Home > CNC > Choosing a benchtop mill

Choosing a benchtop mill

Have you ever found yourself wandering a hardware store looking for some piece of hardware that might work for a project? I’ve probably spent hours and hours doing this, just to find the right thing, but getting home and finding out that it won’t work. Then, if you have the energy, you gotta go back to return it or just accept the loss of both time and money.

Having machine shop capabilities at home can solve this problem. You can make your own stuff: how you want it, when you want it, and out a really strong material. Wood is great and cheap, but metals really make a huge difference in what you can do and make.

Buying a mill and lathe has been on my mind for a long time, especially with a CNC setup, but holy cow it’s an investment. But, the way I see it is that it’s a life long investment. If you have a mill and lathe, you can literally build or fix any machine: motors, grinders, bike hubs, casting molds, milling PCB boards, tooling setups, new pistons for your car, fix your laundry machine, upgrade a cheap saw with better parts, etc. The list can go on and on.

For now, I’m only looking at a mill. The lathe will come later.

Here are things I’m looking for in a home mill:

  • Benchtop sized – Small and relatively light. I don’t have much space for a full blown machine shop and I don’t want to have to use a forklift to move this thing.  If it takes two people to move it, it’s still too heavy. The idea of using a spare closet for a small machine shop is not out of the question, especially because an extra closet is in the temperature controlled niceness of your home.
  • Precision – Out of the box precision. I really don’t want to spend several weekends tweaking and fixing a cheap, sub-par mill. Like Apple products, spending a little more on a quality product will give you less headaches and overall a better, happier, more pleasant, and productive experience. More time making, less time fixing. Precision is really important for more complicated parts. For every machining operation you do, the error of the machine compounds into your part. So for a complex part, a good precision mill can be the difference between making a good complex part the first time, rather than the second or third time around.
  • Support – Not customer support, but an online forum or large user base and long history. With a lot of people already using the machine, they will all have some tips and tricks to fix any issues or how to do a job faster and better. They will have also worked out any problems with the machine and the manufacturer will have likely solved it. Books and magazines are a big plus.
  • Machinist Approved – I work with some great machinists, who eat, breath, and sleep this stuff. There were only a few that they would recommend in the benchtop size range and what I would use it for.

The contenders:

  • Sherline 5000/5400 mill- They make great small 35lb, high precision machines and have been doing it for a long time. There is a ton of literature with people using them. The working area is relatively smaller compared to a lot of other mills (5″x9″ to 7″x9″). First mill recommended by my machinist friends. They don’t look very robust (not a problem , see later), but can create very intricate, highly precise parts out of the box. Lots and lots of off-the-shelf parts and good upgrades.
  • Taig mill – A middle ground machine. (5.5″ x 9.5″ to 5.5″ x 12″) 65 lb. Heavier and more stout than Sherlines for the same or slightly larger work area. Can machine steel very well. Claims to efficiently “hog” out material due to stiffer setup. Seems to be an answer to what Sherlines are not. In production for nearly as long as Sherline. Fairly large online community. High precision, but not sure that it matches the Sherline out of the box.
  • Smithy – Large machines. Make great combo mills and lathes. Expensive, but can make large parts and quickly. If I had more room and a forklift/not plan on moving in the next 10 years, I would get one of these. Highly recommended by machinists.
  • Harbor Freight/Seig X2/HiTorque/Grizzly mills – These definite “look” the part. Big, heavy, and stout, but looks can be deceiving. The work area is the same or SMALLER (4″ x 9″ to 5.1″ x 11.8″) and weigh roughly 130lbs! All manufactured off-shore, which makes for a low-cost machine but a crap shoot in quality. Most owners of these machines online seem to post more about upgrading/fixing the mills than actually using them for projects. I can’t deny the cost, but I don’t have a lot of spare time these days. I’d much rather be making stuff than tweaking the mill to a high precision. I think this is worth the extra cost on its own. These are also very, very heavy for their size. They are made with large portions of cast-iron, which is cheap, heavy, brittle, and prone to cracking. I have also seen reports that people receive warped work tables due to improper cooling and aging of the cast iron by the manufacturers. If precision is not in your list of needs, there’s nothing wrong with these machines, just don’t be surprised that some of you parts might come out a little off.
  • DIY Hobby CNC Mill – Not really an option, as it is more of a router than mill. As fun as a project making one myself could be, most of these options are made of wood or plastic, which makes for a not very stiff mill. You end up with a mill that only do certain materials well, but metals are pretty much out of the question. Aluminum is doable, but not recommended. There is too much flex to get any reasonable precision and is really limited to making PCBs, stencils, and delrin plastic. The cost isn’t too different from a machining mill, but one plus is that you can make it just about any size you want.

The Sherline and Taig mills are probably the best bang for the buck and for a benchtop, precision, ‘light-weight’ mill. Both are great machines, but each with their pluses and minuses. Compared to the foreign-made mills, the cost difference is only a couple hundred of dollars, and less if you add in cost of freight shipping a 130lb mill compared to UPS for a 35lb mill. And if you’re a patriot, Sherline and Taig are made in the USA.

The most common complaints I’ve seen for the Sherline mill is that they look small, are only for miniature model makers, has an underpowered motor, or not stiff enough. These are all generally true. This is not a machine made for hogging out tons of material very fast, as you would want for production. But, it will cut and machine any type of standard material, but the harder ones, like stainless, will cut just a little slower. Since the machine is small and will not be making large parts, you’re really not going to waste a ton of time. For large parts, you will want a large machine like a Bridgeport or Smithy.

In my engineering opinion, the Sherline 5000/5400 mills are correctly sized for the work area. The amount and type of material are all in the right places, giving you the proper stiffness all in the right ways. It’s well designed. However, this can be good and bad. This gives you a lightweight, precise milling machine, but it’s already near its limit. You can’t upgrade it’s capabilities too much without sacrificing some stiffness and precision, unless you stiffen up and replace everything like A2Z mill parts do. I don’t like the milling column on the updated Sherline 2000 mill for this reason, which features an 8-way Bridegeport-like z-column. It looks to make for a too compliant z-axis, although Sherline claims otherwise. Forum users of the Sherline 2000 state, you can get almost as good stiffness as the standard Sherline 5000 series only when you pull the headstock as far back as you can. Anywhere else, there can be noticeable flexing. As an engineer, I would have to agree with this in theory and would think that vibration would be an issue.

Taig mills are a little rough around the edges, a design that looks cobbled together, but a great mill too. They can be upgraded without worrying about compliance, since they are overly-stiff/over engineered by design. Roughly the same price, slightly larger working size, and twice as heavy. The online community doesn’t seem as large as the Sherline community, but I could be wrong. There isn’t a catalog of readily available parts, tools, fixtures like Sherline has, which can be good and bad (cost). But, mainly, the Sherline parts are sized for the Sherline machine, meaning you won’t have search around for properly sized vice, rotary table, or any other specialty item for the Taig mill. It’s nice to know that these options are there if I need these speciality tools or fixtures for future projects.

It’s basically a toss up on what’s more important: Larger community of users, a large catalog of readily available parts and tools, light-weight, high precision VS. more robust, can machine faster, better for steel and hard metals machining.

Personally, I’m opting for the Sherline, mainly for the precision, weight, and the wealth of knowledge. I don’t plan on doing a lot of machining with steel, mostly aluminum. But, the reasoning that pushed me over the edge is the fact that a lightweight machine also makes it easier and cheaper to upgrade to a CNC setup. You don’t need larger, heavier, high-power motors to run it, which gets really expensive, really quickly, because you need to buy more powerful power supplies, expensive motor controllers (sometimes), and bigger motors. The plan is to build an Arduino based CNC with some cheap robotics motor controllers, an ATX power supply, manual control with a PS2 controller, and a DRO based on stepper increments. This should all cost less than $200 for the upgrade. The Taig could be done for marginally more, but it would require large motors which would make a large and heavy machine, larger and heavier.

More to come…

Categories: CNC
  1. Nemo
    March 10, 2013 at 11:49 am

    I have a sherline cnc mill and a taig cnc mill. I’ve been using them over 4 years now. As a machinist for 17 years, I have say, the taig machine outperformed the sherline. The taig is more sturdy, precision, able to cut more variety of materials, and will last a long time.

    Sherline could only perform light cut and small passes. Heavy cut and harder material, machine will flex and twist all over. Over a long period of use, the Aluminum Slides will wear out, and you have to replace new one.

    • March 10, 2013 at 2:13 pm

      After using the Sherline for these last couple of years, I’d agree with you, but the Sherline really isn’t built to be fast or cut a lot of hard materials. It mostly designed to be small, lightweight, and capable, which it is. Its a little cheaper, too. As a starter mill working with aluminum, brass, and delrin, the sherline does pretty good and with a CNC setup doing the work for me, cycle time really isn’t that big of an issue for me. But,if I were to buy a CNC ready mill all over again, I think I would have thought a lot harder in purchasing the Taig instead, for the reasons you state. Then again, if I were to buy another machine, I’d think real hard about picking up a full size Bridgeport style mill to machine much larger parts and harder materials faster instead too.

  2. Travis
    March 29, 2013 at 5:56 pm

    “They are made with large portions of cast-iron, which is cheap, heavy, brittle, and prone to cracking”

    Cast iron is the good stuff. This is what you want your machine to be made out of. Cast iron absorbs vibration and provides excellent thermal stability (doesnt change size as much over a given temp range). Bridgeport mills, monarch lathes, and all the rest of the good old American industrial machines are largely made from cast iron.

    As far as the machines you listed, I would go with an X2 every time. Sure its basically a kit-mill that you have to do some accurizing on. But with study, it’s pretty easy, and you can (mostly) use the machine to do it to itself. In the end the machine you end up with will eat the Taig or Sherline for lunch, for about half the cost (in dollars, assuming your time is free).

    The best option for a hobbyist, in my opinion? Find a good used American benchtop machine. I started with an X2, and got pretty far with it. I also have access to Bridgeports (and Mori Seiki CNC’s) at work, so I know what is possible. I recently bought an 1950’s American benchtop mill (Armor JP) and it’s great- 400lbs, and it is every bit as rigid as a Bridgeport (just smaller!) and I found it on craigslist for $150.00 in the Pacific Northwest (which is a machinery desert!).

    • March 29, 2013 at 6:15 pm

      Cast iron can be great, if you are assuming two things. One, you don’t mind the weight and have a semi-permanent place to setup the tool. Two, the cast iron was properly aged, and there aren’t any internal stresses that can cause warping. The latter applies if you buy something really cheap from a manufacturer that cuts corners. If I were to buy a full-size machine, or more capable, I would definitely opt for good-quality cast iron that is if and when I have a place to put it. I really do like being able to take my mill inside and place it on the dining room table to test out new things I’ve installed or long g-code programs, especially on very cold winter nights.

      I’ve learned a lot in the two years since writing this post, but my viewpoint still hasn’t changed. There is a trade-off with time vs money. How much is your time worth? What I mean is that if you are a newbie, as I was at the time, how much time do you really want to spend setting up a cheap, potentially-questionable machine, learning how to set it up correct, second guessing yourself constantly, and hoping you reduced the backlash enough to make it serviceable enough to machine new anti-backlash nuts. Or, buy something a bit more costly, that you likely don’t have to almost anything to get going and start making parts. If you know what you are doing already, by all means get whatever you’d like. The time a pro would spend setting up a machine and getting it work is minimal, but this all comes with lots of experience and know-how.

      It also all comes down to what you are planning to make. I have no real use for a very large machine, as I don’t work on cars, guns, or anything that large, nor do I have use for the cost/storage space associated with needing larger tooling and fixtures. Most of the things I machine are small aluminum brackets, parts to small machines/mechanisms, etc. At the time, it was mostly the price to entry as a newbie. Overall it was relatively affordable and low-risk, that is if I decided that CNCing wasn’t my cup of tea.

  3. December 3, 2013 at 3:44 pm

    This probably the most helpful summary and comments section I’ve come across in over a week of constant research. Thanks!

    I run a small fabrication shop that deals mostly with custom one-off electronics builds that rely on microcontrollers. I don’t have time to mess around with the fine tuning of a machine. I need something now that will just work after I spend a weekend learning the workflow.

    For that reason, I appreciate your outlining of the pros/cons as related to ease of use. Also, I’ve found a good way to get a feel for the kind of customer service you can expect is to just call up the companies that make these machines and ask to speak to one of their engineers, or “technical guys.” I did that with Sherline and Fred was extremely patient with me, answering all of my n00b questions. It reassured me that even though there are drawbacks to the Sherline, I have someone I can rely on with 40 years of personal experience in milling when I come into a problem.

    Also, I think it’s also good to remember that if this is going to be your first mill (as it is mine), then finding the right tool to last you a decade isn’t the way to think about it. Instead, find a solution for what you need right now. Learn the machine, the techniques, the materials and what you are looking for in a machine should you decide to scale up. Then you can make an informed decision.

    Thanks again!

  4. Randall Reid
    February 1, 2015 at 5:32 am

    I own two Sherlines and a Taig dsls3000. Sherline has the best website, accessories and forum support. Taig has the best mill by any parameter you choose to consider. Far stiffer and more powerful. Sherline mills can cut steel slowly, but if you do you will destroy your mill. There is no practical way you can prevent swarf from getting under the x axis and it will eat the x axis slide. Taig comes with shield that has done an excellent job though thousands of hours of milling to protect both the leads screws and the heavy brass gibs. The Sherline mill has a variable dc motor with ample power for its range. The AC 100% duty cycle motor on the Taig is fixed in speed but the the pulleys are easy to change to get up to 10000 rpm. The Sherline is much more difficult to get into the high range and the motor runs incredibly hot. I can cut steel at higher feed rates on the Taig than the Sherline is capable of of cutting anything. The Taig has limit switches built in. The dls 3000 will detect overload and missed steps and shut down immediately. The shear mass of the spindle and motor on the z axis of the Taig keep it in place. The Sherline will frequently drop the z axis into a part with varying unpleasant consequences. The lead screws on the Sherline are tiny and if you do rapid moves especially on the Y axis they will whip around and beat on the mill unless you add a restraint. The Taig moves at 60 inches per minute without a tremor.
    While I laud the premise of linux and open source software, Mach 3 is far superior, and if you do choose a sherline, Mach3 is available for the Sherline for a modest price.
    Sherline produces very good accessories. Their rotary table is excellent. If you are going to work (slowly) with aluminum, wood or plastics their mill would be a good choice. If you want speed and stiffness (essential in a mill) go with a Taig.
    Customer support from both companies in my experience has been excellent.

    • February 2, 2015 at 7:21 pm

      I completely agree with your comment that “Taig has the best MILL by any parameter you choose”, except for the accessories and forum support, as you first said. For a newbie, a Taig has a higher barrier for entry IMO, mainly due to the exact fact you stated. It doesn’t have ready-to-buy and complete kits (except maybe at certain vendors) or as great of a support base. Just about everything you need is available from Sherline and they are of good quality. If you know a little about machining, the tooling/fixturing you need, and are interested in cutting steel, the Taig becomes more of an attractive option with its capabilities. However, I’ve been able to cut aluminum quite nicely and quickly on my Sherline once my feeds and speeds were dialed in. It’s not nearly as bad as you describe.

      But I do disagree with some of your leadscrew statements. With the machine volume only being on the order of a few inches, 60 inches per minute is a bit overkill. My Sherline goes about 30 inches per minute comfortably, which means, going from end to end of the build volume, is only a few seconds of difference. Realistically, this translates to only few minutes saved on a CNC job, if the feeds and speeds for cutting are the same.

      Lastly, Mach3 is great and powerful. LinuxCNC is also very capable and great, mainly because it’s free. But, Grbl is becoming great as well. It’s free, simple, and you can install it on a $3 chip that can be integrated by vendors into their machines. Just keep in mind that CNC is now becoming available to everyone, not just the experienced CNC/machining community. There’s room for all types.

      • Randall Reid
        February 3, 2015 at 3:19 am

        I purchased my first Sherline about 10 years ago for exactly the reason you described. Everything was available from a single site with good documentation and tutorials and lots of quality accessories. The Taig site then looks about the same as it does today and I have no idea why they don’t do something to improve it. I needed a mill to create parts that I was having wirecut at the time for over $1000 a part and weeks of wait time and had not been in a machine shop for 30 years. I still use many of the accessories such as the rotary table and their vices. The Taig vise is a joke and should be used only to create a real vise. Taig sells a modified rotary table from Sherline.

        With regard to the speed, it is far more than a few seconds saved. I just finished a heat exchanger on the Taig that took 24.5 hours running a .25 inch diameter 4 inch long carbide at 2.5 inch depth. .010 cut depth at 22 inches per minute. With the feeds and speeds of the Sherline it would have taken 4 days. Except that the Sherline could not feed a 4 inch .25 carbide at any speed because the mill is not stiff enough. Believe me, I have tried. The Taig is running right now cutting stainless motor mounts. The only attempt I ever made to cut stainless on the Sherline was my last.

        The Y axis lead screws on both of my mills whipped around so badly that they dug a channel in the bed. I had to mill nylon blocks and glue them to the bed to prevent this.

        The Sherline cnc 2000 did a great job milling Styrofoam for use in lost foam aluminum casting. It did an adequate job with short mills at slow speed in aluminum. It has been under a dust cover since the day the Taig arrived 3 years ago. I still use the manual Sherline for small jobs.

    • February 3, 2015 at 7:49 pm

      Duly noted.

      But, feeds during cutting is different than rapids. High rapids rates don’t make much of a difference in time, because the majority of time is spent in feeds cutting.. If the machine has to take lighter cuts with lower feeds, like a Sherline has to with harder materials, of course, it’ll take a lot more time.

      I agree Taig REALLY could use some overhauling and marketing (and better DC, rather than AC, motor). They emphasize on cheap but capable way too much. I’d pay more, on par with Sherline costs, to have a cleaner machine, good accessories, and guarantee out-of-the-box precision like Sherline does (still within 0.0002″ and squared after 4 years).

      Lastly, I own a Sherline 5400, so I never seen the lead screw whipping problem. It has a shorter Y-travel and lead screw, which is probably why. IMO, I don’t like the Sherline 2000 at all. It looks to be horrible in the z-axis stiffness. I’ve read lots of posts stating that you can’t aggressively cut with the 2000 because of the lack of stiffness.

      • Randall Reid
        February 4, 2015 at 6:02 am

        I opted for the 2000 because the work envelope of the 5400 would not accommodate the parts that I needed to manufacture. I doubt that the stiffness issue is any different between the two units because the z column is identical aside from the connection to the base plate. The y axis whipping would be less of a problem on the 5400 with the reduced y travel.

        Until they start using brushless technology I would opt for the Taig ac motor over the Sherline brushed motor. You will find references to cutting with HSS bits will give you a better finish, but when you run a carbide bit at higher speed you will find the cost effectiveness of HSS will lose over the durability and cut quality of carbide. You get what you pay for… And if you want to get more than 2800 rpm out of a Sherline you are going to have to do a bit of work. If you find an HSS bit that cuts the same after 30 hours I would love to know where you got it. I would buy a gross..

        I found your Grbl reference interesting. I have (at least) a dozen ardunio based pieces of equipment in my shop largely as data collection and test equipment setups and a 3d printer. If they come up with 4th axis support I will be forced to cast a bed to make use of it!

    • February 4, 2015 at 3:47 pm

      It’s not the Z-column on the Sherline 2000. It’s the connection from the XY-base to the column. There simply isn’t enough material and mechanical leverage to provide a good solid base. It’s made worse by too many joints, being made of aluminum, and having a longer lever arm than the 5400. There was an old CNCzone post about a guy testing out “hogging” capability of a Sherline. He found that his 2000 was horrible and couldn’t achieve half the removal rate of his 5400.

      Anyway, I happen to be the lead developer of Grbl (which kinda just happened) over the last four years, or at least when I first posted about it. 4th axis support is on the priority list of things to do! For what its worth, I concentrated on stability and speed first, rather than features. Here’s a link(http://youtu.be/85C88YrdhHg) to a colleague experimenting with HSM tool paths on a low-stiffness, gantry-style hobby CNC.

      • Randall Reid
        February 4, 2015 at 6:11 pm

        Congrats on the Grbl development. Sorry I didn’t make the connection. I read a piece some time ago about it referencing Simen Skogsrud. I see Grbl shields popping up all over the place. Have you commercialized any of your hardware?

      • March 10, 2015 at 7:24 pm

        Thanks. Simen stopped development somewhere between 2010-2011. I picked it up and continued developing it since 2011 on my own. I’m responsible for v0.7, v0.8, and the current v0.9. There are definitely a lot of references that Simen is the lead developer, especially in the 3d printer world. I never really tried correcting people until this last year when Grbl started to get a ton of attention. Developing for this was more of a selfish desire to get Grbl working as well as I wanted to.

        As for Grbl shields, I’ve never officially commercialized any Grbl hardware, but I’m starting to work with some people to get that rolling. It’ll be announced soon enough. 🙂

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