Announcement

Collapse
No announcement yet.

power feed for surface grinder

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • power feed for surface grinder

    I have been looking at ways to make my BP surface grinder have a power feed X axis because I now realize it will take allot of cranking the hand wheel to grind any part.

    The most interesting way I have found so far is in this youtube video.

    http://www.youtube.com/watch?v=8GFXPWknWXg


    Anyone else retro fitted or home built a power feed X axis for their surface grinder? I'd like to get some ideas.
    Andy

  • #2
    that's a pretty novel idea and I don't see why it wouldn't work along with a speed control for the motor.
    It's only ink and paper

    Comment


    • #3
      Question being would it be "Smooth Enough" not to leave marks in the work

      There is a reason why they use Hydraulic Table Feed on Surface Grinders.

      I don't see why you couldn't mount the ram outside the table. Automatic Surface Grinders have the hydraulic ram mounted underneath where it is less likely to be hindered in it's movement.
      Last edited by JoeFin; 02-15-2010, 05:05 PM.

      Comment


      • #4
        I would think just about any repetitive motor operated power feed would leave less marks and be better than hand operation? Would I be correct on that?
        Andy

        Comment


        • #5
          Originally posted by vpt
          I would think just about any repetitive motor operated power feed would leave less marks and be better than hand operation? Would I be correct on that?
          This is plausible. A gear-reduction motor could be just the thing to maintain a steady feed back and forth.
          Sometimes the professional is hidebound by tradition while the skilled amateur, not knowing it can't be done blazes a new trail. -JCHannum

          Comment


          • #6
            waste of time imo. you still have to stand there doing the the in-feed and a cheapo motor and gearbox are going to introduce vibration.

            I've had a grinder for 10 years and sometimes i get a fleeting thought of automating it....but its never proven a big enough bother to make it out of the fleeting thought category. Work with the machine awhile, then decide if its worth it to you to do anything about it. I would not do it unless it was fully automated though...the advantage I see is being able to walk away and do something else while it works
            .

            Comment


            • #7
              The bad thing about hydraulic systems is they leak eventually. Also they are noisy*. Maybe not something you would want in a basement shop. The good thing is they are smooth. Smoother than the Yahoo idea (non-constant surface speed). I think what most people do not know about table cylinders on surface grinders is the cylinder rod is not clamped tight to the table. the end of the rod is undersize to the bore it goes through in the table and the nuts are set so that the table has some end play to the rod. This is done to prevent binding and lifting the table.

              *maybe using the power steering system off of a car might work for a hydraulic supply. Just make sure to meter the flow to tank not the supply line.
              Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

              Comment


              • #8
                Originally posted by JoeFin
                Question being would it be "Smooth Enough" not to leave marks in the work

                There is a reason why they use Hydraulic Table Feed on Surface Grinders.

                I don't see why you couldn't mount the ram outside the table. Automatic Surface Grinders have the hydraulic ram mounted underneath where it is less likely to be hindered in it's movement.
                Is the reason for hydraulics smoother finishes or a less troublesome drive?

                TMT

                Comment


                • #9
                  I did one some years ago with a rodless pnumatic cylinder and shuttle valves on the end strokes.

                  .
                  .

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



                  Comment


                  • #10
                    The pneumatic deal sounds interesting do you happen to have a pic of that setup John? Hydraulic may be an option.

                    What other ways are there?
                    Andy

                    Comment


                    • #11
                      Personally, I think people are getting a bit overboard on the idea of somehow inducing vibration.

                      Yes, I know that surface grinders are sensitive, and getting a good finish almost seems voodoo, but people were getting good finishes back in the days of gear-driven rack-and-pinion drives. I fail to see how a small, high-speed motor, heavily gear-reduced, will add enough vibration to the mass of the table to induce a detectable error to the finish.

                      Personally, I think that cam/eccentric idea is brilliant. It wouldn't take much at all to whip up something like that for mine, and a few refinements like a sliding pivot point to adjust the throw, would make it quite useful.

                      Yeah, it only does the recip rather than doing a full automatic conversion. It's a start, and I know I get awful tired of crankin' on bigger parts.

                      Doc.
                      Doc's Machine. (Probably not what you expect.)

                      Comment


                      • #12
                        Doc - I thought yours was an automatic machine

                        Originally posted by Doc Nickel
                        I fail to see how a small, high-speed motor, heavily gear-reduced, will add enough vibration to the mass of the table to induce a detectable error to the finish.

                        Doc.
                        Sensitive ? - Nah.... just the table hitting a 12/3 electrical cord at the very end of its stroke is enough to cause the machine to burn into the work. At 2700 lbs, I don't consider my machine light weight either

                        It appears fairly obvious when the cam on that motor is in it's downward stroke it is going to lift the table to some extent.

                        Originally posted by Spin Doctor
                        The bad thing about hydraulic systems is they leak eventually.
                        I've been using the same 2 gal of hydraulic oil since I first got my machine. Simply Amazing what a little Teflon tape will do for your plumbing.

                        The "Trick" of using Hydraulic is fairly obvious once you look at the circuit. An open circuit with the metering on return side. A little 2-way valve that switches the lines at the end of each stroke. Basically "Both" sides of the ram have pressure on them - just 1 side more then the other

                        Comment


                        • #13
                          What if the electric cam motor setup was reversed with the motor mounted on the Y axis bed and the arm went to a pivot point on the X axis bed? There would be less chance of lift than correct?
                          Andy

                          Comment


                          • #14
                            Some day some one will "Really figure it out" and use magnetic coils to move the table back and forth like the they do Hi-Speed Rail

                            Comment


                            • #15
                              Originally posted by JoeFin
                              Doc - I thought yours was an automatic machine
                              -Nope, all manual. In fact, I asked here about the possibility of using steppers or servos and some sort of controller to convert it to automatic, as I agree with what was noted earlier- I'd like to set it up and let it run for a larger part, while I go off and do something else for five or ten minutes.

                              Sensitive ? - Nah.... just the table hitting a 12/3 electrical cord at the very end of its stroke is enough to cause the machine to burn into the work.
                              -And I'm told that if you hit the stops too hard on mine (they're actually spring-loaded to buffer it somewhat) it'll raise up a tiny bit. Ditto if you yank the one-shot oiler while in the middle of a cut.

                              However, the proper setup for the grinder is to overtravel the work by whatever margin is necessary to prevent that sort of lifting.

                              It appears fairly obvious when the cam on that motor is in it's downward stroke it is going to lift the table to some extent.
                              -I disagree that it's "obvious". There's not enough rotary mass to cause any lift from inertia, and the fulcrum of the arm gives it little leverage to pry the table up.

                              I'm not saying it won't or can't, I'm just pointing out there's a lot of the usual "Oh, that'll never work!" going on, in no small part due to the somewhat exaggerated sensitivity of a grinder.

                              Doc.
                              Doc's Machine. (Probably not what you expect.)

                              Comment

                              Working...
                              X