Remodel electro-fretsaw into electro-file.

    Files – is a class of bench tools which were for some reason avoided by electrification although the necessity of evening, filing or widening arises in modern bench work as often as one hundred years ago. However, like a hundred years ago, we have to roll up our sleeves and get down to work. No wonder that in some time you start to think over how to improve this social injustice. Fortunately, civilization didn’t waste time last hundred years and though it didn’t give people ready-made electro-file but brought forth a number of devices which can facilitate our task. In particular, electro-fretsaw is a nice source of reciprocal motion :).

    In fact this device is almost a ready-made electro-file. Its modding takes no more than half an hour. Thus, fretsaw. We need one of devices of the lowest price spectrum (less than 20$). We choose the lowest price spectrum because advanced systems of saw clamp in more expensive models are completely inappropriate for our invention. We are interested in the most primitive system in which the saw is fixed with a block drawn to the connecting rod with two screws:

    Second thing we need is the future work tool itself, i.e. a set of “bare” broach files (without shafts). It’s desirable that they have the shank end of the same width as a standard fretsaw (6 mm). It can be wider but not narrower.
    Unfasten the clamping block from the connecting rod and measure the distance between the screws (in other words, measure the groove width in which the fretsaw is fitted). I got nearly 2 mm, i.e. much more than the width of the fretsaw itself. This is good; as you might have guessed we have to grind the broach file shank end in such way that it could substitute the fretsaw. So, turn on electro grinder (you may use dremel tool but this will take more time) and recall what is made with logs in a saw-mill when they need planks. Our “plank” should have width of 2 mm (to fit between the screws without warp). At second stage we grind the obtained “plank” finally in accordance with the shape of the groove section. I’ve got a kind of elongated triangle: