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Designing a CNC for making PCBs on no real budget with no real idea what I'm doing   Those bottom rails slot into a drill press table I can probably convert for a Z axis.
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Oct 31, 2013 21:59
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kafkasgoldfish posted:Setting up parallel guide rails can be pretty tricky (at least for hobbyist 3d printers). It looks like you're just going to capture the rods in holes in the angles on each end, but getting four holes that allow for two perfectly parallel rods is easier said than done. Maybe you could include some adjustability there? I was going to maybe add a couple square tubes in the centre to join the square tubes/increase rigidity instead of just relying on the angles. You've got a good point with the holes in the angles. I was thinking of maybe using my drill press to go right through both sides of some square tube, then cut that into two angles. That will still result in mis-centred holes on opposite sides of the face, though. Hrm. Drilling long-ways through rectangular tube and then splitting it might work. I don't like that, though. What are my odds in being able to make a jig out of wood and keeping the holes pretty accurate? Splitting the pieces shouldn't be a problem. I can put another piece of angle behind them to keep the rods in, it'll be able to keep them square, too. I dunno. I'll think about it. Tomorrow I should have a revised version. Amateur machine accuracy is so difficult.
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Nov 1, 2013 03:14
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I'm planning on spending almost no money on this if I can help it. All of the linear motion stuff is salvaged from a bunch of free printers/scanners I got. Some 13" rods and brass bushings. I can carve out a pillow block for the bushings out of some 3/8" acrylic or something. Aluminum extrusion would save me some hole-drilling in the square members, at the cost of some stiffness. So I might do that for a prototype, I'd ideally like to throw this together as fast as possible. So I've got this, now:  I added some squares in the middle, and I'll just use some threaded rod through the whole assembly and torqued down really tight to keep everything stiff. The linear rods are held by holes in the inner angles, and kept from slipping out by a solid/undrilled outer angle. I'm really not sure about the rod straightness solution I had going in my head last night, though. I'll do some googling for good ways to make it pretty accurate, but maybe I'll have to do some loving around when it's all built. Oversize the holes, fill them with hot glue and slide the platform back and forth a whole bunch? I dunno. I'll work on the motor assembly and coupling next.
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Nov 2, 2013 05:28
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Seems to me that the linear rods are necessary for accuracy. I could lower the platform like you say, but then there's nothing stopping the side-to-side motion or the up-and-down. Square tubing isn't exactly built to tight tolerances, so bearings wouldn't go over the surfaces perfectly smoothly. Or am I overlooking something?
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Nov 2, 2013 19:38
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I've got a bunch of rods salvaged from printers and scanners and no access to a welder or mill. A mill would be pretty keen 
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Nov 3, 2013 20:34
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kafkasgoldfish posted:This is just a pcb mill, seems like solid tubing, milling and welding are a bit over the top. He could build the frame out of dimensional oak 2x2s and cheesy galvanized brackets from THD it'd be more than rigid enough. Yeah, the rods are all around 13". On this one axis with a 5" table, so I should be able to get 7". That's plenty for most of the PCBs I'd want to build. I'm in Canada, so shipping makes Misumi not really worth it (although they have an awesome system). I can and probably will get some extruded rails locally. And for making PCBs, I've used the UV exposure method, and I found dialing in all the timings to be an enormous pain in the hole. At the time, I was working a stupid amount of hours, so my time was more valuable than just sending it out. Ideally, I'd like to slap this together really quickly, and have all of the errors at least repeatable enough that I can correct for most of them in software. Basically I want to be able to design something and then press "print" and have a physical copy in a few minutes. I don't know how realistic that is, but it's good mech engineering practice in the meantime.
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Nov 4, 2013 23:53
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What's the difference between a $30 chinese controller and a $300 one? I'm considering reverse engineering a good one and cloning it. I also probably have access to a cheap one I'm told it's slow and has a lot of backlash(doesn't software correct this?).
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Nov 22, 2013 23:23
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Casted?
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Aug 13, 2014 00:06
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You put a sacrificial sheet underneath.
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Oct 7, 2014 05:59
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A man builds a CNC https://www.youtube.com/watch?v=XNvoFTV5tIE
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Nov 23, 2015 07:13
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Acid Reflux posted:It's easy and extra cheap to make too, if a bit time consuming. I sacrificed my small deep fryer for Fun fact! Shoppings bags are made of either LDPE or HDPE. I know many many people with huge bags full of the things, way more than they'll ever use. Look up recipes online for machining wax. I've done this, and it really does work great. Bad Munki posted:So I've been thinking more about this. I did a continuity check and everything looks hunky dory. And then this post was made: It's unlikely to be causing enough noise to go back through the power supply, onto the AC line, and then through another power supply. You want to be looking at the PS->router cable itself. That's be causing electromagnetic interference with cables nearby. Keep at least a couple inches between that one and all others.
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Dec 4, 2015 23:24
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and made a small batch as a test, came out beautifully. You can use HDPE too - pieces of a Home Depot bucket make for a lovely bright orange end product. 
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Does that file import as a solid body? I've never had any success with modifying imported files, I didn't think it was possible. 'Most of the stuff I need to import at work is faster just to take measurements and remodel, though.
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Dec 19, 2015 18:12
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Solidworks is the wrong tool, then. Something like Blender can actually edit the model, I think. Someone might be able to suggest some other options, but more artistic software should be able to import stuff better. I dunno why SW doesn't do that, seems like a pretty big oversight
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Dec 19, 2015 18:59
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See here for how many cans it takes to make a teeny tiny puck of aluminum: https://www.youtube.com/watch?v=lSoWxG30rb0 Whether or not that's worth it to you depends heavily on your location, bank account, and spare time.
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Mar 23, 2016 05:02
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Oh man, you're in for a nasty shock
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Apr 11, 2016 00:10
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Check the pinout on the second page: http://www.geckodrive.com/images/cms_files/images/G540%20REV8%20Manual.pdf And take your multimeter (you have one, right?), measure the resistance between different motor wires to figure out the windings. So if you get, say 100 Ohms between red and orange, plug them into pin 9 and 8, and same thing for the other pair. Read up on identifying stepper motor windings for more info. I have done almost literally no research on your particular setup, so my 2 seconds of looking tells me you have a unipolar stepper, but you can leave the centre taps unplugged to treat it like a bipolar stepper, like the Gecko seems to expect. Again, 2 seconds of research, take with grain of salt 
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May 14, 2016 01:07
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Should be able to fabricate a vinyl cutter head for cutting paper for either machine. Or a 3W laser if you're feeling dangerous e: Drag knife. That's the phrase I was looking for.
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May 19, 2016 07:12
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Machinable wax is also cool and good for testing your toolpaths. Look up recipes online, and it takes maybe an hour and almost no money to whip up a batch
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Aug 30, 2016 04:06
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I just use a pot and a hot plate with an IR thermometer, although my results aren't as clean as that. You can use HDPE as well as LDPE, just keep them consistent in a batch. And if you have a local place you go to a lot with coloured bags, then that's the colour your wax will be, no crayons or anything needed. I have put vanilla extract in before, though, that smells great when you're machining it.
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Aug 31, 2016 00:31
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AliExpress is okay for small tooling.
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Sep 3, 2016 00:25
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Consistent tapers? Use your high school trig to determine angles, which is more reliable. Then use the "revolve" function in Fusion 360 to generate an accurate model.
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Feb 5, 2017 04:56
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Lots of hobby people are going to them, because you can get drop in replacements for the existing steppers
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Oct 3, 2017 02:22
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CarForumPoster posted:Just a heads up you will spend your life saying you have an engineering tech degree when people ask if youre an engineer/what you studied and other engineers will ask. If its not much extra time I highly recommend a regular ol' mech eng degree. Not industrial. Not manufacturing. Mechanical. Or Electrical if youre feeling more ambitious and want to really go in to automation. As an electrical engineering technologist, this is exactly right. Don't do what I did.
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Dec 19, 2017 18:34
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He's talking about putting an MDF waste board underneath his work, so when the endmill goes through the bottom of his work, it doesn't gently caress up the bed
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Oct 10, 2018 18:51
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Have you priced out an exhaust system?
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Oct 11, 2018 02:01
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Harvey Baldman posted:I know absolutely nothing about CNC machining. I do a lot of 3D printing, but I know that's a completely different kind of process. You're looking at minimum $200 for anything professionally CNCed, metal laser cut, or waterjet cut. Have you looked into Shapeways metal? Or just plastic with some good chrome paints? Or paper stencils on some sheet metal and careful file work.
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Jan 9, 2019 08:09
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Repeating my suggestion of Shapeways, too. They can print in metals and quote you just by sending an STL
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Jan 9, 2019 22:26
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The audience is dated
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May 30, 2019 20:37
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I remember people doing the magnetic upgrade a lot back in the day. The end effector falling off is a feature, not a bug. If you're crashing into something hard enough to knock it off, you're doing something badly wrong, and the whole assembly falls off instead of stripping pulleys or otherwise loving poo poo up
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Jun 15, 2019 03:42
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Toss the bearings in the freezer for a bit, yeah It's almost like knock-off bearings are made to poor tolerances
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Jun 29, 2019 03:07
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I have done cycle testing on assemblies worth six figures and it's really stressful. Did not enjoy it at all
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Aug 1, 2019 21:59
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Longer stepper motor wires are what most systems do. Make sure they're shielded and the shield is grounded.
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Nov 24, 2019 20:35
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That seems like a strange rabbit hole to go down. Check to make sure the PCB is what you expect, check that the firmware is as expected - I dunno what the board is, but if it's one of the common ones, you should be able to easily flash whatever popular firmware is around lately. Is marlin still a thing?
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Dec 24, 2019 07:43
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Watch the kickstarter video for the product that thing is ripping off and see the most horrible, cringe inducing danger product that will never ever ever be legal in any kind of way
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Jan 7, 2020 00:59
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That's not reeeeally the way to go about it. For anything moderately complicated, you'll be using the CAM software and the most you'll be doing is tweaks to the G-Code based on your setup. There are like, a handful of commands you'll pick up fairly quickly, and then you'll be fine. Commands like "move to this location", "change coordinate system", "home z", stuff like that.
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Jul 24, 2020 20:42
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Does it have CAM software included in the package you have? If so, then yeah, just learn that. I don't know about PTC Creo, but if it's anything like SolidWorks, then Fusion 360 will be very familiar, and their built-in CAM tool makes a lot of sense. There are also a million youtube videos out there.
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Jul 24, 2020 21:16
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Yeah, it's like, five clicks And then maybe a few hours of tweaking
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Jul 24, 2020 23:15
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NewFatMike posted:Got free Educational SOLIDWORKS Premium for my makerspace, woohoo! Now all I have to do is make some tool cribs/libraries for our ShopBot, Shapeoko, and Tormach in Fusion 360 and SWX How does one go about doing that? The local makerspace got one in 2013 or so, but then the D'Assault CEO changed or something and that contact was lost
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Aug 20, 2020 16:29
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Thanks! I'll let you know!
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Aug 20, 2020 17:14
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Apparently you can't get educational SW files into pro SW packages though, the file is permanently tainted
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Sep 17, 2020 04:32
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