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Question on machining tool slot on AXA blanks

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  • Question on machining tool slot on AXA blanks

    Just working on my first batch of AXA sized tool holders for my South Bend 10K, so far I've squared up the stock and cut the dove tails on my shaper. I'm pleased with the dovetails, they turned out quite well, but am not 100% satisfied with how I squared things up after coming off the saw (squaring up the saw is on the list). So, to eliminate any further error I'm thinking of dropping them onto the tool post and cutting them on the lathe, and I'm wondering if I should cut it with a 1/2" end mill, or use a smaller cutter and re-adjust the height and make extra passes.... Or, am I barking up the wrong tree here? I also have a cheap and cheerful little drill/mill, but I haven't used it much for milling and when I have I wasn't overly impressed and was only planning on using it for the drilling and tapping part.

    Thanks, Don
    If it wasn't done the hard way, I didn't do it.

    Lillooet
    British Columbia
    Canada.

  • #2
    Nothing beats milling in place for spot on alignment. But, in general, the alignment does not have to be perfect since the tool holder is adjustable and the tool can be moved around too.

    If you want to square it up on the mill, you can take the toolpost off the lathe and use it as a mount to the mill's bed.
    At the end of the project, there is a profound difference between spare parts and extra parts.

    Comment


    • #3
      Yeah, I'm probably over thinking this as far as alignment goes, but I want them as close as I can get. These are kind of a practice project ahead of machining a tee slot cross slide, which I am hoping to use the shaper for as much as I can. Deep slotting/chatter has been an issue so far, gib adjustment has helped, but with-out a table support I doubt I'll be able to eliminate all of it.
      I guess the question is down to 1/2" cutter or smaller/more passes. As far as tool holding, I have a Jacobs headstock chuck and mt3 Er40 collet chuck (will need to make up a drawbar) as the top two options.
      Thanks again, Don
      If it wasn't done the hard way, I didn't do it.

      Lillooet
      British Columbia
      Canada.

      Comment


      • #4
        I'd square up the blocks on your mill first. If you think the dovetails are no longer square to any other surface, fixing that would be the first job. First, I'm assuming that the side with the dovetails is finshed? Then you can put that side face down in your vise and machine the otherside parallel to it. Next, you can use a couple of small rods/ drills wedged in the dovetails to get the dovetails square to your vise, then shim the toolholder, remove the rods and tighten the vise. Machine the top of the holder, then that becomes a reference surface, so you flip it over and machine the other side parallel to it. The two sides (one of them with the dovetails), top and bottom should now be square to each other. If you want, you can machine the ends square by holding the block in the vise and cutting each end with the side of an endmill. Even if you were able to cut the slot in your lathe, the set screw and height adjustment holes won't be drilled and tapped square unless the top of the holder is square with the slot and the dovetails.

        Going through making some QCTP holders myself right now (at the blank stage) so I've been thinking about this a bunch, especially for holders that will have a drill chuck in them.

        Comment


        • #5
          oh, and if you want to slot, get a roughing end mill some bit smaller in diameter than the slot you want to make. Do the initial slot in as many passes as necessary, then step over and mill each side to near spec. Then swap the rougher out for a finishing endmill of the same diameter and side mill the last few thou to tidy up the sides.

          Comment


          • #6
            Why are the blanks not square? There's a good number of YT videos on the steps for squaring up blocks fresh off the bandsaw. And the procedures for the most part can be done on the mill or shaper.

            Before you cut the dovetails what did you use for removing the bulk of the waste for the dovetail?
            Chilliwack BC, Canada

            Comment


            • #7
              Its already been mentioned, but a 1/2" end mill wont cut a 1/2" slot, itll cut oversized. Dunno if thats critical for a toolholder, but if youre trying to get everything spot-on its worth remembering. A 1/2" end mill will also have a considerable amount of force trying to move it around during the cut, your lathe may or may not be able to handle it, should you go that route. My preference would be to use a smaller cutter and step off to bring the slot to dimension.

              My preference for the operation would be to properly square up the sawn faces on the mill, then cut the slots there as well, but if your mill isnt up to the task then it isnt up to the task, and you know your tools better than any of us would. That said, if your shaper was up to the task of cutting the dovetails, why would it not be up to the task of squaring the holders up and cutting the slots in?

              Comment


              • #8
                That's true about the slot width. But by the time the 1/2" makes a couple of plunging passes for depth then a cleanup pass or two set off a little to either side and we end up with a slot that is roughly 9/16" wide that's not a bad thing. It's nice to have a touch of clearance.
                Chilliwack BC, Canada

                Comment


                • #9
                  Thanks for the replies guys. I think I'll try and press forward with slotting on the lathe. I don't have a roughing mill, (and won't in time for this batch) but will add them to the ever lengthening list of must-have tools.
                  To try and answer a few questions, I have several chunks of "yer guess is as good as mine" steel laying around that barely fit in my 4x6" bandsaw, that I cut four slabs off of that were just big enough to get three holders out of each (only using half of them in this batch, so six holders). Those, I squared up in the shaper, and am fairly pleased with them, next, I cut the dovetails on the shaper by using a slotting tool to remove the bulk and cleaned up the bottom with the dove tail cutter at the same time I cut the sides. Fit and finish is pretty good and the tool post slides end to end with-out getting tighter or looser and the handle tightens nicely when pulled to lock the holders through-out the length. Next I cut them off on the not so perfect bandsaw, leaving me with four that I could square up and stay in size and two that will be a little smaller,only by 20-30 thou or so,(I did try tickling the slabs to see if they'd grow a little before cutting, but, no love) Back to the shaper I went and cleaned up the cuts, might even be able to say I squared up three of 'em and got one pretty close out of the four that had a chance of being on size and will clean up the two slightly shorter ones next, and they will be the initial "guinea pigs" that I'm going to slot. At this point I think I am more than close enough to square that I'd be fine no matter which method I use, and most likely I'll do a couple on the lathe, then try a couple on the mill and maybe back to the shaper to try and work the bugs out of my slotting technique.
                  Upon reflection of this post, the main purpose of the use of band-width was likely just me trying to dip my toes into the pool here a little after years of mostly just sitting poolside and trying to absorb as much as I can...... Might even get brave enough to belly-flop in with a picture or two.......
                  Thanks again, Don
                  If it wasn't done the hard way, I didn't do it.

                  Lillooet
                  British Columbia
                  Canada.

                  Comment


                  • #10
                    So.... like a 1/4 x 1/2 tool with a little relief ground into the sides? Sort of like a lathe parting tool? Or what size did you make for this?

                    I'm still very much a shaper newbie. I've had some wins but mostly a lot of my first shaper steps were less than stellar.
                    Chilliwack BC, Canada

                    Comment


                    • #11
                      Originally posted by 140mower View Post
                      Thanks for the replies guys.

                      [ some deletions here ]

                      Upon reflection of this post, the main purpose of the use of band-width was likely just me trying to dip my toes into the pool here a little after years of mostly just sitting poolside and trying to absorb as much as I can...... Might even get brave enough to belly-flop in with a picture or two.......
                      Thanks again, Don
                      Welcome, and hope you have good luck on your project.

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

                      Comment


                      • #12
                        Originally posted by BCRider View Post
                        So.... like a 1/4 x 1/2 tool with a little relief ground into the sides? Sort of like a lathe parting tool? Or what size did you make for this?

                        I'm still very much a shaper newbie. I've had some wins but mostly a lot of my first shaper steps were less than stellar.
                        I'll be honest, in my attempts to grind these slotting bits, I tried to shoot for function over form and wasn't too concerned about exacting widths, as my slots were going to be wider than the bits. Having said that, I ground them out of a piece of 1/2" hss, I used cheap purposely purchased Chinese steel for this learning experience rather than the good stuff I already had on hand. The small end was about a 1/4" in width and the other end started out as close to a half inch as I could, and gradually got narrower until it was probably 3/8" wide as I hunted for that "sweet spot". I did find that it did better if I gave it a pretty heavy cut as opposed to too light of one as far as chatter went (right up until I broke the cutter off, then I backed off on the cut a bit.) And, yes, a little clearance in all directions, very much like a parting blade on a lathe, both operations, although on different machines are essentially the same I believe.
                        I'm still quite a newbe to all of this myself.... When I first started in this hobby I thought to myself, is this ever easy!!!!!! Years tend to go by, and then the light comes on....... I swear to god guys, I thought we only collected them.......

                        They tell my I'm trying...... sometimes I think we might be using different definitions......
                        If it wasn't done the hard way, I didn't do it.

                        Lillooet
                        British Columbia
                        Canada.

                        Comment


                        • #13
                          Originally posted by danlb View Post

                          Welcome, and hope you have good luck on your project.

                          Dan
                          Thanks..... I've been hanging around here for quite some time, so forgive me if at times I seem to know many of you better than you are likely to know me.
                          If it wasn't done the hard way, I didn't do it.

                          Lillooet
                          British Columbia
                          Canada.

                          Comment


                          • #14
                            Originally posted by 140mower View Post

                            I'll be honest, in my attempts to grind these slotting bits, I tried to shoot for function over form and wasn't too concerned about exacting widths, as my slots were going to be wider than the bits. Having said that, I ground them out of a piece of 1/2" hss, I used cheap purposely purchased Chinese steel for this learning experience rather than the good stuff I already had on hand. The small end was about a 1/4" in width and the other end started out as close to a half inch as I could, and gradually got narrower until it was probably 3/8" wide as I hunted for that "sweet spot". I did find that it did better if I gave it a pretty heavy cut as opposed to too light of one as far as chatter went (right up until I broke the cutter off, then I backed off on the cut a bit.) And, yes, a little clearance in all directions, very much like a parting blade on a lathe, both operations, although on different machines are essentially the same I believe.
                            I'm still quite a newbe to all of this myself.... When I first started in this hobby I thought to myself, is this ever easy!!!!!! Years tend to go by, and then the light comes on....... I swear to god guys, I thought we only collected them.......

                            They tell my I'm trying...... sometimes I think we might be using different definitions......
                            Just went and looked at this bit again, and I ground it further than I remembered, it got down to about 1/8" at the small end and 1/4" at the other end. I've been toying with this project on and off for too long already, really need to start finishing a few projects.
                            If it wasn't done the hard way, I didn't do it.

                            Lillooet
                            British Columbia
                            Canada.

                            Comment


                            • #15
                              if you've already squared up part of the blanks on the shaper and then cut the dovetail you're going to have a couple of surfaces that are square already. Use those as a reference to square the others on the mill or shaper.

                              Personally I'd avoid slotting the tool holder on the lathe. Slotting is one of the hardest processes to do on a machinetool in my experience (along with using a large thin slotting saw) and a lathe is not the best milling machine out there. Do it on your mill with a 1/4" or 3/8" end mill, then step over to width. Start the slot in the middle as the edges will be uneven from the slotting. Or better yet, do it on your shaper.

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