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  • #16
    Originally posted by Tom S View Post
    [snip]

    alanganes where did you get that tach for feedback? ...
    You remember cassette tapes? A cassette tape drive uses a small DC motor for the capstan. It would make a good tach feedback generator.

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    • #17
      Originally posted by J Tiers View Post
      One thing to look out for.....

      Some of the KB drives are NOT ISOLATED, so the control pot is live with the AC volts. You need to use a pot that has a plastic shaft, and keep the case of the pot from being accessible, including the attachment nut.
      Thanks for the heads up, that's important information. I ordered a KBPB-125 (supposed to be a compact version of the KBCC-125R) last night and added in the KB recommended pot because of your comment.

      Discovered that KB also has a board that can be connected up to a hall sensor or encoder to provide tach feedback. So that's an option if I feel the need to go that route.
      Cayuga, Ontario, Canada

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      • #18
        Originally posted by Tom S View Post

        Thanks for the heads up, that's important information. I ordered a KBPB-125 (supposed to be a compact version of the KBCC-125R) last night and added in the KB recommended pot .
        Also the power resistor has to be added, selected for the correct motor size.
        It is also wise to ensure the chassis is mounted on a earth grounded enclosure of some kind.

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        • #19
          Originally posted by Bob Engelhardt View Post

          You remember cassette tapes? A cassette tape drive uses a small DC motor for the capstan. It would make a good tach feedback generator.
          Heh.... Some of those HAVE a form of tach in them.
          2730

          Keep eye on ball.
          Hashim Khan

          Everything not impossible is compulsory

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          • #20
            Originally posted by MaxHeadRoom View Post

            Also the power resistor has to be added, selected for the correct motor size.
            It is also wise to ensure the chassis is mounted on a earth grounded enclosure of some kind.
            Yep, ordered one for the 1/2 hp motor size as well.

            Would you be able to elaborate on your earlier comment about using the inhibit input while reversing? I've been going over the wiring diagram and can't quite make sense of how that wiring would look. Or do I not need to bother since this is a reversing model?
            Cayuga, Ontario, Canada

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            • #21
              It is just a contact closure across the I1 and I2 terminals, as in the manual.
              When using relay reverse methods, it helps to close these terminals in order to make sure it shuts the drive down, and resets the accel before it is re-powered.
              You may not require it if you go with Diag C page 15 ?

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              • #22
                Originally posted by MaxHeadRoom View Post
                It is wise to ensure the chassis is mounted on a earth grounded enclosure of some kind.
                Is this also true for the earlier analog boards, specifically the MC60?

                metalmagpie

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                • #23
                  Ok. I'll have to see if I can fit that in somewhere.

                  I'm debating how to set up the controls at the moment. At the moment I'm thinking of setting up a drum switch to S1, S2, S3 to provide the fwd-brk-rev operation and mount the pot remotely near the drum switch. Right now I have a drum switch controlling a single phase motor on another lathe and I love the tactile feel it gives - I can switch the machine without having to take my eyes off the work I am doing. And it can basically act as a jog function since it's easy to give a quick bump to the lever when needed. I'd pair that up with a disconnect of some sort so that I can de-energize the controller easily when I'm not using the machine or doing some function where bumping the lever would be a bad idea. Other option would be a series of push buttons (fwd, break, rev) with the pot mounted near the buttons, also paired up with a disconnect.
                  Cayuga, Ontario, Canada

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                  • #24
                    Originally posted by metalmagpie View Post

                    Is this also true for the earlier analog boards, specifically the MC60?

                    metalmagpie
                    The aluminum chassis on the MC60 TM version should be isolated from the circuit and in this case could also be earth grounded

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                    • #25
                      Originally posted by Tom S View Post

                      alanganes where did you get that tach for feedback? I took a quick look online but it looks like a pricey component, unless I'm looking at the wrong thing. Good to know of the option, I had seen that in the wiring diagram for some of the KB models but though it was for a tachometer readout, not for feedback.
                      The tach feedback on those drives is simply a DC voltage 7 volts/1000RPM. You can scale to other voltages with a couple of resistors.
                      I used a small DC motor I had laying around and mounted it to be driven by the motor shaft. There is a bit of a description and a few photos here:

                      https://bbs.homeshopmachinist.net/fo...-rpoject-again

                      Overall, it works really well. The tach generator is the small black motor you see hanging off the end of the worm drive gearbox.

                      I can get a few more specific photos if you would like.

                      Edited to add:
                      The manual for my drive is here, the info about doing tach feedback starts around page 13 or 14:

                      https://www.galco.com/techdoc/kb/kbcc-225r_rm.pdf
                      Last edited by alanganes; 11-24-2021, 06:44 PM.

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