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  • Brand New LittleMachineShop Lathe Owner

    I did it.

    I bought a LittleMachineShop 8x20 lathe. I can see from here that I'm in over my head.

    https://littlemachineshop.com/produc...ory=1271799306

    My first problem is, I hope, a simple one.

    If I understand this correctly, (I can build a hip roof and pour concrete upside down under water. Metal work, not so much.) the feed rate is determined by the speed of the lead screw.

    On this machine, the speed of the lead screw appears to be set solely by the change gears. There also appears to be exactly two (and only two) speeds.

    With everything I've read about how important feed rate is, I was surprised that there are only two speeds to choose from.

    Am I wrong about this? Is there another way to adjust feed rate on this machine?

    What have I missed?

  • #2
    Generally lathe feeds are set in inches per revolution, such as .020" IPR for 3" diameter steel parts when roughing, depending on finish requirements a good number is .004-.008" IPR for finishing at this size..

    This works for me yet may not work for you, I start the job at the high end of feeds and speeds.

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    • #3
      It looks to me like on this lathe, I can choose between two and only two feed rate.

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      • #4
        The feed rates will be set by the change gears. Which feed is determined by using different gears in the different positions in the gear chain. The choice of 2 feeds is probably the choice of threading (TPI) or feeding (IPR). Look up changing gears in the manual.
        Last edited by Bob Engelhardt; 12-16-2021, 09:12 PM.

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        • #5
          Originally posted by Jammer Six View Post
          It looks to me like on this lathe, I can choose between two and only two feed rate.
          Very limiting indeed, a very unfortunate situation.

          I took a gander at the Little Machine Shop website, it was quite instructive.
          Last edited by Bented; 12-16-2021, 09:29 PM.

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          • #6
            Is there a link to the manual of that machine? I may have missed it but I didn’t see it on the webpage.

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            • #7
              Originally posted by Jammer Six View Post
              On this machine, the speed of the lead screw appears to be set solely by the change gears. There also appears to be exactly two (and only two) speeds.
              -I don't know about that specific machine, but generally, they'll come with a packet of gears of varying sizes, and somewhere on the machine or in the documentation, will be a chart saying which gears go where to achieve a certain feed rate or thread pitch.

              If you did not get them- cost cutting is everywhere- they're available separately from eBay, LMS, Grizzly and other places that generally sell the little Asian lathes.

              Doc.
              Doc's Machine. (Probably not what you expect.)

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              • #8
                You have two from the carriage, but both of those are affected by the change gears. Essentially you have as many feed rates as you have different threads you can cut- so no, you are not limited to two feed rates. Granted, most of those would be too coarse for a feed rate, but if I'm not mistaken you can cut up to 150 odd threads per inch. Once you figure it out, you'll see you don't have a problem.

                I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                • #9
                  According to the link you posted change gears are included for threads from 8 to 80 tpi. Just need to read the manual and change gears. Do some reading elsewhere as well. Maybe southbend how to run a lathe or an equivalent would be good place to start. There is some math to figure out but it’s pretty simple
                  Last edited by Captain K; 12-16-2021, 09:43 PM.

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                  • #10
                    I have no knowledge of the machine you hve bought. However, as a beginner you might do worse than learning how to move the saddle( Thats the name for the whole of the tool holding arrangements)slowly enough by hand that you can reduce the diameter of a rod and get a smooth even round job. The leadscrew may have a handle on the very end of thelathe bed (that is the long screw which runs the length of the lathe) and the screw may be attached to and released from the saddle by a lever on the saddle. Put a piece of bar, aluninium 6061 for preference about 1/2 in diameter in the chuck, stick it out about 1 inch put a knife took in your toolholder, set the lathe speeds to as fast as it goes, lubricate the work with alittle WD 40 or similar, touch the tool to the work, move it in a very little bit and very slowly move it by hand, trying to turn the handle as evenly as you can. Practice a few times, maybe many, till the rod is down to 1/4 or less, Then get a fresh piece and begin again, Once you get reasonabe results then look at power feeds, Regards David Powell.

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                    • #11
                      That web site is awful. I did find this document explaining the change gears and how to change them:
                      https://littlemachineshop.com/instru...readingSC4.pdf

                      This document is only for threading so I assume the owners manual will have similar instructions to set the feed rate.

                      You will enjoy your new toy once you get started. As others have said the two speeds you refer to are for feed and threading. Read the document and look over the charts. Good Luck!
                      Robin

                      Happily working on my second million Gave up on the first

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                      • #12
                        Originally posted by Jammer Six View Post
                        I did it.

                        I bought a LittleMachineShop 8x20 lathe. I can see from here that I'm in over my head.

                        https://littlemachineshop.com/produc...ory=1271799306

                        My first problem is, I hope, a simple one.

                        If I understand this correctly, (I can build a hip roof and pour concrete upside down under water. Metal work, not so much.) the feed rate is determined by the speed of the lead screw.

                        On this machine, the speed of the lead screw appears to be set solely by the change gears. There also appears to be exactly two (and only two) speeds.

                        With everything I've read about how important feed rate is, I was surprised that there are only two speeds to choose from.

                        Am I wrong about this? Is there another way to adjust feed rate on this machine?

                        What have I missed?
                        You've discovered the pitfall with new, small lathes. Nothing is easy or quick. Giant used machines come with lots of features, up to and including gear change headstocks, quick change gearboxes that cut metric with the flip of a lever, self lubricate, etc. Hell, I've got a lathe that can change feed rates, feed direction, and spindle speed right on the saddle. The tradeoff is that they are big, heavy, complicated, expensive, or worn, and often damaged.

                        But, I don't want to be too disparaging to your new purchase. It can be a great machine! It just requires patience. There are people doing unbelievable work on those little things, just not very fast. On yours, you'll have to physically swap greasy gears to change the feed rate. That's the nature of the beast. I'd recommend finding one you can stand for about every operation, and hand feed the rest. As far as spindle speeds you have the DC motor control dial on the front.

                        Feed is important, but there are different cutting strategies. The important thing is to make a controllable chip that isn't stringy and won't get wrapped up and hurt you. On cast iron, this is trivial. Cut it at any speed for feed. On aluminum and plastic, it will probably be impossible on your machine. Use small tool nose radius tools so you can push a heavier feed at a smaller depth of cut, and you'll have a better chance of making the chips you want. Hopefully I haven't gone too in depth. Just ask questions as you go along.

                        Cheers and good luck.
                        21" Royersford Excelsior CamelBack Drillpress Restoration
                        1943 Sidney 16x54 Lathe Restoration

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                        • #13
                          One, no, I'm told that there is no manual for this specific machine. I received a hard copy of a manual for a similar machine, and the link I found on their website for my "manual" also led to a similar machine.

                          I don't know if I'll ever see a real manual, Little Machine Shop simply told me there was no such manual, and sent me a PDF of the same, similar machine. When I suggested my name be added to the list for the new manual, whenever it comes out, they didn't answer. Apparently I assumed too much.

                          Be all that as it may. The situation is quite satisfactory between Little Machine Shop and I, I've done virtually all my shopping there, and they've been fast, courteous and helpful at every turn. Their website contains options and information I found essential when I was making my decisions, and at the moment, as far as I'm concerned, the main thing they've sold me is the assurance that everything they've sold me works together, and that no, Jammer, it's not the machine. It's the right part.

                          Two, I never thought about doing it by hand. Of course! Now I'm going to need more aluminum rod... The lead screw on my machine ends in a hole in the casting (cast iron) that has a bearing and an oil ball fitting. I'll try it by the feed wheel.

                          Three, I haven't paid a lot of attention to the chips yet. (Except to assume that when it stopped making a chip and started making powder the (HSS) insert was shot. Rotating it fixed it.)

                          Four, of course! The light comes on! I can use whatever-this-feed-is as the feed factor, and then adjust the rest of the equation to suit whatever is required.

                          Five, I'm going to swap the gears out just to try a different feed rate or two, and just to see exactly how difficult and time consuming it is. I imagine a guy could get good at it.

                          Six, Time doesn't matter. I bought the lathe to learn something new. I traded mere treasure for fascinating questions about a new world.

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                          • #14
                            P.S. I still don't understand the difference between the power feed and the half-nut. It sounds to me like they do the same thing.

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                            • #15
                              Did you ask others about this lathe? About Sieg products? And they told you to buy it? Did no one try to steer you away from the trap of thinking you needed a "beginner" lathe to get started?
                              Well, that's all water under the bridge now. Best thing you can do is just start to use it and make some chips. watch some youtube videos and ask questions like you are. It's a lot better than the 7" lathe, glad you didn't buy the mini lathe. I would of suggested anything over a Sieg product though.

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