Quantcast

Search results

Help Support HMEM:

  1. E

    Sheraton 9A Headstock Lapping

    I am in NSW. Some of the states have various levels of mask wearing, border closing and movement restrictions. Here masks are recommended - and common, but not 100%. Indoor groups limited, restaurants and bars have restrictions. NSW tests over 10,000 per day, infections are down to about 5, with...
  2. E

    Sheraton 9A Headstock Lapping

    Dubi, Thanks for the comments, and photo. Each spindle end inserts into its respective bore without any looseness, and rotates firmly. Started adding longitudinal marks with non-permanent wick pen to assist assessment. Can insert spindle all the way axially by hand without twist, then extract...
  3. E

    Sheraton 9A Headstock Lapping

    The rear bearing was an exact fit, bore to shaft, so some work expected. Side-stepped the possibility of using a hone for now. Used the previous approach, timber lap in the mill with Z-axis cycles programmed on the CNC. Worked for some time before I could achieve entry of the spindle. Then...
  4. E

    Sheraton 9A Headstock Lapping

    Job done, for now. Made a timber lap mounted on a M12 stud with a Dia 20 mm cylindrical nut at one end. Mounted in the lathe with an ER32 20 mm collet, sized the lap to about Dia 44.5 mm. Reduced an ER32 collet nut down to Dia 43 mm so that it would enter into the headstock bore. (The nut...
  5. E

    Sheraton 9A Headstock Lapping

    Thanks for all the comments, especially the warning on lapping with a grit. I have made a timber lap, and tried it with just light oil. The CNC repetitive cycles works a treat. Scraping is a big step for me, I have only ever done small flat CI surfaces as test pieces. And, I cannot get the...
  6. E

    Sheraton 9A Headstock Lapping

    The Sheraton 9A is close cousin of a Southbend 9A, and a close copy of the Hercus 9A both built in Australia. My 9A #1167 was purchased in 2007 and operated successfully for a couple of years. I read all the books and diligently kept a good supply of oil up to the headstock bearings. I taught...
  7. E

    Cast Iron - Thin Sleeve Insert

    Finished the strip down and clean. Had to use 2T press to separate the work spindle from its end bush. Sheared the intermediate key into two parts, and caused some swelling of the end bush above its keyway. Assembled with grubscrews in lieu of a key, really could do with re-making the end bush...
  8. E

    Cast Iron - Thin Sleeve Insert

    Thanks for all the responses. I have finished the job: - made up some setting aids and bored the casting out on the vertical mill, - turned extruded CI to correct size for a glued fit to the casting (with 0.05 mm relieved centre), - held piece in a large collet and bored out for fit to the...
  9. E

    Cast Iron - Thin Sleeve Insert

    I have a Spanish tool grinder, Premeta SL, a reasonable copy of a Deckel SO D-bit grinder. The general condition is OK, but the sliding clamp fitting to the main horizontal shaft (Main Axle) is excessively worn. A proposed correction requires boring out the original casting and fitting a...
  10. E

    Swarf Catching

    The job was several height adjusters for Dickson tool holders destined for a Harrison M250. 25 mm bright bar on a Colchester Bantam with HSS producing a long curl of swarf. I was watching the build-up of swarf below the bed and slowly filling the bed between the ways. I thought "must stop and...
  11. E

    Gearcutting

    I agree with vcutajar that the 3 slots are a limitation. I have a HV-6 and I have made dedicated slot nuts and slot nut extensions to extend clamping options. My RT has an incorrectly engraved vernier scale, not a real problem once you get your head around the error. Check that the vernier...
  12. E

    Rotary Table minutes seconds

    Bob, my comment about modern imperial verniers being double length is not quite correct (thinking lapse !). The vernier is actually (2N-1) x main scale units. This is the normal (N-1) main scale units for the standard vernier + N main scale units to double the scale length. So the imperial...
  13. E

    Rotary Table minutes seconds

    Bob, Living in an apartment 1500 km from home gives one time to think ! The 9/10 factor does not apply to the rotary table scales. This factor applies when the primary scale is divided into 10 parts by the vernier. Each vernier division is 9/10 of the main division. A movement of 1/10 main...
  14. E

    Rotary Table minutes seconds

    Bob, you may be correct, but I am not sure. The 9/10 effect is something like what I observed. I thought the vernier should span 10/10 of a the main scale. That is, the 120 seconds of vernier spans main scale graduation to main scale graduation = 2 minutes. The 6 graduations on the vernier then...
  15. E

    Rotary Table minutes seconds

    J, I have a 6 inch Vertex that has got an incorrectly engraved scale on the vernier. It was very perplexing until I twigged to what the problem was. I am away from home at the moment, so I cannot be more specific, but I know it was easy to allow for the errors once I became aware of them. The...
  16. E

    Stain on Mill Table

    Hi, I have a stain on my mill table with a thin line following exactly the outline shape of the milling vice that had been clamped there. Small vertical mill, FB2 clone. Interposing bedding sheet of paper that had been discarded from my wife's volunteer activity printing. Standard (cheap) A4...
  17. E

    Small Boring Head Leadscrew Pitch

    Hi, Thanks Guys for all the comments on this subject. I think Bob Ward may have hit the nail on the head. A 33 1/3 TPI with 30 divisions would be usable for imperial jobs (0.001 in), and 0.75 mm the near equivalent for metric. Perhaps the 34 TPI is a very smart choice by the manufacturer. No...
  18. E

    Small Boring Head Leadscrew Pitch

    Hi, I have just purchased a small boring head from a prominent UK retailer. It was supplied as a metric 40 mm unit with a MT2 arbor. The adjustment leadscrew thread is 34 TPI (yes, 34) with a rotary scale of 50 divisions. The pitch is definitely less than 0.75 mm. This makes one scale rotation...
  19. E

    Centering With Low Tailstock

    Hi, My lathe has a significantly low tailstock, perhaps 0.15 mm close to the spindle with minimum tailstock extension. I intend to correct it 'one day', but in the interim I would like to progress a few jobs requiring centres (like 5 inch gauge axles). It seems to me that the orientation of...
  20. E

    South Bend Class Lathe Spindle Bearing

    Hi Miker, Yes, the photos are virtually identical to my machine. I am near Penrith, send me a message if you would like to chat about lathe problems. I notice in my original post I wrote 0.005 mm, that is way to optimistic for the grooves I can feel through the shim slot with a thin wire probe...
Top