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    Long tapered pins on a manual lathe

    A dead zone of backlash take up is normal in a taper attachment that uses a telescopic leadscrew. This happens when using the cross slide to dial in successive cuts and cutting OD from small to large. Essentially, feeding in with the cross slide dial pushes on one side of the leadscrew nut, and...
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    Lots of Hardinge lathes in Anderson, SC

    I have actually visited him and impulse bought a small lathe and tap grinder and pantograph from him. I can’t quite remember his name, but it was back in January. Very helpful loading, gave some good prices on the weird stuff I bought. Most of the machines have been sitting for a long time and...
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    Trim Tool grinder

    That looks like a grinder specifically for brazed carbide tools. Most I have seen have a little cup up above the wheel that would drip water onto the wheel for cooling, and then run off into the collection tray. I think having a wheel running directly in water would make an unusable mess. Looks...
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    15HP 240/480VAC 1760 RPM Motor

    Alright. I have my eye on it. I have to sort stuff out in the next few weeks to see if I need it.
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    15HP 240/480VAC 1760 RPM Motor

    Did you end up selling this motor? If not, I might need it for a machine, exactly a 284U motor and that speed/voltage. I am in VA.
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    Why do people buy massive lathes for their home shop?

    I feel like this is partially aimed at or prompted by my L & S sale. Sure it is big for my “home” shop. But really, I want space…for an even bigger lathe. I had a 14x40 import for a while. Couldn’t take a decent cut without the cross slide backing out or fighting tailstock deflection. Size is...
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    Lodge & Shipley Powerturn 1610 18” x 78” For Sale VA

    Here is also a link to the Facebook listing I made (the photos might be higher resolution there?) Log into Facebook
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    Lodge & Shipley Powerturn 1610 18” x 78” For Sale VA

    For want of space etc, I guess I am going to sell. Looking for about $6500 I suppose. I am selling a Lodge and Shipley Powerturn model 1610 lathe. It swings 18” diameter over the carriage, and 10” over the cross slide. It takes 78” between centers. It is a D1-6 camlock spindle with a Morse...
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    OT- Math question about a ratio from an old SAT exam

    Oh for sure. I think tests show just as much about the designers as the takers. For all my complaining, I do think that if you walked up to me on the street, gave me the two circles, and the question, I would return you with an answer of 4. And I think that answer is valid. While not...
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    OT- Math question about a ratio from an old SAT exam

    Come to think about it, the question doesn’t explicitly say that there isn’t any slippage between A and B. At least it doesn’t seem that way to me. But of course, you could argue that our fuzzy assumptions, call it intuition, is a more powerful tool in a lot of ways. It allows us to not just...
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    OT- Math question about a ratio from an old SAT exam

    EPAIII and others, I get what you are saying, and fully understand the answer could be 4. However, you must remember that there is no generalized mathematical definition for rotational count when dealing with planar displacement. That is why I called your method “orientation”. The question...
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    OT- Math question about a ratio from an old SAT exam

    Absolutely, I agree with what you. But badly worded questions do give us fodder to go around and around in circles on internet forums!
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    OT- Math question about a ratio from an old SAT exam

    See, but that definition of rotational count does not stand up to strict mathematical analysis. If the movement was pure translation, then the arrow would stay in the same orientation the entire time. Or what if circle A was an oscillating rotation (around the instantaneous center) as it...
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    OT- Math question about a ratio from an old SAT exam

    Orientation being defined as a directional vector drawn on circle A (visualized by the head on the coin). When orientation is the same, the current vector is parallel and in the same direction to the vector drawn when the circle A was in its starting condition. I think counting matching...
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    OT- Math question about a ratio from an old SAT exam

    The problem is that the definition of rotation (movement of a body where one point, or n-2 dimensional cross section stays stationary) doesn’t hold up when you have planar rotation and planar translation (as in this case, or analogous movements for higher dimensions). You have no fixed center of...
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    OT- Math question about a ratio from an old SAT exam

    So, what we have going on here is a fundamental misunderstanding of “rotation” as defined for rigid body mechanics. Essentially rotation in two dimensional examples is defined by a movement of a body that keeps one point in the body fixed relative to the rest of the body (the center of...
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