[HN Gopher] Show HN: I built a CNC-machine from scratch, using 4...
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Show HN: I built a CNC-machine from scratch, using 40x 3D-printed
parts
Author : mfi
Score : 256 points
Date : 2021-11-03 16:33 UTC (6 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| jaxn wrote:
| Really neat project!
|
| Maybe I missed it, but is there a general cost estimate anywhere?
| I saw the BoM, and assume most the cost is in the router and
| stepper motors, but is this like ~$500?
| mfi wrote:
| Thanks! I think it spent around $1100 in total, but then I paid
| for fast shipment and ordered quite a lot of parts that I ended
| up not using. You can probably build it for $600-$1500,
| depending on where you source the parts, what quality you buy,
| speed of delivery etc.
| j_walter wrote:
| Reminds me of the Root CNC project. https://rootcnc.com/
|
| Great work!
| mfi wrote:
| Haven't seen this one before, thanks for sharing!
| IgorPartola wrote:
| This looks great. I do love that MP-CNC tells me immediately
| the approximate cost. Wish more projects did that. I can't tell
| if a Root 4 would cost me $200 or $2,000 without looking for
| all the parts individually.
| j_walter wrote:
| I did look for the parts because I was interested in getting
| one made...however many of the parts still aren't ready to go
| (control side), but the hardware cost other than that was
| fairly reasonable in the $500-800 range depending on how big
| you were going to go and which motors you chose to use.
| axegon_ wrote:
| Congratulations! I'm working on one in my spare time but I've
| decided to cram in as much features as possible(as far as not
| being able to cram all the features into an arduino or esp32 so
| ultimately I'm opting for a raspberry pi for connectivity,
| monitoring, safety and so on). I got it working about a month ago
| with some tools and hardware I borrowed from my dad but the
| problem there was... My dad's negligence, meaning all the tools
| and hardware were half dead. In any case I managed to cut out two
| pieces I needed for a different project(and see that it works
| after all). And I also plan on open sourcing it. though most of
| the code is written in Rust. With the exception of a small
| webserver for monitoring the process remotely(even visually with
| a tiny webcam) - no point in wasting so much effort on that and
| dealing with all the async-await-read-write locks that come along
| with it. The webserver mostly parses logs and makes system calls
| to binary files.
| mfi wrote:
| That sounds like an amazing project! Please open-source it, I
| would love to read more about it :)
| newintellectual wrote:
| Not to be too big of a critic, but ...
|
| This, and other projects like it, are NOT "from scratch". It
| doesn't include little things such as a motor; wires; other
| electronics; the metal frame.
|
| Until "consumer" 3D fabrication can do more serious fab than
| random weak structural plastic components, it will remain as a
| hobby. The industrial machines able to sinter metal into strong
| parts or using carbon fiber - those have serious practical
| utility. I'd be much more interested in a low cost, high
| precision metal sintering 3D printer than a project such as this.
| gtirloni wrote:
| What's 40x? I feel brain challenged today as I can't understand
| what that means in this context.
| finder83 wrote:
| I read it as "40 individual 3D printed parts."
| wipash wrote:
| They mean 40 separate 3D printed parts:
| https://github.com/maxvfischer/DIY-CNC-machine/blob/main/BIL...
| mfi wrote:
| Exactly, I meant 40 unique 3d-printed parts
| phkahler wrote:
| Do any of these small CNCs support G02 and G03 for circular arcs?
|
| I was recently looking at G-code output from Solvespace and
| figure we need to update it to produce those codes rather than
| tiny linear segments. But will the home-built CNCs even support
| that?
| vvoid wrote:
| LinuxCNC will (http://linuxcnc.org/docs/2.8/html/gcode/g-code.h
| tml#gcode:g2...) - but your CAM may not.
|
| Edit: did not realize I was replying to solvespace, bring on
| the arcs!
| opencl wrote:
| Most of the small hobbyist machines I've seen (including this
| one) use Grbl, and Grbl does support G02/G03.
| Robotbeat wrote:
| I think Marlin supports it.
| MayeulC wrote:
| This got me wondering: most CNCs and 3D printers use switches for
| calibration, plus stepper motors for positioning.
|
| Has anyone tried to use cameras or a Valve Lighthouse (0.3mm
| precision), maybe with accelerometers and encoders, for tracking?
| That would allow the use of cheaper, faster, torquier, more
| efficient DC motors, as well as release the accuracy constraints
| for a lot of parts (depending on which part is being tracked).
|
| The goal would be to trade hardware complexity and price for
| software complexity, since it's easier to re-purpose software
| (and something like lighthouse base stations has multiple uses,
| so the price could be shared between projects).
| vvoid wrote:
| In a way you are describing state of the art robotic arms, but
| computer vision in that domain is less about economizing and
| more about coping with everyday materials and objects that are
| difficult to characterize.
|
| The OP is coming from the CNC milling world where positional
| accuracy is more or less solved: you use cheap steppers or
| servos but expensive, precision-ground ballscrews; then you
| swear on Machinery's Handbook not to drive your machine too
| fast.
|
| The real demons in dimensional accuracy come from things like
| spindle runout, deformation of the tool, and flexing and
| vibrations of the machine, fixture and workpiece (that are
| often different going in one direction than another!). Certain
| operations like drilling can't be corrected in real time. There
| are additional concerns like minimum amounts of material that
| can be removed with each pass - too little and you are just
| burnishing the workpiece.
|
| Machinists actually do solve these problems in software when
| they generate toolpaths and fixturing.
| LeifCarrotson wrote:
| Yes and no: No, no one I'm aware of has tried using DC motors
| and cameras instead of steppers to control a printer.
|
| But yes, industry uses optical technology in large CNCs all the
| time. Some homing switches are physical clicky switches, some
| are inductive proximity sensors, but an optical 'horseshoe'
| througbeam/fiberoptic sensor is the standard for highly
| repeatable sensor-based homing. Depending on your control
| system, homing to a hard stop by measuring motor torque can
| also be highly effective, then you don't even need switches.
|
| I've personally worked on a number of CMMs (coordinate
| measuring machines, basically a CNC with a probe tip for
| checking that something was machined within tolerances instead
| of a spindle for actually cutting it) that use 90V DC motors
| and Heidehein glass scales for positioning. We calibrate them
| using laser interferometers; another optical technique - just
| with a single beam. Those same CMMs are being phased out across
| the industry in favor of optical measurement systems, just
| because they're faster.
|
| Shane of the excellent "Stuff Made Here" Youtube channel
| recently made a big CNC painting robot that did optical
| tracking for a coarse positioning stage and used steppers for
| the local stage: https://youtu.be/osUTMnDFV30
| tupshin wrote:
| I think there's a very big future in adding more (optical and
| other) feedback mechanisms to CNC machines, but 0.3mm
| resolution is really only good enough for the crudest of
| devices.
|
| For comparison, a typical ball screw, has positioning
| accuracy/resolution of around .02mm
| MayeulC wrote:
| Right. I'm not suggesting using that directly, or as the only
| mechanism. Time of flight sensors could be used, for
| instance: https://hackaday.io/project/47141-sub-mm-accuracy-
| from-the-v...
| randyrand wrote:
| look into ODrive.
|
| It uses brushless motors and encoders.
| MayeulC wrote:
| https://odriverobotics.com/
|
| Quite interesting, thanks for mentioning. They attempt to
| directly emulate stepper motors with brushless motors and
| encoders.
| metal_am wrote:
| This. Rotary and linear encoders exist are are exponentially
| more accurate. Using cameras just overcomplicates things for
| worse results.
| MayeulC wrote:
| > Using cameras just overcomplicates things for worse
| results.
|
| If you use a crude algorithm, maybe. But given what's
| possible with photogrammetry, I think you can use that as
| another sensor fusion input, with a kalman filter or
| something similar, and get even more precision at the
| output.
|
| That's way more complicated when it comes to the algorithm,
| of course. But the idea was being able to plug more sensors
| and improve precision.
| roland35 wrote:
| Very cool! I am actually also making a 3d printed pen plotter! I
| love how easy it is to get common hardware like bearings, plus
| how nice it is to print parts on demand.
|
| Edit to add the link to the plotter:
| https://www.thingiverse.com/thing:2349232
| mfi wrote:
| Yeah, the 3d-printer is a game-changer in these type of DIY
| projects!
| metal_am wrote:
| For anything CNC, there's no substitution for stiffness. And
| you're not going to get that with aluminum extrusions. Something
| like the PrintNC would be 1,000 times more capable due to using
| steel.
| sleavey wrote:
| I happened to come across this project yesterday on reddit [1]
| and have spent the last day dreaming of building one. The
| quality of the documentation and activity on Discord is a big
| plus. First I need to build a super strong table for it to go
| on...
|
| [1]
| https://www.reddit.com/r/engineering/comments/qkn996/almost_...
| KennyBlanken wrote:
| Preface: from your username I'm guessing you mightknow most of
| this, so my comment is for the benefit of non-machinist HNers.
|
| It depends. Also, to be more accurate, you need high modulus
| (vibration dampening) and strength. An extremely strong
| material that doesn't dampen vibration isn't helpful, for
| example.
|
| If you need to produce "Live Laugh Love" signs, you need enough
| stiffness and dampening that you can cut wood or plastic and
| have it look clean visually / need minimal post-processing
| before applying a finish, and do so quickly enough that your
| labor costs aren't high (never ever EVER leave hobbyist-level
| CNC machines unattended!) If you can do so with something
| approaching ideal chip load on the tool so you don't wear
| through them like crazy, even better (also you get more chips
| than dust, which is better for you, your dust collection
| system, etc.) Endmills work best when they take a nice bite out
| of whatever you're cutting; heat from cutting leaves with the
| chip. Too small a bite and you're just rubbing the workpiece,
| and the tool cutting edge isn't cutting, but getting polished
| smooth.
|
| If you need to produce accurate parts, you have to do spring
| and finish passes anyway (for those who don't know: even very
| stiff CNC machines still have flex in them. You do a rough cut
| at ideal chip load for your endmill, then one or more "small
| bite" follow-up passes where there is far less load on
| everything and thus the endmill face is closer to where it
| should be.) Since you're doing those passes to get your
| dimensions, machine "stiffness" mostly just lets you do it all
| faster.
|
| When it comes down to it, all you really _need_ in a CNC
| machine in terms of "stiffness" is enough to let your endmill
| spend most of its time working at an ideal chip load without
| wandering all over the place. If the endmill's positioning
| changes too much with the machine flexing or vibrating, then
| one flute of the endmill could end up getting much more of a
| chunk to bite off than it should, and...snap.
|
| Beyond not destroying your endmills, more stiffness just lets
| you go faster. And like they say in the car world, speed costs
| money; how fast do you wanna go?
|
| Stiffness is not the only important factor; dampening is also
| important. That's why you see some epoxy-gravel composite
| builds. Lots of mass, very strong (the stone), very high
| dampening (the epoxy.)
|
| One of the unfortunate things about hobby-level CNCs is that
| they use palm router motors with extremely high spindle speed,
| but they're not terribly stiff, and most of them come with
| software that has rudimentary CAM path generation. The high
| spindle speed means that you have very little tolerance between
| the tool flute getting too little of a bite and too much of a
| bite, which is easy to do when the frame isn't very strong (and
| at high spindle speeds, vibration dampening starts to get very
| important, too.)
|
| Hobby-level CNCs benefit enormously from more advanced milling
| techniques like trochoidal milling, or "adaptive clearing", as
| Fusion 360 calls it (I think.) Trochoidal milling maintains
| tool load while optimizing for using as much of the side of the
| endmill as possible (spreading wear on more of the tool.) The
| machine appears to "nibble" away, instead of steaming along
| whatever profile is being cut. A simple profile on a weak frame
| machine means a very shallow depth of cut to keep forces low,
| but that means all of your cutting is being done by a very
| small portion of the endmill.
|
| They also benefit from having as slow a spindle speed as
| possible. There are speed controllers available to help reduce
| the speed of a palm router, which also lowers noise and reduces
| bearing and brush wear.
|
| I'm in kind of a rush so hopefully someone can correct or
| clarify where needed.
| jacquesm wrote:
| Another reason why you don't want aluminum is due to the
| expansion as a function of temperature variation, which can be
| considerable over a longer run. But for this small size you can
| probably get away with that unless you start to move really
| fast, or have a head that generates a lot of heat.
| redis_mlc wrote:
| Just to express the parent more bluntly, this CNC project is
| junk. I've seen stronger window frames than this.
|
| I wouldn't even expect to cut several pieces of wood with this
| toy CNC machine.
|
| It's like something you'd cobble together in a WW2 prison camp
| behind enemy lines.
| justinclift wrote:
| PrintNC reference info:
|
| The wiki: https://wiki.printnc.info/en/home The Discord (very
| active): https://discord.gg/RxzPna6 The GitHub repo:
| https://github.com/threedesigns/printNC
|
| There's also the "PrintNC Store": https://threedesign.store
| ElijahLynn wrote:
| The pictures on that README are insane! So HELPFUL!
|
| And, I already have that same Makita router so I am more tempted
| to try this... because of the pictures!
| mfi wrote:
| Haha yeah, I spent quite a lot of time to document everything.
| I sometime have trouble following tutorials because they leave
| out things that are obvious to them, but not to the reader. So
| I've really tried to include every step in detail, even though
| they might be "simple" and obvious.
|
| What's stopping you? Go for it! :D
| amelius wrote:
| Most hobby CNC projects have only 3 degrees of freedom, whereas
| most high-end commercial projects have a few DOFs more.
| sokoloff wrote:
| 3-axis mills are the most common configuration for commercial
| mills (probably by a wide margin).
| thedingwing wrote:
| This is not true. 5 axis mills and 9+ DOF CNC mill/turn centers
| exist, and they are becoming more common, however 3 axis
| vertical mills are still the backbone of most machine shops.
| bartwe wrote:
| I recommend building a cnc, had a lot of fun building a mpcnc
| aidenn0 wrote:
| Now we need someone to make a 3d-printer out of 40x CNC'd parts
| and we'll have a never-ending supply of both!
| rytis wrote:
| Great work!! What router bits are you using for milling wood and
| aluminium?
| mfi wrote:
| Thanks! I'm still very new to the CNC-space, so I'm currently
| exploring different bits. So far I've only bought some low-cost
| flat end mills from Amazon, but I'll probably work my way up to
| higher quality when I've used it more.
| Wesxdz wrote:
| I'd love to have an open source CNC machine to design joinery
| with http://ma-la.com/tsugite.html Ideally a whole house and most
| of the furniture...
|
| If anyone has any ideas on how to accelerate build times of open
| hardware, that's something I'm trying to solve. Creating high
| quality instructionals is a huge amount of work and I think
| instructionals should be automatically generated by computer
| vision and have interactable elements, ideally AR, but even just
| highlighting wiring diagrams on hovering would be hugely helpful.
| Even if things are well documented, replication is still insanely
| pyrrhic without economy of scale or universal fabrication. It's
| time consuming because it's hard to replicate knowledge/tool
| environments quickly.
| mfi wrote:
| I can't help you with ideas of how to accelerate build times of
| open hardware, but thank you so much for sharing that link.
| Looks really promising, will probably test it using the CNC-
| machine someday soon!
| gunshai wrote:
| I forwarded this to a structural engineer who specializes in
| timber design. That website you linked is really cool.
| cinntaile wrote:
| Do you know how accurate it is?
| dogma1138 wrote:
| That would depend on many things including the material and
| feed rate.
|
| For plastic/wood you can get pretty decent precession on these
| machines within 200-300 microns or so since it should be rigid
| enough to not deflect much with these materials.
|
| For smaller parts any issues of gantry squareness would also
| not translate to the milled part as much.
|
| You can also cut aluminum as long as you are going slow to
| avoid deflection but don't expect excellent surface finish and
| sub 500* micron tolerances.
|
| *High end industrial machines can do tolerances within 10
| microns when they are operated by an experienced machinist. 100
| microns off spec not to mention 500 microns would result in
| parts being binned normally at least for critical tolerances.
| mfi wrote:
| I milled a test block in wood to check the accuracy, and it was
| sub-millimeter accurate. I can't measure further than that as
| my tools doesn't allow it. But I doubt that it's super accurate
| due to the 3d-printed parts, aluminium instead of steel etc.
| wolfram74 wrote:
| Being a spherical cow loving physicist, I still get caught
| off guard by what counts as "precise" in engineering
| contexts. Even when I'm making stuff in meat space I don't
| think I've ever bothered to intentionally get better than 1%
| relative precision.
| sokoloff wrote:
| For a framer, 1/8" is precise enough. For a finish
| carpenter, 1/32" is precise enough. For a 3D printer,
| 0.004" is precise enough. For a machinist, 0.0005" is
| precise enough.
| curtain wrote:
| 0.004" is read as "four thou", and 0.0005" as "five
| tenths", as in five tenths of a thou, FWIW.
|
| I only picked up imperial thanks to binging This Old Tony
| videos.
| mNovak wrote:
| Unless it's PCB, in which case its "4 mil", as in
| milliinches, among the great bastardized units
| sokoloff wrote:
| If you enjoy https://www.youtube.com/c/ThisOldTony, you
| might also enjoy https://www.youtube.com/c/Clough42
| https://www.youtube.com/c/Blondihacks and
| https://www.youtube.com/user/JohnGrimsmo
| ggcdn wrote:
| Being a structural engineer, I usually think the same way.
| But then I started tinkering with 3D printers, built a
| MPCNC, and have since busted my share of endmills due to
| accuracy and repeatability issues. Being off by a fraction
| of a mm is enough to bust your tool or mess up the
| workpiece.
| whatshisface wrote:
| It really depends on what you are doing and what 1% means.
| For example, a tiny ridge on a sliding surface will result
| in a noticeable catching of the slider down to even
| visually imperceptible heights.
| 542458 wrote:
| Nice! I built an older model MPCNC years ago, and was able to get
| pretty great results with it relative to the tiny cost and huge
| flex in the frame. I managed to cut some brass Christmas
| ornaments that I'm pretty proud of.
|
| I like that you're using racks here - the belts on the MPCNC were
| a major weak point in my experience. I wonder if you could get
| away with 3D printed racks and pinions. There's a lot of
| structural plastic in there already, would the hit from accuracy
| from using lesser racks make a difference?
| metal_am wrote:
| You can buy ball screws somewhat cheaply direct from China.
| That'd be the way to go.
| bmsleight_ wrote:
| Love to see the brass Christmas ornaments have you a photo ?
| mfi wrote:
| I just finished my latest project, building a CNC-machine from
| scratch using an Arduino Uno, GRBL and 40x 3d-printed parts. It's
| able to mill wood and aluminium, up to ~20mm thick.
|
| As with all my other projects, I think they should be executed in
| the open where other people can learn from my mistakes and get
| inspired to build their own things! Therefore I've spend a lot of
| time writing a free complete tutorial of the build, documenting
| every step with text and detailed images, creating a complete
| bill of materials (including STL-files for the 3d-printed parts)
| etc. I don't want any dependencies on DIY-websites, so I've
| hosted it on GitHub, where anyone can clone it locally.
|
| I built this machine to gain more knowledge about mechanical
| engineering, electrical wiring, stepper motors, GRBL, CAD, CAM
| etc. Also, I guess I can build new fun things with the machine?
| Overly-engineered birdhouses maybe?
|
| Setup:
|
| * It's running on an Arduino Uno, CNC-shield and GRBL.
|
| * 40 parts are 3d-printed (all the red parts in the video)
|
| * It's based on Ivan Miranda's blueprints, but I've adjusted some
| parts and structured the bill of materials.
|
| * It uses 2x 19:1 geared NEMA17 stepper motors for the Y-axis and
| 1x for the X-axis. The Z-axis is using a standard NEMA17 motor.
|
| * HTD5M belts and pulleys are used for X-axis and Y-axis. GT2
| belt and pulleys are used for the Z-axis.
|
| If you have any questions, feel free to contact me. You'll find
| my email in the top of the guide :)
| dekhn wrote:
| I understand you put thought and time into your approach and it
| was a hobby to learn more abotu the process (and thus you know
| about MPCNC but decided to make your own). I've also build
| similar systems and I've learned some timesaving tricks that
| have paid off in terms of hobbyist enjoyment.
|
| I really like buying the majority of the parts from a place
| like OPenBuildsPartStore, rahter than assembling frames from
| channel manually. Time/cost/quality tradeoff is hard to beat
| here.
|
| I strongly recommend switching to Grbl_Esp32
| https://github.com/bdring/Grbl_Esp32 with external controllers
| (this board https://www.tindie.com/products/33366583/6-pack-
| universal-cn... with these plugins
| https://www.tindie.com/products/33366583/external-stepper-mo...
| and these controllers
| https://www.amazon.com/STEPPERONLINE-1-0-4-2A-20-50VDC-
| Micro...). That's what I ended up with because tuning current
| using the little pots is dumb, and you want a TON of current
| going to those huge motors. ESP32 + Grbl has a bunch of nice
| features that aren't in plain old Uno GRBL.
|
| My system has high torque NEMA23 with no gears (same motor for
| all 3 axes), I can't see any situations where adding more
| torque to the X or Y axes using a smaller gearer stepper makes
| sense.
| giantg2 wrote:
| "I can't see any situations where adding more torque to the X
| or Y axes using a smaller gearer stepper makes sense."
|
| Generally agree. Torque is only needed to a specific
| threshold. If it requires a lot of torque, then that's
| probably a good sign to slow the movement down (for the sake
| of the machine's longevity).
| aquaphile wrote:
| Nice work! You made a lot of great design choices.
|
| +1 to those that recommend upgrading your extrusions and motor
| mount on future iterations. The rigidity is well worth it.
|
| If you are ever deciding between belts and ballscrews, I
| recommend ballscrews. It is worth the extra $$.
|
| For the milling of aluminum, I suggest adding a compressed air
| nozzle. It will make a huge difference in milling AL. Also,
| some of the new bits are fantastic at hogging out aluminum. For
| reference see pic at
| https://drive.google.com/file/d/1BWvOOwmaQljwhdBzYNvilYDKdsy...
|
| We built our own 5-axis CNC too, to do large envelope parts
| trimming. It looks like Frankenstein, but works pretty well.
| See a pic at https://drive.google.com/file/d/0Bydp4fsq-
| EhtUndOTlZTcU1fTEU.... We use it to trim the chassis parts for
| our baby car seats at https://kioma.us
|
| Keep on building!
| giantg2 wrote:
| You mention aluminium. Any plans to add a lubricant sprayer?
| 2muchcoffeeman wrote:
| > _I can build new fun things with the machine? Overly-
| engineered birdhouses maybe?_
|
| I don't have space for a workshop. I live in an apartment. So
| I'm pretty limited in the sorts of materials and tools I can
| use. 20mm of wood is probably quite useful. My table top and
| shelves aren't 20mm thick. If this can go through MDF I'd say
| it's really useful.
| eduardosalaz wrote:
| The CNC Shield is a blessing, shame the Gerber files aren't
| being published for newer versions.
| mfi wrote:
| 100%, it helps so much with the wiring.
| zwieback wrote:
| Awesome. Can it mill aluminum? If so, would you consider
| replacing some of the 3D printed parts with machined parts?
| mfi wrote:
| Yeah it can! Ivan Miranda, the guy who has created the
| blueprints actually updated his machine with aluminium parts,
| milled on the CNC-machine. That might be something I'll do in
| the future!
| jhgb wrote:
| Von Neumann probe when?
| jacquesm wrote:
| Right after you figure out how to 3D print solid rocket
| fuel without things going 'bang' prematurely.
| billconan wrote:
| very cool! thanks for sharing. I don't have the equipments to
| drill holes on aluminum parts, I will probably need to use
| https://8020.net/ to build one.
| arnado wrote:
| You might also want to look at the mostly printed CNC, which
| uses standard conduit/pipe for the frame.
|
| https://docs.v1engineering.com/mpcnc/intro/
| AdamTReineke wrote:
| Be warned these plans require you to drill a couple holes
| in the conduit. I managed with just a handheld drill though
| the holes weren't quite aligned. Definitely use a file or
| hacksaw to create a flat spot on the conduit where you want
| the hole so the drill bit doesn't wander as easily.
| johndough wrote:
| Since the mostly printed CNC already requires a 3d
| printer, you might as well print a jig to help drill
| those holes.
| https://play.fallows.ca/wp/tools/3d-printer/mpcnc-
| drilling-j...
| Tossrock wrote:
| My favored approach to offset drilling / drilling on
| curved surfaces is to use an endmill. Doesn't wander,
| goes straight in. Of course, you need an endmill for that
| approach, but id you're building a CNC those should be in
| ready supply.
| Nick87633 wrote:
| Or a center punch (helps on flat metal too).
|
| One favorite trick of mine is to print out 1:1 drill
| pattern drawings and center-punch through the paper onto
| my metal workpiece for all the drill locations. Fast and
| accurate.
| mfi wrote:
| Aluminium is quite soft, so it might work if you have access
| to a screwdriver and a step drill
| haliskerbas wrote:
| I'm not an expert here but I've heard 8020 is expensive
| enough such that purchasing a drill press would probably be
| cheaper, if feasible, correct?
| genewitch wrote:
| There is also handheld drill press rigs that may be
| useful.
| IgorPartola wrote:
| I picked up a used drill press for $45 or $50 (I don't
| remember now), and a tap and die set from Amazon for about
| $20. 10/10 would recommend if you have the space.
| convolvatron wrote:
| I use a cordless hand drill to drill and tap aluminum all the
| time (as does this project). adjust the speed until you are
| pulling out long ribbons instead of dust. you can use a
| little oil, but its not necessary. the only issue is trying
| to stay perpendicular to the work, but usually a little
| deflection doesn't matter. also pay attention to 'wowing',
| where instead of drilling your perfect round hole the drill
| bit starts to bounce around a triangle or pentagon and you
| end up making too big a hole. its often best to start with a
| pilot drill and then a final pass to clean it up. also its
| often easier to use a centering drill to setup the holes. it
| provides a pocket for the drill to rest in so that it doesn't
| wander, and you can use the centering drill to fine-tune the
| hole pattern before you make it permanent.
| sokoloff wrote:
| To easily stay perpendicular to the work, use a tap guide
| block. You can 3D print one or drill one out of stock on a
| reasonably square drill press.
| jacquesm wrote:
| What a fantastic project. Is the design parametric, in other
| words, are there parts that would need to be scaled up to have
| larger x, y or z axis or are those all off the shelf and are
| the various STL files for the components the same if the design
| is scaled up?
| mfi wrote:
| Glad you like it, most cred should go to Ivan Miranda for the
| core design, I just executed, updated some parts and wrote a
| guide around it :)
|
| No, it's not parametric in that way. But it is possible to
| extend the "mill-bed" by:
|
| * X-axis: Increase length of frame and bridge profiles. Buy
| longer MGN12H rails used for the X-axis.
|
| * Y-axis: Increase length of frame profiles. Buy longer
| MGN12H rails used for the X-axis.
|
| * Z-axis: Increase the vertical beams between lower and upper
| frame. Buying longer MGN12H rails used for the Z-axis and a
| longer acme rod.
| roland35 wrote:
| what material did you use for 3d printing? I would think PETG
| or ABS is probably best?
| mfi wrote:
| I actually used normal PLA
| naasking wrote:
| PLA is actually the stiffest of those materials, just keep
| it cool enough that it doesn't warp! I expect that would
| only be a problem around the spindle which can get quite
| hot, and maybe stepper motor mounts.
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