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Making / Grinding An Offset Dowel Pin

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  • #16
    Originally posted by Dan Dubeau View Post
    Perfect job for a Harig grind-all and surface grinder. Lacking that, your 4 jaw approach seems reasonable for the job at hand.
    looking at the price tag on some of those.... It's just not in the cards. Doesn't Suburban make something like that?

    JL.....

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    • #17
      Joe
      Eccentric pins can present problems if they rotate.
      I say fix the error and not worry about it- do it right
      Several approaches can be done
      1. Line up the parts and make a new Pin hole in both pieces . You could even do a 1/8" hole as it is for location only
      2. Position a part in the mill and rebore to next size( offset) BUT match location of other hole to allow a step pin ( Not offset pin) say 7/16-3/8"
      3. Plug one hole with steel and Loctite-and rebore/drill/ream to proper location
      4. If size permits, use a taper pin reamer to realign the offset holes and use a taper pin

      If you must use a offset pin, grind a line on the end (ie Dremal cutoff wheel) , so you know what the orientation is
      Rich
      Green Bay, WI

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      • #18
        Originally posted by JoeLee View Post
        looking at the price tag on some of those.... It's just not in the cards. Doesn't Suburban make something like that?

        JL.....
        You've come this far, don't let a few grand get in your way now lol . Yeah, suburban make a few styles. Various other knock offs and other brands also work well. A VERY handy piece of kit for a surface grinder. There's a few different styles too, from a basic sliding vee block spin fixture/punch grinder to one with a 5c internal collet as well and other bolt on fixtures like wheel dressers, and indexing wheels etc. You can get as complicated as your wallet is thick. A basic import vee block punch grinder can be had for a few hundred dollars. We've got a couple import ones at work, and they are pretty decent. Not as nice as a harig (never used a suburban) though. As always, you get what you pay for.

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        • #19
          Originally posted by JoeLee View Post
          looking at the price tag on some of those.... It's just not in the cards. Doesn't Suburban make something like that?

          JL.....
          Owh man! You need to catch up!
          All those grinders you got !? ? ?! and no whirlie gig?
          Yes mine is a Suburban.
          I got a sore dick deal, and paid $320 for mine.

          -Doozer
          DZER

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          • #20
            I would be tempted to replace the dowels with taper pins. Position the apron properly, then ream the holes. A no. 7 pin would be about the right size.

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            • #21
              Originally posted by Rich Carlstedt View Post
              Joe
              Eccentric pins can present problems if they rotate.
              I say fix the error and not worry about it- do it right
              Several approaches can be done
              1. Line up the parts and make a new Pin hole in both pieces . You could even do a 1/8" hole as it is for location only
              2. Position a part in the mill and rebore to next size( offset) BUT match location of other hole to allow a step pin ( Not offset pin) say 7/16-3/8"
              3. Plug one hole with steel and Loctite-and rebore/drill/ream to proper location
              4. If size permits, use a taper pin reamer to realign the offset holes and use a taper pin

              If you must use a offset pin, grind a line on the end (ie Dremal cutoff wheel) , so you know what the orientation is
              Rich
              Rich, I don't think a pin with .022 and .014 offset will rotate especially after their tap fitted in the cast pivot arm. That small amount of offset just isn't enough to make the pin rotate.

              I'm going to have to slightly elongate the apron bolt holes to allow for the apron to be moved up, just slightly on the bottoms of the 4 holes.
              I would have to do that first and then without a dowel pin in place I would have to jockey the apron to the right height on both ends and tighten it down to the pivot arms.
              Then I would have to remove the apron as an assy. leaving the pivot arms bolted in place. Then I could set up and drill the original holes out to the next dowel pin size up which would probably be a metric size because 7/16" would be pretty close to the edge in the cast pivot arm, I think I still would be safe though.
              But the biggest issue I see in this method the fit of the pin in the pivot arm, for the tap fit that hole should be reamed. I really don't want to mess with the original parts.
              Making the offset pins is still the safest bet.

              Relying on an 1/8" pin to hold that apron is risky business it could break.
              You have to remember that those dowel pins aren't just for location purposes but also serve as a secure way to prevent the apron from being pushed down during bending.

              Think about the force against the length of that apron when you bend a piece of 16 ga. sheet metal the full length 24" That is going to be s substantial amount of force wanting to push that apron down or away from the bend, the bolts probably wouldn't prevent the apron from slipping, the dowel pin does.

              JL..................

              Comment


              • #22
                Originally posted by Dan Dubeau View Post

                You've come this far, don't let a few grand get in your way now lol . Yeah, suburban make a few styles. Various other knock offs and other brands also work well. A VERY handy piece of kit for a surface grinder. There's a few different styles too, from a basic sliding vee block spin fixture/punch grinder to one with a 5c internal collet as well and other bolt on fixtures like wheel dressers, and indexing wheels etc. You can get as complicated as your wallet is thick. A basic import vee block punch grinder can be had for a few hundred dollars. We've got a couple import ones at work, and they are pretty decent. Not as nice as a harig (never used a suburban) though. As always, you get what you pay for.
                OK, I will start a GO FUND ME PAGE !

                JL................

                Comment


                • #23
                  Originally posted by Illinoyance View Post
                  I would be tempted to replace the dowels with taper pins. Position the apron properly, then ream the holes. A no. 7 pin would be about the right size.
                  That would work too and I wouldn't have to drill or be fussy with the hole size. The reamer would take care of that. That is a good thought for the future.

                  JL...................

                  Comment


                  • #24
                    Originally posted by Doozer View Post

                    Owh man! You need to catch up!
                    All those grinders you got !? ? ?! and no whirlie gig?
                    Yes mine is a Suburban.
                    I got a sore dick deal, and paid $320 for mine.

                    -Doozer
                    $320 ??? you do suck, I don't remember seeing that gloat posted.

                    I've looked at them before but never really had the need for one......... until now.

                    I can get it done with the 4 jaw a lot faster than I could make sub off set collets.

                    JL.............

                    Comment


                    • #25
                      Standard dowel pins are not that hard and may be turned using carbide tooling.

                      Comment


                      • #26
                        Originally posted by JoeLee View Post
                        Rich, .................................................. ................. Relying on an 1/8" pin to hold that apron is risky business it could break.
                        You have to remember that those dowel pins aren't just for location purposes but also serve as a secure way to prevent the apron from being pushed down during bending..........
                        JL......
                        Joe you are right, I am not familiar with your tool and some manufacturers use a dowel to prevent shear forces in the fasteners, rather than/or inclusive of location alignment
                        If that is the case, then a small dowel is not functional as you mentioned
                        Rich
                        Green Bay, WI

                        Comment


                        • #27
                          For the orientation, cut a slot in the offset end, with the high spot at one end of the slot. (cut slot first, then PUT the high spot at one end) Now you have a way to tell which is what, and a way to see if it turned, and maybe even a way to hold it straight while knocking it into the hole.

                          You can tell which end is the high spot, so that is not an issue.
                          Last edited by J Tiers; 12-22-2020, 08:39 PM. Reason: clarification
                          2801 3147 6749 8779 4900 4900 4900

                          Keep eye on ball.
                          Hashim Khan


                          It's just a box of rain, I don't know who put it there.

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                          • #28
                            Originally posted by JoeLee View Post
                            $320 ??? you do suck, I don't remember seeing that gloat posted.
                            haha, I got mine in the bottom of a pile of stuff, lot price. Didn't bargain on it so consider it free

                            I've got a little centreless pin grinder you use on the surface grinder that make short work of them. Similar to Alan's idea, drill and ream an eccentric hole a round bar and hold the pin lightly with a set screw
                            Last edited by Mcgyver; 12-22-2020, 08:38 PM.
                            in Toronto Ontario - where are you?

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                            • #29
                              I many times use the whirly gig to hold a boring head which holds a small chuck. makes an easy way to get an eccentric pin.

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                              • #30
                                Offset dowel pins?????

                                Sorry, I am in the camp that says to assemble the parts in the correct relationship and clamp them tightly together. Then bore the holes to a larger diameter, perhaps 1/2" diameter and use two 1/2" pins. You can fill the bottom hole with epoxy (JB Weld) to make this task easier. Drill the top hole to 7/16" to start with and continue that size into the epoxy filled bottom hole, using the top hole as the guide. Then move up to 31/64" for both and after that ream to the final size.
                                Paul A.
                                SE Texas

                                And if you look REAL close at an analog signal,
                                You will find that it has discrete steps.

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