No announcement yet.

Optical Centering Scope - How to Use

  • Filter
  • Time
  • Show
Clear All
new posts

  • Optical Centering Scope - How to Use

    Just picked up a "Center Scope" by the Center Scope Instrument Company of Las Angeles, Ca. I'm having trouble seeing much (or getting a sharp image) thru the eyepiece. SPI seems to have acquired the production rights to this product and all major catalogs still list these devices.

    link to SPI catalog page 98:

    Unfortunately, I can't find a viewable or downloadable manual for one of these things. Some of the specific questions I have are:
    1. What is the adjustment know on the front, and how is it used?
    2. Does it have to be at a specific height above the surface that you are trying to center?
    3. Do you have to shine a light (such as a microscope light) on the area you are trying to view?
    4. There is a "nosepiece" that has an angled face. Any Idea what it is or how to utilize it?

    The product specs says it only has a viewing area of .100" and a 45x magnification.

    JHC Dayton, OH

  • #2
    Instructions for scope

    1. The adjustment knob is used to move the internal line image.
    2. Specific height REQUIRED.
    3. Extra light sometimes helps, depending on the object.
    4. Probably a light reflector.
    EDIT found my instructions from Finn Tool & Instruments.

    1. Place Scope in collet, chuck or other holding means.
    2. Focus on work lay-out lines, about 3/4"
    3. Turn spindle either side and adjust work line to match Scope dotted line.
    4. Revolve spindle 180 degrees and if Scope dotted line and work line do not match, turn adjusting screw one
    half the error and again bring the work line to match by adjusting the work lay-out line.
    5. Revolve spindle 90 degrees and place the second work lay-out line to match the dotted line in the
    instrument. When the work lay-out lines and the dotted line in the instrument are centered properly they will match in all positions.

    Finn Tool & Instruments

    I am not responsible for the confusion. I think Chinglish is easier, at least you know clarity is optional.
    Last edited by mechanicalmagic; 10-19-2012, 10:47 PM. Reason: More info


    • #3
      Thanks DJ for the rapid reply to my query. With your helpful information, I will quit fiddling with it at my desk and take it out to the shop and mount it on the BP spindle. I picked it up at a flea market in Portland, Indiana today and was unable to really get it to do anything at the show, so I felt I was buying a "pig-in-a-poke". It seems to be in good shape, so I feel I kind-of got a bargain ($30). It is obvious to me now that you can't just hold this with your hand and look at something thru the eyepiece. It needs to be held steady and focused at a specific height above the surface.

      JHC Dayton, OH


      • #4
        It will need to be checked or (re)set-up each time it is mounted in the mill collet. The set-up proceedure nullifies/negates any mill qill and/or collet error/s.


        • #5
          It looks like the objective (eye piece) lens is missing. I have a different brand on which the eye piece is quite obvious, but no direct experience with your scope.



          • #6
            No, the eyepiece is there and it appears to be fully functional.

            JHC Dayton, OH


            • #7

              I have a similar type of item and the focus distance about 1" from the lower lens and the range over which the work is in focus is very small (less than 1 /16th inch) so trying to focus on something whilst hand holding is virtually impossible.

              I think that the nose piece is slipped onto the nose and a light is shone from the side at right angles to the axis of the scope - the 45 deg. reflector directs the light onto the work and the bottom lens 'looks through' the hole in the reflector.

              Last edited by IanPendle; 10-20-2012, 02:38 AM.


              • #8
                Originally posted by IanPendle View Post
                I think that the nose piece is slipped onto the nose and a light is shone from the side at right angles to the axis of the scope - the 45 deg. reflector directs the light onto the work and the bottom lens 'looks through' the hole in the reflector.
                I have the same unit (apparently they were an OEM option for K&T), and that's correct. Then you turn the objective so the line is facing horizontal or vertical (depending on which axis you're aligning), you line it up with a feature on the workpiece, then move the mill's table. Then rotate the objective 90°, and then align the table in the other axis.
                "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."


                • #9
                  I often refer to my optical centering scope as a "poor mans optical comparator".

                  I bought mine from ENCO about 10 years go. Don't use it often but it has been a handy tool to have. I think mine is in focus 5/8" above the workpiece. The magnifacation is outstanding and I'm amazed at what the tool marks look like.

                  I use mine in the milling machine with a digital readout for reverse engineering. I can find distances from a workpiece edge to corner or profile or other inspection type work.

                  The centering scope is actually for finding intersections of layout lines or center punch marks. They have adjustments so the centering optic is concentric with the shank. I have never used mine for centering so it has never been calibrated.
                  So much to learn, so little time


                  • #10
                    I have a Russian one, it's better than the Western ones in that it works in the dark !

                    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.


                    • #11

                      The original Center Scope documentation is available as .pdf downloads from the Yahoo Groups K&T site:




                      • #12
                        Thanks Mike, I joined the group and downloaded the files. I never would have thought to look on a Kearney-Trecker site.

                        JHC Dayton, OH


                        • #13
                          +1 Mike. Thanks for the link...its the first literature on centering scopes I've ever seen. I have an Isoma scope which is very well made, but the image is reversed in the scope so you have to remember to crank the 'wrong' way to center the crosshairs.



                          • #14
                            The set-up will be OK for a particular collet (scope shank) but it may develop a "wobble" ("conical" and/or "cylindrical" "throw") when in a collet that does not very closely match the "shank collet" for concentricty - but even though the "thow" will (optically) off-set the "scope" setting the true point of the spindle axis will be equi-spaced between the 'scope parallel lines.

                            Ideally, the scope should be in an adaptor where the outside diameter of the bore (same as the 'scope shank) is very accurately concentric with the bore and sized for the shank of the end milling cutter that will be used in the cutting process.

                            While I can see the ease of adjusting the optical axis screw in the East South and West positions ("North" is "up") toward the column of the mill and leaves very little head space with the optical device so close to the job.

                            I'd prefer the "nail/pointer" in a common "wiggler" set as with practice it can be positioned very accurately with minimum time and effort. Any "collet run-out"is negated by the "wiggler" "ball-joint".


                            • #15
                              Originally posted by Jim Caudill View Post
                              No, the eyepiece is there and it appears to be fully functional.

                              Just picked this item up at the swap meet from a machinist for $5.00 works great with youalls help on how to use it. Love it. I think there are other that the optical lens comes out and has replacements, this is the complete unit to use as it is in the picture.
                              Agua Dulce, So.California
                              1950 F1 street rod
                              1949 F1 stock V8 flathead
                              1948 F6 350 chevy/rest stock, no dump bed
                              1953 chevy 3100 AD for 85 S10 frame have a 4BT cummins motor, NV4500
                              1968 Baha Bug with 2.2 ecotec motor, king coil-overs,P/S