Need some more advice on lapping OD
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  1. #1
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    Default Need some more advice on lapping OD

    I am honing a cylinder it is 9 " long 4" diameter. I made the hone and I am using 500 grit diamonds. I managed to hone a .001" taper into it. I have 2 adjusting crews on the hone. Am I not tightening them evenly? or not moving the hone enough? I had a different resistance on the ends and tried to balance it with the screws. Should I just have one adjustment in the center of the hone? the hone is 4" long. this is all new to me . Any practical advice would be appreciated.


    dee
    ;-D

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    Got a photo of your setup? How are you making a hone with 500 grit diamonds? Do you really mean you made a lap? Need to get some better info before offering any advice.

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    Quote Originally Posted by eKretz View Post
    Got a photo of your setup? How are you making a hone with 500 grit diamonds? Do you really mean you made a lap? Need to get some better info before offering any advice.
    here are some pictures of the hone I made...

    img_2822.jpgimg_2825.jpgimg_2828.jpg

    dee
    ;-D

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    Quote Originally Posted by dcsipo View Post
    I am honing a cylinder it is 9 " long 4" diameter. I made the hone and I am using 500 grit diamonds. I managed to hone a .001" taper into it. I have 2 adjusting crews on the hone. Am I not tightening them evenly? or not moving the hone enough? I had a different resistance on the ends and tried to balance it with the screws. Should I just have one adjustment in the center of the hone? the hone is 4" long. this is all new to me . Any practical advice would be appreciated.


    dee
    ;-D

    If that's a loose charge hone, add more diamond to one side in an attempt to have that side cut more (for the large diameter, of course). Preferentially stay on the high side until you bring it down, then focus on uniform finishing with full side-to side lap movement and frequent flipping of the lap to even out cutting.

    Measure frequently, and be sure your lap doesn't have an inherent diameter bias. As a wood device (right?), you may have variations in stiffness and diameter along the lap's length.

    How are you checking cylindricity? Is it good?

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    Quote Originally Posted by Milland View Post
    If that's a loose charge hone, add more diamond to one side in an attempt to have that side cut more (for the large diameter, of course). Preferentially stay on the high side until you bring it down, then focus on uniform finishing with full side-to side lap movement and frequent flipping of the lap to even out cutting.

    Measure frequently, and be sure your lap doesn't have an inherent diameter bias. As a wood device (right?), you may have variations in stiffness and diameter along the lap's length.

    How are you checking cylindricity? Is it good?
    wood.

    cylindricity: Just rolling on the surface plate, height gauge and a 0.00005" DTI, so far round within the resolution of the DTI. I was thinking of using V blocks but that would introduce more errors. For quick measures I use micrometers. Thinking of going to one adjustor in the center, less chance of out of balance


    Thanks for the tips:-)


    dee
    ;-D

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    Quote Originally Posted by dcsipo View Post


    Thanks for the tips:-)


    dee
    ;-D
    Good luck, let us know what works for you. As the lap carrier is wood, even variations in absorption (if you're using an oil or water carrier) could affect it non-uniformly.

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    Yeah, wood was not an ideal choice, to say the least. Hopefully you'll be able to work around it. Have you been flipping the lap end for end as suggested by Milland?

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    Quote Originally Posted by eKretz View Post
    Yeah, wood was not an ideal choice, to say the least. Hopefully you'll be able to work around it. Have you been flipping the lap end for end as suggested by Milland?
    since I was doing it on the lathe between centers it was not a convenient thing.....moving over to the drill press at low speed


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