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Affordable T-rest

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  • Affordable T-rest

    I lust after the W. R. Smith T-rest sold for my Sherline lathe, but the $200 is daunting. I've never really tried doing anything serious with a graver, but want to start and learn.

    So my question: Does anyone know of a quick & dirty option around the elegent Smith tool?

  • #2
    It isn't a precision part so could be build from materials found around the shop, probably in fairly short order. The rest proper could be farmed out for casting using a simple pattern easily made from wood. Many of the parts can be cast, in fact, and the patterns are very basic. Everything can be built up from loose parts too, of course, and would be quite inexpensive.

    I wouldn't consider using one without collets exclusively.

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    • #3
      There was an article in HSM (I think) with dimensions, and instructions. But, it's not that critical. You can pretty much scale it off the drawings in the Sherline instructions that are online. One point is that in a followup article Mr. Smith pointed out that the top of the T should be hardened so that tools won't dig into it as you slide them.
      .
      Mike

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      • #4
        If I remember correctly, William Smith had a build article in HSM several years ago on the T rest as a part of one of his articles on clock making. You might be able to find a back issue, or it might be available in one of the Village Press Projects books.

        Even if plans are not available, he did build the original, which Sherline has duplicated and is now selling for $200.00. I can see no reason an acceptable substitute could not be fabricated by the average HSM in a short weekend with nothing more than said Sherline lathe a drillpress and a few hand tools.

        I was typing as mwechtal was posting, I do remember the hardening reference also.
        Jim H.

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        • #5
          Form-turning and tooling

          For the sake of those that don't know what the topic of discussion is, I decided to "look it up".

          http://www.sherline.com/2110inst.htm

          http://www.sherline.com/gravers.htm

          http://www.google.com.au/search?hl=e...e+Search&meta=

          This is really just an "up market" or smaller version of the traditional method of "form-work" in a lathe.

          It was one of the first things taught in pre-Apprentice-ship training on a lathe - usually a small belt-driven "South-Bend" or copy.

          It was and is a very effective indeed as very complicated shapes can be "formed".

          If it reminds you of a Wood-turners lathe - it should - as the principles are very similar.

          It is essential that low speeds be used and that the support bar be very rigid and as close to the work as possible.

          The support need not be at all precise or involved. The support can be nothing more than as deep a bar as possible in the tool-post of a lathe. A "T" can be as simple as a closed-ended tube bolted to a cross-slide and with a bar welded across the top of it. Height should allow for tool thickness and centre-height.

          All we used - and all I use still - is a good quality 10" or 12" "flat" hand file with the "teeth" run off it on the side of a grinding wheel on a pedestal grinder. The tool edge is really pretty much that of a machine hand-scraper. Put say 2 >5 degree front clearance on it with a "rounded" face (large radius), hand-hone it on an oil-stone and you are ready to go. The whole set-up MUST be as rigid as possible as there are some very large forces here due to the very low speeds and gearing and the usually relatively small diameter work.

          There must be minimum gap between the support and the job - always!!

          It is VITAL that the tool NOT "dive" in between the tool-rest and the job - the tool MUST be gripped very firmly.

          Top and side rakes can be made or adjusted to suit as you gain experience and confidence.

          It is a very old but still novel way of using a metal-working lathe - but a very effective one.

          The file will work very well. Use plenty of cutting oil and keep a firm grip. Use low speeds. Keep the tool edge VERY sharp and honed to a fine edge as it depends on it!!

          You might be quite pleasantly surprised at just how those "difficult" form-work jobs become quire easy.

          This is NOT a job for the "faint of heart" or the "hoggers" and "tear-arses" either.

          Go for it - its fun and very satisfying!!

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