Engineering an Automatic CNC Dust-Shoe

i wasn't really happy with the dust collection that came with my cnc router so i built a new one and maybe just maybe i went a bit too far because now it's full automatic and it moves completely independent of the z-axis and that allows it to permanently stay on top of the workpiece surface and that greatly improves the dust collection performance has a removable brush which is indexed and held in place by magnets the hose can be removed and is also held in place by magnets and it's on the side where it's out of the way for the quick tool changes spindle where now i have enough space to also install the longest bits i have for bit cooling and even more improved dust collection i integrated compressed air nozzles the whole thing moves on two linear rails and is driven by a stepper motor as the fourth axis the intended use for the fourth axis is for the rotary axis but since i don't have one why not use it for automatic dust collection now that it's done i see this whole thing as an engineering project on easy mode and in this video i want to show you why and how i did everything of that from start to finish first of all why did i want to make this upgrade this dust shoe that came with the machine gets the job done but there are a few major issues and limitations with this kind of design first of all it's made for a shopback hose size now i can totally understand why they chose that size because looking at it from a business or selling perspective it only makes sense to offer a port size that everybody can use and everybody with a workshop has some kind of shop vac not too many people have a dust collector with a big hose but looking at it from a technical perspective a dust collector makes much more sense than a shop vac this example shows how close you have to get with the shopback hose and the small dust collector diameter to pick up the dust the bigger hose can pick it up earlier [Music] the difference there wasn't all that impressive but usually when it's used during cutting the chips are not laying on the machine bed they are in the air and the dust collector sucks the chips out of the air so let's test how that performs with the bigger hose this example shows the distance out of which the dust can be sucked out of the air this showed pretty clearly that a dust collector is much better at sucking dust out of the air because it just has lots of airflow it moves a lot of air with dust in it and with this machine being stationary and lots of space around it where you could attach such a big hose makes it the logical choice for this application the next big issue is i don't understand why pretty much every cnc manufacturer attaches the dust shoe to the spindle or basically the z-axis it moves together and that's such a big problem i have a bit installed right now and it's only this long and i have adjusted this dust shoe to be all the way up now when i attach the bristles which really make the dust collection effective they are longer than the bit then when you're plunging into the material all the bristles have to be squished together and that puts a lot of force onto the z-axis which wouldn't be necessary same happens then when you move and all the bristles pointing in one direction but when you change direction they all have to be oriented in the other direction and that again puts a lot of force onto the z-axis let's try that on a bathroom scale without the bit of course two and a half kilos isn't actually that bad and that's because they used relatively thin and wavy bristles which are quite easy to compress but that on the other hand makes the bristles pretty quickly a mess like this and chips really get caught in this and you have to clean that constantly which is quite a pain let's do the same test with my old cnc dust2 brush which has straight and more organized bristles this peaked at almost five kilos and the other thing you can see the brush rotates because that seems to be the path of least resistance but in reality it is kept straight and i repeat the test with keeping the brush straight with this clamp and now this peeks out at about 10 kilos and 10 kilos is a lot and that's only the force straight up as you could see before there are also twisting forces and sideward forces and what not all additional unnecessary loads to the machine another issue is with long bits like this one and you would need to plant really deeply into your workpiece that there's the risk that you crash the brush into your workpiece when the machine is plunging so this needs to be high enough but then again when it's high up and the bit is not plunging really deeply then the brushes are not touching the workpiece surface and then the whole dust collection is basically useless and the last issue i have that really showed when i was making parts for this project that had a lot of tool changes this machine is equipped with a nice quick tool changer spindle but to do a tool change i always have to remove the brush and the hose because both of them are in the way to reach the tool it seems like a minor issue but when i was making parts for this project that had like five tool changes this got really annoying all right these are the issues i have that i now want to fix by designing and building a new dust shoe and adding extra features but how do you tackle such a project since it's so much that i want to add i wrote down a whole list of features and properties that i want to integrate and that makes sure that i won't forget any of it during making concepts or 3d models next i took many many measurements of the machine and anything that could be a potential problem or point of collision and also had to do some minor changes to the machine first of all i made sure that this whole assembly moves centered in the gantry which means that the distance in between here when it's all the way to this side is the same as on the other side next i changed out these screws of the side covers with countersink screws to be flush with this surface because before that these covers were mounted with these kind of screws and the head sticks a little bit out and takes away space in between here and i really needed all the space i could possibly have here then i wanted to be able to control the dust collector with the software and i already covered this in a different video which works now then i wanted to integrate some compressed air to the machine which means i needed to get my compressed airline to the machine which i also covered in a different video and then i had to look for mounting positions where i can mount all the new stuff i want to build and this doesn't really offer a lot of options the only really one being these cable clips and yeah that's what i'm using next i took everything to the computer and started with the 3d model of the whole thing the animation you can see shows the final result and getting to that was a two week process with many iterations and simultaneously i was also sourcing material and components very difficult to show that process in a video but later in the video during the assembly you will see all the parts in more detail but most of the work of this project was done in this step and i spent most of the time making sure nothing collides with anything and getting tolerances right where it's necessary after i had all the parts designed i created two paths for all machine parts with which i could start manufacturing everything here i'm machining all the holes for the linear rails for example and i also machined the functional surfaces for the linear rails in fact i machined every functional surface that has to do with the lining in the end even though the parts are just plywood i thought it would be good practice to do that because if the parts were metal i would also do that and that's also how it's done on the machine almost every part requires machining from both sides i usually try to avoid that but here it wasn't possible some parts also require a little more creative clamping after the wooden parts there is also a metal part that i needed to machine which is a stop collet with integrated washer [Music] and finally some 3d printed parts all right now that i have all the parts made and bought it's time for the most exciting part the assembly before adding all the new parts there is another issue i found and showed in a different video which is the flex within the spindle mount here and while i'm taking many parts of the machine apart anyways i want to fix this as well what i want to do is to add a connection from this plate to this plate with a set screw to install that i have to remove the spindle with only this piece i can mark the position for a hole and drill a hole for your m5 thread back install i can use the same drill bit and the hole to mark the matching position on the other plate then drill a through hole for m5 this block here will help me drill straight then cutting the threads the set screw now fits through here and can be threaded in and in between here there is just enough space for two nuts with washers so you can clamp this set screw to this piece with the thread with the first nut and washer and the second one and another nut from behind here i can clamp to this plate here and then there's a solid connection and this then also allows me to fine adjust the tilt of the spindle but more on that later now it has to go again i quickly built a bigger tabletop for my lifting table to have better access to the machine during assembly and for filming first task will probably be the most painful because i need to route two cables and an air hose through all the drag chains the y-axis drag chain unfortunately is not quite big enough to put more stuff in it so i'm replacing that with this one that i've 3d printed fortunately i still can pull all cables out individually without having to remove everything to get that chain off but still it's quite a pain now on my drag chain that i 3d printed this will be much easier because i included these clips that i can just lift off of course i have to work with what i've got here and i need to route the cables under here and then up through these holes so there's clearance everywhere and they can properly come out of the cover but that will be kind of tricky the air hose just fits through here and that should be somehow possible i could now rod the stepper motor cable through this hole on the other side but then it needs to go under the belt to the air hose again because both of them will come out of this drain relief at the back of the cover and that's not ideal i could also mount it just somewhere here but there are not many places where i can mount that thing i have a neat solution now i replace the bolt from the ground wire with this longer one put a lock nut on the end and this nut to clamp it and this now makes two good spots to put zip ties around definitely good enough to hold it in place and well it will never move it just needs to stay down i did the routing with the zip ties through here off camera because that's just impossible to film and pretty boring let's see if it works through its full range of motion okay here it's how far it will mechanically go and the drag chain is good let's do the other direction that looks good as well the chain seems to be a little too long let's try and move one link that seems much better so far so good the other drug chain will come later next i drilled a big hole for that strain relief into the red cover then i needed to remove the black cover to cut a slot in it the glue pads it was attached with or the worst to remove the slot is needed for clearance and gives me easy access to lubricate the zx spindle i reattach it with some self-adhesive magnetic strips kind of crazy all this effort so far just for these two things coming out the back here now the real assembly begins with inserting all the nuts into the hex shaped holes as i mentioned before every functional surface is machined the surface where the linear rail gets attached to is of course also machined and there's also this edge that i have to press it against when i'm screwing it down that way it's at a defined position and on the other side there is this gap and that's on purpose because i don't want this rail to be jammed in the slot i want it to have play and then be able to press it against this edge all right got both rails attached now comes the same for the blocks they'll mount to the screw together pieces from before and this machine surface is for the surfaces of the blocks and this edge will touch both of these surfaces of the blocks and that will make sure that both of them are mounted straight so far so good let's put them aside for a moment and assemble the drive unit the heart of that is this more or less complex 3d print which is motor mount and fixed bearing housing at the same time so this fits one bearing then a bushing for the outer race and the bushing for the inner race another bearing and this lid clamps everything together one end of the thread rod gears the coupler this i can put through the bearings and that washer will now contact the inner race and for the other end i have to stop call it with integrated washer with the nut i can kind of clamp this together and then secure the stop collet in this clamp position and now the threaded rod is guided by two fixed bearings there is no play and it turns really easily of course the fixed bearing block is far from ideal but for what this is doing this is more than adequate now the motor and here i have access to clamp the coupler to the motor shaft now they turn together and these two assemblies get screwed together with the embedded nuts in the wood here this up here is the reference surface for the motor assembly and the front here just needs to be flush now there's this piece that will house the nut and this will be glued in here with this piece as support this looks good this little pin will trigger the limit switch next comes the part where the brushes and hose attaches it's split in two and houses two embedded nuts and these are holes for magnets making sure all their polarity is the same and then these halves get glued together while it dries let me show the next part which is this big 3d printed part to where the hose attaches and that then goes from round to this kind of weird special shape and also angles it about 45 degrees which in the theory should improve airflow then it's also a little bit of a structural part because it connects both the side and bottom piece and then there's the second piece because i wanted these two to be removable so the actual hose clamps to here and then i can easily separate them and use the hose for cleaning the work piece or the table or whatever and the way this holds together is also with magnets here are three holes for them and in this piece there will be this metal ring glued on top of here and then it can stick together with the magnets in hindsight i'm not quite sure if that was worth it especially if you take a look at what it took to make this ring so let me show you i first made a test ring out of thin mdf and that fits pretty well now i can use this to roughly mark the size of the sheet of metal that i need now i've made a two-part jig to securely hold this on the lathe this fits in here and this part of the jig has this ring surface that then gets pressed against the part and securely holds it all around the ring surface while i turn it there also two alignment pins that make sure that this circular cutout runs concentric with the spindle and then i drive in four screws i'm pretty close one more pass i've now installed the second jig to turn the outside of the ring this here runs concentric with the spindle the inner diameter fits perfectly over that and then i have this piece again with the ring surface which i use for clamping with the ring the bird this should not just drop in place here yes it does nice i used contact glue to glue it secure and super glue for the magnets now back to the assembly these side pieces with the sliders will mount to this on this machine surface like so but drilling a hole into this edge for a bolt is impossible with a 3-axis cnc but what i could make is these kind of cutouts and they now fit half of a t-nut and then i have a second piece with the same cutouts and this fits on top and will be glued in place and now i have a thread in the edge of this piece now these square holes with the embedded nuts inside line up with these slots and the fact that these are slots means there is some adjustability and from below there you can screw it on one on either side and then there comes the 3d print and for this magnet that's sticking out here there's also a cutout in the 3d print and that fits mounting screws here and here and on the final assembly i can also screw in here and then this is all connected and more rigid so far so good now let's mount stuff on the machine the side pieces just get screwed in here to ensure that the linear rails don't end up binding i need to make sure that the mounting surfaces of the blocks here are parallel to each other for that i have this piece that has parallel edges and this just gets clamped in between here and so the rest should also end up parallel piece of threaded rod with a nut on the end this piece has matching slots and a nut from the other side and then this also has a second alignment purpose because with only one screw this can just rotate but it of course needs to be square to the table so while it's not clamped together i make sure that it is square to the table on both sides of course i press that parallel spacer to the black cover and clamp it in this position now it's parallel and square to the table but only if it's rotated so that the spacer touches the cover and to ensure that this never happens i lock it in the right position with this 3d printed piece that will hook into the edge of this red cover indeed a bit complicated but with the limited mounting options i couldn't think of a better solution pretty smooth motion so far nothing binds and nothing jams pretty good when there are no brushes attached and this is all the way up the lowest point of the machine is still this red cover one little issue since these sides are only connected down here is that there is some flex i expected that flex and that will be fixed on the final assembly when also everything is painted then i will screw a connection plate to the back here that's also why there's a flat spot now it's time to shorten the threaded rod and cut threads in one end now the motor can move it up and down and if i go all the way down until it hits the end screw the rails are just still in the blocks and again the threaded rod is not the lowest point of the machine it's still the red cover the limit switch is screwed to this plate and gets mounted here and there's lots of room for adjustment you can hardly see it but you should hear the click okay next i guess is making the brush this piece has a bit undersized holes for the magnets in it and on the other side a channel for the brush the channel is made to fit that brush perfectly only problem are the corners i'll try to just bend that brush or else i have to help with the heat gun wow that bending is actually surprisingly easy great yeah so much for that so i tried bending it with the heat gun and it works but it will be really difficult and this side quickly got messed up with this piece i'll try to protect bristles from the heat and that didn't really work let's see if i can at least get it into shape not really though less heat that first bit fits oh god that will take forever now it's snapped apart again maybe i have to simplify this shape and make it only straight sections or get a different kind of brush that is a lot more flexible let's try some more concentrated heat with a soldering iron and that seems to work still have to be careful not to touch the bristles but now i can bend this radius this definitely has more success by far the most difficult part is dealing with that other end of the brush that's just a nightmare definitely still has some spring back but let's see if i can fit that all the way in and it actually fits unfortunately the first corner i made is a bit messed up and i do have enough brush left to do another one but honestly who cares to install the magnets i remove the brush again because they need to be pressed in and that's easier without the brush it needs to stick out two millimeters so i stuck two magnets that are two millimeters thick next to it and now just can press down and that's it with these magnets sticking out this will not only hold it up but also prevent it from moving side to side and now with the brush nice now the hose connection here will be the only wood screw of this construction because here i couldn't be quite sure where exactly this piece will end up when i mount it as you can see this hole did not end up in the perfect center of this part here but in the 3d model it does and i was afraid of exactly that and that's where i made it a wood screw and drilled a hole during assembly i've now installed a spindle real quick to check clearances and as you can see the space on the side here is about the same as on this side and that's plenty of space for this to move up and down and also if you look at this from the top this also looks good but what i'm really interested in if it works is when i'm doing a tool change for that the brush will move all the way down great the brush will move all the way down and the spindle moves all the way up and now there is plenty of space to even put the longest bit i have in there no problem and i didn't have to remove anything to do a tool change the hose can stay in place and this would have been so nice for making all of these parts there's another brush to install in this slot and that will create a brush seal between the spindle and this piece this is a very good fit i definitely got some practice from the other brush later of course these bristles need to be shortened there we go let's see if he can fit this i will shorten the bristles later but that's all the mechanical parts for now there is one more part to install which is this pretty cool air nozzle but i can't install this until i can move the z-axis again so that will be saved for later the stepper motor cable and two wires for the limit switch i'll sort into this connector i only used one screw to close that but that's on purpose because the cable that will come out the back of the machine will have the matching connector also with only one screw and like this i can screw it to the side and then everything is fixed the wires just need to be held in place with some zip ties and then i think that's a nice solution probably this length the matching connector is done and that's it for the wiring up here first thing to do now is to route the cable and the hose through the other direct chain but getting access to that is again a bit difficult much better access now unfortunately this drag chain is a bit bigger and has space for the new stuff all right everything is in the direct chain and if you take a look at this i couldn't fit any other wire through there even if i wanted the stepper motor and limit switch cable will already end here since i have the for access controller this port is wired up for the rotary axis i just use it for a different purpose and i'll just let the cable come out down here wired up to another connector and then this is already done but i need to install this solenoid valve for the compressed air i only could find in 24 volts and the machine only has 48 so i also need to install this 24 volt power supply and then a relay to control it and since this will take up more space i'll also install another one of these thin relays to replace the one that's currently controlling the dust collector so i can remove one of these and need to add all of this that will be fun already a dumb issue these two relays are too tall for this box i would have never anticipated that but i'm quite lucky here because with the relays mounted exactly here the parts that sticking out will end up in this space here and then it works now the valve is wired up and i've set up the machine for testing just connected the controller and it's already on and my mouse cursor is on the m7 button which will control the valve so now when i click with the mouse this should also click and it does perfect i can't really show much of the wiring since it's impossible to properly film in here and in fact it's already done it can show you what is new so the power supply and red wire from the power supply goes to this vargo clamp from there gets spread to the two coils of the relays and one goes to the valve the output of the first relay is connected to 220 volt ac for the dust collector and the second relay is just connected to the valve i tried to tidy up in here but honestly it's still kind of a mess but good enough for me now another important setting is at the stepper motor driver because at the moment it is set for a bigger motor than i use my motor is rated for 2 amps and i can take a look at this table and this tells me the right dip switch settings the other three are for the micro stepping that's set to 1600 at the moment and that's okay the solenoid valve i screwed to a plate and then just double sided taped it to the side of the electrical box the air hose i could draw together with the cables back here and into the valve air supply will come from this manifold here that i screwed to this cover with a hose connected to the valve last thing to do now before i can do more testing is to wire up this end of the cable for the motor with another one of these plugs and therefore i got one with terminals and that makes it really easy for troubleshooting if i did anything wrong with the wiring elsewhere there's also another addition which is this box back here whenever the dust collector is plugged in because before it was directly wired into the machine and used its power to run i'm not quite sure but sometimes i think this caused issues so now to be on the safe side this is wired into this box to this relay and this box has its own power source so now these two machines are separate let's test it to rely functions first when i press m8 the dust collector should turn on and it does and when i press the m7 button i should get compressed air out of this hose and i do perfect on the hand wheel the axis now let's see if it moves it does [Music] nice [Music] and now with a bit more speed [Music] seeing all of this working for the first time on the first try is really nice i've set it up so that this axis has its zero position when the brushes touch the spoil board and when i now have a work piece that's for example 17 millimeters thick i just set this axis to this thickness and there you go when it's time to flatten the whole spoil board i do that with a macro and take off like one millimeter of the whole surface when it's finished it will also set the new zero position one millimeter further down so everything still works and it's all automatic this also means that this axis can move further down without the brushes but that's only necessary when the spoiler board gets thinner i've also designed it that when it's at the slowest position that all the components are also maxed out so the linear rails right here and the length of threaded rod ends right here and when it's at its highest position with the brush attached there's still no collision there's about half a millimeter of a gap there there's also no collision on this end and on this end next now comes the hose when i have a hose like this where i also use it to kind of clean up a workpiece or something i hate these pointy ends of these hoses previously i had this much shorter and kind of clamped it underneath the hose clamp but this time since i printed this anyways i integrated a hole for that where i can fit this in and with that it's really out of the way and i can't hurt myself on it up here i also upgraded this adapter which only was a press fit and sometimes came loose and fell down to this year which i 3d printed and it has a hose clamp and this can be clamped on what you can also see up there is this wire which is a ground wire and i connect this to the coil of the hose because during use it always gets a little bit statically charged and when i then go to it to clean something up with it i always get a tiny shock nothing dangerous just uncomfortable but now not any longer last part to install now which i'm pretty excited about is this nozzle for the compressed air it's a wonderful example for good use of a 3d printer because this is all one piece has internal piping directional nozzles printed in threads for this connector mounting positions stiffening and all while being ultra compact and this actually mounts to the holes where the old dust2 was attached so these holes still have a good use this is also designed to be just above this collet about half a millimeter and these nozzles are directed to about the average bit length that i'm using no special fastening for the hose it's just organized together with the other cables and now this works the amount of air coming out of there is not that much it's just coming out fast in fact it's only half a bar on this gauge and for the purpose of it that's plenty for getting the dust airborne so it's easier to suck it out of the air for the dust collector and to get the dust out of deep grooves especially the ones that are cut with a down cutting bit the new parts of course also get some paint that matches the machine while the paint is drying i tram the spindle one direction i have to do with shims the other direction i can now do with the set screw i explained the whole trimming in more detail in another video before painting i taped all the important surfaces and now comes the satisfying moment of removing the tape again but i didn't film the final assembly alright now with some color and finish it's done let's try it out and cut something i start with flattening the whole [Music] spoilboard as you can see the dust gets picked up very well all right it's flat again and there is no dust laying on the table some is here but that's unavoidable because it comes from when the brush overlaps here slightly and not making full contact with the surface and yeah then this always happens but so far i'm pretty happy next i want to cut a bit storage thing for a drawer [Music] here you can see how i programmed the behavior of the new parts during a tool change [Music] [Applause] me all right that came out great and perfectly dust free some dust around the part which came from cutting the pocket because there was a gap between the surface being cut and the bristles so there's some dust that can escape but the part itself is basically dust free now i have a nicely organized drawer with all the accessories and bits that i usually use nice and labeled with two numbers and sizes for the reducer collets what i especially like is that i can very easily grab any bit by its shank and don't have to touch the cutting edges these are v-slots which means they fit any bit diameter i don't understand why so many people like to store their bits upright like this and you have to touch them by the cutting edges that's pretty stupid to me on the side of the boxes i glued some pieces of wire into the grid which now indexes all the boxes and keeps them in place all right i think it's time to give this a wrap up in the beginning of the video i mentioned that i see this whole thing as an engineering project on easy mode many of you know probably think what the hell is he talking about and indeed this making this had its difficulties and was by no means straightforward but what made it a lot simpler is i had control over everything i decided what it can do how it should look and how much it costs and the other thing for engineering project now is i don't have to market this and have to make it mass producible and that is a big deal see as good as it works and as cool as it is it is very expensive i easily spent 400 euros on parts and material for this no manufacturer would include such a unit on a hobby class machine like this the cost far outweighs the benefits and i only had to build this single unit and can live with it and i'm very happy with it the big deal for me was the learning experience and the fun i had while making this i mean designing it making the parts assembling them seeing it all come together and seeing it work for the first time was just a blast and i really really enjoyed that and i also learned a lot especially how time-consuming some parts could be about making two parts that make good parts took so long but well here we are now with this finished result that i'm very very happy with as i said i really enjoyed this whole project and i hope you did too follow me along during the video and if you want to support me with project like this a good way is to do that through patreon you can join me there in fact your support through that enable me to also tackle more expensive projects like this one with ease so i guess then i see you in the next video ah finally he stops talking yeah i like the video subscribe to the channel ring the bell whatever come to an end

Channel: Marius Hornberger

Views: 113,776

Rating: 4.9747477 out of 5

Keywords: woodworking, workshop, DIY, homemade, How to, selfmade, jig, random, stuff, machinery, making, make, tbalesaw, bandsaw, drillpress, tools, woodshop, interesting, awesome, thinking, smart, video, tutorial, art, nice, great, good, crazy

Id: IF8U8nd5oSM

Length: 40min 40sec (2440 seconds)

Published: Fri Jun 11 2021