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Adjustable hand reamer in lathe?

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  • Adjustable hand reamer in lathe?

    I'm fixing up the control linkage on an old tractor; worn pivots, etc. One of the pivots that goes thru the governor housing has a replaceable bushing, but the pivot shaft is worn tapered. I'm planning to turn the pivot shaft down a bit undersized, but very minimally, a few thousandths, as it has an "O" ring in the center, and I can live with a few thou undersized & keep the O ring as is. So I need to turn a brass bushing to fit. It will have a clearance hole for the turned pivot around .380" or so, and I want to have the bushing fit with a thousandth clearance or so.

    I have a set of adjustable hand reamers in the right size. I figure I could drill out to 3/8", and creep up on .380 with light cuts, a thousandth or two at a time, until I had a nice fit. However, I've never used these in the lathe.

    So I'm wondering, anyone have suggestions? Material is brass, so it should be no issue, but I'm wondering about speeds, feeds, lube, etc. and any other observations. (I've heard these can set up chatter when used in a lathe....)

  • #2
    These are hand reamers. Always turn in one direction and never reverse turn even when you back it out. If you do it can lock up in the bore.


    • #3
      I know they are hand reamers; but I want to try them in the lathe.

      I learned the hard way 30 years ago that you never turn them CCW!

      The problem I have had with hand reamers "by hand" is getting a good consistent hole all the way through. I figure chucking in the lathe will help concentricity of feeding it, even if I have to turn the spindle by hand.


      • #4
        If by an adjustable reamer, you mean the ones with the adjusting screw in the end, it should not be a problem, just keep speeds low. If you are referring to the blade type expansion reamers, I would not advise it.
        Jim H.


        • #5
          I didn't think it would be a problem... until I tried one and made a helical reamer out of a straight blade adjustable Musta been too big a bite?
          Design to 0.0001", measure to 1/32", cut with an axe, grind to fit


          • #6
            Not the best option

            A reamer will tend to follow a drilled hole. My temptation would be a boring bar while it is still in whatever part holder you are using. Drill close and single point with the biggest boring bar you can get through the hole. If the "O" ring is the seal, you will want close to a polished finish or the bushing will eat the "O" ring.


            • #7
              When using a tool such as a reamer in the lathe under power, support the reamer with the tailstock center in the center hole of the reamer. Hold the reamer with a tap wrench on the drive square. If the reamer grabs, let it slip out of your fingers and spin free. Make sure there is room for the tap handle to spin, so it does not hang up on some part of the lathe.
              Jim H.


              • #8
                Don't use brass for bearings, use bronze or sintered bronze. Brass makes a very poor bearing. Bore to finish size, the reamer will likely jam and crash on you unless you are turning the chuck by hand some way. Peter
                The difficult done right away. the impossible takes a little time.


                • #9
                  Bore it?

                  If the job is in the lathe, why ream it at all? Why not bore it? Why not drill the bush out to say 5/16" to 3/8", press it into the lever, mount the lever in the lathe as you seem to be going to do, and then bore it out?

                  Why brass and not (phosphor/bearing or "sintered") bronze?

                  Reaming is always my last option as I prefer to bore if I can. But if I must ream, I prefer to get to reaming size by boring as well.


                  Sorry Peter (Brockley) as it seems I was typing as you posted.

                  [End edit]

                  [Edit 2]
                  It is quite possible that the reaming load will make the bushing slip in the lever and jam on the reamer - and then you may well have another problem.

                  [End edit 2]
                  Last edited by oldtiffie; 03-16-2009, 10:22 PM.


                  • #10
                    The adjustable hand reamers are only good cutting a few thousandths at a time. If your insistant on using the lathe then use a center in the end of the reamer and feed the reamer in with the tailstock as you turn it by hand with an adjustable wrench.

                    I would not recommend running the chuck to power ream it. They are definatelly not designed to be power driven.

                    You can, however, buy a replacement if you destroy it.

                    I agree, don't use brass for the bearing if you intend it to last a long time. If it is running in an oil bath it may work.
                    It's only ink and paper


                    • #11
                      Don't use brass for bearings, use bronze or sintered bronze. Brass makes a very poor bearing. Bore to finish size, the reamer will likely jam and crash on you unless you are turning the chuck or the reamer by hand some way. Peter
                      The difficult done right away. the impossible takes a little time.


                      • #12
                        DONT run the hand reamer under power.

                        You will destroy the hand reamer as they are not made for use under power. The reamer will build up a chip in frnt of the cutter and stick, followed by snapping reamer shaft or splattering cutter blades.

                        That being said, go ahead and chuck the work in the lathe and use the tailstock center for guidance, but realise that perodically you will need to back up the cutter to remove excess chip buildup.

                        If determined to do this on a lathe under power, get a chucking reamer or use a boring bar.


                        • #13
                          Whether a chucking or hand reamer, the chips accumulate in the flutes, and the reamer should be removed and cleared frequently in either case. If chips are allowed to build up, poor finish or damage to the tool will result.

                          Aside from the difference in the shanks, the only real difference between hand and chucking reamers is in flute length and entry taper. A hand reamer has a longer flute length and a more gradual taper at entry. The purpose is twofold, to reduce power requirements and to guide the reamer.

                          A chucking reamer has much shorter flutes and, usually about a 45 degree angle on the end for entry as the machine provides the power and guides the reamer.

                          I have used hand reamers under power for years with no problems.
                          Jim H.


                          • #14
                            Not a hand reamer - an adjustable hand reamer


                            I'd agree that a hand reamer could work OK, but I have seen them twisted off depending on what they are being put through.

                            In this case though I think what is being used is an adjustable hand reamer where the blades are separate and are held by threaded bushings at each end and may have blade slots in the threaded shank. These are remarkably delicate when compared to a solid reamer. With these, what usually happens is the end of one or more blades snap off and the shank twists off if used too aggressively.


                            • #15
                              I agree that the blade reamer should not be used under power, and mentioned that in my first post.
                              Jim H.