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Optimum 2x72 belt grinder design for general fab

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  • Optimum 2x72 belt grinder design for general fab

    Optimum 2x72 belt grinder design for general fab (not for knife making)?

    After googling and perusing dozens of the various but similar-to-KMG designs, and having/liking a Ridgid EB4424 belt/spindle sander, I’m sure I want mine to have the ability to go horizontal.

    I like having the horizontal table for work support and easy visibility of the edge being ground.

    Then I wondered if I need the vertical orientation at all, and the design is simpler w/o it.

    Anyone see any issues w/horizontal-only 2x72 belt grinder for general fabrication (I don’t make knives)?

    My only misgiving is if horizontal is problematic when doing heavy stock removal on the contact wheel, but maybe that’s just because I’m accustomed to doing it that way on my bench grinder.

    Maybe all it takes is a workstop to keep the work from getting flung sideways, and getting used to it.

    What do you guys think?

    Another question is whether it’s worth the time and/or expense to incorporate a small wheel attachment.

    I already have both sizes of Makita hand-held belt sander/grinders and an Astro pneumatic one, as well as a CNC mill for machining profiles, so I’m thinking I wouldn’t use it much.

    Or is it one of those things that you wonder if you need, but once you have it you can’t believe you ever lived w/o it?

    If I'm going to be fishmouthing round tubing, it's a no-brainer, but not sure I will be; generally I prefer square/rectangular.

    I guess I'll leave a place to incorporate it but wait until I need it.
    Last edited by noah katz; 07-09-2017, 08:52 PM.

  • #2
    It's mostly the knife-making crowd who use those. Fab shops gravitate toward wider belts.

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    • #3
      Originally posted by Lee Cordochorea View Post
      It's mostly the knife-making crowd who use those. Fab shops gravitate toward wider belts.

      Hmm, I've already gathered a lot of the 2" parts, but I guess I could double up for 4".

      Either way, my above questions still apply.

      Comment


      • #4
        Originally posted by noah katz View Post
        Hmm, I've already gathered a lot of the 2" parts, but I guess I could double up for 4".

        Either way, my above questions still apply.
        If you build your 2x72 horizontally isn't wider by definition?
        Location: Long Island, N.Y.

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        • #5
          I built a two by 48 inch grinder years ago with the capability to lay it down and have never used the option. I do mostly metal fab work an its the most used tool in the shop and always in the vertical position. Great for drill bits and cutting tools also. I would suggest you go with at least a two inch belt.

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          • #6
            Darn nice job . You will get a lot of work out of it.Why you didn't make it a 4x36 is a mystery to me. That is just my two cents.

            Dave

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            • #7
              digr,

              Nice machine, I love the stout industrial grade construction!


              Originally posted by digr View Post
              I built a two by 48 inch grinder years ago with the capability to lay it down and have never used the option.
              Do you mean lay it down as shown in the pic's?

              I mean horizontal in the sense that the wheels' axes and belt surface are vertical.

              Comment


              • #8
                As a knife maker im horribly biased here, but the KMG style grinder is the style to beat in my opinion. Being able to lie the belt sideways might be a handy feature. Once. Beyond that one time though, dunno how handy it would be. The biggest advantage i can see for the vertical design is belt direction. A vertical grinder is going to direct all the force down into the work rest, its extremely controllable. A horizontal grinder is going to send all that force sideways, and a 50 grit belt moving 60mph with 2hp behind it WILL rip a piece out of your hand and launch it across the shop if you arent careful.

                Story time, when i built my 2x72 grinder, during one of the first uses i stupidly left a hand plane blade loose near the belt. Vibration from the machine led to the blade falling onto the moving belt. Way faster than he eye could follow, the belt pulled the plane blade through the drive wheel and launched it clear to the other end of my shop before i blinked. I still have that blade, only now instead of being flat its curved to the exact radius of the drive wheel. Grinder did that with a 1/2hp motor.

                Not something you want to have happen twice. If my belt ran horizontal, i could easily see i work piece getting flung sideways out of my hand with the same violence. Also noteworthy is the fact that a vertical grinder will throw the swarf onto the floor, instead of sideways on to everything else.

                I also dont know that id go with a wider belt. Wider means more power needed for one, and ive managed to slow down a 2hp motor a bit with a 2 inch wide belt. Wider also means different, possibly less common belts. I can also say, even for general purpose use, which i do a lot of with my grinder, i dont think ive ever found myself really needing any more width.

                Tlr version - Go with a vertical 2x72 in a KMG style. Platen attachment should probably be the first contact surface, and possibly the only. Its a real workhorse that one. Next up, a contact wheel in the 6-8 inch range. Small wheel attachment is also handy, but youll either need a way of slowing your grinder or deal with massively premature bearing failure, a 1/2" diameter wheel moving at 4000sfpm (pretty common belt grinder speed) will be making in the neighborhood of 30k rpm

                Comment


                • #9
                  What type of fab work are you doing? That will decide what you actually need. Small stuff then a 2" belt will be OK. For anything over 1.5" then you need a wider belt to be efficient. For fab work a 6" wide by 72" is what you want I think. In my shop in Texas that is all we had were 6" wide belt grinders. Remember a belt grinder is like a lathe. You can do small work on a big lathe but not big work on a small lathe.
                  Location: The Black Forest in Germany

                  How to become a millionaire: Start out with 10 million and take up machining as a hobby!

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                  • #10
                    I like the 72" belts because they are so long, that they last a long time.

                    Not related but...
                    I have a very old 4" x 36" belt sander from the 1920s, or when ever
                    3M invented sanding belts. Anyhow, it is all cast iron, has tight and
                    loose pulleys for line shaft drive, and was imported from England.
                    It has no tracking adjustment, only a crown in the sanding belt
                    drum. It has roller bearings in the drums, and the rollers are almost
                    4" long and oil filled. It is so heavy too. Weighs over 100 lbs for just the sander,
                    no motor or stand. It might be the oldest belt sander around.
                    I will have to take some pics for you all.

                    --Doozer
                    DZER

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                    • #11
                      I have a Jancy RadiusMaster Ram1000, a 2" x 48", 3500 fpm, belt grinder/sander, that can be either vertical or horizontal.

                      https://images.search.yahoo.com/sear...der&fr=yfp-t-s
                      Last edited by platypus2020; 07-10-2017, 08:56 AM.
                      jack

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                      • #12
                        I would say that my experience is that when making knives, I want to be able to work on a vertical platten, or have access to the contact wheel directly. For fab work, I've gotten a lot of use out of the flat platten both vertically and horizontally, depending on what I'm grinding, and having the ability to go back and forth has been handy. But for the fab work I've done, the contact wheel has always been the star of the show, It's easier to lean into it and let it remove material more quickly. That assumes a rubber faced contact wheel of course.

                        I've had a number of 2x72 grinders, and I would agree with the folks who mentioned a wider belt for fab work. There have been plenty of times I wished I had a 4" or 6" wide belt. A properly designed grinder can run narrower belts. I've used 1" belts and even 1/2" belts on a 2x72 for freehand inside radius work. No reason you couldn't use a 2x72 belt on a 4x72 or 6x72 grinder as long as you plan for it properly.

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                        • #13
                          Originally posted by noah katz View Post
                          digr,

                          Nice machine, I love the stout industrial grade construction!




                          Do you mean lay it down as shown in the pic's?

                          I mean horizontal in the sense that the wheels' axes and belt surface are vertical.
                          IMO I don't think that would be very handy at all.

                          Comment


                          • #14
                            Originally posted by noah katz View Post
                            digr,

                            I mean horizontal in the sense that the wheels' axes and belt surface are vertical.
                            Originally posted by digr View Post
                            IMO I don't think that would be very handy at all.
                            A sander with the belt and the wheels axis vertical would be handy in a woodworking cabinet shop for edge sanding panels.
                            Last edited by reggie_obe; 07-10-2017, 12:12 PM.

                            Comment


                            • #15
                              Another problem you get with a horizontal mount is that all the grit and debris from grinding will get thrown sideways rather than down, as in a conventional vertical setup. I built my own 2x72 grinder using salvaged material and have a water bucker set up under the contact wheel so most of the dust goes into the water, thereby reducing the dust flying around the shop.

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