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6" Jointer - Dangerous Cutter Head Guard?

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  • 6" Jointer - Dangerous Cutter Head Guard?

    My first Jointer, the 6" Ridgid seems excellent in all respects but one, and maybe there's something I'm not understanding. The bottom edge of the head guard sits 3/4" off the table top. I assume that this is designed so that thinner timbers slide under it without moving it aside. The problem is that, when planing, as the board thickness gets close to the height of the bottom edge of the guard, it tends to jamb between the table top and the bottom edge of the guard. I have also found that you cannot Plane to the full width of the cutter blades unless the board is considerably thinner than 3/4" as the top edge of the board will jam into the head guard out near its pivot pin (no, I have not gone thinner than the recommended 1/2"). It seems like it would be a lot less dangerous and scary if the head guard's bottom edge was close enough to the table top so that it was pushed aside by all boards, regardless of their thickness. Is there something I don't understand about this guard's operation? I have considered machining off some of the bottom of the casting to lower the guard closer to the table top. Also increasing the width of the notch very slightly out near the pivit pin so that the full 6" width of the cutter head can be utilized.

  • #2
    Wmetcalf
    Someting must be wron or I do not understand you. The guard should not go over the wood, It should turn out of the way as the wood go through. This is trure for 3/4" stock. Check the installation.
    Do not slide it under.
    SCWood

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    • #3
      Me either - what are you actually doing???
      Wish I had the answers ..... even half of \'em

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      • #4
        The apron at the bottom edge of the cutter head guard sits close to the table top for the first three inches either side of the pivot post. From there, for the rest of its circumference, it is notched up so that its bottom edge is 3/4" off the table top. This allows any board that's less than 3/4" thick to slide beneath it along the table, without pushing the guard aside (This does not effect edge jointing). Because of this high clearance between the guard and the top, one assumes that the machine is designed to pass boards beneath the cutter head without engaging it when planing. When planing stock thicker than 3/4", such as S2S, eventually you get down near the 3/4" thickness and the board begins to jam itself underneath the bottom edge of the head guard and the table top, especially at the tail end of the board. It's scary!

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        • #5
          I noticed this with my jointer also. I have begun to hold a push block close to the leading edge to make sure the guard is out of the way.

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          • #6
            I have had the Ridgid jointer for several years and have never had a piece of stock go under the guard. I would check to be sure the guard is all the way down. I will check the height of mine when I go home. Be care and check the manual. There may be a slot or something that lets it go down i do not remember.
            SCWood

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            • #7
              it almost sounds like your face planing not edge jointing not really recomended except for streightening a warped board bill

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              • #8
                The guard's 1/2" pivot pin is inserted into a hole in the underside of the casting. The guard is forced to its current height by a slight cast extrusion, on the underside, where the pin enters the guard. This extrusion bears against the table, holding the guard at its current height. If the pin could be extricated from the casting (unlikely), the extrusion could easily be ground down, lowering the head guard another 3/16" or so towards the table. This would still not be perfect, as a 1/2" thick board (the recommended minimum planing thickness) would still be able to slide under the guard. As I study this thing, I have to believe that the notch on the underside of the guard was put there to allow boards to go under it during planing operations. Otherwise, the notch makes no sense. If this is the case, I think a possible solution would be to place several large washers on the pivot pin before inserting it into the hole, thereby RAISING the guard, and allowing ALL planed boards to slide underneath without moving the guard aside. The curved end of the notch near the pivot pin would still have to be machined a tad wider to allow a board the full width of the cutter head to be planed without hanging up on the guard. I don't know if passing planed boards UNDER the guard is accepted jointer practice. It seems logical, as the cutter head would then be covered during planing operations, regardless of board width. Other jointer guards may be configured the same way. I never noticed. As it stands, this guard has to be modified to either go up or down from its existing position, to eliminate a potentially serious hazard.

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                • #9
                  Based on your description I'll try and explain what I think is happening. In order to get a truly flat surface on the jointer the workpiece must be held firmly down on the outfeed or rear table. At the beginning of your cut a push block will pivot the guard out of the way. As soon as practical position both of your hands on the outfeed table and keep "leap frogging" your hands one over the other keeping downward pressure on the workpiece and outfeed table. Now if your board is long enough(and thin enough) or depending exactly how you position your hands the guard may pivot back against the fence allowing the workpiece to pass underneath it. However, when you approach the end of the cut once again a push block may pivot the guard out of the way. I know this is kind of a long explanation, let us know if you need more clarification. Thanks!

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                  • #10
                    I see the same issue on my newly assembled Ridgid jointer (grey model). I can slide a full 3/4" thick board under the guard, without pivoting the guard itself.

                    I see Bdueker suggesting that it is ok for the guard to pivot back over the workpiece as the workpiece continues over the cutters. I don't have a lot of jointer experience, but this is not what I would have expected to hear either. I would think irregularities in some boards, coupled with just the right thickness board, could cause a situation where the board gets squeezed between the guard and the table. Just doesn't seem like the guard should pivot back over the workpiece.

                    If it is permissable to plane down to 1/2", it would seem safer to also expect that same 1/2" thick board to push the guard out of the way, and keep it out of the way, as it passes the cutter.

                    I understand the notch on the infeed side of the guard provides necessary clearance to the cutter head as the infeed table is lowered, but it does seem excessive. Perhaps the notch height could be reduced, so that a 1/2" to 3/4" thick board would push the guard out of the way.

                    Bdueker, this seems very suspicious. What am I not understanding?

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                    • #11
                      I looked at mine last night. I guess I have not planed a 1/2" board or as DBueker said the grippers they give you just move it out of the way. It is 1/2" high but have never had a problem.
                      I use thickness planer for most work, but do use it at times.
                      SCWood

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                      • #12
                        I may not have been clear enough on my other post. The correct technique when face planing is to try and keep both hands(push blocks) behind the cutterhead on the outfeed table as much as possible. Keep "leap-frogging" one hand over the other. The push blocks will keep the guard away from the fence. Thanks!

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                        • #13
                          Thanks to all for your responses. Thanks bduecker for your suggestion. Today I planed and jointed a piece of S2S Walnut and was careful to use your suggested technique with the blocks. Of course that still doesn't solve the problem. As one poster mentioned on Woodnet, the head guard is mounted to the infeed table, requiring some margin of space under the guard if the infeed table is lowered. This is really a bad bit of design and my ignorance precluded me from even looking for this. If I were buying today I would look at the competitors in this class to see if they had the same flaw. I am going to look at ways of holding the guard aside when planing. One possibility might be to drill a hole for a pin into the table surface underneath the guard casting. you could then move the guard out from the fence incrementally and mark several locations on the underside of the guard, using the hole in the top as a guide, then remove the guard and drill the holes. You would then be able to swing the guard out to various positions and immobilize it with a pin dropped down through the appropriate hole. This is not perfection, but at least it would allow you to get partial coverage of the cutter head on boards of different widths

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                          • #14
                            Guys, the guard must have the clearence you have described. All 6" jointers can cut 1/2" deep rabbits and since the guard is mounted to the infeed table at max cutting depth there is now only 1/4" clearence between the guard and the cutter head. My delta has an 11/16" gap.
                            When face jointing stock less than 3/4" it passes under the guard and through the knives without 'jamming'. If the stock is tapered insuch a way that the beginning is less than 3/4" and at some point becomes grater than 3/4" the wood catches or pinches the infeed side of the guard and pushes it out of the way, this is how it should work. If your stock becomes jammed I can suggest two possible causes. 1) you have way too much spring tension on your guard forcing it toward the fence. 2) your outfeed table is slightly higher than your knives. The outfeed table must be exactly the same height as the apex of the cutters. If not the jointed piece will bump into the outfeed table and if the wood is exacltly the thickness of the 3/4" gap of the guard then even the slightest offset between the cutters and the outfeed table will cause 'jam' on the underside of the guard as it tries to climb onto the outfeed table.
                            Jointer technique ...
                            Always face and edge joint with the crown facing up and grain running "downhill" from the outfeed table and away from the knive's rotation produces the best results (least tearout).
                            You can sucessfully straighten a piece of wood that is at most twice the length of your jointer bed
                            I would also suggest that you do not put excessive dounward pressure on the boards you are trying to straighten since they are quite thin. Too much pressure will flatten the board on the infeed table and the knives will take off an even slice across the length of the board. When you remove the pressure the board will spring back and you will have a board with the same amount of cupping just a bit thinner.
                            When I face or edge joint I always keep my hands on the infeed table until the end of the peice I am jointing is fully supported by the infeed table then I move my left hand to the outfeed side maintaining the majority of feed pressure on the infeed side
                            Hope this helps

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                            • #15
                              wbrooks: Excellent post. Very informative. Thanks!

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