Announcement

Collapse
No announcement yet.

Fixing a little shaper.

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

  • Fixing a little shaper.

    I'll be using this thread to talk various projects about it.

    -It is not yet identified. Could be an early model of the 'royal' brand.
    -Not sure what kind of oil to use for it, is the gear oil supposed to be different from the way oil? I'm working on a self-lubrication system.
    -I'm experimenting with rubbing alchohol coolants. It should spit about one drop every few seconds, nothing dangerous. Having it spout 'mist' is dangerous!
    There's another thread discussing pros/cons. I'm just testing for fun.
    -It has not been bolted yet. Hockey pucks were a disaster (the machine was stable, but the finish was poor), and I don't recommend this for even a small shaper like mine. An interesting story here about large shapers having danced their wait across the shot floor, even after being bolted (albeit incorrectly) http://www.neme-s.org/shapers/column...column_11.html. Update:
    -I'm currently working on a control box (Originally here,http://bbs.homeshopmachinist.net/showthread.php?t=46629)
    -I'm trying to adjust for the waves and poor surface finishes it produces with a properly sharpened shear tool. Here's a 50x magnification taken from my phone with a jeweler's lens. Material is a block of some cheap generic steel, cut was rather heavy at 1/8th, but no chatter:


    Various depths in aluminium:

    The ondulations isn't a camera effect in the previous picture - you can feel it with your thumb.


    The scales (like the hair) produced could be due to the tool retracting back over the block being cut. Some shapers have a mechanism to lift the tool as it's sliding back, though I think the purpose of this is to not dull the knife as its sliding back over abrasive materials such as cast iron and rusted metals. In one of Kay's shaper documents, they also recommend putting a chamfer on the ends of these materials, so that your cutting tool doesn't dull.

    Update: 3/16ths cut in aluminium works great (the left-most chip is 3/16ths):
    Last edited by Elninio; 03-14-2011, 04:22 PM.

  • #2
    Here's some pictures to help identification (continued from http://bbs.homeshopmachinist.net/showthread.php?t=41996. Lots of pictures here of similar small shapers):






    This is the plate of the distributor, I've emailed them but no luck.


    The motor rotary vane pump of the motor.
    Last edited by Elninio; 03-08-2011, 06:17 PM.

    Comment


    • #3
      Control box based on schematic found here http://www.neme-s.org/shapers/column...column_55.html:

      My variation of the plan comming shortly.


      The large green button is for backing out the table out of a limit switch after it has been stopped after an automatic operation. The button glows green to show me the shaper is powered on. The schematic above doesn't need four LEDS; if switch two is tripped, three and four are not powered. The reason I put four is to know that my switches aren't broken before running an automatic operation. What's worth more to you; a few extra LED's, or a busted gear train? The switch contacts will be covered in some sort of cast plastic to protect against oils - I think i'll do epoxy. How well does epoxy survive temperature changes? It gets as cold as -30 celcius in winter and 30 celcius in the summer; will it crack? The LED's are green/red. I used 220 Ohm resistors for the red, 200 Ohm for the greens. Here's a link explaining how to calculate LED resitances: http://www.kpsec.freeuk.com/components/led.htm


      These are the switches I used, four of them. The current they will handle is 600mA, 12V, 7$ each (if I hadn't throw out my old dot-matrix printers, I could have salvaged the switches from there, maybe I still have them somewhere).
      Last edited by Elninio; 03-08-2011, 06:05 PM.

      Comment


      • #4
        The undulations in the finish may be caused by too much clearance in the Ram ways. The ram is running on a film of oil and pressure from the tool could be lifting it. I had this problem on my Ammco (V-way ram) after I rebuilt it. Resetting the gib fixed the problem.

        Also check the front clearance of the tool bit - should be about 3 degrees. Too much and it can dig in.

        Geoff

        Comment


        • #5
          Originally posted by ammcoman2
          The undulations in the finish may be caused by too much clearance in the Ram ways. The ram is running on a film of oil and pressure from the tool could be lifting it. I had this problem on my Ammco (V-way ram) after I rebuilt it. Resetting the gib fixed the problem.

          Also check the front clearance of the tool bit - should be about 3 degrees. Too much and it can dig in.

          Geoff
          This is with an 8degree tool all around, after changing form hockey-puck to 1/2" plywood between the base and the floor.

          The finish is between these two pictures (camera effect in both):




          50x magnification:
          Last edited by Elninio; 03-14-2011, 04:42 PM.

          Comment


          • #6
            How much back rake do you have on the tool bit. Too much will cause the tool to dig in. I try not to put any on my bit. I grind to one side and and have maybe 3-5 degrees on the bottom of the tool to have it clear the part.
            Another thing to consider is how far is your bit sticking out from your pivot point of the clapper box? I find it better to have the bit as near to the pivot point as possible.

            Comment


            • #7
              I make no claim as a Shaper expert, to be sure. I do have some experience with a 7" South Bend Shaper which resides in my shop and have learned that I get a much better finish when I don't use a tool holder, instead I just place the tool bit directly in the tool post. The additional overhang added by a tool holder can cause spring when machining harder materials. It doesn't seem to be so much of a problem with aluminum.

              Just as with a lathe, rigidity makes all the difference. Another source of "spring" may be from lack of support at the front of the table. I can't tell from your pictures whether your shaper has a support there or not. It appears not to have one. My South Bend does and the support leg must be adjusted properly when I move the table up or down. If your shaper doesn't not have a support you might want to try to design one.

              One other thought is the radius on your tool bit. Just as with a lathe if too much nose contacts the work you can get chatter. You may be seeing the result of chatter in the "undulations" you can see in your finish. If I must use a tool holder for clearance I pay special attention to overhang, sharpness and shape of the tool bit including the nose radius and usually get good results. If I need a really smooth finish I use a shear tool, fine feed .002" or .003"/stroke and .001" - .002" depth of cut to finish. In your pictures it appears that you feed may be greater than that, particularly if you are using a shear tool. It may be only the picture and magnification that gives that impression.

              Another thing to pay attention to with regard to overhang is placement of the tool head. It should not extend below the bottom of the ram any more than necessary for the depth of cut. Be sure the gibs are properly adjusted on all ways including the tool head and that the clapper isn't worn badly with either side play or play in the taper pin at the pivot point.

              I don't think it would cause the trouble you are seeing, but it's easy to get the stroke/feed directions reversed. The sideways feed should take place on the return stroke. Getting them reversed is easy to do if you reverse table feed direction without changing the "side of center" of the feed per stroke adjustment. The main thing is to be sure the table moves on the back stroke of the ram and remains motionless on the forward cutting stroke.

              Lastly, the material you are machining can cause trouble. Hard spots and some cold rolled steels don't machine well. Think about some hardware store bolts that people occasionally complain about machining and getting a rough finish. The same problem exists on a shaper.

              You mentioned you have no gib adjustment on the vertical gib. There may be a shim pack when you disassemble the machine with several shims glued together. You peel off shims in various thicknesses to adjust the gib clearance. The chamfer you mention may help with preventing tool dulling but it also is to prevent a burr at the edge of the work.
              Last edited by firbikrhd1; 03-09-2011, 01:38 AM.

              Comment


              • #8
                First, thats not a little shaper! My Adept Two is a little shaper.

                On my little shaper I found it was much better at taking a wide shallow chip than a deep narrow one. When you think about it that puts the majority of the stress on the pushing the ram sideways rather than trying to lift the ram.

                I initially had patterns exactly like you show there and it was just a matter of adjusting to cut more on the side rather than the end of the tool tip. Tightening the ram gibs also helped in may case.

                It took me months before I could confidently put a bit of steel in the shaper and expect a fine finish but then I am a rather slow learner.

                Comment


                • #9
                  Editing this post to add more content:

                  One of Darin's tools, it's got a high rake, and 1/8ths radiuses on the end. He broke the edges with a very smooth file (and the tool tips). Produces a nice finish. The piece in the background is the shaper's table - looks pretty rough, no? Recently I put a micrometer on the ram and noticed it's cutting perfectly square over three inches. I find it hard to believe, will try a test cut with the piece on the table; the pieces held in the vice were not square.


                  The finish on the left is with his tool, the finish on the right is from my old tool, mentioned in previous posts. Check out the chips. They're smooth, no chatter marks. The cut was about 3/16ths. The shear tool next to Darin's tool produces a similar (the same) finish - perhaps it needs more side rake?


                  Chips from Darin's tool, and from my old one
                  Last edited by Elninio; 05-04-2011, 10:26 PM.

                  Comment


                  • #10
                    Originally posted by firbikrhd1
                    You mentioned you have no gib adjustment on the vertical gib. There may be a shim pack when you disassemble the machine with several shims glued together. You peel off shims in various thicknesses to adjust the gib clearance. The chamfer you mention may help with preventing tool dulling but it also is to prevent a burr at the edge of the work.
                    Just to be clear, we're talking about the gid that is horizontal, but when tightened holds the ram down. This cannot be shimmed as any shim you add increases the play.

                    Comment


                    • #11
                      that strange artifact on the square tube looks like a material fault, skin lamination springs to mind
                      mark

                      Comment


                      • #12
                        I would say try the bit alone instead of using the tool holder. It seems very viable to me that your tool holder may be springing in the material. I would also check the amount of advance of the table per cut.

                        Comment


                        • #13
                          Blue up and check the clapper hinge pin. On my Ammco shaper, the hinge pin is tapered. Over time, wear of the pin, clapper, or the ears the pin passes through will allow the clapper to pivot or shift slightly when it enters the work and wander around on long cuts. Odd patterns will be especially noticeable with a radius on the end of the tool as it can ride around more.

                          The clapper should be a snug sliding fit and sit flat into it's recess as well. Make sure the clapper box is very clean and lightly oiled.

                          If the clapper sticks "up" a tiny bit (i.e. wont close all the way), the tool may enter the work shallow then settle in leaving an odd finish.

                          Try checking the down feed slide for a worn nut or loose gibs, and make sure the down feed slide pivot is holding nice and tight.

                          Comment


                          • #14
                            Originally posted by boslab
                            that strange artifact on the square tube looks like a material fault, skin lamination springs to mind
                            mark

                            I doubt it, that is just what my little shaper does if the ram gibs are loose. I presume the tool hits the work and the rake digs it in and starts the cut. At some point, maybe due to spring in the tool holder or something else, the tool bounces up as the ram lifts and from then on the tool skids across the surface. Next cuts sees this step and it bounces up too, and so on.

                            In my case, I put my hand on the ram and could feel the 'bump' at the start of the rough part.

                            Comment


                            • #15
                              The small undulations cannot be felt on the aluminium work piece, but can be clearly felt if my hand is on the ram. I think the problem is the brass (square piece?) that pushes the ram forward and rides connected to the gear - there is a bit of play in that and a slight click can be heard as the ram changes directions. The sound goes away if I assist the ram into changing directions by pushing it. I don't know if this is known to cause this much of a noticeable problem, but it is not adjustable, and am afraid if I rebuild this piece, I'll have to rebuild it again in the future. Could also be caused by the temperature in my garage. The fellow who made this piece probably did it at ambient temperature, and its about -5 celcius in my garage right now.

                              Comment

                              Working...
                              X