Are Minimills Worth It?

These days, the bar for home-built projects is high. With 3D printers, CNC, and cheap service providers, you can’t get away with building circuits in a shoe box or an old Tupperware container. While most people now have access to additive manufacturing gear, traditional subtractive equipment is still a bit less common. [Someone Should Make That] had thought about buying a “minimill” but he had read that they were not worth it. Like a lot of us, he decided to do it anyway. The pros and cons are in the video you can watch below.

During setup, he covered a few rumors he’d heard about these type of mills, including they are noisy, have poor tolerances, and can’t work steel. Some of these turned out to be true, and some were not.

Consider a computer. Sure, you want the giant 100-core monster with gobs of memory. But if your choice is to have a quad-core 4GB machine or nothing, you should probably take the computer you can get.

Honestly, the minimill he is using looked perfectly serviceable to us. Of course, he seems very skilled and we expect the knowledge and experience of the operator makes a big difference no matter what kind of tool you are using. He also purchased a better tool holder which doubtlessly helped.

Of course, these minimills aren’t dirt cheap. If you want bargain basement, you can always hack something together. Or, spend a little more and build something at least somewhat comparable.

64 thoughts on “Are Minimills Worth It?

    1. Yeah, but additive requires orders of magnitude less rigidity and vibration resistance. Nobody will ever make a FDM with a 2-ton cast iron frame like a decent milling machine or lathe would have, it would be absurd. Well.. maybe somebody will build one for youtube clicks

    2. Add some steppers in place of the handles and the minimill could be too… at which point I can’t see how it can not be extremely useful, simply because a 3d printer can’t make things from metal. This mill could, and while the shapes are more limited than for 3d prints, it can still do a lot once under CNC control: gears, track sprockets, mounting plates…

      1. If the quality of the screws is often as poor as on mine you need way more than giving it motors – it just won’t move that precisely and the backlash is really huge but inconsistent across the travel. The dovetails are also less than perfect (though how bad I don’t really know – its useable enough I’ve not found the time to really look at making it better).

        1. I did a conversion on such a machine, and used a kit that upgraded to ballscrews. Not cheap, but extremely economical compared to literally any ready-to-go CNC machine, used/ancient/new. If tasked with doing the same, I’d consider leaving the default leadscrews, and add glass DRO scales to each axis. Both linuxcnc (using a mesa board) and duet 3 (using the 1HCL) lets you attach not just a stepper motor w/encoder, but an additional encoder that you could use to know the exact position of the tool. Simply characterize your existing screws, and ignore backlash forever. Also, no homing routines or cares about step loss.

          1. Ignore backlash forever, right up until you do a move reversal and the tool is briefly uncontrolled. I trepan a lot of *almost* circular holes on my cnc minimill.

          2. smellsofbikes said: “Ignore backlash forever, right up until you do a move reversal and the tool is briefly uncontrolled. I trepan a lot of *almost* circular holes on my cnc minimill.”

            If you are using a Digital Read-Out (DRO), movements are tracked absolutely, backlash typically does not matter. If you need to move the working end five millimeters left, do exactly that. It doesn’t matter if you reversed direction and had to wind the backlash out of your drive screw, just as long as it moved the tool exactly 5mm left. If you have backlash and you are trepanning circles or curves where you must reverse direction, just do it and be sure the measurements are correct. With DRO, backlash gets wound out due to the absolute distance measurements. Movements can get janky though at (for example) the apex of a curve where you have to change direction repeatedly and backlash is present.

          3. Actually, regardless of how well you know where the mill bed is, the backlash still means that you have no stiffness in that direction. I’d think that would be a problem, particularly as forces in that axis changed directions along the toolpath, since the controller would only know something was amiss when the coordinates deviated, at which point it would have to scramble to try to compensate without knowing just how far it had to rotate the leadscrew before it could regain control.

            I’ll admit I’ve never done a CNC conversion, though, so if you’ve succeeded with one using only the original lead screw and maintained anything close to normal machining tolerances my hat’s off to you.

    1. I would say that if you would find one useful, you would already have a hunch. Because you would be rubbing your fingers to the bone making dozens and dozens of small filed metal parts. If you aren’t doing that, or you don’t have an ambition which would realistically have you doing that, probably you don’t need one.

      Like most tools, whether you need one or not depends on your aims

    2. Pros: It can make solid metal parts
      Cons: Not CNC out of the box*, can’t make complex shapes**

      * = But you just need stepper motors on the handle spindles, it’s a super common conversion.
      ** = But you can achieve a surprising amount with some skill & a few accessories (see Blondihacks or This Old Tony on youtube)

    3. > waste time watching the video

      Watch the video, or don’t – but you not being interesting in watching a video doesn’t make it an objective waste of time. Especially when you’re apparently interested in what it has to say.

    4. He didn’t really make a list of pros/cons. He did complain that the lead screws are metric while the hand wheels are imperial, which means you have to do a lot of math in your head. However the main point of the video is that the machine was far more capable than the naysayers would have you believe.

  1. I’ve got one, and use it for all sorts of small work when I’ve got setups on the larger mills (and also cause I’m a tool…. Collector :-)). They’ll cut steel fine, they’ll hold tolerances fine, IF you work within their limitations.

    A hogging pass might only be a 20 thou depth of cut. Sure your feeds and speeds calculator might say you can take more, but the machine is too limber for it.

    The biggest issue I have with it is the silly pitch on the screws giving me 0.0625″ per full revolution. One of these days I’ll replace them with screws having a reasonable pitch.

    1. How many endmills do you have to wear the last 20 thou out on before it becomes worthwhile to spend more then $200 on the machine? Depends on how cheap your mills/hoggers are, obviously.

      It’s generally better to take a shallower cut in radius and longer cut in length. But it all depends.

      No rubbing! You’ll grow hair on your toolholder.

      1. Use a combination of end and side milling, and you get decent cutter life. I can say for sure that jamming them in and letting them judder along takes a whole lot more life out of them.

        I’m not really sure what my endmills cost each, TBH. I bought a toolbox full at a shop closeout auction. Not looking forward to the day I have to buy new again. :-)

    2. > The biggest issue I have with it is the silly pitch on the screws giving me 0.0625″


      My Dad had one of these. It was a perfectly serviceable machine for what he needed, but I found it frustratingly unusable because of the lead pitch.

      His was .125″. Who the hell can add eights in their head while working on a part!?!

      I ended up buying him a cheap DRO. Maybe that was the plan all the time.

  2. The problem with these things isn’t that they are all bad, it is that you don’t know if you are getting one that has be finished even remotely properly and is actually pretty good or really barely functional garbage that weighs too much to be used as a paperweight so has no real function at all.

    For instance I have had one that appears to be the same model from a local reseller for years now, the spindle and gearbox are really great, but the bed really needs some work I’ve not found the time to really look at or do (that would no doubt be much easier if I already had a functional mill – though I don’t actually know how bad it will be as I’ve just put up with the table and used my lathe that is good quality whenever practical). And I’ve seen somebody that had another similar looking model where their bed was seemingly much better than mine, but the gearbox was all the leftover parts that should have been discarded…

    So for me this comes down to do you want a project? If yes one of these is probably fine, but do you have the space to house a bigger old iron machine? As that type of machine will once you have refurbished it be a more useful machine, and can often be found quite cheaply and often come with heaps of tooling bits – so maybe even work out cheaper than fixing everything wrong with the cheap mini-mill and getting in the tools you’ll need.

    With a final question of are you intending to make remotely high precision parts, and do you have any experience in machining? As if you are skilled and careful even a garbage machine can produce pretty good stuff, however its going to be much harder to teach yourself if you can’t be sure the failure is yours and not the machines… So going up a quality bracket would probably be my suggestion – then you’ll be able to figure out much easier if you are out of square because the side milling was deflecting badly or any similar user error – as you can ‘trust’ the machine isn’t the problem.

    1. The problem with your reasoning is that it applies almost exclusively to the US. may apply to some other industrialized countries, but probably not.

      in most other countries there weren’t countless machinists with every tool under the sun. and people selling their gear do it almost exclusively after their machine is worn beyond repair. the secondary market of used tools is just not there. well, it is, but it’s basically full of old machines that can’t be fully restored.

      of course there’s also the thing with hobby users. north America has so much disposable income that buying a whole workshop as a hobby isn’t a problem. this is absolutely impossible in most other countries. probably some European countries may but there’s also the “huge american home” factor. usually houses outside NA can afford to dedicate so much space to a hobby

      and people selling these machines likely sell it for almost new price. because they are “Good machines and they don’t make them like they used to”.

      my dad had a mini lathe for a number of years and decided to upgrade to a South Bend 9″. the results haven’t been spectacular. the lathe is very old and worn maybe it can be restored? who knows. but you need tools that cost even more, or need to have it serviced for a very steep price.

      this is where those mini lathes and mini mills make a lot of sense.

      1. Big Iron stuff being around is true of way more than NA, also true of all of Europe, and by extension many of the current or former European colonies too. I see lots of nice things here in the UK for instance.

        The space issue is very true, which is why I mentioned it – Affects me too, with most of the really great deals on machines and accessories for it I could get here are just too big for my space. (Which is probably part of why they are such good deals).

        Would however disagree on ‘sell it for almost new price’, you might be able to get a junky low quality and probably much smaller import that is just as much a project for less. Where here at least you get what you pay for most of the time as far as I can tell – its sold at higher prices when its been at least partly refurbished already, or sold at a price that often isn’t actually much more than the scrap value of its weight + shipping. Which still seems expensive, because they really don’t tend to make them like they used to, the old ones are HEAVY and other than a refurbish every half century or so just endure.

        You really don’t need much in the way of money or tools to restore a big machine either (much of the time anyway) – just lots of patience, some understanding (or research) and a scraper in most cases. And all you need to figure out what is worn in most cases is a straight edge – which you can make yourself reasonably affordably and some feeler gauge or other suitable measuring tool to figure out how badly. Obviously not everything will always be that cheap or easy to repair, though its also true that in many cases once you have the ways trued up the machine itself can now be used to improve itself. Seems to me repairing these old machines is usually less trouble than making the Chinesium grade stuff as good as it can get (I’ve read more than a few folks doing both), and the machine at the end of it is better if you can go old iron.

        1. The only former European colonies that were industrialized are the US and Australia. Latin America never seriously industrialized though, it was always about resource extraction.

          I still have my doubts about the secondary market of lathes and mills in Europe. I’m pretty sure it’s not comparable to the US because of space issue alone.

          1. Plenty of the current/former colonies have been for quite time industrialised often with European old iron machines they could cheaply import – offshoring isn’t a new concept… Not saying the breadth of the second hand market is a huge as it is in the longer industrialised nations, but its very clearly there. Some really talented machinist turn up on the web using old iron in the former colonies.

            And there are lots of great high quality machines that are still in the bench top size in Europe – that size issue also applies to many industry and the richer tinkerers in their sheds even 200 odd years ago across the EU (Myford in the UK for instance do a line of reportedly really good benchtop lathes and are still making parts for the old models). So while the US folks with the generally giant houses might have it easier as they have the space to jump at any machine worth having in the local area, if you can go old iron it may well be worth it. Unless you are buying refurbished old iron you are buying a project either way…

  3. “you can’t get away with building circuits in a shoe box or an old Tupperware container.”

    The hell you can’t.

    I defy you to make one argument in support of that statement that sounds like it comes a hacker and not from a Kardashian.

    There are things the hacker/Maker community needs, but gatekeeping fashionistas aren’t on the list.

    1. My favorite ‘media pc’ was a mainboard screwed to a scrap of 5/8″ thick MDF. Used angle bracket to hold the PSU on. Worked fine as a fanless device in a woodshop for years. (Was fanless because the fan died… no matter)
      Build with what you have, build with what you want.

    2. Representative of the way engineering went.
      It used to be: focus on function, and if you can make it looks good too, then great.
      Now the trend is it has to look good first, and if it is fit to purpose as well, that’s a optional bonus.

      E.g. I used to have a clock designed by Philippe Starck. Got rid of it as you couldn’t turn off the alarm w/o sending the clock crashing on the floor, unless you grabbed it with 2 hands. I probably have other examples but I’ll spare you from having to read a long winded essay.

    3. Granted, my “shoebox” project is a plastic container the size of a shoebox, but it was perfect for it’s use, which was a button box- you push the buttons attached to the lid, and it triggers a sound file to play on the little controller the buttons are wired up to. (there’s also a speaker attached to it.) Faster and cheaper than either sourcing or building a pretty looking enclosure.

    4. Indeed, though with how cheap and good the FDM printer is and things like rapid and cheap PCB production most everyone will have access to all these things if they like to make stuff now – and that does mean the projects we see tend to look nicer and its now easy to make ours that way too. Which does mean we are likely to not accept the shoebox and hotsnot in our projects ourselves… So while I’ve no problem with the shoebox/tupperware, will use that sort of thing myself no trouble. I do think the Author had a point, they just came at it from the wrong side really – you can’t bring yourself to ‘finish’ a project in a shoebox…

      (one of my CM4 IOboards is on standoffs screwed into a plywood scrap with a PCI card bracket made of some scrap L profile metal and more plywood all covered in a bent and glued cereal box cardboard cover to keep the dust out… Janky as you like, but durable and practical)

      1. I do think the author has a point, and one that’s shared by much of the public. I just consider it a bad point: a cargo-cult mindset that displays ignorance of the subject. The equivalent of someone who wants to learn to cook and sets their definition of success as the ability to start from scratch and reproduce a McDonald’s cheeseburger.

        It isn’t even “play stupid games, win stupid prizes.” It’s “play stupid games and lose because the game has been rigged against you from top to bottom.”

        PCBs aren’t the only way to build electronics, or even the best way. They are, however, easy to scale up for mass production if you’re willing to invest in a specialized form of printing equipment. The killer app of PCB fabrication is panelization because you can make a hundred copies of a board in only a little more time than it takes to make one. Using that system for a run of five boards is the worst possible way to use the technology.

        Injection molded plastic parts and enclosures exist to leverage capital investment for market advantage. The company willing to spend a quarter million for injection molds beats the company that pays $50k, and both of them lose to Apple which pays $10M to make seam lines invisible.

        And both those technologies are optimized for the low end consumer market. As you start moving up the quality scale, you see more use of techniques that can’t scale economically for mass production. Instead of leaning into techniques and practices the low-end consumer manufacturing economy can’t afford to use in mass, we see people running a 3D printer for 16 hours to make an inferior copy of a $7 TV remote. It’s a mindset that aspires to blow-molded soda bottles on the principle that they’re everywhere so they must be good.

        Low volume producers can absorb costs that mass producers can’t consider. Dell will change a design to save 3c per motherboard, while I can spend another $2 for better components without caring because I’m only making one or two copies of the device.

        Even the argument I’m making could be construed to place more value on what’s conventionally pretty than on what’s technically valid or interesting. The first transistor wasn’t pretty in the injection molded enclosure sense, but it’s a logical arrangement of parts that all have a purpose. I’d rather look at it than at a hundred variations on an injection molded air fryer.

        I won’t sit still while people say vapid mimicry of cheap consumer goods is the star we should all strive to reach.

        1. I do agree with you in general. I am simply saying people are generally wired to want things to look neat, tidy, deliberate etc, they also tend to like durable and nice to interact with. Which PCB fab, cheap CNC (additive or subtractive) etc really enables. So now its so easy to make things looks better and being more durable than the shoebox full of cobbled together bits and bobs project most people won’t accept the scrappy look for their own projects – its entirely on them that they want their project to actually look ‘finished’, have some nice ergonomic contours, etc. They want that because it is now so attainable to get it.

          Your form from function type argument in many ways is an argument for exactly what you are trying to claim it is not – about the only time it won’t be is in the most early prototype stages of an idea. Which is a perfectly fine point to stop and leave something if you want to, but most people won’t… Or perhaps in the most bespoke and thus stupendously expensive one off artistic end – which will then not look like a tupperware box full of electronics (at least it shouldn’t, but as Modern ‘art’ is a thing)…

  4. I deliberately did not click on the video because of the title. I have just had it with these types of titles. Who are the people who are lying to us? Can anyone name names?
    The reality is that there is endless puffery and hype in every category of tools and perhaps everything else too. This video may help one know about the quality of one particular machine from one vendor at one moment in time. We have all heard of quality deteriorating as time goes by.
    For the hobbyist, the best approach is to go with a reputable vendor with good after-market support. Unlike the computer analogy, where a fancy computer will perform basic functions like get a newbie to Hackaday just as well as a cheap one, a poorly made mill may lead a novice to just giving up in frustration.

    1. Yeah, that kind of thumbnail should make a used car salesman or a soviet propagandist blush. The algo is a monster and everything will be min-maxed for absolute highest engagement at any cost, sacrificing all other ideals and concerns.

      I’ve noticed that one of the algo-tweaks that has become POPULAR lately is selectively putting CERTAIN words in ALL CAPS seemingly at RANDOM. SUPER annoying, there’s just NO way to STOP your inner monologue from SOUNDING like a JUNKIE SCREAMING at you

      1. > I’ve noticed that one of the algo-tweaks that has become POPULAR lately is selectively putting CERTAIN words in ALL CAPS seemingly at RANDOM. SUPER annoying, there’s just NO way to STOP your inner monologue from SOUNDING like a JUNKIE SCREAMING at you

        We see this in social media posts too. The other one that makes me immediately disregard what you have to say is when the first Letter of random Words Is given a Capital for No reason.

        1. “The other one that makes me immediately disregard what you have to say is when the first Letter of random Words Is given a Capital for No reason.”

          That’s because you don’t understand German ;)

          1. There are capitalization rules in German that are different than English. They aren’t random – or shouldn’t be. Unfortunately, some Germans have no more understanding of the German rules for capitalization than many English speaking people do. As a German speaking American living in Germany, I see this everyday.

            People seem to get this idea in their heads that they should capitalize “important” words, where “important” is some random concept that is important to them but to no one else.

            If you aren’t sure about capitalization, look it up:

    2. I assume it’s the creator of the video who is lying. That would be about the only way of the title having some truth in it. I also did not watch the video because of that. I don’t like being lied to.

      1. “They” are the internet experts who maintain that unless it’s a $50k industrial CNC machine that can hold micron tolerances it’s junk and not worth it.

        The reality is, much like 3D printers, close enough is good enough especially for hobby projects where you can live with a fair degree of tolerance and you’re not making a batch of 1000.

      1. Exactly, and in this day and age you are invisible without clickbait, especially for the “niche” area that makers occupy. The video did pop up in my feed, since I watch a lot of machining channels, and the combination of the title and thumbnail made perfect sense: he did pretty much debunk the myths of the minimill that everyone seems to push. They have their limitations but they aren’t as useless as conventional wisdom says, everything just takes longer and requires more care (Julian Mowlam is building a 2″ scale traction engine and his mill is remarkably small for such work but he gets good results without the need to shoehorn a Bridgeport-alike into his workshop).

        1. The “being lied to” part (apart from the clickbait), is the proposition that these things would be useless, or can’t mill metal, or whatever else he’s cocked up. I never heard such talk. A lot of the people who work with such a mini mill are very happy to have one, because it enables them to do things they could not do otherwise. Most people who are not so happy have often outgrown their limitations and longing for a bigger better and stiffer mill. For a great and positive video, look at This old Tony’s video of the “mini lathe”. He does not skimp on it’s limitations (and also does some upgrades, bearing replacement etc) but despite it’s limitations it’s a fun toy that enables you to make round metal things.

          But I am both surprised and annoyed how badly these things are made sometimes. I’ve seen video’s of the sledge of a lathe being millimeters off so it does not fit the bed. The RF30 (round column drill/mill) I bought over 30 years ago had the bearings for it’s X-axis displaced by almost 5mm and because of that I could not use the full X axis. That machine has also gotten a lot of upgrades over the years.

          The minimal / mandatory “upgrade” with most machining stuff is to take it apart, clean out all the grid and grime, do some deburring and oiling during re-assembly.

  5. For starters, the chances of getting me to watch anything posted on YouTube is slim-to-none.
    Second is that I have a “not expensive” bench mill and bought it with no experience of using one. Figuring it out took minutes and it did exactly what I wanted.
    If you can’t buy/make what you need then you need to re-evaluate your dreams (or montize yourself on YouTube until you can afford what you need).

  6. I’d suggest if you are interested in doing precision work with small machine tools everybody go peruse Blondihacks. She gets awesome precision, likes the size advantages of minimills / lathes, and has lots of tips on her channel on how to get the most out of them. Here’s a very thought out video on what to look for in a lathe

    Also here is the video when she upgrades to a slightly bigger mini mill and talks about the advantages/disads:

    But to summarize, if you buy from precision matthews / grizzly vs no-name it will be more expensive but you probably have much less of a project on your hand.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.