest of the bearing pads. Somehow, I didn’t quite have enough to go around, either. I realized this as I had taken all my measurements off the Y axis rails but wanted to see if the parts would look better on the X axis. With all the shims needed to get the pads nice and tight, my parts wouldn’t fit alongside the brand name brackets at all. However, they did fit the Y axis just beautifully, and I get to save all that time not having to shim and adjust. 

In the words of Ace Ventura, “Like a glove!”


More Doing

In trying to shake this funk, I have come to realize that I no longer have a space in the house to claim as my own. There is a desk with a computer, but said computer is about to give up the ghost as well. I don’t really get quiet time to sit and do anything productive, either. 

Still, I have to make something. It’s just what keeps me able to wake up day to day. I shouldn’t imply that my family doesn’t do that for me, but I really lose the wind in my sail being little more than a babysitter day in and day out. I have to do stuff, keep my hands and my brain busy. 

I’m wishing I had a shop space again, as power bumps screw with the machine and usually makes it freeze. I also have just barely enough room to walk around the thing. Nonetheless, I finally got what I was after. 

I’ll take any kind of success I can get right now! 

Finally, back to making sawdust! 

That’s really all I have wanted out of life for a while. To stop this thing from being something I’m working on doing, and to finally say it’s what I do

Service Counter

Finally installed, and I really enjoyed making it. The counter top came out pretty nice, and I’m now pretty happy that I have an extra panel of oak glued up for my own enjoyment. I’m thinking a coffee table would be nice. 

Really, given the color of everything else in the room, I feel like this was a bit light. They went with it because they liked the red in this stain. 

Classic supply chain management fail right here. First, I priced out and built these doors based on ‘saloon door’ double action spring return hinges. I bought them from a local supplier who urged me to opt for gravity return hinges at about 3x the price. After those hinges sat in a bag for a week, I came around to their thinking and decided these folks would not appreciate the ‘Ka-Thunk!  Ka-thunk ka-thunk thunk thunk’ while focusing on their laptops. So, I went to install on Sunday. I live in a city, and weekends are indistinguishable from weekdays in my life, so I hadn’t thought that the store would be closed. 

No big deal, I thought. I got the girlfriend on the job of finding those hinges while I loaded everything up and made the drive to the site. She called around then finally called me to report that nobody in town that’s open on Sunday had those hinges. Fine, let’s just get these janky ones from the big box store. I opened the app, found the ones I need, confirmed they were in stock, and texted her the description, SKU, etc. 

She couldn’t find them, and Sunday I walked away from the install without doors hung. 

So, Monday I went back to the first store to swap the hinges out, pay the extra $40 and get the doors hung. I already stopped by the orange box to return what I didn’t use and spotted the hinges I had sent Kim for the day before. They were fully stocked. I looked them over real hard, then decided against purchasing them because I wasn’t sure if they would hold open as needed. It was only $7, and I had just returned $20 of stuff I purchased to ensure not running out of anything during the project. I didn’t buy them. Then later in the morning, after circling the hardware store 3 times to find parking, I am standing there in line waiting to finally get these damn hinges. The attendant was the same one, so I tell him to swap em out and I wish I would have taken his advice earlier. “Did I tell you about how I installed these hinges in my…?” he begins. I nod and he tells me all about it on our way back. He hands me two boxes and I inspect them. “Are these the hold open type?” I ask to confirm. Nope, they weren’t. The hold opens would be yet another $15 more per hinge. Ugh! Well, 4x the price pretty well blows the budget, but I want to deliver quality. I shake my head and tell him whatever, just put them in my hand so my wallet can go get sucker punched and I can get on with life. Oh, there’s only one hinge. Can I get it expedited? Sure can. For another $40. How soon? A week at best. Gah! 

I then kill an hour slogging through traffic to go to the orange box and buy their stupid hinges. They are crap. They irritate me with their blatantly careless design that makes the door just refuse to rest exactly centered. But they were fully stocked, so I threw down my seven bucks, hung the doors, got paid. 

Whew! Lesson learned, purchase absolutely all the materials at the beginning of the project, even the expensive things you don’t need until the end. 

Artist’s Eye

So, I’m gluing together this counter top and thought I’d share a bit. ☺

Choosing pieces to go together. I cut down a pretty healthy stack of lumber to produce all these pieces, so I have to pick and choose the ones that best fit my idea of what this should look like. 

No, that’s not it. 


Okay, I’m satisfied. Time to glue. 

Ugh! One board oriented wrong and somehow I made it too short. All that time and energy, only to make it wrong. 😣

Okay, so I just passed time practicing on a, uh, coffee table? Sure, I’ll just make this one into a table. 

Take 2. Action!

Alright, making sure it’s the right size this time.

Some marks might help me keep it straight!

So far, so good. 

Whew! Finally got it all glued up the way I wanted it. Now the question to answer is do I screw around with the hand plane or buy a bit and fire up the CNC inside my storage unit like I’m not supposed to do and plane it the quick and awesome way? Hmm, decisions. 😈