Ep06: DIY Milling Machine | Putting the big bits together!

Added: 2026-05-30

[00:00:00]Welcome back to the workshop. So, in the last video, we got the side plates mounted, the linear rails, and most of the head assembly. And in this video, we need to take most of the side plates off again cuz they're steel. So, we'll get those painted, and then we'll get started on the drive assembly that lifts the head up and down. Okay, so we painted the upper parts now. So, we got this uh cross beam here that's all painted back on. Got the side plate over there, ready to go on. Everything's nice and dry. And then this plate as well.

[00:00:26]I'll just give you a close-up look at this. I really do like this Rustoleum uh sort of metallic finish. You can see I used it. This is on the original drawer press. It's just it goes on beautifully.

[00:00:38]You don't need a primer. Dries in 15 minutes and it really gives a robust finish. You know, some paints I've used, they kind of scratch and flake off. This seems really robust. And to top it off, gives a nice kind of contrasting color with the aluminium. And we've got this lined up using that edge there. And then we got it fixed. And then all the leveling screws are in. You might see that the leveling screw system at the rear is different to the front. Uh it's kind of done the other way round. So it's fixed with the two small ones and leveled with a I think it's an M10 grub screw. Reason for that is just the layout of trying to get everything to fit. You know, this rail ended up being too close. So I had to use the smaller fixings there and it was okay at the front. Uh and then you can see uh the little leveling screws there. So basically I've tidied it up just loosely because I know this plate is very flat.

[00:01:24]I've checked it. Just sort of nipped these up. Then got the levering screws in so they push hard against this surface back here. And then torque these up so it doesn't bend the plates in because it's pulling up against those kind of grub screws there. So this should remain pretty flat to put the rails on and it should be pretty true there. Okay. So the two upper panels have been painted, the two L lower panels are painted, everything's been aligned again and we've got our connection block down the bottom. So the next thing to do is to get the linear rails back on. get that pretty close to being dialed in and then we'll get the main head on.

[00:02:02]So, I fitted the main panel on the front of the head and then fitted the closer plate goes on the back.

[00:02:09]Okay. So, as you can see, I've got all six carriages here on both those rails.

[00:02:13]I've got that on both sides. So, hopefully that'll be pretty rigid. Um, so now we need to fit the ball screw.

[00:02:19]So, that's the floating bearing goes in that bit there. And then the ball nut itself goes onto a block on there that we haven't made yet. And then the upper part, which is got the fixed bearing in it, goes into that plate. And this goes onto the top of the machine. So we need to fit this next.

[00:02:37]Okay. Got all our bits. So ordered these a while ago. Just been sat in a box over there. So got our fixed and floating bearings. Uh we got the little ball screw nut, but I won't be using that cuz I couldn't get that to work in my design. And you'll see it's got the threaded holes on the back, which would have meant uh putting it up against the plate and then somehow having access from the other side. So instead, I mean, this is a 3D print what it's going to look like, but it'll basically be like that. The hole is so you can get it around uh the ball screw itself without having to disassemble anything. Uh and then it'll just bolt on there from this side rather than have to bolt from the back. So we'll see if that works. If that works, we'll machine one of those out of aluminum.

[00:03:18]So, we'll get these bearings. Oh, yeah.

[00:03:20]I'm going to show you one more thing, which is this is a 20 mm ball screw with associated nut. Pretty standard machiny.

[00:03:28]Got the the blank at that end with the circlip. That's the non-driven end. And then at the top, um I asked if they could uh put a little keyway in it. 5 mm keyway.

[00:03:40]And as you can see, they did that. So, I gave them a drawing cuz I wanted an extra length on here as you often do to get pulleys to fit nicely and then they did that little keyway. So, I don't think there was very much more money. It was hard to tell in the overall price of everything. It didn't really seem to factor. So, it's worth asking. Uh, I'll put a link to the supplier that I've used over many years to buy bits and pieces. Um, they were originally recommended on the My CNC UK forum, you know, so I'm not claiming to have discovered that supplier by any means, but I've been really happy with the quality of stuff they've sent over the years and uh, you know, they can do your keyways for next to nothing basically as part of the overall cost.

[00:04:21]Um, so let's get this set up and then we'll see what it looks like.

[00:04:27]So there's the floating end. As you can see, that bearing will just slide in there and uh take up any tolerancing or yeah, thermal expansion if there is any.

[00:04:37]I wouldn't have thought there'd be much the amount of use this is going to get.

[00:04:43]It's not machine.

[00:04:55]Okay, that's good.

[00:05:00]So, we're only uh mocking this up, but I'll make sure uh that I get the grease nipple there lined up on the outside so it's easier to grease. But for now, just going to see if it's all going to go together.

[00:06:02]All right. So, we've got it roughly installed. Nothing's particularly tight.

[00:06:05]So, we've got that loose. Got our ball nut. Obviously, we're not going to keep that. We'll machine that in aluminium. I just wanted to make sure this gap was going to be okay between here and here and adjust it in the 3D print before I go and make something. See at the top.

[00:06:18]So, here's our top plate. It's loose at the moment. So, we got room for adjustment.

[00:06:23]got room for adjustment there. And then there's some fixings here cuz this where we're going to have our motor that will drive this via a 3:1 uh belt reduction.

[00:06:31]And then the other things you can see these holes are so that uh when you bring this up to the top and get to those grease nipples and uh put some grease in.

[00:06:44]Okay, it's time to machine up the ball nut. So, I've taken the 3D printed part off. I've made a few changes because I wasn't super happy it was going to be strong enough. So, um, as you can see, I've now made that continuous circle.

[00:06:56]All it means is you need to assemble it, uh, when you're putting the ball screw in, and you can't take it off afterwards without taking the ball screw apart.

[00:07:03]But, I thought that was worth the trade because there's going to be a lot of force on this, you pushing down there, and it's only held in with these two M10 fixings. So, I know this flexes a bit, but you'll get that kind of effect in aluminium as well. Okay, so we've got a scrap bit of aluminium we're going to use to make the bonnet bracket. I just got to watch out. There's a hole in the side there and tapped hole. Just got to avoid. So, I'll just mark that out. And then the only other things are I'm going to cut this out on this line here, leaving plenty of material. We'll hold that or machine those parallel to each other. Then we can hold those in the vise. Drop it on some parallels. And then I can machine it out using contours and hold it in place using tabs.

[00:08:02]Okay, you probably saw it jumping a little bit because it's quite a compact machine. The blade has to twist very quickly around the wheels to uh get back into line to do the cut. So, it twists quite aggressively inside here. And you know, it does occasionally kind of jump a little bit on these wheels as it rides up. And uh this bit of the blade is actually dipping down like that. And it's because where it's welded, it's about to break. So I'll order a new blade about 3540. I won't do that last cut and have it break on me. Uh I'll have to just cut this last bit by hand.

[00:08:38]Just from there to there.

[00:08:45]So after I finally saw through all that material, it was on to just machining both sides parallel. So I did one side, then turned it around, machine the other. Then I could hold it nicely in the vise between those two parallel sides. After that, it was on to drilling the holes, which will eventually hold the ball screw in. So just uh pecking these. Now, I don't want the drill to snap, so I'm just doing a a peck and then coming back out again. Uh, my camera doesn't like filming some of this close-up stuff, as you'll see in a moment. Uh, it likes to vibrate a lot and, uh, yeah, cause lots of issues for the audio if you get too close. And here we are just decking off the top surface there to make sure that's nice and flat.

[00:09:23]Gives us a nice finish.

[00:09:27]And we're on to boring the main hole in the center of the uh, of the bonnet.

[00:09:34]This went okay. Just to make sure I'll definitely go get any uh, chips stuck.

[00:09:37]cuz I was trying to get the the airline optimally aligned.

[00:09:41]Yeah. And then to get in really close, uh I had to take the external microphone off that's got a wind sock on it. Um and that relied on the internal mic and with the airline being so closed. Yeah. It wasn't happy. So overloaded. So I took some footage from a bit further back which avoids that issue, but then you can't really see what's going on. So I need to sort something out on that.

[00:10:03]Uh this is the other issue you get if you get a lot of vibration through the main machine. that seems to come through onto the camera and it makes the image jitter. Um, so we're back onto a handheld here. That's why it's moving around a little bit. I really need to move on to a project where um I built some kind of isolation system, isolated mount for the camera, but uh that's a project for another day.

[00:10:26]So, just going down in slow depth. So, this was uh working out quite quite well for the roughing cuts.

[00:10:33]And then uh we're just using tabs just to hold the part on. make sure it doesn't fall out as you can see there.

[00:10:40]So, I've just got those scattered around and then it was on to the finish pass.

[00:10:44]So, I did this in a couple of depths um rather than do it all in one. It's quite deep. I think 25 mm deep part and yeah, just to bring it to the final dimension and make sure you get nice finish uh on the edge of the part there.

[00:11:01]finish pass of course has also got the um little tabs in it as well so we don't machine through those and then we were done.

[00:11:11]So then I manually opened up those to the tapping side which I think was 5 mm for the M6 and then out with a tap and carefully tapping the threaded holes which will hold the bonnet into this bracket.

[00:11:24]Just make sure the threads are super clear so I don't uh strain the tap every time I go in. taking my time and making sure we get the job done.

[00:11:34]Then it's time to remove the part and cut those tabs free. I use this kind of hacksaw blade thing to do that. I'm just being really careful not to scratch the original surface. I'm going to cut away from the finished surface. But little bit of soaring and a bit of wiggling, we got the part free. And then I don't think I filmed it in the end, but I just had to file those smooth where the tabs were to get me the finished part. And then the second op is to drill the holes which will hold this on. So I'm just using the end of the calipers there to make sure it's nice and level. And then I manually So I move to the correct location for the hole and then manually peck down to make sure I've got clearance. Being really gentle cuz I don't want to tip the part up in the vise cuz it's only held by the center portion of that part. And then once I'd relieved that main material, got through to the other side. Obviously there's two of those. It was onto the uh counterbore to open well not a counter but a boring operation to bring them final size which probably would have been about 10.5 mm.

[00:12:31]Give some clearance to the 10 mil bolt.

[00:12:33]Again go nice and gently. I didn't want the force of this uh spiral bore operation to tilt the part up because again it's only held in the center. So I could have gone a bit quicker but wanted to play safe. Now I've got a lot of time in this part.

[00:12:47]Chips are flying nicely. It's making nice sound and going well.

[00:12:53]It's so hot in the workshop today.

[00:12:55]Generating nearly 8 kW on the solar and the temperature in the workshop is nearly 36°.

[00:13:05]And I've got this to keep me cool.

[00:13:11]Okay, finished machining the bonnet bracket. So, that's looking pretty good.

[00:13:14]I'm taking the ball screw off and the top plate cuz that'll make it a little bit easier to set the next thing up. So, those of you who followed the build series for the drill press will recognize this stepper motor and this arrangement. So, this was off the uh knee, the lifting knee. So, we had a rotating ball nut that went into here and that lifted the ball screw up and down kind of the res the reverse way around that you'd often do it. So, I was thinking um of putting this stepper motor and possibly the braking system on there uh onto this machine. Now, the reason for that is what I originally planned for this was to use a servo. It was a 750 W AC servo and it was pretty reasonably priced around £130, but it's been out of stock for uh three months now in the UK.

[00:14:02]I've had it on uh on a watch list so that you know they'll email me when they get it back in stock. I've also emailed them about a month or so ago uh saying um you know any chance it's coming back in stock and they basically said just buy it from Germany. The problem with that is I'll then pay uh that and import duty and I think it came to nearly £200.

[00:14:22]So do I really want to pay another 70 just to use that servo? I mean, still pretty good value. And ultimately, yeah, I guess this probably needs a servo to to give it the power and torque that I need for drilling and boring and machining and so on and lifting that head. But I think for now, for testing and definitely getting the code running, this stepper, it's quite a big one. It's a 3 Newton meter, 4.2 amp, and it lifted the knee, which is pretty heavy. So, yeah, maybe it will lift um this head.

[00:14:51]It's also going to be on a 3:1 ratio, whereas this one was more like 1:1 and 1/2. So, it will be geared a lot more favorably. So, uh to do that now, this is the original, uh 3D printed part just to see if it was going to work, see if I was happy with it. So, this is where the servo was going to go. And that would sit um on there like that, bolted through there.

[00:15:14]Obviously, this would be fabricated or plasma cut and welded together out of sheet steel or uh CNC machine out of Alium Parts. But yeah, that was ready to go on there for the 750 W servo. But cuz I'm going to give this a go at least to get it moving and get the software sorted out, I printed up this. So that gives me the option of putting the brake into there and then the stepper on here.

[00:15:38]And then like we've got here um where they kind of join together in the middle instead of that it will be um the pulley the small pulley. So let's break this down, get it mounted in here and put it on there and get the whole thing assembled and see if we can get the head moving up and down.

[00:15:57]All right. So, just in case you haven't seen these brakes before, that can be used with a stepper motor if you've got a heavy load and you don't want it to back drive when you turn the power off.

[00:16:06]Um, so that's this particular brand here. Anyway, they're all very similar.

[00:16:11]So, basically, they've got this kind of friction material inside there and then there's a spring that's pushing this plate against that friction material and holding it against this plate. So, it's jammed and can't rotate. If you look at it this side, there's that friction material and it's got a square cutout in it. And into that, it's rather crudely, you put this square nut, and then that is uh clamped onto the rotating shaft, which is spinning round and is connected to your motor. Or if you've got a double-ended one of these and the shaft comes out the back, uh the hole spacing on these should match up with uh yeah, those little tiny threaded holes in there, and you could have that on the back if you had it doubleended one. Um or if you don't, you have to make something work with an extra shaft. But basically what happens is that is on the rotating part and it clamps on and it goes inside there. And when there's no power applied, the spring pushes that and grabs it and stops it. And when you apply 24 volts, there's a little solenoid in here that pulls this plate down, allows that friction material to become free. And then it can rotate. And obviously then the nut can rotate and the shaft can rotate. Okay, I've got everything mocked up. So these are tight, but these ones are loose to allow some adjustment. We got that in there.

[00:17:24]That's loose. Um, I got this 3D printed pulley uh just before I commit cuz they get quite expensive in this size. So, just make sure it's going to work. I've managed to just to tap some grub screws in there in two positions. Uh, yeah, one there, one there. Um, the key stocks arrived 5 mm. So, I've just cut a bit off and just had to very lightly dress that to make that a nice fit into there and onto the ball screw itself. And we got the ladder.

[00:17:54]Got our stepper installed. Um, this is the wrong size pulley. It needs to be a bit smaller. Needs to be this size.

[00:18:02]U, but this has got the 19 mm bore because this was ready to go onto the servo. But as I mentioned a few minutes ago, yeah, it's either really expensive or it's not in stock in the UK anyway. Uh, so I've got a slightly bigger one on there, but that's fine for testing. And then I've got little nuts in there where I can put the brake assembly. I did have it in there, but it's quite awkward to get all this together, get to tighten the little grub screw on there, get the shaft into there and into there, tighten onto that nut. Basically, I need to reconsider the order of assembly and maybe design this in two or three parts.

[00:18:36]But for testing, let's see if we need the brake. I suspect it will back drive cuz this is quite heavy. And this 20 mm ball screws got a new design of seal on there and there's basically no resistance. If you've used these before, you know, where they got the white seal made of nylon or whatever, there's quite a lot of friction in there. But these glide, you know, just its own weight, it will just drop down no problem. So, I suspect even without the the milling spindle on the front, this will probably drop. But, uh, let's give it a go. So, before we assemble it, let's just see if I manually wind this if I can onehanded. Oh, that way to lift it. Okay.

[00:19:19]I suspect this will drop, but let's see what it's like when it's connected to the stepper. All right. So, if I gently let go, I bet that'll just go, won't it? If I just give it a helping hand. Oh, yeah.

[00:19:41]You see it's going.

[00:19:44]It's probably hard to see it's rotating on camera.

[00:19:51]See that's slowly going around again with no effort.

[00:19:58]Yeah. Basically wants to fall down. All right. Well, let's get this on. Get the key in. Grub screws tightened up. Get it into that belt. This is just the belt I had lying around. So, it's a little bit uh too big and I think we can't quite get the full range of adjustment, but if it, you know, drives it and let's see what happens. So, let's set that up and then uh we'll give it a test run. Okay, the belt was a little bit too long and I didn't have enough adjustment to go rearward enough. So, I've taken the screws out and just clamped it on both sides. Switch this unit on which used to drive the knee and a bit of luck. We might be able to move it up and down.

[00:20:39]All right, it's ready to go.

[00:20:50]That's come on. So, turn this right down quite low.

[00:20:57]Uh, good news is it's not said limit, so it's probably going to run. Uh so the question is which way we going up or down. Right. Let's just tap it. Let's try up.

[00:21:16]No, that's trying to go down. Right.

[00:21:18]Let's go the other way.

[00:21:38]And I think we have movement.

[00:21:45]We have our first movement. Okay. It's with a 3D printed pulley.

[00:21:51]It sounds pretty smooth.

[00:21:54]Now, if we let go, does it back drive?

[00:21:59]Nope.

[00:22:06]I think for initial testing we probably don't need the brake. Go on then. Let's try 15 and see what happens. Now the down is up.

[00:22:22]Well, it's doing it.

[00:22:24]Belt's jumping a bit, but it's not really adjusted, is it? Let's go back down again.

[00:22:35]Nice.

[00:22:37]Right, let's keep going. Let's see how fast we can go. Let's go. 25.

[00:22:41]At some point, I think the motor will probably stall out. Here we go. 25 mm second.

[00:22:54]Yeah, it definitely goes quicker going down.

[00:22:58]Oh no, I don't know. Maybe not.

[00:23:01]I guess it shouldn't be. So, there's a bit of a noise coming from the belt.

[00:23:05]It's rubbing on the 3D printed part at the top, but yeah, details. Main thing is it's running. All right, let's go. 35 down obviously is okay. Up.

[00:23:22]I'm staying near the bottom because I fear something bad's going to happen up there and it might come crashing down.

[00:23:27]In fact, let's just get a bit of wood in there.

[00:23:30]Yeah, just in case.

[00:23:33]Give it a soft landing.

[00:23:38]Right, let's keep going. So, go on then.

[00:23:41]Let's try 50.

[00:23:44]Okay, we'll go up.

[00:23:52]It's doing it. It's jumping a bit, but it's doing it. Come back down.

[00:23:57]Sorry, that was me.

[00:24:03]All right, let's keep going. Go on then. Let's do Let's go to 100. Oh, go then. It's 80.

[00:24:11]Let's see what happens there. Surely it will store.

[00:24:16]Nope.

[00:24:27]Okay.

[00:24:28]100.

[00:24:32]Sure this will get near the stall speed of the motor. Here we go. 3 2 1.

[00:24:38]No.

[00:24:52]Okay, I don't know about you, but I'm going to call that a success. So, the reason for doing this test was to make sure everything ran smoothly. There were no glitches, no issues, no binding. That seems super smooth to me. I've built quite a few machines over the years, and you get a bit of an ear for it. I think that sounded okay. Obviously, it's running a bit rough at the drive end up there. The belt's not quite the right length. It's rubbing on the 3D printed part, but that's details. we can sort that out. Um, at least for initial testing, it doesn't seem to backdrive very readily, which is good. Maybe once we get the the milling machine on there, the bracketry for the motor and the motor itself, which I think is another 10 kilos, 15 kilos, it probably will be in that territory. But I think for testing, testing out the code, that kind of thing, this is okay. I still not got to look into um you know getting all this servo because I really want to drive it with a servo and that makes the drive system up there a little bit simple as well because I haven't got to incorporate an external brake. It's got that built in. Obviously I can go ahead and order the correct pulleys now. I know it's going to line up and the correct size belt. But for now we got movement. Okay, I think that's it for this video. I need to go ahead and order some more parts. Now I'm confident it's going to work and that runs pretty smoothly. So, very pleased with that progress. Uh, if you're enjoying this video series and you want to follow along, feel free to subscribe. Hope you enjoyed this episode. Uh, leave a like and a comment. It's always good to hear what you think. Um, especially on something a bit unusual like this. That being said, thank you very much for watching and see you next time.