A quick video about making an easy adjustable mirror for centering tools on a small lathe. Enjoy!
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17 thoughts on “Using a mirror for centering”
  1. Avataaar/Circle Created with python_avatars Burnintrees384 says:

    Hey Fran. Love your videos! I am a 10 year machinist so not really an expert. But when I want to set my tool to center on a manual lathe I stick a piece of round stock in and bring my tool to the side. Then I put a scale in between the material and the tip of my tool. If u squeeze the scale against the round stock and it is not straight up and down then you are off center. Very fast and accurate enough for the vast majority of turning you will be doing on a manual.

  2. Avataaar/Circle Created with python_avatars MrAccipiterStriatus says:

    In the numerical calculus at university I used plane mirrors to trace perpendicular lines to curves and from them the tangents. Nice trick, I need to find a mirror like this one

  3. Avataaar/Circle Created with python_avatars Darrin Wagner says:

    I take it from your own comment that you use a lot of inserts, hell I'm sorry but I go back to when you would grind your own tooling, we could still do all of the same things it would just take a little longer plus we didn't try HSS on Inconel or any other modern alloys. at my last job I did most my work on CPM-M4 from Crucible Steel, witch is made by mixing the primary alloy then grinding it back into a powder and then forming back under pressure so as to leave a very fine grain pattern. Hard as all hell but bridle as hell also.

  4. Avataaar/Circle Created with python_avatars Darrin Wagner says:

    I had a small magnetic V block with a rod standing vertical threaded into it. on this rod I had three tell-tales cut into it. One was from the ways of the bed of the lathe the second was from the carriage and the last was from the cross slide that way I could set my tooling from any place and know that I was dead on centerline.

  5. Avataaar/Circle Created with python_avatars Michael Murphy says:

    I just use a 6" steel rule. You need to measure your centre height above the cross slide. Once you know that, any time you drop in anew tool just measure up from the cross slide to the tool tip to check. One of these days I'll machine up a quick go/no-go height gauge to check but for now the ruler works fine.

  6. Avataaar/Circle Created with python_avatars DDE_ADDICT says:

    man if all women had your personality and brain nobody would get divorced

  7. Avataaar/Circle Created with python_avatars Hola! In the Real World says:

    I made a piece of steel on the top of the cross-slide that is the height of the centerline of the lathe. If you slide it up to the tool you are trying to center you can slide a piece of flat material across the to of the gauge to the top of the tool and tell exactly when it is on center. If you need the measurement to be super accurate you can slide an indicator over the top of the gauge block and the top of the tool and compare the height. This is much more accurate than a mirror.

  8. Avataaar/Circle Created with python_avatars Dan Patterson says:

    The "magnifying" side of the mirror has a slight concave curvature, which in reflection acts like a positive lens, so that side is capable of focusing sunlight per the warning card. Maybe not very well, but with enough aperture…

  9. Avataaar/Circle Created with python_avatars Abraham Delatorre says:

    Loving your lathe. Good tip. I have the cheaper mini lathes that you get from Harbor Freight. This one was bought used from some guy who upgraded to a shop tier. I've since tuned in the lathe to do pretty precise work but still, I want to do bigger projects near future. I don't know any women who work with lathes good to know one that does.

  10. Avataaar/Circle Created with python_avatars Thomas LaMora says:

    a very clever and elegant solution to a problem we all face. everyone hates to face something in the lathe and end up with a tiny nub . well done.

  11. Avataaar/Circle Created with python_avatars me. kerfuffles says:

    Hey Fran!
    I am a huge fan of the Edge Technology CNC Lathe Gage. Since you are also using a quick change post, this might be for you (though the mirror obviously also does the job). The nice thing about that gage is, that you can quickly set up all your tools – even upside down ones and drilling rods without fiddling to somehow make the cutting tip touch the tailstock center. I used to use the tailstock before, but would not want to go back to that. 🙂
    It is also not too complicated to DIY one of those from some scrap materials and a bubble level vial.

  12. Avataaar/Circle Created with python_avatars Gazr Gazr says:

    It's all smoke and mirrors,good tip,cheers,Gaz

  13. Avataaar/Circle Created with python_avatars David George says:

    Nice mini lathe, you could branch out into clock repair, seems like you are so multi talented.

  14. Avataaar/Circle Created with python_avatars aintlifegrate says:

    Better stick to what you know and this is not it!

  15. Avataaar/Circle Created with python_avatars Ian Darley says:

    Is it witchcraft I got the scent of pine as you sanded that wood!?

  16. Avataaar/Circle Created with python_avatars JPilot2 says:

    G'day, Fran! Great video! But, "I don't get people who stumble into mirrors. They need to watch themselves." Lol! 🤣 Cheers! 😊✌🏼❤️

  17. Avataaar/Circle Created with python_avatars Fran Blanche says:

    After posting this video I realized that my quick comments at the end may cause confusion about setting a parting tool – I should have elaborated on parting but I'll have another video about the parting operation. I chose that tool to demonstrate the mirror alignment procedure because it is easy to extend and see for the camera, but it is also the only tool in my set that you have to remove, sharpen, replace, and set to center every time you want to use it – the other tools just have to be set to center once. I'll have to show all that in another video.

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