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Setting stock onto parallels - brass hammer, lead hammer, dead blow ???

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  • #16
    For many years now I've used an old "bullet" scuba weight as a lead bumper. Works like a treat. The lack of a handle sometimes bothered me but in reality it's an advantage more than it's a hindrance.

    After about 10 years use it's getting pretty mushroomed and hollow and I'm considering options for melting and re-casting it to last for another 10 years. I've got a melter for doing bullet casting so that's not an issue. I guess I'll need to buy some foundry sand to make a mold. Or I'll need to do something clever for a steel mold that is tapered so I can get the halves apart.
    Chilliwack BC, Canada

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    • #17
      Dan; less time should be spent working up excuses to avoid starting the machine.

      When you start it for the first time it will be scary. Lots of mass is moving all over the place. Just let it cycle well clear of the table etc; it will cycle like that just fine. After a bit the action it takes will be less intimidating.

      PS: I would NOT be tying the machine to the floor for a bit. You may well find it sits there just fine.

      After you have watched the ram go back and forward for a bit you can move onto engaging the lever to move the table. Again; do this without cutting anything. Take note of how the action works to move the table. Try to workout how you alter the feed rate. Set the feed rate low initially.

      The next scary action is to actually put it into a cut. The fear is that the ram (cutter actually) is going to push the work off the vice etc. Use something soft (like aluminium) and make a low depth of cut. The block of stock can be anything, but for the first cut try something that is like 2" x 2" x 2". This will allow you to put (grip) a lot of it in the vice and allow clearance so you feel comfortable "letting it go".

      For my first cuts I put the vice so that the work was pushing against the vice jaws. This is the most rigid and (of course) does assume that the cut will happen.

      The other option is to put the vice sideways; hence if the cut is too much then the work will be ejected from the vice.

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      • #18
        As it happens I was just using my own smaller size shaper a couple of days ago because the mill was already set up for a cut and I needed to make some clamp pieces quickly to do the job.

        It reminded me of two things. First is that it's a very unforgiving machine. Make it a habit to run at least one stroke "on the clutch" or with a manual crank of some form before you engage the power fully. It won't care if it's cutting metal, pushing the work out of the vise or busting out a piece of its own casting. Anything in the way is going to be dealt with in very certain terms.

        I was also reminded that it's a hellishly fun machine to run and that I need to find more excuses to use it...

        Early on I also rapidly learned that the right place to stand is on the right hand side where all the controls are located. Standing at the end is a great way to end up with a chip sequined shirt and possibly dent my forehead when the ram comes out and bops me upside the noggin. As luck would have it I just got the chip sequins and not the bop on the head. But I quickly found out that I wanted to be around the side where it's safer....
        Chilliwack BC, Canada

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        • #19
          When I first started my 12" Vernon I put a piece of mangled excavator boom hinge pin in the vice and cleaned it up so I might be able to use the now squared off chunk for something someday. I had made a new pin for the owner of the excavator and kept the broken pieces. He said "what are you going to do with that junk?", but the shaper turned it into useful stock. The main thing I do and have read to ALWAYS do when starting the shaper is to turn it over by hand for at least one cycle to be sure you aren't going to "crash" it.

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          • #20
            Agreed on the "by hand" thing where possible. But some of the larger machines use hydraulics to move the ram. So some equivalent "safe" way to run the ram motion test where it can bump and stop without any risk needs to be used. I've never looked into that style so I just called it "on the clutch" above.
            Chilliwack BC, Canada

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            • #21
              Deadblow.
              Paper between parallels and work.
              Paper cannot come out or does not move = ready to cut.

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              • #22
                You folks suggesting deadblow hammers.....

                What type do you use?

                Lixie, which I have never had one of, is like a replaceable plastic face hammer but with shot in the body. Seems like a good design,

                http://www.lixiehammers.com/LixieCatalog.pdf

                Most deadblow hammers are NOT like that, they are a one piece cast plastic hammer with the shot etc in the head. Often called "Compo-Cast", with plenty of offshore versions.

                https://www.grainger.com/product/STA...w-Hammer-5C934

                https://www.mscdirect.com/product/de...71939?fromRR=Y

                The Lixie hammers come in a bunch of sizes, and seem as if they would be fine for the purpose of tapping down the parts. The "compo-cast" type all seem to be medium or larger, have faces VERY different from the Lixie type, and are the type I have one of... very unsuitable for most tapping down of parts. The face won't stand hitting anything much smaller, or having sharp edges, etc.

                Then there are the hammers that just look like a Lixie, they have the replaceable faces, but do not have the shot loading, so they are not really dead-blow. Lixie makes those also, I believe.

                If you are using a Lixie type dead-blow, OK, I understand that. If you use a big compo-cast type.... well, I don't "get it".
                CNC machines only go through the motions

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                • #23
                  natural

                  Originally posted by J Tiers View Post
                  You folks suggesting deadblow hammers.....

                  What type do you use?

                  Lixie, which I have never had one of, is like a replaceable plastic face hammer but with shot in the body. Seems like a good design,

                  http://www.lixiehammers.com/LixieCatalog.pdf

                  Most deadblow hammers are NOT like that, they are a one piece cast plastic hammer with the shot etc in the head. Often called "Compo-Cast", with plenty of offshore versions.

                  https://www.grainger.com/product/STA...w-Hammer-5C934

                  https://www.mscdirect.com/product/de...71939?fromRR=Y

                  The Lixie hammers come in a bunch of sizes, and seem as if they would be fine for the purpose of tapping down the parts. The "compo-cast" type all seem to be medium or larger, have faces VERY different from the Lixie type, and are the type I have one of... very unsuitable for most tapping down of parts. The face won't stand hitting anything much smaller, or having sharp edges, etc.

                  Then there are the hammers that just look like a Lixie, they have the replaceable faces, but do not have the shot loading, so they are not really dead-blow. Lixie makes those also, I believe.

                  If you are using a Lixie type dead-blow, OK, I understand that. If you use a big compo-cast type.... well, I don't "get it".
                  i like rawhide no bounce no marks

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                  • #24
                    All the above.

                    How hard the whack - or tap - depends on the grip, the softness of the work, etc. Strike too hard and the work may rebound a trifle. This is a place where your ears are your most reliable aid to gagg when and how hard to tap. Sometimes a bump with a weighty lead hammer is just what the doctor ordered. Another situation may call for a sharp tap with a light brass hammer.

                    But wait! There's more! A light hammer in the right hands is a real detecting tool. A few taps on flat work secured to the table with clamps and step blocks will tell you if its solidly seated between clamps. Or if fasteners are tight. Lost is things.

                    Have all three hammers in the cabinet by the milling machine. Sooner or later you'll use them all and learn which is best for what.
                    Last edited by Forrest Addy; 11-22-2017, 04:19 AM.

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                    • #25
                      Originally posted by Lew Hartswick View Post
                      It isn't the hammer material it's just how tight the vise is. No matter the hammer if the vise is too tight the work won't move and if too loose the work bounces. So get the vise just right. It only takes a little experience. :-)
                      ...lew...
                      I agree, I have a small steel hammer with replaceable brass ends that I have used for years to seat work in my BP vise. It's just a matter of snugging up the vise just right and a light tap. I also put downward pressure on the work with a finger as I lightly tap it and that helps prevent any rebound. I can tell when my work is seated by simply sliding or trying to slide each parallel. I can feel the play.

                      Also my old BP vise as nice as it is has a tendency to slightly kick the work up in the front when I give it the final snug. Sometimes I put a dowel pin between the jaw and work to compensate for this although I don't like the idea of it.

                      JL................

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                      • #26
                        When it comes to the actual tapping, there is a way to hit with nearly ANY hammer type that will not cause rebound.

                        To paraphrase Musashi, you hit softly but solidly with a "sticky, pushing feeling". Then the force seems to go into the target with no rebound. Practice makes perfect.

                        As for the vise, it is no use tapping until the vise is snugged somewhat, since what you are doing is to counteract the tendency of the vise to raise the part up. So you must have the vise beginning to be tight in order to have any of the raising up that you want to counteract. Snug. tap, snug more, tap.

                        If you clamp down tight to begin with, your part will raise up, but the vise will be too tight to allow the part to move without excess violence with the hammer, causing marking and damage. So it usually takes two rounds, unless your vise is very good.
                        CNC machines only go through the motions

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                        • #27
                          Originally posted by Norman Bain View Post
                          Dan; less time should be spent working up excuses to avoid starting the machine.
                          How DARE you understand me?

                          Well, not completely. Everything about this machine is taking MUCH longer than I expected. For example, getting the 500 pound table up off the floor and mounted correctly took all afternoon. It might have taken less time if I had known what I was doing, but I had to learn. The table has a hooked lip on the top that holds onto the slide mechanism. There are also three bolts to hold it in place. Turns out I couldn't put the bolts on the machine face plate and put the table on from the front. If one lifts the table enough to get the hook over the slide then the bolts won't go in the hole. When I tilted it to get the hook over the slide, the bolts wouldn't fit into the angled holes. I finally realized I had to suspend the table in space at the right location and slide it sideways onto the holding plate. EXCEPT - the engine hoist legs wouldn't allow that... they kept bumping into the base. So, I had to build pair of U shaped rails out of 2x6 and 2x4 that went over the baseplate and allowed the hoist to slide side to side freely.

                          The good news - that helped me get the vise into place. That only took 2 hours.

                          The bad news - the vice wouldn't close. Examination showed that a bolt was out of place. No problem, except I had to .... etc. etc. etc...

                          ANYWAY... I have actually started it. I have watched the ram go back and forth, and timed the back gear/and selection box settings versus ram strokes/min. Well, most of the 8. The top one was too scary to count. By looking at the other ratios I guess it was about 85 strokes/min. With the 10" stroke I was using to make counting the strokes easy that was scary as heck. So, now I have a excel spreadsheet of gear box setting and stroke vs SFM. I am going to sharpen a cutter this afternoon, and I plan to cut some stock today or tomorrow.

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                          • #28
                            Jeez--I can remember the big old shapers at Stephens Adamson where I served my apprenticeship. Young draftsman were often asked to take ammonia reeking blueprints out to the shop office for distribution. The shapers they had would peel of a chip 3/8" wide x about 0.070 thick, so hot it would be a dark blue color and smoking. If you got hit by one of those chips it was a life altering event. The old machinists generally had some kind of a cardboard guard jerry rigged into place to catch the chips, but not always. We stayed well clear of the shapers.
                            Brian Rupnow
                            Design engineer
                            Barrie, Ontario, Canada

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                            • #29
                              I can confirm you want a light tap, often a very light tap. I see guys flailing away beating the part up but never seating it on the parallels. Think of lifting your hammer 1/2" and letting it drop of its own weight. Real light tap. That's usually all it takes!

                              metalmagpie

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                              • #30
                                Originally posted by metalmagpie View Post
                                I can confirm you want a light tap, often a very light tap. I see guys flailing away beating the part up but never seating it on the parallels. Think of lifting your hammer 1/2" and letting it drop of its own weight. Real light tap. That's usually all it takes!

                                metalmagpie
                                Exactly!

                                Sometimes it may take 2 or 3 inches drop, but hitting it harder probably WILL cause a rebound.
                                CNC machines only go through the motions

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