All posts by David Lively

Electrical Engineer, Coder, Graphics Nut, Husband and Father, in order.

CNC Router Progress

I’m nearly done with version 4 (or maybe 5) of my CNC router. Last year, I started building this from parts I had on hand, including unsupported steel rail and linear bearings, red oak, some crappy lead screws and HDPE (aka, Walmart cutting boards.)

The mostly-complete version 1 router.
The first version of the CNC with unsupported aluminum rail and misc. wood and HDPE cutting board components
Original X/Z carriage made from plywood, red oak, aluminum plate and HDPE
Version 1 X/Z carriage with HDPE cutting board router mount for the RIDGID trim router

That version mostly worked. But, it wasn’t the most accurate machine.

So, I started replacing wood with 1/2″ aluminum:

Version 2 of the X/Z carriage, from 1/2″ aluminum riding on 20mm steel rail

That worked pretty well, but the unsupported rail had a LOT of deflection. I could easily twist the two rails over an inch in the middle of the 38″ span, which is not sufficiently rigid when cutting hardwood.

I had to decide then between different linear motion systems, including fully supported rail, flat carriages, or wheels. I went with OpenBuilds c-beam aluminum extrusion and hard Delrin wheels. I was initially skeptical about the wheels as I suspected they might compress under load. However, so far they’re pretty awesome.

I made custom plates for the carriages and motor mounts and went with a belt drive the long (49″) axis. The short axes use T8 ACME trapezoidal lead screws with Delrin antibacklash nuts.

The mostly-complete version 4 router
New version using OpenBuilds C-Beam, dual lead screws and belt drive
Y/Z carriage made from two sheets of 1/4" aluminum and lots of OpenBuilds wheels
Custom plates and motor mounts from 1/4″ aluminum

I used my OpenBuilds minimill to make all of the end plates and carriage plates from 1/4″ 6061 aluminum. I broke at least five endmills before switching to a 1/4 router bit. That worked significantly better, but due to the nature of router bits, I could only take off about 0.25mm per pass. It took a little over 30 minutes to cut each of the large carriage plates. But, it’s worth it.

The belt drive is (unsurprisingly) very fast, and so far is accurate and rigid enough for my purposes. Next up: cable routing and dust collection. Depending on how the accuracy tests go, I may need to add some sort of gear reduction system to the belt-driven axis.

Fun, fun, fun! I wonder if this is what it was like to have an erector set as a kid.

CNC Build Part 1 – Electronics Test

I started building a CNC router a number of years ago, but never really got around to finishing it. Kids, school, job, cars, and occasionally being in the same room as my wife sort of took priority.

While working on the table, I needed to plane some rough sawn lumber. But, I don’t have a planer.

So, I dug up part of the frame for the CNC, bolted up a sled, and did a pretty decent job of flattening the stock. (See pics in the previous post.)

Of course, that made me want to finish the CNC. I’ve assembled most of the frame, other than mounts for the motors, lead screws and nuts, limit switches and, oh yeah, I still have to build a Z axis. But, it’s a party.

See the video for some electronics test fun with an old laptop, Mach 3 and an XBOX controller.

 

 

More Table Fun

I needed to plane some rough-sawn lumber for the table top, and didn’t really want to pay someone to do it. There are a lot of videos and articles out there on how to do this, many of which require a planer ($$$$) and a jointer ($$$). I have neither of those, and I’m already over-budget on this project. If you happen to have some long, straight lumber, plywood and a slight excess of time, you can build a traditional router sled, as shown in this video by the Wood Whisperer:

174 – Flattening Workbenches and Wide Boards with a Router

(By the way, most of Marc’s videos are awesome. Sometimes I just leave his YouTube channel playing in the background when I’m working in the shop.)

It’s a great solution, but I didn’t really have the time or patience to build that.

Fortunately, I have a bunch of parts for a CNC machine that I never finished building many years ago. So, I made this out of the X/Y axis setup:

(The router lines scraped right off. I suspect they’re a side effect of a slightly uneven table.)

The rails keep the router flat enough for wood, though I’d like some more support if I were machining aluminum or any precision parts. It does generate a LOT of debris, which reminded me that I really need to put together some sort of dust collection system.

I was able to route a bowed, twisted 7′ x 11″ x 2.5″ board down to a perfectly – and I mean perfectly – flat usable piece in about 15 minutes. A larger router bit would’ve sped up the process significantly.

This experience, of course, makes me want to finish the CNC build, so I found the motors, controller board, amplifiers and other misc. bits in the garage where they’ve been for the past six years. I hope to get the Z axis done in the next week or two – not a lot of time with a new baby in the house – source some lead screws, fabricate mounts and get everything up and running soon. Should be fun!

Here’s the assembled, ultra-heavy table top before sanding:

Note that it’s not glued yet. The house is 172 feet from the shop, and this thing is heavy. I’ll glue it up when it’s in its final resting place.

Cheers!

I don’t remember screaming

Her name is Maria, and I don’t remember screaming.

When Wyatt was born, he didn’t move.

He didn’t cry.

He didn’t look around.

He didn’t do anything.

He was, for all intents, dead.

Yeah. Stay with me – there’s a happy ending.

We used to watch this show called “House,” which was about a medical doctor-version of Sherlock Holmes. It featured a weird-ass protagonist who was kind of an asshole, but really, really good at his job.

For whatever reason – anyone who knows me well has heard a lot about it already – we decided to have a home birth with our first child. Which would have been fine, except for when it suddenly, violently, irrevocably

Was.

Not.

Fine.

Today, we had our quad-annual ARD. That’s fancy Dept. of Education speak for “get together with the teachers and figure out how to get your kid to do what he needs to do.” Wyatt spends a big part of recess chasing different groups around, trying to find someone to play with.

Here’s a tip to Future Readers: the one thing you absolutely do not want to read in a report is that your kid has no friends, that he or she is desperately trying to fit in. A lot of us had to do that as kids. I was lucky enough to find  a few really amazing people in my late teens – phenomenal people with whom I am still friends.

You don’t want your seven year-old to have to wait until he is 40 to figure out what a good friend is.

Maria was our charge nurse, assigned when we arrived at the hospital after 36 hours of labor at home.

That may seem like a long time.

There’s this super-awesome thing called “Group B Strep,” which is fatal for kids (and, sometimes, moms) in a surprisingly-high number of cases. Considering a home birth? Google it.

Maria was about 5’6, brunette, soft-spoken, clearly very good at her job. She reminded me of my big sister, Tara. Not physically – just her manner. I felt *safer* with her there.

She stayed on well after her shift ended, and was the one that pushed me out of the way when the emergency team came into the room.

She was the one that, when I was holding Audrey’s hand post-delivery, looked me in the eye. And that look told me that, no, in fact, I was not crazy. Shit was, in fact,, going sideways.

She was also the one that grabbed my hand, and told me to come see my son. Because, well, I probably  wasn’t going to get another chance to see him breathing.

To my knowledge, Wyatt is the only person in our “immediate” (we’ll include me/Audrey, +- 1 generation) family to ride in a helicopter.

I spent the next two weeks shuffling between hospitals – Audrey and Wyatt were then at different places – occasionally finding time for a shower. I am grateful to have had that opportunity. I’d crawl through broken glass and drain every drop of my own blood, and do that again, and again, and again if it meant that my wife and my son made it home safe.

My son has no friends. I’m considering putting him into soccer, or maybe guitar lessons.

I don’t really know what to do. But, WE have the chance to figure it out. Mostly, because someone named Maria was there to hold our hands, tell us when we were wrong, and help us try and fix the biggest mistake I’ve ever allowed “us” to make.

I hope that, one day, we’ll meet again. I’ll probably cry. But, hey, whatever.

Shit happens.

 

 

 

 

 

What I Saw: Kids, Priorities and Why Some (Most?) of Us are Doing It Wrong

I saw Gwen running.

Up and down the aisle, around other tables, happy as could be. She would stop every now and then and look back, just to see if we were watching her. (Hey, everyone loves an audience, right?)

Gwen is two years old, three this August. She is adorable, and not just in that way that every parent thinks that their little girl is adorable. She’s always happy (I’ve learned to get over my mistrust of people who are always happy) unless there is some dire threat to the Unbreakable Rightness of the Universe, such as an empty sippy cup or a locked door inhibiting her access to power tools.

She is amazing.

I saw Walt throwing a ball, again, after having been told multiple times by multiple Persons In Authority to NOT THROW THE BALL.

Honestly: it’s a kind of place where people bring their kids, and kids throw balls that they just won, at great expense, from fickle games (aka, vending machines). It bounced and bounced. He dived under tables, chased it around the room, asked me to throw it to him (I am NOT an athlete, but at two feet I do alright) and threw it right back. Sometimes, directly at my face. From two feet away.

I have a thing about things being close to my face. Not sure why, but such is life. Anyway.

He was so very, very happy.

I saw Wyatt shoving yet another piece of pizza into his mouth, glaring at me because I told him he needed to eat before he could play. His cousins, brother and sister were already playing, but I didn’t focus on that. I had told Wyatt that he needed to eat, and I was sticking to my guns.

The other kids – Walt, Gwen, four cousins – were playing video games and running around like little hooligans. But, I made him sit and eat. And, when he ran off and didn’t do as he was told, I took him to the car and sat with him until he calmed down (he was upset because – duh – I’d taken him to the car when the other kids were playing.

I took him back inside, watched him eat half of a slice before letting him go.

And, then:

I saw him having  a blast.

(In my defense, I also saw him very hungry for pizza after we left, much later.)

I saw my wife, bringing everyone together so that the kids could play and, for once, just *be kids*.

I saw myself, mostly oblivious to all of this until hours later.

I saw myself complaining about having to go out with everyone to a place where there is nothing I can eat (long story).

I saw myself complaining about the time it would take that I could be spending on something “productive.”

I saw myself being impatient with my wife and the kids trying to get ready for this, and with others involved because there wasn’t a real plan or procedure involved, just a random “hey, why not?” impetus.

I saw people who loved me, who wanted to be together, tolerating my intolerance and impatience.

I am thankful for my kids, and for my wife. Without her, they would not get to just be kids. I am, sometimes, too focused, too concerned with outcomes, to the point that I miss the experience. Without her, my life would be a critic’s review, not the movie.

I saw Audrey, an amazing mother, partner and all-around bad-ass, making it all work.

I am grateful, undeserving, and humbled.

 

State of the Union

So, brief update:

I’m now a “Developer Technology Engineer” at AMD. It’s pretty awesome, but doing things like solving perf problems in a VR title without source access is difficult.

Honestly, graphics debugging and profiling is a black art, even when it’s your own code.

But, yeah: no pressure. 8-(

The kids are getting older, and I’m getting older, too. I’ve been ‘fraid of changing, ’cause I built my life around… Uhhh, no Stairway.

We’re having a boy! Only four more to go before I have to stop making fun of my brother.

My new office/workshop is not even remotely done, but I still spend 8-12 hours a day here. I’m loving the 172 foot commute from the house. My lovely wife bought a beer fridge for the shop last year, and I’m now building her a dining room table. Mastering a bunch of different joinery techniques was not easy. I still wouldn’t say I’ve mastered them but, hey, it’s close enough for a carpenter.

The universe does not want me to have a left index finger. I have a 2″ longitudinal scar from a flap disk (removing paint and welding high points from the Solstice door and quarter panel), then took most of my fingernail off on my router table. Despite initial fears of accidental auto-exsanguination, my finger tip actually looks fine – but the nail resembles Florida.

VR: The Vive is dusty, the Rift software is most frequent cause for a reboot, and the Touch controllers are very cool.

I’ll be presenting at GDC this year:

David Lively, Developer Technology Engineer, AMD

… which should be fun. If you’re in the area, swing by and say “Hi1”

(If you say “hi one”, I’ll know you read my blog. and may find a reason to excuse myself as to avoid uncomfortable conversation.)

Cheers