Scratch Build – In Progress Dimidium - A Build In Two Parts

Dimidium | A Build in Two Parts​

Hello bit-tech! I have come here to (hopefully) redeem myself. Several years ago, I finished my current PC build, a very lightly modded system that has been, uh, how to say this...disappointing. Unfortunately, while crudely drilling a hole in the top of my case for a fill port, I left the reservoir of the watercooling loop open and lots of steel chips got in, promptly infecting my loop with rust, longstanding corrosion problems, and dumpster-tier temperatures. Rookie mistake, I know .

With the sad backstory over with, it's time to show off my extremely over-engineered solution to the aforementioned problems: Dimidium.

The build will be separated into two halves: one with all the main components like the CPU, GPU, etc. while the other will contain the radiators and the PSU, along with any RGB hubs or extraneous cables.The wood used here is American walnut, while the other panels (that aren't distribution plates) are aluminum. The build is just barely too big to hit the magic sub-20L size requirement for true SFF. Oh well, I just want something vaguely small anyways. The entire thing will be milled using a cnc router I mostly built in my 1 bedroom college apartment so this should be... interesting.

Specs:

• CPU: AMD Ryzen 9 5900X
• GPU: AMD Radeon RX 6900xt (XFX Speedster Merc 319 Black to be specific)
• Motherboard: Asus ROG Crosshair VIII Impact
• RAM/Memory: 32Gb Corsair Dominator Platinum RGB, 3200MHz
• PSU: Corsair SF750
• Storage: A 512Gb M.2 SSD and a 1TB M.2 SSD salvaged from my current build
  
• Corsair LL120 fans (x4)

Watercooling Hardware:

• Hardwarelabs Nemesis 240GTS (x2)
• Bitspower Crosshair VIII Impact monoblock
• Alphacool Eisblock Aurora Acryl GPX-A Merc 319 waterblock
• Bitspower's 12mm OD chrome plated brass tubing
• Bitspower Premium 12mm hex fittings (mostly)

Stay tuned, the build is already well under way !

 

I'm guessing pics are still behind the wall of first post moderation? It sounds promising. Welcome to Bit.

 

Thanks! Feels good to be here instead of lurking. And yeah, that's probably it. The site has a seizure every time I try to add pictures... hope I don't look too silly gesturing at photos that don't exist

 

Update 01: Renders, Design, and a Sneak Peek

I couldn't get the build renders working on the initial post, so I'll just post them here, in the first update.


All of those holes on the side of the wood panel here are for cables. The motherboard, GPU, and pump are on this bottom half, while the radiators and PSU are on the top half.

Here's the other side! The fill port is here on this walnut panel, and beneath it is the GPU. I don't know how to model textures too well, so it's just that indiscriminate flat spot in the window.



This build is pretty ambitious and there are a lot of reasons why it may or may not end up working, foremost among them being my anemic modding experience. As you'll see, the quality (or lack thereof ) of my cnc router ended up being a huge roadblock in the construction of this thing. Still, I have reason to think it'll work out great! Here's why:

Next update soon!​

 

I love the concept, but the anchoring wires in the render are not good. I'm not even sure you you could get that assembled by disconnecting the mounting brackets. Also, they take away from the clean look, and any flex would potentially cause the fittings to leak.

 

Fair enough! I originally designed this as a tensegrity style build but shifted away from it later on, which is mainly why they're there. I don't think assembly will be a problem as I can just hold the halves together and crimp the wires in place, though I could see flex being an issue. I do have some ideas on mitigating that if it crops up, though

 

My main issue with your tensegrity setup was the hooked wires. You'd have to pull them past max tension to hook.
Something like a flat aluminum plate mounted on the case with a hole in the middle to pass the wire through would look cleaner, and you could potentially remove for maintenance easier.
The cable could have soldered anchors on each end or just a bend to keep then from passing through. -Depends on what you use.
You could hide the other connection behind a 1/4" -or so aluminum backplate for your wood.

...Sorry, I like throwing build advise around.

 

Np, and thanks for the advice
I've altered the design a bit and I definitely like it better.

 

Interim 01: Sorting out the Tooling

To construct a build like this, some kind of CNC mill/router is obviously a necessity. Given the fact that I started this thing while still in college, outsourcing the work would likely have been too expensive, inflexible (can't fix mistakes easily), and boring. Still in the phase of life where I value my time far less than my money, I went the insane cheaper route and built a CNC router from scratch. I mean, I managed to put together a 3D printer before this, how hard could a CNC router be?

Spoiler: Very hard.


The (mostly final) design of the cnc router. Lots of Chinese parts here! It sucks when your ambitions are held back by your wallet. Anyways, the blue parts are all mild steel, laser cut by a local company. They're the only custom machined(?) parts that I had to outsource, but have mercy on me-the most advanced tool I had at my disposal was a geriatric 3D printer. And a cordless drill

The first real milestone was getting all the electronics and hooking them up! This thing is controlled by a raspberry pi 3 B+ I had lying around, and a Protoneer RPi cnc hat. They do a pretty good job overall, though they obviously get smoked by a 'real' cnc controller in almost every metric.

Apologies for the dodgy image quality! These are the first parts I received for the frame of the CNC router.

I immediately got to cleaning, degreasing, and then rust-proofing all the laser-cut steel plates. I just used parts of the build and a bike stand I had as a janky sort of drying rack for the parts. I used some rust-oleum primer and then matte blue spray cans for this, and did several coats over the course of a night.

Got all the parts sorted out, now I just gotta build this thing! ('just' he says, lol)

Welp, that was fast. The first roadblock, and it's a doozy, too. Turns out, I had ordered a few mismatched parts. The aluminum extrusions that are parallel with the gantry in this pic are all 30mm too short. That meant many of the steel plates had holes in the wrong spots, and a gigantic aluminum bed I ordered is now too wide to fit. I have no real way to cut it to size, so I'll have to figure something out....
Also, that's my brother in the pic, he's helping me make this

Well, after tons of re-drilling holes, cursing, and time, I got this thing to sorta look like the final product.
Now we're talking! Got the Z axis built. It wasn't any easier than the rest of the build, but that's another story

Moved the whole thing into my folk's garage and got most of the electronics squared away. No box for them yet, they can be pricey, and I have a lot of stuff to squeeze into one.

After borrowing a circular saw from my parents, I cut the aluminum bed for the machine to size and it fits perfectly! And printed a dust shoe. This particular shoe didn't work amazingly well, but I replaced it with a better one later.

The router needs to be on something, and that setup I had before was a plank of plywood balancing on some old IKEA desk legs. Yeah. Time for an upgrade!

Took a few days, but this looks usable now! Sorted the electronics as well, that was a bit of a project in of itself but it didn't run into too many issues (minus almost frying all my power supplies ).

The first real part! I used the cutoff from the base plate to make a bunch of these. They turned out pretty rough, and I broke 3 end mills doing it (they were super cheap though), but they do the job pretty well.

Time to make the fixture plate. This is a big ol slab of 7075-T6 aluminum, and I'm about to do some serious cutting to it.

This took several days of straight machining, but I got it! It came out far from perfect, but it's good enough. I lost my x-y position a few times and that messed up some of these dowel holes (the ones on the far side of this pic), but I don't have the time, money, nor energy to care. I'm just glad I made something somewhat usable!

That's pretty much it for the CNC log. I want to focus on the build itself, so that'll be it for now, but it was an odyssey in of itself to say the least. It took me almost a year to get from basically nothing to having a functioning CNC router. Of course, I had to deal with work + my studies during this time, so that slowed things down a ton, but it still would easily have taken several months to do without any distractions. Now onto the build itself!
​

 

Update 02: First Chips

Alright, time to get this build started. I'm starting with the smaller/simpler parts first since I'm not 100% sure this machine won't have a seizure and do something dumb. Or that I won't just tell it to do something dumb . Not that I haven't put it through its paces already, but you never know. I've already had plenty of crashes under my belt while doing random side projects


Just got this bad boy in the mail from McMaster! It's an 8mm diameter carbide cutter. The largest flat end mill I had before this was a measly 4mm, so this was sorely needed.

This ^ is the part I'm planning on making first. It's the top half of a distro that plumbs directly into the GPU waterblock. Figured a small part without too much craziness going on would make a good first candidate. I'll start by facing it off with the 8mm cutter from earlier.

Why face it? Well, I live in freedomland™, but I ain't using the dogwater imperial system for this build . Or for the CNC itself for that matter; it's all in metric. Unfortunately, that means I can't just buy stock material in the exact thickness I want, so I get it slightly oversized and then face it down to what I need. Is it a pain? Yep! Do I care? Nope!


The stock's clamped down and the g-code's loaded and ready to go! Time to get cutting

...

...crap.

That was fast. Real fast. I already broke a tool and ruined the part

The culprit? This ^ godforsaken g-code SolidCam pulled out from the bottom of a port-a-potty. See that diagonal line close to the mouse cursor? That's a rapid move, telling my machine to move the cutter from the bottom of that line to the top. In other words, ram straight into the stock and then move up above it. Which is exactly what it did

The worst part? I had noticed the machine was barrelling straight for this spot, stopped it with a feed hold, and then restarted it thinking it was all hunky-dory like a caveman.

So much for my 2.5mm carbide drill from Datron, the part, and my underwear... You can sorta see the dent in the part from here. I had just finished facing it and milling out the G1/4 ports for the fittings. Fortunately the drill and the stock weren't expensive, but I'm super antsy to just get this mod rolling. It's been a year since I started planning this thing after all. Replacing broken tools/stock isn't much fun either.

On the bright side, the retry of this part went alright. You can see it milling the countersinks for the M3 screws. Now I'm just glad I started off with the small parts that I can afford to screw up!

Finally done! This was way harder than it needed to be, but I got the first (and hardest) side of this done. Now I gotta turn it over and cut some o-ring channels on the other side.

They turned out pretty good! In hindsight, a double-sided part was probably a risky first choice, but it turned out to not be an issue at all.

The eagle-eyed among you can see how nasty the fixture plate is here. The air compressor I'm using for the MQL coolant system is a super old boy (way older than me for sure) I picked up on craigslist for next to nothing. It basically spews out about as much oil as it does air, hence the mess. I'm gonna retire the crusty old thing when I finish this project as the drain valve has rusted shut and it leaks, so it's probably definitely a safety risk as well as an annoyance. I usually flip it on and off with a long stick.

That's it for now. The next update will counterintuitively feature wooden parts instead of more acrylic since there's a bit more room for error. Which ended up being important ​

 

Been there. At least you didn't work off a typo on the data sheet and fall victim to revisions in the parts. Fancy bits on a janky chinese part rig is probably overspending.
Metric: Honestly, I find US coarse thread screws less likely to strip out in plastic. Compare the threads on M4 and 6-32.
Compressor: Aux/replacement tank and a filter... and a mild *ss load of re-plumbing.
It looks like you are cutting your parts out with a single pass. You want to widen the cut groove and have the bit cut about .002 off on a final pass.

 

See, it LOOKS like I'm cutting in a single pass, but in reality, my CAM-fu is just lacking. It gets better. Sometimes. Still, thanks for the advice

 

Too bad, but don't worry, this won't be your last crash.
Amazing what you pulled off with the router build in the first place

SolidCam is mighty. Very mighty indeed.
I looked into it as well for my router and although I love the possibilities, I finally settled with the HSM Xpress plug-in.

I find it easier to deal with, it is basically self explanatory and unless you have a lot of true 3D milling or multi-axes usage you won't miss a lot.
As a CAM beginner myself, I like the SIM tap, where you can quickly identify operator brain lock.

Which CNC software you run on the Arduino?
Is there an appropriate post processor in SolidCam available for it?

 

Thanks! Yeah SolidCam is super overkill for this router, but I use it because I learned Solidworks in my time at university. Which is also why I even have access to it in the first place.

I thought about using HSM Xpress, might have to try it out! Not for this build though, I'm too entrenched as is.

For the Arduino, I'm using bCNC. It has its warts but it's super powerful and it has some very useful features-my favorite being the tool change capability! It'll touch off on a tool setter like some of the big boy machines (or like a Shapeoko with a bit setter accessory) each time I put in a new end mill and compensate for the new length. Saves SO much time compared to the alternatives...

And yeah, I had to dig around for a post processor, but Hawk Ridge Systems has a decent one. You have to give them your email and they'll send it to you later. Kinda annoying but it was either that or write one myself

 

nice work and nice project
where you found your spindle 2.2KW?

 

Update 03: The Struggle Begins

After getting spooked by that tool breakage last time, I thought it was time to move onto a 'less' risky material. At least, that's what my tiny little brain deduced.
Think I'll start with this panel shown below. It doesn't quite have the crazy contours on the inside that the other major wood panels have despite the presence of that central cutout. Plus, bringing these panels into the world will give me a much better idea of what this build will actually look and feel like. The wood here is American walnut I picked up from a really nice local hardwood store. It's a bit pricey, but oh so pretty to look at.





Started off by facing the board down a few mm. Gotta get the panels down to 20mm in thickness and make them relatively flat. I'm a little weary of any collisions with the edge clamps... I really need to get the proper length M10 bolts as the ones here are too long. Fortunately, this process went without a hitch.



Got through most of the machining of the pockets in the inside of the panel! There needs to be lots of space for the distro plate, along with RGB accommodations and the like. This'll contain the fill port as well.

Unfortunately my rather janky dust shoe seems to have failed me in my time of need, as you can see. The bristles are way too long and get caught on stuff. I haven't gotten around to making it height adjustable yet . On top of that, the coolant line there is doing all of absolutely nothing because the solenoid that controls it poops out electric noise like crazy, causing the system to alarm out when it switches off (I did eventually fix this with a flyback diode). In hindsight, I'm not really sure why I have it pointing at the end mill. Maybe it's because it makes it look more like I know what I'm doing

Ugh, and now the shop vac filter's all clogged with sawdust, rendering it useless... what else is gonna start giving me trouble?



Oh...that else.

Yeeeeeah, the part's trashed now. Bad toolpath AGAIN . The large pocket in the center is, uh, not supposed to extend that close to the edge of the stock. Or have giant gouge marks to rival the Grand Canyon. Ugh, I gotta check my g-code more thoroughly in the future. The machine was cutting this part beautifully-until it veered off course like a 90-year old taxi driver having a stroke. It sounded like a cnc machine having a stroke in here, too.



...oh.



My God, what did I do? The Y axis coupler got absolutely shredded by my little mistake! Though in hindsight, it wasn't exactly a quality item-just the classic Amazon/eBay special. One major issue I ran into when constructing this machine is that the ballscrew shaft diameter for this axis is maybe like...0.01-0.03mm too wide, making couplers basically impossible to attach easily. I sufficiently battered this poor thing into oblivion trying to force it onto the 'screw, and I finally paid the price for it.

I did slap another cheapo coupler I had lying around on it and attempt the part again, but both met the similar fate as these. I left and came back to the machine swaying back and forth in X and Z while the Y motor was just vibing by itself

Time for the ultimate, the foolproof, the absolutely ironclad solution that nobody likes: throw money at the problem until it goes away!



Alright, I got a halfway decent diaphragm coupler on that motor and tried the part one last time. It seems that the machine actually made it through this nightmare of a process for once, and the part looks pretty good to boot! Too bad that I, in the end, used up almost an entire 1.25m board of walnut just for this ONE part. Still, this does make me glad I started off on a more forgiving material instead of diving straight into the deep end.



Time to do some deburring! I'll be doing the real surface finishing of everything in a later stage, but I want to get the low hanging fruit now while other parts are being machined.
​

 

Thanks! The spindle is just from eBay. It also needs a proper VFD, a shielded cable (with the ends of the shielding grounded properly) between the two, and 220-240V power. Despite how *ahem* inexpensive the spindle was, it's worked really well and I can't really complain.

 

Update 04: Continuing With the Main Panels

Hello again! Apologies for the delays, I was doing jury duty for the past week

I think it's time to machine the rest of the walnut panels on the case exterior! Now that the machine seems to be working as intended (mostly), hopefully there shouldn't be any more issues, because I'm starting to run low on stock and I have little room for error. Not that buying more would be the end of the world, but I still really don't feel like it. These are all double sided parts, but I'm just doing the insides of them first.



Started off the day with machining the I/O panel that the motherboard and GPU will interface with, though not directly. I also shortened the bristles on the dust shoe before this and it works waaaay better. They finally stop getting caught on everything!



The roughing is done and it looks good! I did most of this with the 8mm 2 flute end mill from before. My chip clearing here could be better, but I think I simply forgot to switch on the air blast before starting this.




Here I'm doing the finishing passes with some smaller end mills. I gotta say, this machine does a good job when it isn't throwing a terminal hissy fit.



The finished product! Well, mostly. I have some post processing to do, and I gotta fix some small mistakes and cut out a pocket for the cable anchor. I'm not going to do that until I get a halfway decent probe or something though. My current method has some... issues.

But enough about that, there are 2 more panels to make!



Halfway into making the front panel, I'm learning a little bit of the trials and tribulations associated with machining wood




I think the part looks good regardless, and this missing chunk won't be visible anyways. There's also a visible gouge in that U shaped cable channel, but that was just because I forgot to tighten an end mill in its collet enough

...yeah, that was actually almost extremely bad, and I have no idea how it didn't break. It was a 4mm 2 flute end mill. I call it the doomguy cutter because it's survived some positively heinous mistakes and crashes on my part without getting so much as a scratch or chip



Finally, the last panel! This will have routing holes for the cables coming out of the PSU. Not gonna lie, I'm a little worried about this one. Just look at all those pock marks and divots. This is 'rustic' walnut, which is pretty much the same as the normal stuff, but significantly cheaper. Not hard to see why! I think it'll be fine, though. The backside, aka the visible portion, is much cleaner looking. Plus, I'm not looking for absolute cleanliness or perfection since, well, this is an organic material. The blemishes add character anyways!



I wanted to clamp on the sides, but this stock is too skinny for that. I narrowly avoided a collision with the spindle and this edge clamp here
Thank the stars I saw a disaster in the making and moved it out of the way!




Not bad, not bad! This panel is the simplest of the four, so it was the easiest too. That probably means I should have done this one first, eh? Oh well.

Finally, the CNC router seems to be working properly. About time! I've machined a decent amount of stuff before this project, so the sheer amount of machine-related nonsense I've ran into is rather unprecedented. I've already had to
fix a bunch of issues before starting this thing, but stuff just kept cropping up...

Anyways, I'll be doing the backside of these panels next update. I would hate to ruin any of these panels, so to put it lightly, I'm going to be extra careful.
​

 

If you are not against altering the grain, you can cnc glue-in patches in the flaws/damaged spots.
"Rustic" = Wormy.
You can avoid clamping collisions by changing your cutting setup. I use tape and glue to sacrificial mdf panels.

 

Interim 02: AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

Alright, I've been downplaying this a lot bit as to not seem too negative and bring down the mood of this project log, but hoooly crap using this CNC router I built SUCKS. Like it really just blows. There's always some little issue, some $3 part blowing a gasket, some completely unpredictable hardware failure, some coronal mass ejection or cosmic ray or whatever that just grinds the pace of this project to a screeching halt. It's immensely frustrating, but in the interest on not inundating my project log with complaints about this machine, I've decided to condense it all into a nice little post here so you all can enjoy my suffering-and so I can vent a little. Okay, maybe a lot.

So what's actually wrong with this thing anyways? Well,

Spoiler: Pain.

• The issue with the coupler on the Y axis you all saw in an earlier update.
  
• The coolant system has been MIA since forever. Flipping the solenoid valve that controls it on or off would give my CNC controller a migraine, force-stopping whatever it was doing. A flyback diode on the solenoid make short work of this issue, but it was still a pain.
  
• My dust shoe popped off of its fixtures mid-job and got absolutely choke-slammed by the machine. That was fun! Somehow the part I was actually trying to cut was totally fine

Rest in peace to our fallen brother. You will be missed.

• The power supply for the X axis steppers (both slaved together) slowly died, and it kept triggering the drives' OCP protection mode-shutting the motors off mid job. Doesn't take a pro machinist to see how that could be bad. I just had to buy a replacement
• RIGHT after fixing the dying PSU issue ^ the gantry started stalling on the X axis AGAIN, for a completely different reason! The motors were stalling because the linear rails the gantry rides on weren't parallel enough, causing binding issues. Turns out building a precision machine tool without an indicator of any sort is a recipe for failure. I had to take the entire gantry off, align the rails properly, and then rebuild it. That took several days
  
• Not two seconds after rebuilding the whole machine, the spindle decided to give up on life ! The threads on the rotor and the collet nut somehow got locked into a dance of death with each other, making it. IMPOSSIBLE. to separate them. I still have no clue how this happened. Either way, the solution was to brute force them apart with the collet wrenches. This involved hammering the wrenches, stepping on them, jumping on them, etc. It worked, but not without mulching the threads on the spindle and the nut. Thankfully, a thread file and some new collet nuts fixed the issue. Whew

The threads on the spindle, post filing. As you can see, the damage is all on the bottom 4-5mm or so of these M25x1.5 threads. Had this been unfixable, the spindle would be trashed as this is part of the rotor, which isn't realistically replaceable.

• Alright, spindle's fixed, so what's next? The VFD, of course!! Shortly after fixing the spindle's threads, it ran into an issue where it would try to spin up but then shut off seconds later. It didn't take long before I couldn't get it to get to speed, ever. I noticed the CNC's controller was majorly freaking out during all of this, and after a ton of trial and error, I narrowed the issue down to the user-programmable relay in the VFD. Yeah. I wouldn't have guessed that either. For whatever reason, whenever it flipped states it would barf a ton of emi into the area, giving my controller a seizure. Fortunately, I wasn't relying on it for anything important, so I just unhooked the stuff I had going through it (some status lights) and that solved the issue.

...yeah. That wasn't everything, by the way. Just the highlights. Mind you, this is all in addition to any dumb mistakes I make because I'm human, like writing bad G-code or under-tightening a collet nut. Every one of these issues meant ruined parts, wasted stock, and constant babysitting of the machine, which I absolutely hate doing. The only thing that didn't happen through all of this-which is hilarious, by the way-is any end mill breakages. I don't even know anymore.

On the bright side, I did eventually work through all of this BS and it did get better. The machine is actually quite reliable now, and I can make parts super quickly! Now I only have myself to blame for any mistakes

But man, for anyone thinking of DIY-ing a CNC router, mill, lathe, etc... please don't let this post stop you, but also realize that there will come a point where you will hate your creation. A point where it will fight you tooth and nail, refuse to do what you want, and become a time and money black hole. A point where you'll seriously consider just setting the thing on fire, walking away, and sending the project off to someone else who can do it in your place.

And that's okay! If I just wanted to have a custom-machined PC and nothing else, there are way faster and more reliable ways to do it. But that's not why I built this thing. Working through the ups and downs of building a machine tool has been immensely rewarding, and I now have a reliable piece of kit that I can call my own

Anyways, the regularly scheduled project logs will resume soon! I just needed to get this out of the way.​