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Thread: Single-tooth broach geometry?

  1. #31

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    This is a Morrison keyseater that I run several times per week, the tooling is very simple.
    There is no side rake only front and top rake. If you include side rake the tool will become narrower when you grind the top for sharpening.
    It has an amusing Steampunk feed advance mechanism, it also backs off the table .05" on the up stroke.


  2. #32
    Join Date
    Nov 2017
    Location
    Watford, UK
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    583

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    Quote Originally Posted by Mcgyver View Post
    imo, 8mm is getting to be too much for a single pass. This would be better done in the mill with a smaller broach and just step over to get the dimensions you need. And plunge an end mill through it first to remove the bulk of the material. This manual broaching is great, but too wide a cut and you have to put a lot of force into in a direction/manner that might over strain something (perhaps even you )
    You may well be right.....but I fear I have to learn by trying and failing at this point. The wheel is aluminium so it should be a little more conducive to being 'sliced'. I'll give it a try and if it's not working I'll rethink - the mill is not currently in a state for doing this anyway as I'm midway through fitting a DRO....badly.

    Quote Originally Posted by Bented View Post
    This is a Morrison keyseater that I run several times per week, the tooling is very simple.
    There is no side rake only front and top rake. If you include side rake the tool will become narrower when you grind the top for sharpening.
    It has an amusing Steampunk feed advance mechanism, it also backs off the table .05" on the up stroke.
    A very nice piece of kit for the job. Sort of a vertical shaper in a way. I'd spotted that the side rake would result in exactly what you say....but I'm figuring this to be a one-off at this point. If I'm honest, it's not the full 8mm anyway as I must have nicked the very end with the grind wheel - I think it's only 0.2mm off so I figure I can file that at worst.

  3. #33
    Join Date
    Mar 2005
    Location
    Toronto
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    10,997

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    good point about the AL....I was mentally referencing the last large one I did which was steel. AL will be easier and it may be fine. Sometimes you just have to try something....so long as failure doesn't mean busting a machine . To bad about the mill not working, as it really makes the job easier to take out the bulk of it with an endmill
    .

  4. #34
    Join Date
    Nov 2017
    Location
    Watford, UK
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    583

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    Probably not going to bust a machine....just some patience. Nothing a beer can't fix
    The mill will be back up and running at some point. I just have to work out if I REALLY want all the mounting holes I've drilled and tapped or if I can tolerate not using one of them on the grounds that I can't get the last of the cobalt drill bit out of it!
    If it doesn't work as-is I'll probably have the mill up and running to rough it out with an endmill.

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