Can we DIY an Industrial grade CNC? Lets Build It and find out!

hello friend this is our quest to make an industrial grade cnc machine with diy type resources it wants to fit an eight by four sheet on the bed fabric cut softwood munch through hardwood machine aluminium and plastic have a go at cast iron maybe even be able to do a bit of steel quite an ambitious goal let's have a go at it [Music] there are a million variants on this basic design t-slot aluminium profile making the frame and the z-height gained by expensive pre-milled aluminium plates i felt this style of machine was unduly popular it seemed to come with stiffness damping and cost problems cloaked in a sheen of convenience don't get me wrong that stuff is extremely handy for makers we've used it ourselves on the chainsaw mill for example it just doesn't seem to fulfill the requirements of a massively sturdy vibration damped frame very well in fact the one thing that aluminium really has going for it is its strength to weight ratio and because the frame's not moving anywhere we're not too bothered about weight now machine makers do something very curious they design the machine and then they go on and make it whether it's a lack of formal engineering education or cad experience i don't know but my brain just doesn't work that way unless i'm hands on cutting and lifting and scavenging my way through designs well they just tend to suck so forgive me if we're just launching into the build here but it's kind of how it happened so here's the starting point and the foundation of our machine it's a hefty structural i-beam with some more i-beam welded on for legs it's been used before so it's been painted which is a blessing and a curse and it came straight from ebay with those big plates welded on the ends initially i thought the eye profile was far from ideal because of how weak it is at resisting twisting forces but the more i thought about it and the more i had ibm profile to hand the more attractive it became what if we could actually turn the weakness of i-beam into a strength in this case the sheer mass of this amount of steel is going to lend it good rigidity but the shape is super crucial too you can see plenty of triangulation i um dinard about whether to triangulate the legs in this direction as well but given the width of the leg compared to its length it seemed unnecessary turns out it's pretty useful to store things under the cnc machine and bracing in that direction would have restricted access so i'm glad i didn't give in to my natural inclination towards over build on that one things are gonna get a lot spicier when it comes to the weight but we're already into the exciting danger weight category and the swanny the engine hoist is super useful here i'm flipping it up and about the place just to make the welding easier and it's stitch welding throughout this construction which just means doing no more than say an inch or so at the time to limit the heat pumped into a single area this should reduce the amount the frame will warp now and later when stresses get relieved through machining hey hey [Applause] sorry sorry i wanted you to enjoy the full magic of that noise my attempt at vibratory stress relief or vsrs is known a good welded joint can be quicker and better than a bolted one but when we're talking about precise machine tools it can also introduce dimensional instability through preheating good joint design and stitch welding i'm hopeful we didn't introduce too much stress to the frame trouble is without cutting up or machining it and carefully measuring any movement it's very difficult to be sure now it's all together the frame won't fit into the kitchen oven and neither does that go up to 700 degrees which is roughly what you want for heat treating this budgie version of vsr i'm doing is like super cheap insurance it didn't cost me anything but i don't really know if it's helping with a super simple diy circuit which i explain in detail in another video and the accelerometer on your smartphone you can vibrate the whole assembly at its resonant frequency and that's the key to this whole witchcraft which should hopefully relax any residual stresses caused by welding if you didn't wonder what these small stubby bits of pipe are that i'm filling with expanding foam my guess is that either you're a fortune teller or you worked out based on the number of clues that or you thought cnc stood for cats need cuddles and all you want to know is when this video is going to get down to business if none of those apply and you were wondering perhaps this epoxy bonding coat i'm going to call it we'll give it away it's a mix of one part far set epoxy to one part anti-slip grits that are designed for flooring i think sand would have worked just as well but it's what i had when i did the other side the rebar got in the way of spreading the epoxy so this time i'm welding it in after i'm using a bit of mig welding wire here just to check the epoxy scratch coat is tacky but set enough that it will resist the stones from scratching big fun bag of ballast uh as you can see it's all the same rock it's just being crushed to different sizes it's very definitely in the jagged range of smooth to jagged this is the aggregate for the concrete mix i'm bringing it inside and drying it out taking measurements so that now when i do the final mix i know how much water is going in the same is done for the sharp sand this mix doesn't have any of the stone in just two sands and one cement this allows it to get into all the corners and nooks and crannies and make maximal surface contact with the tacky epoxy layer one of the funny quirks of concrete conventions is that the cement to aggregate is measured by volume and the rest of the things are measured by weight and that's against the weight of dry cement powder plus pozolan one big hurdle for concrete use in machine tools is that it tends to shrink but this problem can be minimized by reducing the amount of water used but reducing the gauging water also reduces workability which is where super plasticizer and consolidation tricks come in i was initially aiming for a water to cement plus pozolan ratio of 0.28 but after testing it about the best i could manage was a ratio of 0.35 for way more on mixed design i'll write up some of my research and leave a link in the video description the main difference between this main mix and the previous one is that now it's got stone so it's one cement to one sharp sand to two stone if you were on a building site and this was a concrete slab or foundation or you're making something like that there would no doubt be lots of swearing it would be just unmanageably dry but because we're making such a contained specific shape here we can give it the attention it deserves really consolidate it down well all this is in service of making it as dense stiff and strong as possible to fill the whole side of the profile took a good number of full mixes in the cement mixer each layer gets very well consolidated before moving on to the next we're quite nicely done sd has worked amazingly to compact it with a little plate thing did have one minor breakage one of the bottom plate bits broke off so we're just going to make a non-gravel mix now that we can smooth over this top bit with why would we go to the trouble of filling this section with concrete it's stiff but concrete's not as stiff as cast materials like cast iron it's good at vibration damping though it's not as good as things like epoxy granite but here's the thing compared to those it's unbelievably cheap and readily available and therefore you can have masses of it once that was as smooth as it was gonna get we used some old plastic packaging and plenty of tape to keep it nice and moist for its long cure so this frame was absolutely crush-a-tronic before making it a concrete monstrosity once it was unwrapped and settled it was left several more weeks to dry before we painted it to try and seal the concrete surface here it is the huge challenge for cnc builders everywhere getting those long linear rails perfectly level and co-planar there's only a few methods we know of one is to have a machine that's bigger than the one you're making accurately mill the surfaces for your linear rails another is to use either shims or scraping or a combination of both to level the surfaces and then there's what we're attempting here using the self-leveling epoxy method the theory is beautifully simple you create a series of walls and bridges and pour in your epoxy then using the off quoted little understood magic of gravity it assumes a shape similar to the curvature of the earth which for our purposes is pretty damn flat well there's the pre-handle anyway what you just saw was as testing my first fail at pouring the epoxy to do that test on top of the cured epoxy we poured in water with a bit of dish soap to lower the surface tension and then used a ruler to check the depths at different points now water really does self level quite well so when we found the depth different at different points we knew that that hadn't really worked to do this subject justice i'd need to make a couple of videos just on this process alone enough for now to make a few important points one the epoxy needs to be the slowest set epoxy possible two the temperature needs to be carefully controlled three it needs to be as liquid as possible so very low viscosity and four it needs to be completely non-shrink so solvent-free epoxy is important and finally what we didn't do right is to allow the finished depth to be high enough if there's not a deep enough pool of epoxy it just doesn't self-level well due to surface tension and other vagaries on the plus side epoxy is relatively soft so correcting errors is not such a big issue though it is kind of tedious for this i'm using a very precise engineer's level and a long engineer's straight edge i tried various things to remove the material from standing knife blades to sanding all of them work quite well and i stopped short of using power tools and in the end there's just no getting away from the time consuming exacerbation accuracy equilibrium roundabout i've got a lot of holes to drill all the way along two mil holes so i've done the ones through the epoxy already with 2.5 mil and now i'm gonna use unfortunately my only drill bits that are two mil these ridiculously long ones i'll push very hard so yeah i've got about 50 holes to drill so wish me luck these holes are not to boil down the rail but to hold anchoring spooks which will tie in the shoulder that the linear rail is gonna butt up against manufacturers of linear rail want the frame of the machine to bend the rail straight rather than vice versa hence these spokes are getting driven through the leveled epoxy into the steel below then we're using the straight edge and the metallized epoxy replication technique to create this perfect shoulder we're using thk shs 30 linear rails which we've never would have been able to afford except for a crazy ebay deal the length wasn't quite right but often for the diy or on a budget it's worth working around those kinds of things after a lot of drilling and tapping through into those little protrusions with foaming you saw earlier so the drill bits didn't get blunted immediately by the concrete this is our lap of glory where we're clamping the rail hard against the shoulder and bolting it firmly into place the other rail opposite doesn't have a reference edge shoulder to clamp to and instead that's going to rely on the gantry to work as kind of a jig to align it in relation to the rail i'm doing now rails can be joined together though it's not ideal but they need good support and very square ends i wasn't sure if i was going to do this but i've been fabricating this end piece that's going to brace the two side rails i don't want to disturb the nice flat set of the parallel linear rails that we've got now i'm going to have a metallized epoxy bonding to one side of this so it becomes absolutely flat and has full contact and it should brace this piece here from being tugged back and forth by the ball screw okay one done it's possible [Music] we want the epoxy to bond to this surface of the cross brace so that's getting roughened up and well acetoned as usual i start with a scratch coat of epoxy rich metallized epoxy that gets really scraped into the surface before a thicker putty like consistency is mixed up to make the bulk of the jointing [Music] as it material it wasn't too bad at all this type of construction sure does take a long time compared to welding but each joint should add some more constrained layer damping which should cut down on vibrations and ultimately lead to better surface finish cancel everything we've had a complete change of design of how we're going to drive the x-axis and it's via rotating ball nuts versus rotating the screw itself there's three main parts to this the motor mount the bearing housing and the rotating part that bolts to the ball nut i had all sorts of adventures making these parts which i'll spare you there's a bit more detail on the flowering elbows for supernerd's channel essentially the bearing housing is old alloy wheels melted into shape and carefully machined to accept the bearings rotating parts made from this old steel and some old pipe i had melted together and cut carefully while spinning exceptionally fast one end is threaded to accept lock nuts which adjust the preload on the angular contact bearings the motor mount is made from a particularly old rusty bit box section mounted to a flat piece which is then cut so it has two flat perpendicular surfaces so it can bolt to the rest of the assembly here's the point of all this this is the mass of the rotating part on the scale is actually gonna be a bit of a challenge this whole thing will be spinning around and changing direction that's a lot of inertia versus the very small assembly and the rotating ball on that with the rails nice and straight i don't really want to be welding this anymore because it'll move but i'm not happy with this and how the ball screws going to be tensioning this part so we're putting in some more bracing we get getting there with this we just need to work out how to fix this whole thing the ball screw nut drive assembly to this guntry side plate so that one drives the other and then we mount the ball screw going all the way down here and boom now that'll be exciting oh can taste it [Music] there's another video on the freakish yet remarkably effective gantry design and it going on is quite a milestone because the weight becomes important on a moving gantry the tactics used to maximize strength stiffness and vibration damping are all really quite different to those used on the frame right then hopefully this is going to be able to perfectly center the ball screw like say [Music] gonna be the first try of this with both axes plugged in let's hope the guntry doesn't tear itself apart and max 3 is making the slave access work all correctly so they mirror each other exactly ok either they're going in different directions or something else is going on turns out that's exactly what happened and luckily because i was going so slowly with the jogging it threw up an error on the servo driver which is set up to cause an emergency stop in mach 3 so everything was okay it's just a tick box in the settings to reverse the slave axis so that was an easy fix it's quite a dangle i know at least a few people comment saying it's super cheap to buy cable chain and not worth making your own but on the long 2.4 meter access for reasonably sized as in big enough to take all the cables and decent quality cable chain is really quite expensive and anyway it seems like a reasonable project to start learning how to use this machine monster which clearly i can't do yet at some point i'll learn to use the camera properly as well and anyway this is helping make a dent in the 1 8 inch ply skip hoardings have been cluttering up the place [Music] [Music] after making the cable chain itself we need to make some mounts that would hold it above the balls through and these kind of doubled as braces for the frame as well and they were epoxy bolted in so it should also help with vibration damping the second hand servos here came with cables but to reach the full eight foot length of this machine we're needing to extend some of them quite nerve-wracking for the nine pin encoder cables we've done that nicely [Music] here's the bit that should be on there frustrations are plenty there may have been but almost miraculously there were no cross wires or any problems of that type and it makes it all the more satisfying now it's going the cable chain creaks a little bit disconcertingly here and there but seems to function perfectly well after wanting to make flat square surfaces and finding clunky work around so many times on this build gratification has never felt quite so circular [Music] okay that is a very nice finish i can't feel any lines whatsoever and just look at that grubby reflection there indeed that plate became flat enough that we were able to cut exactly halfway through this 9.2 millimeters thick piece of vinyl with a budged up unsprung drag knife we've had quite a few adventures with this machine now but i still feel like we're only just scratching the surface of what it's capable of most of that proper full-on testing's gonna have to wait for the next video this is already quite long frame itself feels like a really solid and dead foundation and i really like that the rail and ball screw are raised up and that's where the z axis gets its height from rather than two flippery gantry plates at either side having it raised up also means the and rail are a bit further away from the bed where all the chips and debris are flying around even so some chips especially when milling aluminium make it up there and our ball screw has very poor protection against that kind of contamination the bellows or similar would be a way to cover it but over such a long distance of travel you lose quite a bit at the ends where it bunches up as well as it being quite costly they actually stick out quite a way now but that's okay because i don't foresee using this area too much excepting when we've got a big stump or something in here [Music] well the facing on this was promising it was an 8 mil cutter going up 10 000 rpm now we're on a smaller cutter for the details not pushing the feeds or speeds it's going at 700 millimeters per minute after a bit of chamfering that whole part gets flipped and machined on the other side to become an exceptionally square 90 degree bracket to hold our somewhat ridiculous laptop stand that's on the end of the cnc machine hey i'm pretty pleased with that there's no big dramas it just straight off the bat seemed to work i won't hesitate to put steel on this in the future it was a bit of a hassle to set up the missed cooling and the drip tray to stop it soaking the mdf spoil board so i might even not bother with that in the future [Music] the clamping method could have probably been much better for the milling of this cast iron even so though i'm really pretty pleased with how it's coming out the servos at the moment are all on their factory stock tuning and i'm noticing that the curvy diagonals are quite a lot more ripply than anything in either the x or the y direction alone it's leading me to suspect i might need to look at the tuning there's been so much to learn building this machine and the potential of this new tool is kind of mind-blowing to me i had to leave out so much in this video so if you've got any questions leave them down below check out the description for links to epoxy recipes and things like that we'll probably end up writing a whole book about cnc related stuff the next video on the cnc will be testing the spindle motor so we'll see that bye

Channel: FloweringElbow

Views: 521,575

Keywords: cnc, Flowering Elbow, concrete cnc, concrete CNC machine, cnc mill, diy cnc, diy cnc router, concrete cnc router, flowering elbow cnc, cnc router, cnc machine, cnc machining

Id: cqYJS27aC4w

Length: 27min 30sec (1650 seconds)

Published: Wed May 04 2022

Reddit Comments

[u/MrUlterior]

His channel has a lot of the qualities that attracted me to Jaime's channel, so I thought I'd share

[u/lord_mundi]

wow... very cool. and you're right... this scratches a similar itch. Watching this video, it's obvious this guy is not only very smart, but also practical and thoughtful.