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Am I expecting too much?

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  • #16
    Thanks Evan, Rich and Errol for your helpful replies.

    Evan you are right, I would like to get the machine to be as accurate as possible. Probably David had got all there was to be got from it.

    However I was struck by the by the slope of the base. I attached the dial indicator to the table to make this measurement. Since I am not a machinist and know nothing about shapers I wanted to investigate more or understand better.

    I did put a piece of 3/4" glass plate on top of the table and used a DTI stuck on the clapper. It appeared to be very flat, but I only checked the x axis along the left side of the table, and the Y axis close to the rear of the table.

    It will take me a while to do what is suggested. I will get back when I have news.



    • #17
      I am waiting for some cast aluminum plate (which was delivered to a relative in the US as the seller did not ship to Canada) to try the test recommended here on the list.

      Meanwhile, using a surface gauge, I learned that the base of the shaper where the foot runs is not parallel to the top of the horizontal way for the table. The way is about 6 thou lower than the surface gauge scriber at the right hand top of the way than it is at the left, where the scriber touched the way top.

      I then moved the table to the far right position, extended the foot to the base, and clamped it tight with its retaining bolt.

      Using 5 thou brass shim stock I was unable to get the shim between the foot and the base. As I moved the table to the far left it became possible to insert the shim between the base and the foot and move it to the right several inches.

      This means that using the foot to correct for other problems (by setting the foot when the table is a few thou high, and then lowering the table a few thou) is going to result in varying amounts of lift to the table. If the table is moving right during shaping as it goes to the right, the RH table corner will tend to be pushed up. Does that make sense?



      • #18
        I'm making the rash assumption that you are doing the "indicator in the clapper" checks by cranking the machine by hand. If so, try doing the same but under power (if you've tried it under power, ignore the rest of this post). Shaper rams (and planer tables) "plane" on an oil film that forms as the machine runs. A machine with a worn ram will behave differently at running speed than at hand speed. The ram may not appear worn in any of the usual tests, but will show up in the at speed test.



        • #19

          I haven't used the dial indicator on the ram with the shaper under power.

          The previous owner, David Powell, made many measurements (see his posts here) and I would guess they were static. He and some members of this list (I think) concluded the results he was seeing were likely the result of wear to the ram. There seems no doubt to me this is a factor.

          I am still wondering whether an additional problem is added by the 6 thou difference in distance between the base for the foot and the knee way.

          I assume the wear to the ram ways will show up with a dial indicator on the ram under power? I will see what happens when I try it.



          • #20
            With a dial indicator held in the clapper, I found the top of the table closest to the machine was higher than the far end of the table by about 3.5 to 4.5 thou - this was with the foot not bolted onto the knee/table. This was both moving the ram by hand, and under power.

            I found it hard to see the indicator with the shaper powered up, but I think the manually powered and motor powered readings were very similar.

            When I bolted the knee in place, the downward slope seemed to decline to about one thou (under power). I noticed this only on a narrow width of the table.

            However, when I moved the knee/table to the left, and locked the foot down (at the low end of the base), with the indicator static on the ram, above the far end of the table, as expected, as I moved the table to the right, the height of the table increased about 4 to 5 thou.

            I then noted the clamps holding the underside of the knee on the dovetail way were not bolted down at all. Would they be, ordinarily?

            So- taking the shaper body off the base to look for dirt or other stuff makes sense. The bolts involved are much easier to get at when the base is unbolted, but the beast is too heavy to handle unless I take it apart. Which I might be able to do...

            Anyway, I have found someone local to help me sort this out. Still, any comments are welcome.