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

Yeah... I'll miss that poor dust shoe. Actually, not really. TBH it kinda sucked (pun intended ) as it would sag super hard under the weight of the vaccum hose, lifting the backside and letting chips stream out. The bristles kept working their way out of the slots, too.

I'll have to get creative with workholding on the other side of this part for sure, but I have some ideas

...Dang, I'll have to tell him how lucky he is then. I'm just gonna mount the pump normally and hope for the best. Well, unless the noise is unbearable or something!

 

ooo, very interesting design, you'll certainly have a very unique computer if you can pull it off. I foresee you may end up needing to use soft tubing between the two halves, but could be wrong

 

Thank you! Yeah, I won't be too sad if I need to resort to soft tubing, but I'm going to try the rigid stuff first. Hope it works! If not, it'll make for an interesting story. I just hope it isn't too interesting

 

Update 09: Downward Spiral, Redemption Arc

Alright machinists, experienced modders, and just people with healthy amounts of common sense, don't judge me too hard for this one.

So, this log marks the start of the aluminum parts for this build. I was quite pumped to be cutting these because they're generally less geometrically complex than the previous stuff, sometimes by a TON. The tradeoff, of course, is that they make up the bulk of this build in terms of sheer part volume. I'm not 100% done with the acrylic and wood parts, but I hadn't written the CAM and figured out fixturing and whatnot for the rest, so they're staying in limbo for the time being. Anyways, onto the cutting!




I clamped this big ol sheet of 1/8" (3.175mm) thick 6061-T6 aluminum here. It's gotta be 3mm thick, so I'll start by facing it off.

...see the problem yet?




Since my dust shoe bit the dust recently grin: yes I know that pun was bad), I'm just holding the shop-vac like this. Not great, but I'm impatient to finish milling the rest of the parts for this build so I can get onto the juicy stuff! Despite my efforts to contain the mess, these little curlies are getting EVERYWHERE, and they were launching towards me at supersonic speeds-which didn't feel too great. Feels like a tiny knife shower



Alright, enough teasing. SO, as some of you might have been able to see, my stinky pinky workholding wasn't gonna cut it at ALL. I clamped only the edges of this spindly aluminum sheet like an idiot and the middle bowed out like crazy. I was so impatient to get this started that I essentially just ignored the warning signs... and then this happened

I didn't think it was possible for my not-terribly-rigid stepper-driven machine to do this (before chattering like crazy anyways), BUT I completely overloaded the 2.2kW spindle and it stalled mid-cut! The bow in the center caused this to take a much deeper cut there than it was supposed to and eventually stopped it dead in its tracks. The machine kept going anyways... and it bent the shank of this cutter like it was butter.

What I should have done instead is clamp this with some kind of adhesive or use some kind of vacuum table. I don't have the latter, but I have plenty of painter's tape, superglue, double sided tape, etc. that would have done a much better job. I don't use those as much as I should because I'm trying not to cut into this nice fixture plate I painstakingly created months ago.



Despite this, I licked my wounds, dried my tears, and decided to at least attempt to salvage this piece of stock. So I fixed it to the bed with some painter's tape and superglue and pressed on.






...but not without creating this new dust shoe! This one is soooo much better than the previous two. It rides on those rods and circular bearings (usually used for 3D printers so they were dirt cheap) which keep it 'floating' on the workpiece. It works really well! I cut it from some old HDPE sheet I had lying around and it's decent for this-though a stiffer material like acetal would probably be better.








My valiant, albeit fruitless attempt to salvage this aluminum stock and make some usable parts from its battered corpse...

Unfortunately, the bow in the center warped the whole sheet into a large metal pringle, the center was waaaay too skinny while the edges were way too thick, the finish was garbaggio... you get the idea. I just scrapped this stock because it wasn't in any shape to make good parts out of anymore.

Man, what a mess. One lapse in judgement and I was completely down for the count! Honestly, I really didn't take workholding that seriously until this point, making this a serious wake up call. Edge clamps are nice, but they're not a panacea.

I decided at this point to take a breather and do some spring cleaning while I rewrite most of my CAM for the rest of the parts for this build. This series of unfortunate events made me reexamine my cutting strats and workholding techniques big time. Oh, and I went ahead and reordered some 1/8" aluminum stock so I can try these parts again at a later date.



Ew. This brass exhaust fitting sits inside of the tank and draws coolant up the line I'm grabbing in this photo. My coolant tank is a bit, *ahem* cloudier than when I initially filled it and the spray from the business end was getting rather anemic. Now I know why. I just trashed this fitting and put some biocide in the tank. It flows SO much better now. The tank doesn't look quite as nasty either.

Well, I would rather not end this update on a low. Time to redeem myself



I'll start that process by making this ^ panel. It's a super important structural panel, but it's really simple. Simple is good. I like simple.






NOW we're cooking with fire!





Well, that went rather swimmingly! The keen-eyed among you might have noticed that there needs be two of these bad boys, so I'll do the second one real quick.









If the quality of these parts is anything to go by, I think this build will turn out quite swimmingly by the end! I probably shouldn't jinx myself though.

Welp, that's it for this rollercoaster of an update. A bit of a rocky start with metal, but I'm slowly getting my act together. Until next time!​

 

Very impressive, looking forward to see this build

 

Looks great.
I've had a couple of people ask what happens if you jam a finger in the machine somewhere... Now you know too.
Clamping fun: It gets wilder. I've melted the glue on the blue tape with smaller parts.

 

Ouch...
Stock and endmills scrapped because of brainlock...haven't we all been there?
If you don't mind, I have a few observations, mosty based on f..k-ups on my own behalf...

Machining sheet metal (generally thin material) that is not supported/fixed in the middle is not a good idea. It tends to get sucked up by the endmill - you already figured that

The face mill looked to me as if it was more intended for wood, rather than metal...

Looks like you are using some really strong steppers that they can actually bend a shaft like this.
Ideally the machine will stop if the servo or stepper looses a predefined number of steps - a safety feature to avoid such an issue or even worse things.
Check the parameter setup. You can play around with these settings.

Then...6061 is quite popular, but not very good for machining. It is relatively soft. You really need a lot of cooling to avoid build-up and clogging of the endmil.
If you take a closer look at the milled edges you notice that the flutes do not cut off the chips, but rather tear them off, creating an uneven milled surface with a nasty burr on the top.
2017, 5083, 6082 and 7075 are much better for maching. If you have access to them...

And the chips look like you are too gentle to your machine. They are too small to take away the heat from the endmill and even more important...the stock.
Granted, slotting soft aluminum is difficult and after the mess with the face mill I can understand why you took it easy with this one.
But your motors seem strong enough to drive a Ø6mm endmill in a 2.2kW spindle properly through aluminum

Anyway, well done after that little shock. The facing of that plate looks nice

And I like the new dust shoe

 

Thanks! Also I hope you were wearing your best pair of brown pants

Thanks! I agree with pretty much everything you've said here. The fixture plate is made out of 7075 and that stuff is so much nicer for machining. The main reason I didn't go for that with the build was peer pressure. All the cool kids seem to use it so I figured they knew something I didn't. Plus, I plan on media blasting and then anodizing the parts, and all the tutorials for the latter I found used 6061. I didn't want to risk using an alloy that was less forgiving in that respect. Were I to do this again, however, 7075 for sure.

Yeah after that mistake I decided to take it easy on the depth and width of cut on these parts. My focus has been on taking light and fast cuts with itty-bitty tools rather than slow and steady with the big boys. Suits my machine better since this spindle spins so fast. Also, the controller I'm using isn't terribly smart and doesn't take any kind of feedback from the steppers, not that they provide any to begin with... meaning if they lose steps, the controller doesn't know and the machine will just keep humming along like nothing is wrong even while it derails catastrophically. I didn't have the money for the closed loop stuff

 

No brown pants, The part would just shift away from the cut, and make a nasty finish. Somewhere in the GlassGreen logs I started playing with metal.

 

Update 10: Speak of the Devil...

I'm feeling a bit confident after seeing how those window panels turned out. Not to mention I'm DYING to see how this build will look/feel in real life-I've been staring longingly at the 3D model for way more time than any human should. So with that, this update I'm working on some large and important parts that should give me a much better idea on what this will look like when it's done!




As per usual, I needed to face this 1/4" stock (~6.3mm) down to 5mm. This always takes forever since my router isn't exactly the fastest thing in the world.




Hard to complain about the speed when it turns out this nice though





These pockets turned out great! All I need to do now is drill some countersunk M3 holes so this panel can be mounted to the case, and then cut the part out of the stock.



An enclosure for this router would be nice, eh? Too bad I'm lazy. And cheap.



The chips are small, but they look pretty nice. Light and 'fast' cuts really seem to be the way to go for this router.



Alright, now I just gotta cut the part out of the stock!




It's never that simple, is it? I left while this was cutting and came back to this mess. The 4mm 2 flute carbide end mill I was using to cut the part out of the stock got clogged with gummy 6061 and... LIVED??

I've brought this up before, but I've christened the well-deserved title of 'doomguy' to this nigh-indestructible chunk of tungsten carbide. I have no clue what secret sauce OSG (the manufacturer of doomguy) puts into its carbide but whatever it is it's keeping my frequent dumb mistakes from ever killing their tools! Honorable mention goes to my machine for alarming out mid-cut before it could send this end mill to the great machine shop in the sky. I have no idea why or how it stopped because I have no provisions in place for catching mistakes like this outside of crapping my pants and slamming the E-stop button.

And yeah, I was literally JUST talking about how 6061 is a sub-optimal alloy for machining, and now I get to experience why firsthand. Speak of the devil...

The aluminum was mega stuck to doomguy but I had a trick up my sleeve: bathe it in a solution of sodium hydroxide (aka lye) for a few minutes and the aluminum will dissolve right off! Just be careful, lye is super nasty stuff. Wear safety goggles and gloves and work in a well-ventilated area if you're gonna use it for anything! Now the end mill is pretty much like new again.

Unfortunately, the same probably can't be said for the part it was cutting. Just look at that burr this thing was raising. The machine wasn't cutting so much as it was unceremoniously plowing through the material...




Regardless of the obvious issues, I decided to cut this part out anyways and see if the part is salvageable. It doesn't look too bad... I think?




Honestly? I'm ok with this! These gouges are not very deep at all and they'll be mostly covered by other panels anyways. As much as I'd like to be super anal about upholding the highest possible standard of quality or whatever, I still have like 30+ more parts to make, and redoing large and thick stuff like this is really not desirable at all. These gashes will almost certainly buff out anyways. I got super lucky and most of the really deep nicks and gouges were relegated to the stock material instead of the finished product.

I still need to cut the panel opposite this one (this one goes on the top of the build). For that (and subsequent 6061 slotting) I switched to using a nigh-uncloggable single flute end mill and it works much better.







Nice.



Last but not least for this update, these ^ small window holders/covers. They'll hold the side panel windows and have cutouts for magnets to keep them in place. They'll be cut out of the same stock as the previous panels as they're all supposed to be the same thickness.









Each one of these parts were relatively straightforward to make. And I didn't run into any issues! That's a liberating feeling.




Lookin' pretty good! They're not completely done as I plan on chamfering the opposing sides, but that will be done later.

I plan on bonding these with some tempered glass I got custom made for this project. Probably with some kind of UV glue or clear epoxy, though I'm open to suggestions on that as I'm not completely clear on what the best bonding option is for glass and metal. Loctite Impruv looks promising, but at $35 a bottle it's just a wee bit pricey...

While I can see why they're so popular in the modding community, I do NOT like acrylic/plexi side panel windows. In my experience, they get statically charged easily which attracts tons of dust, get scratched when a cat thinks about them, and they just simply don't look as clear and premium as tempered glass. Of course, this build is absolutely inundated with external distro plates made of acrylic, so maybe I'm undermining my own point a little? Not saying acrylic is never a good option (especially for funny-shaped windows), but for this build I really wanted tempered glass. Especially because the custom made panels I got were surprisingly inexpensive at like $45 USD including tax/shipping



Bonus picture of the TG panels. Yes, the edges are a bit green, but the center of the glass is crystal clear. Next up are more chunky parts, so stay tuned!​

 

DoomGuy could use a visit from the oily toothbrush every minute or so.
...That sounds kinky.
Glass glue: aquarium silicone.

 

lol

I'll have to look into that, thanks!

 

Update 11: A Major Upgrade!

The next logical step in this project for getting its main structure build-able as quickly as possible are these chunky boys here:



...which also happen to be the most complicated metal parts in this project. And the largest/thickest too. So you know what that means: mistakes = $$! I keep referring to this part in the plural sense because I'm making two of them-one for each side of the 'cooling half' of this build. Not only will the fans/radiators mount to it, but it also has a pocket for dust filtration as can be seen, along with spaces for some large magnets to couple with some fan grill panels I'll be milling soon.





You all know the drill at this point: make some G-code with SolidCam, stick the ~6.3mm (1/4") stock to the bed of the machine, and face it all down to the thickness I need



I left an island in the center as that part needs to be 1mm taller than the rest of the panel. The magnetically attached fan grills that I plan on mounting to this part will rest on top of lip left by the island, though it's debatable if I'll actually need that. Cheap insurance can't hurt though! The finish here also looks darn good, which I'll never get tired of looking at/bragging about



Roughing in aluminum with a 2mm single flute end mill is a bit terrifying. I feel like they'll snap while slotting like this if I fart too loudly nearby. Fortunately it held up fine!




I roughed out all of the deeper pockets here with a 3mm single flute end mill from Datron with SolidCam's 'Volumill' a.k.a. trochoidal cutting strategy. It worked great! The hole drilling also mostly went well, but I noticed the spindle was cutting them at a bit of an angle... not good at all. The holes came out alright, but I'd be surprised if the 3.4mm carbide drill I was using makes it through many more of these holes. I'd better check the perpendicularity of the Z axis...





Nice! That's the mounting holes, the fan holes, the magnet pockets, the anchor wire slot, the pocket for the dust filtration... need I go on? Now I just gotta cut the part out of the stock... and do it all again.







It looks great! However, this took hours. My machine is really quite slow... I am being conservative with the cutting parameters/feeds and speeds though. I really don't want to baby sit this guy the whole time it's working or break anything. Also, I completely forgot to include a routine for facing down that island with the little slot in it, so after the part was finished, I left it in place and manually jogged the machine with the spindle spinning to face it to 6mm in thickness (while the rest of the panel sits at 5mm). Sometimes it's faster to take a page out of manual machinists' book than write the G-code you'd need for a specific task









And that's basically it for these parts! But not for this update



The fan holes left behind these guys. I don't have a surface plate or anything, so I can't check how flat they are, but they seem pretty spot on. I can definitely use these cutouts for something in the future, but I don't have anything planned at the moment. I just think they're neat!



So why did I call this update a 'major upgrade?' Because of this beaut I just received in the mail here-a wireless 3D touch probe, straight from Belarus! Along with its signal receiver, of course. Oh, and say hi to my old and crusty PC in the background

So what does this do, exactly? For the uninitiated, the tip at the end will deflect at the slightest touch in almost any direction. When it does, it opens a circuit in the probe and then it sends a signal back to the receiver saying 'Hey! I touched something!' to it. So, you chuck this into your spindle like any other tool, probe in the direction(s) you want, and then set your work coordinates accordingly. You can probe edges, holes, bosses, etc. with frightening accuracy and speed-making the process of cutting multi-sided parts a breeze. This probe claims <= 0.003mm of measuring repeatability-about half the diameter of a red blood cell. And in this case, for just shy of 300 clams($)! It also can be used in wired fashion too. What can't it do?

Sure, it ain't a Renishaw, but it's awesome. Using it on my puny CNC machine feels like pairing a dual-core CPU and 4 gigs of RAM with a 3080




Before using it, ya gotta calibrate it so it runs on the same axis as the spindle. I should really be using a test indicator for the job, but this is all I have. It did the job alright. Oh, and I also have the probe sit flush with the collet face on the spindle so it can repeatably probe in Z.

For my dumb-as-bricks CNC router running on an Ardiuno, a probe this swanky seems a wee bit mismatched... a sentiment I wholeheartedly agree with. At some point in the distant future when I get the time, money, and space, I plan on building a much better CNC mill to complement or even replace this router (and to really let this probe flex its muscles). My current CNC router is a lot of fun to mess around with but even in perfect working order it has a ton of drawbacks. I'd prefer to enjoy the machining process more than fear it, and have it take a lot less time for projects like this.

For those who are wondering, I got this probe at https://vers.by/en/. They sell tool setters as well, and wired versions of this probe for significantly less money than the wireless ones like mine. No affiliation or anything, I just really like it! So far, it's completely transformed my CNC workflow for the better. No broken tips yet, either!

Well that's all the ramblings I have for now. It's back to the grind for me as I still have quite the gauntlet of aluminum parts to get through ​

 

I did fancy this one too, but finally settled for the wired 3D-Finder.
I would be interested to learn about the accuracy relative to the time lag caused by the wireless signal.
Means how far does it travel before the receiver picks up the signal and how repeatable it is.
Because wireless is a major convenience.
But my wireless pendant looses a step here and there, so it would be nice to know how reliable the probe works...

And I am afraid, but depending on how accurate you want it to be, you might have to repeat the indicating every time you clamp it again.
Might be a good idea to mark the position on the shaft, collet and probe and always use the same collet in the same position...

 

I don't have much of a reference point for accuracy, but in terms of repeatability, with this probe I consistently see it within <0.005mm or so. This is based on what my dumb-as-bricks CNC tells me though, so in all likelihood it's different from that. Either way, I'm not complaining!

Sometimes the receiver will have some signal interference with the probe and send a false positive signal to the controller, which can be annoying but it's pretty rare. My receiver is tucked away in my noisy electronics box for the CNC which doesn't help. There's also the usual suspects like cosmic rays, coronal mass ejections, gravitational waves, etc.

When clamping, I always match up some lettering on the collet and collet nut with the power button on the probe, which does a good job. It's obviously not going to get you CMM-like measuring tolerances but for my needs it's good enough. Like I said, this probe isn't really meant for my current CNC anyways. Ideally I would just throw it into a tool holder or something, but I don't need KERN-like tolerances just to make a pretty PC

 

True
Even they probably do not need them in the first place

 

Yeah, I agree you don't need crazy-tight tolerances. You do need to know how to build with bad tolerances in the mix, though.
-Guy with a sandbag under one corner of his current rig.

 

Amen to that

 

Update 12: Hexagons are the Bestagons

Title shamelessly stolen from CGPGrey

Speaking of hexagons, I'll be milling dozens of them this update. I've also gotten to playing around with the new toy (the 3D probe from last post), and it's awesome! Since my CNC runs GRBL and isn't terribly...advanced, I had to write a custom plugin for bCNC for probing corners of parts, which took a some elbow grease to pull off. It works great though, with some caveats.

Anyways, onto the parts!



On a manual tool changing spindle like mine, a tool setter is, in my opinion, basically mandatory for long-winded projects like this. Not having one means you need to post a new g-code program for every tool used on a part. That's sorta okay if you're just making a simple part every so often, but for something like this... no thanks! Most of my parts for this build have like... 5-8 tool changes.









The hexes turned out really good! I did most of this with a pretty small end mill, so it took a while. Now I just have to do it again!




For the second part, I just tool some shots of the finishing passes. These panels serve as the fan grills for the radiators, and they have cutouts for magnets to mount them to the case semi-permanently. The center pocket amidst the hex pattern will give some clearance for a dust filter too, well, assuming I didn't bungle up my measurements...



One measurement I did bungle up was the thickness of these panels. I've been undergoing no small effort to not cut into the fixture plate, but now I have a permanent reminder of my failure to measure things properly. Oh well, it's not an expensive cast iron t-slot table or anything, and I can always just re-face it later. I just don't feel like it.



Remember that stock piece I mauled a few updates ago? Well, I still kinda need to remake those parts I was gonna to use that for...







This spiral pattern took F O R E V E R. Hardly an optimal finishing strategy but hey, it looks sick!






This part looks so much better than my previous attempt, my God. Just goes to show how much of a difference it makes to take the time and effort to do things correctly even if your equipment isn't the best on the planet...






The facing on these parts is only taking off ~0.175mm, so some low and high spots aren't unexpected. Well, at least in this garage, anyways. As long as it's not off by some crazy amount (>0.5mm or so), I don't really care.



Anyone guess what this panel is for?




I've never made a custom motherboard (or GPU) IO setup before, so all I can say is that I'm praying this setup fits. I'm pretty sure it's fine, but you never know... On the bright side, it won't be crazy expensive to fix any insurmountable issues, but I'm less worried about the cost and more about the time/sanity investment.



Last one! ...I forgot to take more pictures. This guy is for the front panel, so those small cutouts on the front are (left -> right) the drain port, the power switch, and a USB 2.1 gen 2 port.



And the money shot! These all turned out really solid, but they're also all double sided, so my job ain't over yet...

These mysterious parts all go inset into the large wooden panels on the outside of the case. Their job is to provide a sort of clean and low-profile interface between the wooden outer shell of the case and the metal interior parts. In other words, they'll only barely be visible, so I have some room for error. Still, it's fun to try my best to do a really good job even if they won't get seen... aaaaand in case I make any weird mistakes, I can cover them up easily

That's it for now. Next time is a bit of a break from the metal cutting-I just received some acrylic stock in the mail, so I think it's high time I finish off the rest of those parts for realsies next time! It felt like I left off on the acrylic parts last time on a bit of an L, so I want to change that. Especially now that I've cleaned up my CAM-fu a little since then!​

 

You dun guud!
Different CAM files for tool changes are called, "Stopping points so I can go to bed," -here.