Announcement

Collapse
No announcement yet.

Lathe Power Cross Feed

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

  • Lathe Power Cross Feed

    Wanting to pull the trigger on a small bench lathe. Space is the constraint, pretty much limited to 4' overall length max (40" or less preferably). Looking for 'new' as I don't want a pile of headaches, rust and dirt. Rather spend the cash/time fleshing out areas of improvement on a new import. Looking at Optimum, LMS (HiTorque) or a Grizzly variant.

    How valuable is the power cross-feed? Seems like a significant benefit to me. I have done a ton of reading looking for the best-in-class small import but can't identify a solid contender. Thinking I can land a decent one under $2K.

    Thanks!

  • #2
    About the only time I use mine is facing. It is handy and makes the finish nice on larger ODs. (Small too but less noticeable.) Some use it for parting too but I don't have enough machine or cutter to do that--I manually feed while parting.

    Comment


    • #3
      Obviously used for a consistent finish in facing, but for me, essential for parting. I went for ymany years using a lathe without power cross-feed, now I wouldn't have a lathe without it.

      Comment


      • #4
        I must admit I'd call it an essential myself,but there is always a but, make sure surfacing is engaged before surfacing, not sliding, it's easy to get them mixed up!
        It's always a nice suprise when facing you find the carriage heading towards the headstock and your facing cut turning into a reducing cut, always makes me laugh, not
        Always check, then check again
        Mark

        Comment


        • #5
          Originally posted by boslab View Post
          I must admit I'd call it an essential myself,but there is always a but, make sure surfacing is engaged before surfacing, not sliding, it's easy to get them mixed up!
          It's always a nice suprise when facing you find the carriage heading towards the headstock and your facing cut turning into a reducing cut, always makes me laugh, not
          Always check, then check again
          Mark
          Can't be done on an A/C. It breaks gears in the carriage if you attempt to engage the cross feed while the carriage feed is engaged. Or engage the carriage feed while the carriage is locked, like it should be for facing.

          Comment


          • #6
            If you find a lathe you like but it doesn't have a power cross feed, all may not be lost. You probably can fit a small DC gear motor to drive the crossfeed when you want to for less than $100 in parts. On my milling machine I have a Dayton 90V gear motor that is driven by a half-bridge rectifier feeding a household dimmer switch. Works great. You'll need to disconnect it mechanically when not in use but that can be done by removing the belt or sliding the drive gear out of engagement, however you end up connecting it. A window lift motor from an automobile would do the trick too and may make sourcing the power supply easier. I am in process of doing this on my SB 10L, though the taper attachment is making the a connection on the back end difficult. Just a thought.....

            Comment


            • #7
              Power cross feed was one of my must have options and I ended up with a classic 10" Logan (gear change type). Holding out for a quick change gear lathe would have made the power feed more user friendly. Ultimately I'll probably add a variable feed motor. Got the lathe for a really good deal (needed minor work) so....

              DS

              Comment


              • #8
                Originally posted by CCWKen View Post
                Can't be done on an A/C. . .
                I don't know what an 'A/C' is, but on my Sheldon you can only engage one or the other. The difficulty, as boslab stated, is remembering which is engaged before you pull the clutch in.

                Comment


                • #9
                  The Emco V10P has power cross feed, but only the P variant. It's interlocked so you can only use cross or longitudinal feed at any one time. Yes, it's "nice" to have.

                  Comment


                  • #10
                    Thanks for the opinions. Power cross feed narrows down the options, which is good I guess. Can I ask about the value of a continuously variable motor vs pulleys? Variable speed seems preferable, or do you typically use a fixed rpm for a given material?

                    Much appreciated.

                    Comment


                    • #11
                      I have power cross feed, and cannot recall ever using it.... Maybe a few times to see if it was worth bothering with... that got answered "NO" very quickly.

                      Main reason is not having a QC box for threading. When you are set up for a coarse thread, then to use the crossfeed, you have to change gears, because there is a fixed ratio between them, feed wise. Usually whatever you have set from the last threading task will be wrong for a smooth facing job, and ditto as far as cutoff feed. (Alternately, if you always leave it set for feed, you will have to change and then change back whenever you want to cut threads)

                      If you have a QC box, then it's a few seconds to set for a reasonable feed rate. And a few seconds to set back to your next thread pitch.

                      So if you insist on buying a partly finished "lathe kit", (aka small cheap chinese lathe) then make sure to get one with a QC box that has useful thread pitches (not just whatever they thought was easy).
                      Last edited by J Tiers; 01-15-2016, 12:36 PM.
                      1601

                      Keep eye on ball.
                      Hashim Khan

                      Comment


                      • #12
                        Interesting - thanks.

                        I don't see doing as much threading as machining so I don't mind a little occassional inconvenience. I also, I don't see the luxury of QC box in my near future given the constraints and offerings in the marketplace.

                        Looks like LMS' Sieg variant (8.5X20) offers the most in a reasonable package - variable speed brushless, power feed in both axis. I stumbled on a Bolton branded 10X22 but no variable speed. I am reluctant to go Grizzly for some reason and the Optimum, which may have better overall quality doesn't have the cross-feed.

                        I will just mull over it some more before committing. The main obstacle for me is not knowing what I don't know.Fortunately it's intuitive but unfortunately deciding what 'gives' and 'takes' is the hard part i.e. should I give some spindle bore diameter in favor of a little extra weight or power... There's lots of that for me to consider. I am probably making too much of this at this entry point anyway.

                        Thanks again.

                        Comment


                        • #13
                          I'd put one of these near the top of my list, although you might have to wait for one. Comes in on your budget price-wise and the 10x27 lengthwise. The 10x30 isn't much more money, so I'd try and figure out a way of squeezing it in.

                          Comment


                          • #14
                            If I had to use change gears I would be inclined to agree with J Tiers. I would probably use manual cross-feed more often. At this point it's doubtful I would revert to a lathe without a QC gearbox.

                            Comment


                            • #15
                              Maybe I don't fully understand a QC gear box. Would the effect not be the same as continuously variable 3 phase brushless motor driven lathe where you simply turn a dial and the RPM changes? I get that the QC lets one maintain a constant head speed/rpm while varying feed rate. Given that I may not be turning at an optimum rate, could I not achieve the same results just changing motor speed? Also, there are some options with a two speed electronic switch and I think some have both variable motor and switch like Sieg's SC4 (the LMS variant I mentioned). I am definitely confused about all this functionality.

                              Comment

                              Working...
                              X