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      E-MAIL   Tony@lathes.co.uk
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      Walram Lathe Fine-feed
      and Speed-varying Attachment
      Drummond Home Page   Drummond Round Bed




      A stage beyond the usual third-party backgear systems sold for the Round Bed Drummond (and probably designed for use on a variety of lathes), the ingenious Walram attachment was bolted to the end of the headstock casting and driven from the normal countershaft by a flat belt. The unit, which allowed the spindle to be driven through either reduction or step-up gearing, also provided a means of powering the leadscrew and would have been able to generate an ultra-fine carriage feed. The fine feed was achieved by means of an additional compound reduction gear train where two gear, one large and one small, are pinned together on a common shaft. Normally the Round Bed (like most other lathes) would have been able to accommodate only two compounded gears but, with the Walram in place, three could be assembled. For example: with gears sets of 21/40, 20/63 and 20/64 in place a feed rate equal to 192 T.P.I. could be generated, far finer than that available with the standard set-up
      As the Walram employed the left-hand threading bracket as part of its mounting it could also be used to generate left-hand pitches and so was able to be left in place for all normal work..

      The Walram being used to provide a left-hand threading drive to the leadscrew. It could also be assembled to give an ultra-fine carriage feed by means of an additional compound reduction where two gears--one large and one small--were pinned together on a common shaft. Normally the Drummond Round Bed lathe would have been limited to two such assemblies but with the Walram in use three could be set up

      The Walram arranged to drive the headstock spindle through gearing (though as arranged in the picture the final speed would have been little different to a direct drive). To obtain a reduced speed a compounded train would have been needed i.e. a small gear would have been fitted to the top shaft driving a large gear beneath to which would have been pinned a second gear driving to a large gear on the end of the spindle




      The basic Walram unit




      E-MAIL   Tony@lathes.co.uk
      Home   Machine Tool Archive   Machine-tools for Sale & Wanted
      Machine Tool Manuals   Machine Tool Catalogues   Belts   
      Books   Accessories

      Walram Lathe Fine-feed
      and Speed-varying Attachment
      Drummond Home Page   Drummond Round Bed
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