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  • 3 in 1 differences

    Hello, I am pretty sure I am going to be getting a 3 in 1. I understand that it is better to have dedicated milling and lathe machines, but I am limited on space and money. My only other option would be the mini 7x class machines and they are a bit small for what I want to do. This will be for home hobby and project stuff, and I don't mind taking small, more time consuming cuts and whatnot.

    Anyway, I am trying to figure out whether I want either the BT800 or the AT750 from Bolton Tools ...

    You can click on the machine names in the above paragraph and it will take you to their respective product pages... At first glance, I would think I should be going for the BT800 because it has a larger swing (16" vs 12"), but I am seeing that the two machines are the same price. This leads me to the question of whether or not there is some inherent advantage to the AT750 over the BT800. Would someone be able to provide me with some insight?

    I have more or less decided on Bolton because they currently offer the best price for either machine. Smithy was competitive on the 12" machine until sometime in the last couple of days, when they decided to offer "free shipping" by raising the price of their machines to beyond what they previously cost plus shipping. I will now easily be able to get the accessories I want from Bolton and not pay shipping since I will be in the Los Angeles area to pick it up in a couple of weeks.

    The AT750 is identical to the Smithy 1230LTD and the BT800 is identical to the Grizzly 9729. Smithy claims to be the "original and still the best" but I am skeptical of that claim, as I see that the Shoptasks (shopmasters?) have also been around for a long time. All of these machines are imported form China (yay) anyway, so I am thinking the quality differences between brands is likely very little...

    Thanks for your time!

  • #2
    Bump. First time post with links caused this one to get tossed into the moderation filter.
    George

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    • #3
      Welcome Aboard appeye!

      I've seen the Grizzly version in real life and if you can keep your promise to yourself that you'll stick to smaller items I think you'll find that it's quite decently capable.

      Saying that though you need to understand that this is a far better lathe than it is a drill or mill. And even then there's some limitations brought on by the use of one common set of bed rail for the carriage and tail stock. You will want to pay particular attention to keeping the cutter end or work pieces situated within the "footprint" of the carriage on the bed. You can over hang this when needed but go easier on your cuts.

      A trick you may need to employ is to set the gib on the carriage to bed fit for an easy running fit for MOST uses. That'll save some wear on the dovetail. And for those times you need to bend that rule and if you find the machine starting to chatter or otherwise shake, rock and roll then snug up the gib so there's some slight but noticeable resistance on the traverse wheel. The tighter setting will be more resistant to letting the carriage move even that super slight little bit and become magnified by the long distance between the bed and the cutter or workpeice compared to the size of the carriage footprint.

      The next issue is the distance from mill head spindle to carriage table. 12" can get used up really fast with a long drill bit and depending on what you use for a drill press vise. Think "low profile" in all cases to maintain as much work capacity as you can. And in a few cases you may need to use the bed itself as your work table. In such cases use some sort of thin protective thing to avoid dinging the bed way surface on the dovetails. You may even find that in some cases you need to cut down and re-sharpen some of the longer size drills to get them short enough to fit.

      Speaking of low profile one of the bits of tooling you will need/want to buy is an ER collet to MT4 chuck. It's a lower extension than the Jacobs chuck and the used of the ER collets will allow you to hold a full range of drill bits and end mills in a situation where there is precious little such range of tooling available. MT4 is a common size for the lathe spindle and tail stock but not so common for a milling spindle. But the good news is that you can buy an MT4 to ER collet chuck in a few variations. And that neatly takes care of the issue for a LOT of usages.

      Other than this trick you may need to employ on occasion I have to say that the Grizzly version didn't look as bad as many other 3 in 1 machines. I particularly noted that the dials on the hand wheels on that machine are more readable than many.

      Don't get me wrong. I think there are still a lot of things wrong with any 3 in 1. And this one isn't any different. But if you are firmly locked to the idea of one of these I'd say you would be able to do more and do it better with the BT800 than the other. Just be prepared to have to adapt to some "tricks" to get the best out of it.

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      • #4
        Neither of the pictures shown appear to have a power cross slide or quick change gear box, both very desirable. Can you get by without those. If so the they will probably suffice with a limited milling table area.
        The shortest distance between two points is a circle of infinite diameter.

        Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

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        • #5
          New Shimmer!
          It is a desert topping and a floor wax!

          -Doozer
          DZER

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          • #6
            The biggest difference I see is that the MILL swing is bigger on the 750 by 4 inches. ( Max. distance between spindle center to column)

            On the other hand, the 800 is a heavier ( 616 pounds ) than the 750 (507 pounds) but that's normal for a lathe with a larger swing.

            To put these into perspective, the mill head of the lighter machine sticks out more, which should mean more chance of chatter.

            I don't see any features on one that's not on the other. I'd go with the 800.

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

            Comment


            • #7
              A friend bought a combination machine of that style for making model Stirling engines. He found it to be a kind of an OK lathe, but quite limited due to the large centre height compared to the stiffness of the bed. It's all very well to be able to swing a large diameter, but not much use if you can't take a cut without chatter.

              The mill head he just gave up on. Rigidity was very poor and the work envelope small. He went back to the technique he'd used on his old Myford of using a milling slide and holding cutters in the spindle/chuck.

              We eventually made it more usable by removing the head and remounting it behind (and braced to) the bed, which is how Emco did it. It was then much more rigid and had decent X travel.

              Bolton have their version of that setup; http://boltontool.com/Lathes/lathe-m...rice&order=ASC
              Paul Compton
              www.morini-mania.co.uk
              http://www.youtube.com/user/EVguru

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              • #8
                Get the bt800. I have the harbor freight 44142 version for the last 10+ years and it is a perfectly capable machine. If you have any questions ask me and I'll give my advice on mods that I've done.

                Comment


                • #9
                  EVguru's friend's experience with his 3-in-1 matches mine. The lathe was kinda/sorta okay and the milling head was basically worthless.

                  Where are you located, aPpYe? Someone from the forum might be local and able to help out.

                  Comment


                  • #10
                    If you really want new ....

                    I would first by Little Machine Shop's lathe and save up for their mini mill.

                    Not sure where you live but you may be able to find a good used lathe in a comparable size. Buy that and then buy the Little Machine Shop high torque mini mill. I've found it is much easier to find a good used lathe than mill.

                    The 3 in 1s are OK lathes, but terrible mills. I don't own one, but I know 2 people who do and the mill is a frustrating experience. So much that a mini mill can actually run circles around them.

                    It is also much handier to have a separate mill.
                    www.thecogwheel.net

                    Comment


                    • #11
                      Wow, lots of responses! Thanks for the info! I should have also mentioned that I have never machined anything before, other than spinning things on my drill press. I am brand new. I did get knocked out cold once by spinning a wood lathe too fast when I was in high school... I was vomiting for days! This is all brand new to me, so forgive me if some of my observations are rather infantile. I figure that if this turns into something that I want to continue doing, then I can get a mill (maybe even a "real" lathe) down the road. It is just nice to have at least some limited capability to start with, and see what happens. I do know that I wanted a lathe that was bigger than a 7x ...

                      Originally posted by BCRider View Post
                      Welcome Aboard appeye!

                      I've seen the Grizzly version in real life and if you can keep your promise to yourself that you'll stick to smaller items I think you'll find that it's quite decently capable.
                      ...
                      this is a far better lathe than it is a drill or mill. And even then there's some limitations brought on by the use of one common set of bed rail for the carriage and tail stock. You will want to pay particular attention to keeping the cutter end or work pieces situated within the "footprint" of the carriage on the bed. You can over hang this when needed but go easier on your cuts.

                      A trick you may need to employ is to set the gib on the carriage to bed fit for an easy running fit for MOST uses.
                      ...
                      The next issue is the distance from mill head spindle to carriage table. 12" can get used up really fast
                      ...
                      ...one of the bits of tooling you will need/want to buy is an ER collet to MT4 chuck. ... MT4 is a common size for the lathe spindle and tail stock but not so common for a milling spindle.
                      ...
                      Other than this trick you may need to employ on occasion I have to say that the Grizzly version didn't look as bad as many other 3 in 1 machines. I particularly noted that the dials on the hand wheels on that machine are more readable than many.

                      Don't get me wrong. I think there are still a lot of things wrong with any 3 in 1. And this one isn't any different. But if you are firmly locked to the idea of one of these I'd say you would be able to do more and do it better with the BT800 than the other. Just be prepared to have to adapt to some "tricks" to get the best out of it.
                      Thank you for the tips!

                      ... Can you define "smaller items?" The bed length and the spindle bore size are what I found sexy about this machine over getting separate "mini" machines ... What would be a practical size/length/width of items I can machine on both the lathe and the mill?

                      On both machines, the mill spindle and tailstock are actually MT3, the lathe spindle is MT4... Does this change things?

                      Looks like a vote for the larger machine!

                      Originally posted by loose nut View Post
                      Neither of the pictures shown appear to have a power cross slide or quick change gear box, both very desirable. Can you get by without those. If so the they will probably suffice with a limited milling table area.
                      I believe they both have a power cross slide, but no quick change gearbox. I came into this a couple months ago with the idea of buying a 7x lathe, which also requires manually changing gears, so I think I will be okay. This will just be for hobby stuff, and I am not going to be making hundreds of identical parts or anything like that...

                      Originally posted by Doozer View Post
                      New Shimmer!
                      It is a desert topping and a floor wax!
                      Yeah yeah, I hear you! I bought a foldable creeper that doubles as a sitting creeper a few months back. Total crap. I ended up buying a regular creeper ...

                      Originally posted by danlb View Post
                      The biggest difference I see is that the MILL swing is bigger on the 750
                      ...
                      the 800 is heavier
                      ...
                      I don't see any features on one that's not on the other. I'd go with the 800.
                      Is heaver always better with metalworking machines? Does it reduce the chance of vibration or something? I would have thought there might also be an advantage to having a larger mill swing, in the sense that it would allow for larger mill work...? Again, I am new, so infantile observations are quite likely!

                      One thing that initially caught my eye on the 750 is the second lever on the bottom of the main column, a "Lead Screw Direction Lever" ... but it seems that the 800 has the same feature, at least from what I could glean from the manuals. I would definitely be referring to the Grizzly manual a lot more. The Bolton manuals are definitely poor Chinese translation, while the Grizzly and Smithy manuals read a lot more fluidly!

                      Originally posted by EVguru View Post
                      A friend bought a combination machine of that style
                      ...
                      We eventually made it more usable by removing the head and remounting it behind (and braced to) the bed, which is how Emco did it. It was then much more rigid and had decent X travel.
                      Whoa! I didn't know that would be possible! Do you have any pics? It sounds like a lot of work!

                      Originally posted by ahidley View Post
                      Get the bt800. I have the harbor freight 44142 version for the last 10+ years and it is a perfectly capable machine. If you have any questions ask me and I'll give my advice on mods that I've done.
                      Another vote for the 800! I would definitely be interested in what info you can provide!

                      Originally posted by Fasttrack View Post
                      EVguru's friend's experience with his 3-in-1 matches mine. The lathe was kinda/sorta okay and the milling head was basically worthless.

                      Where are you located, aPpYe? Someone from the forum might be local and able to help out.
                      I am Coarsegold, CA. It is in the western Sierras, near Yosemite...

                      Originally posted by enginuity View Post
                      If you really want new ....

                      I would first by Little Machine Shop's lathe and save up for their mini mill.

                      Not sure where you live but you may be able to find a good used lathe in a comparable size. Buy that and then buy the Little Machine Shop high torque mini mill. I've found it is much easier to find a good used lathe than mill.

                      The 3 in 1s are OK lathes, but terrible mills. I don't own one, but I know 2 people who do and the mill is a frustrating experience. So much that a mini mill can actually run circles around them.

                      It is also much handier to have a separate mill.
                      LMS machines are the first I looked at, and was near pulling the trigger on them, but the lathes are a bit small compared to the 3 in 1 ... I realize that separate machines are the way to go for the very best in precision and ease of use, but the price is right for what I want to do with it. I don't have to have new, but many of the used machines I have seen on Craigslist are either extremely old, like turn of the century old, sitting outside with rust all over them or out of my price range.

                      I figure that if I like making things out of metal, then I can look into getting a better mill down the road...






                      Thanks again everyone for your replies! I really appreciate any information you can provide!

                      Comment


                      • #12
                        I have had one similar to the ones posted and found the drill and the mill part almost unusable because of about 3 inches of travel in the drill spindle with no way to reposition the head in the vertical direction.3 inches total z is very limiting and will drive you nuts. James

                        Comment


                        • #13
                          Originally posted by aPpYe View Post
                          This will just be for hobby stuff, and I am not going to be making hundreds of identical parts or anything like that...
                          That's exactly what I said. I was wrong. As you turn different diameter work pieces or different materials, you'll want a different feed rate. Even if you never do single point threading (which you really should learn how to do at some point), not being able to quickly and easily change the feed for different materials was a huge inconvenience for me. For some materials, you can feed manually and get good surface finish and good tool life but for other materials - even normal stuff like mild steel - having power feed makes a huge difference and not having to pick gears is a huge plus. My Smithy had a high/low range lever and a reverse lever. I eventually found a pair of gears that worked pretty well for mild steel at the typical diameters I was turning so I minimized the number of times I had to adjust the gear train.

                          Originally posted by aPpYe View Post
                          Is heaver always better with metalworking machines? Does it reduce the chance of vibration or something? I would have thought there might also be an advantage to having a larger mill swing, in the sense that it would allow for larger mill work...? Again, I am new, so infantile observations are quite likely!
                          Yes. As many machinists will tell you, everything turns to spaghetti when you start talking about holding tight tolerances. Even a full size knee mill (think Bridgeport) is too floppy and flimsy for my liking these days. You can use lightweight "flimsy" machines, but you have to take hundreds of super shallow passes and there are so many ways for things to go wrong. Some materials just don't like to be cut with shallow cuts or conservative feed rates (e.g. machining 316 SS on a 3-in-1 is a lesson in frustration) and it's not uncommon for things to shift on you. You could get to your 99th pass out of 100 and have the head turn or something else shift and screw everything up. The bigger and more rigid the machine, the better from a material removal perspective. The downside is that they are ... well ... bigger and heavier. It can also mean they are less versatile. For instance, a metalworking planer can take massive cuts from flat geometric shapes with extremely high accuracy but that's "all" it can do.

                          Basically, 3-in-1's do a lot but they do it all poorly (poorly being a subjective term). Specialized machines can only do 1 thing but they do that 1 thing to perfection. Personally, after having owned a 3-in-1, I wish I had skipped the 3-in-1 and gone to something a little more specialized, like a small used lathe and used benchtop mill. Those are still cheap, relatively small and versatile but more capable than a compact 3-in-1.

                          That said, I completely understand the barrier to getting started. In a lot of ways, just buying an affordable new machine is easier than learning enough to be able to confidently buy used machines. So if you decide to buy one of these 3-in-1 machines, I would go for the smaller but heavier one and figure it's a good stepping stone to individual machines.

                          Too bad we're on opposite coasts. I could probably get you setup with my old Smithy. It would need some love; I removed the milling head a while ago and never bothered to put the blasted thing back on.

                          Comment


                          • #14
                            I have owned and used a Emco Maximat 7 I purchased new in 1969 (http://www.lathes.co.uk/emco/page4.html) and I love it. It does have some minor drawbacks though. These are mostly with the mill. The milling table is rather small for one. I have cured this by making a larger bolt-on milling table that fits on top of the cross feed milling table of the machine. No T-slots, just drilled and tapped holes to bolt things down. The other is I wish I had more distance from the milling post to the center of the drill chuck. But I know this close distance is to retain the rigidity of the mill during a cut. You can't have everything I guess. The vertical distance of the mill head on this machine is ample and I am O.K. with it. The lathe itself is superb and very rigid. My machine is similar to the Bolton BP250V (http://boltontool.com/Lathes/lathe-m...rice&order=ASC) except the Bolton is a 10" lathe and mine is a 7" lathe. On the whole, I think in the long run you would be grateful having chosen the Bolton BP250V. More money, but you will be living with this machine for the rest of your life.
                            Last edited by Planeman41; 12-20-2017, 07:29 PM.

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                            • #15
                              One of the things that make it difficult to compare a 3in1 against a conventional lathe and mill is that they seldom include all the normal measurements. For instance, it's good to know the spindle over the bed distance for the max swing, but you also need the spindle over cross-slide for the maximum cylinder that you can turn. It's possible to have a lathe that can turn a 10 inch pulley but not a 6 inch axle.

                              In the case of the 3in1 pair that you are choosing from there are some unconventional designs that make the numbers less meaningful. Max table to spindle distance normally tells you what your work envelope is. The 3in1 requires that you put bracing under the work to bring it within the range of the spindle's 4 inch travel. This reduces the size of the work you can reach.
                              At the end of the project, there is a profound difference between spare parts and extra parts.

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