Announcement

Collapse
No announcement yet.

Newbie looking for a benchtop mill

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Newbie looking for a benchtop mill

    One of my hobbies is knife making, and I'd like to add a benchtop mill to my garage shop. I'm sure it would be used for other projects, one I already have in mind. But I have zero milling or machining experience.

    I've asked other knife makers and they mostly have Precision Mathews, Grizzly, LMS, and a few Harbor Freights. Almost everyone recommends a square column mill. So I've done a little research on the topic. I've also watched FB and CL locally for at least 6 weeks and it doesn't look like used is an option. And anything bigger isn't an option, I just don't have the space.

    So, I'm considering two options.

    1. Buy the ~$600 version from Harbor Freight to get my feet wet. I can get started without spending a ton of money, and I can sell it and get most of my $ back and upgrade later. I could use the same vise, tooling, etc.

    2. Just budget more $ and buy a new PM, LMS or Grizzly.


    I hope to use it for milling guards and small folder parts. These are generally small or thin parts, and I don't think mill size or power are going to come into play here. But I have a few other projects I'd like to try on my own, one of which I'll try and outline below;

    I'm trying to make an attachment for my belt grinder. One part requires milling slots into a piece of 6061 (slots are .25 deep, .50 wide, and 2.5" long) I'll post a photo of what a similar piece looked like;





    Are the mills I'm looking at going to be able to have larger projects like this? Are there any particular features, etc that I should look for based on what I'm needing it for?

  • #2
    My advice buy as big as you can afford and cry once you can buy a couple different square columns for under 3000 if it's in the budget the machines built in Taiwan are way better than Chinese built machines remember you want as heavy as possible the heavier the better. I have a pm 932m besides a couple problems I've been happy with it

    Comment


    • #3
      Your situation is nearly identical to mine a few years ago, i started off making knives, wanted to start branching out into making some of the more complex styles, started looking for tools and had no experience machining.

      I ended up getting a Grizzly G8689, which is a Grizzly branded Seig x2 mini mill. Little secret, for nearly anything labelled "mini-mill", theyre all the same machine, the aformentioned Seig, just with different branding. Grizzly, Harbor Freight, Princess Auto, Cummins, Busy Bee, Micromark, Wen, they all sell the same mill with a different paint job. The only thing that tends to differ is quality control and everything that happens after purchase. Personally, Im pretty fond of Grizzly and would recommend buying from them, they stand behind everything they sell pretty well and are fantastic to deal with. That said, if all you have in your area is a Harbor Freight, you wont lose much buying from them instead.

      Now, is it worth it? I would argue that yes, the mini-mills are a fantastic way to start off machining. A lot of guys like giving them crap, and to be fair, they do have their fair share of issues. For my money, theyre better viewed as a kit; sure, you can buy one, take it home and immediately start working with it, but you wont get the best results, no questions. But, if you put in a little work, you get a massively better tool. My mill, straight home from Grizzlys showroom, did technically work. I spent a few hours the first day getting it aligned and trammed proper, and made some parts with it. Then i shattered one of the plastic drive gears. Honestly, no biggie, gave me the excuse i needed to upgrade to a belt-drive. Got tired of counting dials, decided to install a DRO, but there was nowhere for the DRO on the Z to go thanks to the tensioner arm, so i replaced the tensioner arm with a gas spring, got smoother adjustment of the head as a bonus from that one. Recently i found out that the table wasnt quite flat, nothing that interfered with my work, but it gave me an excuse to play with a surface grinder.

      It all sounds like a lot of work, and there are some times i was tempted to preform some, uh, percussive maintenance, but it all worked out well in the end. Not just because i have a mill, but the experience is invaluable. Had i started off with a perfect, top of the line mill, i wouldnt know how to do nearly as much, or know nearly as well how the thing worked. Now though, ive learned a load, and i have a tool that gives far better results than you would expect if you only heard stories from the "rah rah mini mill chinese crap toy" crowd.

      Thats the plusses, but like everything there is a downside. Make no mistakes, its still a mini mill, and youll never be able to do some things youd do with a larger machine. I will confess, these things are about as rigid as cooked spaghetti. A lot of that comes from the tilting column arrangement, which can be corrected, but a lot is also cause by just thin casting and the small size of the machine. What this means, practically, is youll never be able to take as deep a cut or use as large a cutter as a larger machine. Depending on the exact machine, theres also an accuracy issue to confront. You might be lucky and get a machine thats perfectly in-line and needs no work, or you could get one like mine where the table is about .004"/ft off square in the X-Y direction. Dont fool yourself, for $600 you arent getting a Deckel. Youre getting a machine that, to put it simply, functions. Itll make parts, and itll do it surprisingly well if you take the time to take everything apart when you get it, deburr everything, clean out the grit, reassemble it, adjust it and properly lube it, but be prepared to do some work.

      The really tricky thing to answer is "will it do what i want to", because that question depends entirely on you and what you plan to do with it. If it helps at all, on my machine i know that my comfortable work envelope is about 6"x3" in the X-Y, and i have i think around 6-7" of space between the table and the spindle at max height. I can fit a larger piece in the machine, but it limits what cutters i can use, which is why i quoted my comfortable envelope and not the max. As far as cutting goes, I know that ive drilled up to a 1/2" hole in steel, taken up to a .150" deep cut in cast iron with a 1/2" roughing end mill at about 70% engagement, taken a .1875" depth cut with the same end mill in aluminium at 100% engagement, faced off aluminium, cast iron and steel with a 2 inch insert face mill with cut depths anywhere between .003" and .045", and cleaned up the end of a 2 inch thick bar of aluminium with a 1/2" carbide end mill, cutting off .030" if memory serves. I was pushing the machine with all those cuts, but never beyond its capabilities, and each of those listed cuts left an acceptable finish and cut to tolerance. As far as tolerances go, on my mill i can usually hit +-.005" to my target dimensions, less if i remember to pay attention to what im doing. At present im making a set of handles for a butterfly knife that include a set of drilled and .126" reamed holes, and i know for a fact that i can stack all of the handles up and pass a .125" gauge pin through the holes in the entire stack, so the holes are accurate to each other on each piece to less than a thousandth of an inch. Dont actually know how close they are to the print though... I should find a way to measure that...

      Hopefully my admittedly subjective experience can help you out. Like i said, i can very confidently recommend that you start out with a benchtop mini-mill, especially if thats all you can afford or have space for. They arent toys, theyre tools, and well worth using at that. You can get good results with them, you just have to work inside their limitations.

      Oh, and if you do get a mini-mill, invest in a set of collets that fit the quills taper, either r8 or 3mt, use those to hold end mills. End mill holders and collet chucks have too much stickout for these machines, youll get less chatter with a spindle taper collet

      Comment


      • #4
        There's no scale to your picture so "larger projects like this" means nothing. We all like spending other people's money but get the most you can afford. While you're doing that, you can count on spending 2-3 times that for tooling. Most new-to-the-hobby forget that you need tooling. Without it, it's like buying a car without wheels. Nothing is gong to happen until you have them. But just buy the tooling you need to start and add more as needed. Have fun with what ever you get and be mindful of the hazards that go along with power tools.

        Comment


        • #5
          A Seig mini mill in any of the brands would do what you're after from what you're posting. Some of the larger pieces might take a bit longer due to lighter cuts. Especially in steel. But there's no doubt that with patience and time you can certainly do the sort of things you're asking about even for making the slots for the belt grinder parts. If it'll fit within the limits of the table travel and clearance and within the room between the maximum table to spindle distance less room for the cutting tool then you can machine it. The question is how many passes and how light the Depth of Cut (DOC) must be for each pass.

          One last thing. On the cheaper machines they are put together super fast and without much care. You might find you need to do some of the light finishing work on some of the parts and do some of the basic adjustments to tune up the machine. Work that might be done on the other brands' versions. Hard to say since the mini lathes from all sources all seem to share the same "out of the box" issues and shortcuts that end up being fixed by the folks that are dedicated to such machines.

          Comment


          • #6
            Originally posted by CCWKen View Post
            There's no scale to your picture so "larger projects like this" means nothing.
            Sorry, I thought I had included some dimensions. But in this case, it's a 1"×2.5 bar of 6061, and I need to mill slots (.25" deep and .50" wide)

            Comment


            • #7
              Little Machine Shop has min-mill on sale for $1079. If you can get to the NAMES expo (in MI), they usually offer a 10% discount.

              https://littlemachineshop.com/produc...ProductID=3990

              http://pauleschoen.com/pix/PM08_P76_P54.png

              Paul: www.peschoen.com
              P S Technology, Inc. www.pstech-inc.com
              and Muttley www.muttleydog.com

              Comment


              • #8
                I was in the same situation awhile back. I eventually found a nice 6x26 knee mill on CL.
                About a month after I got it, 3 more machines showed up on CL.
                I say wait a little longer and watch CL, Ebay, or other similar sites.
                The search words you use can be a pain too.
                milling machine, knee mill, manual mill, miller, vertical mill, hand milling machine, these are different search words that can return different search results.

                Comment


                • #9
                  Something I didn't include in my previous reply is a suggestion for a machine.

                  Having had a couple of mills now and the first being quite a lot smaller if I were looking to downsize to a small machine for small work but with SOME bigger jobs now and then to service or build other tools in the shop I would not go down to the mini mill. I'd "settle" for a bench top machine but with a bigger table than the mini mill. Table room and spindle to table room are highly important to allow room for various jigging setups. A plain milling vise won't do ALL the jobs you will want. Sometimes you will need room for an angle plate or rotary table or any number of other factors. So while you might not need a strongly more powerful or heavier machine you will likely find that a mini mill will be too small for some of the shop tool jobs even though it's fine for any and all knife making jobs.

                  I never liked the looks of the new machines that have rectangular "thin" dovetail columns. But from some posts a while back on picking a mill there's clearly a few of those that are not bad. So the mill does not need to be one of the larger bench top versions to be decent.

                  So... .all in all if you think you want a mini mill then I'd suggest one that is just slightly bigger. From the Grizzly pages (but there's nothing wrong with other sellers, I just prefer zooming through the easier to use Grizzly web site) I'd suggest one like this Grizzly G0781 for the larger work table. Or if a $1500 price doesn't scare you too badly then their G0704 would be a great machine for your needs that you would never outgrow at the scale of things you are suggesting.

                  What you get with both of these is a lot more room on the table for work holding devices and room for larger parts to be held as related to servicing, modifying or making other shop equipment. Or even jigs to aid with then using them on the mill to hold knives or parts of knives. And it's surprising how fast the table can fill up and suddenly you've got no room to clamp things on the smaller setups.

                  So unless you KNOW you'll only be doing small things or limiting yourself to small machines and small projects due to having a very tight shop it's better to buy a size or so up from a mini mill. Actually bigger is better but the two I've suggested will do the job and do it without too much complaining provided you pay attention to the tooling setup.

                  A big part of this "tooling setup" is not having a lot of overhang with the end mills. For that reason I suspect that most of us hold the end mills directly in a suitable R8 collet. I've done it this way since I got my new mill and it's working out fine. I checked with felt marker "witness marks" a lot at first to ensure that the end mills do not move in the collets. And even with fairly heavy cuts the grip has always been stable. And it's not like I reef the drawbar like my life depends on it either. Using the collets directly in this way ensures I've got very low overhang from the spindle bearings and that greatly aids with reducing the risk of chatter. It also aids with keeping as much vertical working room as possible. And on a vertical rear column bench top mill it reduces the supportive length and any flex in the column. So it's all good in so many ways. This is something to keep in mind. Keep all work setups short like this whenever possible.

                  Comment


                  • #10
                    the thing that'll screw you with with smaller mills isn't their lack of rigidity, their accuracy or any of that jazz, all of which can be worked around to some extent. It's table travel and, to a less extent, quill to table distance. Going by rough finger dimensions, that piece you showed is 14-15" long, which I might just be able to do on my 6x26 mill, but the LMS minimill (which is a decent machine for its size by all accounts) will not as it only has 11.8" X-axis travel. So think about the largest pieces you can think of doing, double that and then look for the biggest machine you can fit/ afford that will do that. Maybe accept a little less

                    As for looking, took me 3 or 4 months and I got lucky. I'd been watching CL for about 6mths prior to starting to look seriously and nothing popped up. You just have to be patient and look under all the rocks where they might be hiding.

                    Comment


                    • #11
                      Table area, table movement, and the "daylight" between table and spindle are key.

                      "Daylight" always seems like it is less important, until you have an engine block and a boring head to fit between table and spindle......

                      Table area so you have room for a rotary table, or larger itms to be leveled/faced

                      Travel because moving the work to do another section of it is a real pain, as well as accuracy killer unless you are careful.
                      1601

                      Keep eye on ball.
                      Hashim Khan

                      Comment


                      • #12
                        If you put your general area in your profile someone may be able to offer some leads.
                        Last edited by 1200rpm; 04-06-2019, 08:39 AM.

                        Comment


                        • #13
                          I personally own one of the older x2 mini-mills from LittleMachineShop (converted to cnc) it does ok but I really wish I had bought bigger. The nice thing about the x2/mini mill is that at around 100 pounds it is small/light enough to move without killing myself and it doesn't take too much bench space.

                          Otherwise I wish I had a bigger mill almost every time I use it. The travel in each axis is limiting (The Z travel is fine when using collets and milling cutters but quickly becomes limiting when using chucks and/or drill bits). The other big problem is that the spindle isn't fast enough, 2500 rpm isn't fast enough for small cutters and the machine isn't rigid/powerful enough to make good use of larger cutters. I plan to buy or make a belt drive conversion to up the speed but haven't gotten around to it yet.

                          If it is all you have space/money for, you can get your feet wet with them but expect to outgrow it relatively quickly.

                          Comment


                          • #14
                            I have an X1 (sold as a micro mill) that is similar in design to the X2 mini mill. I've done long, parts on it simply by cutting the details for the left side , then moving the part on the table and re clamping it. It's a hassle, but the same concept is used regardless of the size or type of mill.

                            I would not recommend an X1 if you have room for something bigger. It's rated for small endmills, so making a slot that's 1/4 inch deep and 1 inch long takes a several times longer on the micromill than it does on a mini-mill or a 6x26.

                            Dan
                            At the end of the project, there is a profound difference between spare parts and extra parts.

                            Comment


                            • #15
                              Originally posted by danlab View Post
                              I personally own one of the older x2 mini-mills from LittleMachineShop (converted to cnc) it does ok but I really wish I had bought bigger. The nice thing about the x2/mini mill is that at around 100 pounds it is small/light enough to move without killing myself and it doesn't take too much bench space.

                              Otherwise I wish I had a bigger mill almost every time I use it. The travel in each axis is limiting (The Z travel is fine when using collets and milling cutters but quickly becomes limiting when using chucks and/or drill bits). The other big problem is that the spindle isn't fast enough, 2500 rpm isn't fast enough for small cutters and the machine isn't rigid/powerful enough to make good use of larger cutters. I plan to buy or make a belt drive conversion to up the speed but haven't gotten around to it yet.

                              If it is all you have space/money for, you can get your feet wet with them but expect to outgrow it relatively quickly.
                              I had a X2 milling machine and sold it for the larger Rong Fu mill drill. It was one of the best decisions I ever made.

                              A lot of folks really hate the round column mill drill, but my newer Rong Fu (made it Taiwan) is actually a really nice machine to use. The table is a good size and the space between the spindle and table is fairly large.

                              You do have to plan out your work a bit as the limited quill travel can be annoying but for most of my home shop work it's not really that big of deal. You can work around most of this with a set of stub drills.
                              www.thecogwheel.net

                              Comment

                              Working...
                              X