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WARNING: Metalworking Revisited - Deburring With Surface Conditioning - HF SURPRISE

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  • WARNING: Metalworking Revisited - Deburring With Surface Conditioning - HF SURPRISE

    Off Topic Portion: The warning is for trolls. Hopefully when trolls realize its real metal working content they can move on to other topics they will find more enjoyable.

    On Topic Portion: After Jim Wilkins (usenet: rec.crafts.metalworking) comment about abrasive discs I stuck one of my little mandrels in a drill press and cranked up the RPM. The discs were part of a batch I bought from Benchmark Abrasives. Surface conditioning pads. Not knowing which would work best I bought a pack of two different ones. A "red" one and a "grey" one. For some reason I thought they were green on the website. The grey one felt way to coarse, so I tried the red one. Working under the head of the drill press is a little awkward, but it works ok. You are working blind except when working on the side of the disc, but its not to bad. It will deburr the part, and leaves a generally nicer finish than sand paper. After just three molds (6 parts) the disc was about toasted. Being a cheapskate I could get a little more work out of it, but that wasn't really my goal. My goal was faster, cleaner, and more efficient deburring. Given that it wore out so quickly it also left a lot debris on the parts. I'll rinse them all anyway before going back on the machines, but they do need to go back on the machines. The back side needs customer name and catch phrase engraved yet. Still there was a lot of red abrasive bits all over everything.

    Randy and Jim both mentioned belt sanders. I prefer to call them belt grinders, because that's the way I use them. Recently I made some repairs on the little Harbor Freight 1x30 bench top belt grinder. Mostly I just adjusted it and tightened up a bolt that holds the tension tracking assembly in place. I was not hopeful that it would run the surface conditioning belts any better (at all) than it did the first time I tried them, but I tried one anyway. I had gotten a couple each of two different ones. Also from Benchmark Abrasives. I selected the one that felt finer (grey/green this time) and left the red ones in the drawer. It was difficult to get on. I had to wrap my arm around the machine and pull it against my body to pull the tensioner far enough forward to get the belt on. After turning it by hand a couple times I plugged it in back and and turned it on. No pleasant surprises there at all. It still would not turn the belt. Just being a little obstinate I started spinning the large lower idler wheel by hand with a finger tip. A little help didn't get it going, but I noticed it would turn a fraction of a rotation before stopping. I decided to manually spin it a little faster. When I pulled my finger to safety the belt grinder kept going and then it sped up. It wasn't as quick as normal, but within a second or two it was turning at what visually appeared to be its normal speed. I still was not hopeful, but I wanted to see what the conditioning belt would do. I don't think I really ever thought about the machine again as I deburred moderately complex edges on 7 more mold (14 more parts.) Straight edges were easy, but walking round edges for hinge bosses around on the belt and cleaning up inside and outside corners was pretty easy to control. Sure it looks like it was done by hand but it looks good. Those parts are not all covered with a large cloud of abrasive debris. There is some I am sure, but nothing like from the little disc. The belt looks used, but its not worn out. I am sure I could do atleast another dozen parts with it. More since I'm a cheap skate and I'll push it to the end. After the little belt grinder came up to speed I don't recall it seeming to bog down one time while I was using it.

    I mentioned two companies previously in this post purely for reference. That was so people wouldn't find it odd if their Combat Abrasives or their Wen belt grinder performed differently than I described. I am not endorsing or putting down any of the companies named. Just describing how the products I used performed.
    *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

  • #2
    Those little 1x30 belt grinders are quite useful. I once used it as a makeshift surface grinder to reduce the thickness of hundreds of brass washers to a uniform thickness. A small jig held the washer and a set of stops allowed me to move it into position consistently. I used the same belt for most of a year.


    Dan
    At the end of the project, there is a profound difference between spare parts and left over parts.

    Location: SF East Bay.

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    • #3
      I mostly use a Scotchbrite wheel for deburring and polishing. It goes fast and wears a long time. I've been using the current wheel for over 2 years. The trick on those is to not put much pressure, otherwise, you can wear one down in a month. With light pressure, they get the job done quickly and last a long time. I use 8 or 9 S finishing wheels. The S is Silicon Carbide abrasive. Also, I use it in a way that keeps it flat across the front with fairly square corners. It's easy to round them off if you work on the edges too much. If you need a radius one, the best thing to do is get 2, and have a flat one and a rounded one. They come in many widths and diameters.

      I also have a red 6" wide Scotchbrite finishing belt on a belt sander. It's been on there 3 or 4 years, almost time for a new one.
      Last edited by Toolguy; 11-20-2021, 02:31 PM.
      Kansas City area

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      • #4
        Those surface conditioning belts are awesome. I use one on a 2x72 grinder for doing the final finish on knives, in addition to deburring parts for welding. Work fantastically and they last just short of forever, think im on something like 3 years use on mine. Not daily hard use, mind you, just hobby use, but its still going pretty strong

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        • #5
          This thread is a little old, but... I'm wondering if theses might have any applicability to my question about chamfering.

          I'm not too clear about the finish left by the belts. I'm not getting a good impression of whether it is more of a fine brushed finish, or further toward a polished finish.

          Also how much roughness it can clean up.

          I have a 1 x 30 belt machine, mine is a Delta, but is probably similar to yours. I normally leave a Cubitron belt on it, but it's no good for deburring or even some chamfering, because even with the little sander, it eats metal way too fast. And it leaves a somewhat coarse finish, which is fairly hard to clean up.

          I don;t know if the S C belts are up to cleaning that up, and, if they are, how hard they are to control to avoid cutting too fast or rounding corners. The belts look like scotchbrite, so I'm thinking they might wrap around and do some rounding. That's even a problem with a sanding belt, especially if using the belt above the backer plate.
          4357 2773 5647 3671 3645 0087 1276

          CNC machines only go through the motions

          "There's no pleasing these serpents"......Lewis Carroll

          Comment


          • #6
            I don't really care about a fine chamfer. My goal is a simply a part that doesn't slice my customer's hand. No, I don't think it would give that fine uniform chamfer you are chasing. How it "cuts" is dependent on its age. I think the fine tool maker's chamfer you were talking about has to be done with a hard machine tool cutting blade of some kind under proper control and blended by hand in spaces the blade will not reach.

            Like any hand finish the aesthetic will depend on the skill of the operator.
            *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

            Comment


            • #7
              The ScotchBrite wheels are good for deburring, and give a polished rounded corner. They are not good for a defined chamfer. The belts are more for surface finishing, rather than corners.
              Kansas City area

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              • #8
                I was more wondering how badly they would chew up a chamfer that is already in place via some other method (like the Gotteswinter device). Most cutting tools will leave tool marks, which I'd like to remove if possible.

                The SC belts obviously will not MAKE a chamfer, but the real question is how they work to clean up one that is already present. If they turn it into a rounded corner, that's not ideal. If they can clean up the surface without obliterating the chamfer, that's better.
                4357 2773 5647 3671 3645 0087 1276

                CNC machines only go through the motions

                "There's no pleasing these serpents"......Lewis Carroll

                Comment


                • #9
                  Originally posted by J Tiers View Post
                  This thread is a little old, but... I'm wondering if theses might have any applicability to my question about chamfering.

                  I'm not too clear about the finish left by the belts. I'm not getting a good impression of whether it is more of a fine brushed finish, or further toward a polished finish.

                  Also how much roughness it can clean up.

                  I have a 1 x 30 belt machine, mine is a Delta, but is probably similar to yours. I normally leave a Cubitron belt on it, but it's no good for deburring or even some chamfering, because even with the little sander, it eats metal way too fast. And it leaves a somewhat coarse finish, which is fairly hard to clean up.

                  I don;t know if the S C belts are up to cleaning that up, and, if they are, how hard they are to control to avoid cutting too fast or rounding corners. The belts look like scotchbrite, so I'm thinking they might wrap around and do some rounding. That's even a problem with a sanding belt, especially if using the belt above the backer plate.
                  I dismissed the surface conditioning belts earlier when you mentioned it. I used them primarily for aluminum, and they make the parts safe to handle. Aluminum is relatively soft and somewhat difficult (atleast for me) to free hand perfect little edge chamfers. Today I was making some tool holders out of 4140HT (not done) and in between setups truing up the stock I would walk it over to the little sander with the surface conditioning belt to deburr it and save myself from bleeding to death. I wasn't even sure if it would do it. 4140 can work harden so if I didn't get the cut just right that burr can be even harder. The little belt striped the burr right off, and the little shiny spot around the edge was pretty darn uniform. Not perfect near the ends, but I expect that's mostly because I wasn't really trying. Its certainly acceptable for my shop.

                  *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

                  Comment

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