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  • Another Cathead question..

    Hey guys! I just made a Cathead for the rear of the spindle on my lathe. Got a job threading some long rods and I need it. I have the works ready to put in the R/T to drill the setscrew holes. How many should I use? Was going to put in three setscews (to hold the work) but thought I should ask here first. Prolly turn out any number of reasons why I should use four
    I made it so both ends will fit the spindle so if in the future I need two or nine or whatever setscrews then I'll be ok.
    Thanks!
    Russ
    I have tools I don't even know I own...

  • #2
    Do you have any pics? Sorry I am not offering an answer to your question as I have never used one. I can see the need to have it on the back end of the spindle though. Might be another tool I have to make.
    Life Is Grand

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    • #3
      Yeah, take a pix of it please.... I need to make up one some day and maybe yours will give me the needed butt bump.
      If everything seems to be going well, you have obviously overlooked something........

      Comment


      • #4
        Geez...I hope I'm calling this the right thing It's very simple guys. A piece of 3" diameter DOM heavy wall (1/2" wall) that is turned out on both ends so it slips over the end of the spindle. It'll be held on the spindle with a couple or three setscrews. The other end will have (basically) the same holes in it for the set screws (bolts?) that will be used to center the work in the rear of the spindle. The whole idea is so the work can't cock off to one side while in the chuck...or so the longer length can't start to whip. Nothing I hate worse than havin a lathe chase me around the shop
        Russ
        I have tools I don't even know I own...

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        • #5
          Four is my suggestion. I know that just three is enough to hold a part in position, but if you have to actually dial in something, my experience is that three is a PITA. You have to loosen two on the opposite side and I can never get them backed off just the same amount, so it's another round of screw adjustment. Of course four isn't immune from having one plane affect the other, but it seems more tractable to me.
          .
          "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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          • #6
            Sounds like a good description....... but you KNOW how this bunch likes pitchers.

            Yeah, a .500x4-5' rod through a 1 1/5" spindle bore gets pretty wild. I do the occasional gun barrel and though it wont stick out much, I dont want it to MOVE, period!
            If everything seems to be going well, you have obviously overlooked something........

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            • #7
              I can take it one step further and try my hand at threading it to match my spindle. I have never cut metric threads and though I sometimes think I look for trouble I really should try it.

              I second the love for pikturzs
              Life Is Grand

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              • #8
                torker,
                Cool idea, a cathead with both ends able to fit the outboard end of the
                spindle.
                One thought though, if your doing some quantity.

                It could get a little tedious moving the set screws in and out at the....
                ..."free end" each time you have to change the part.
                Also there's a chance you could score the part against the screw tips
                as you insert and feed it in from one end or the other.
                Although that may not even be a concern.

                Thinking about this, it occured to me that one could adapt a small bodied
                four jaw SCROLL chuck to the outboard end.
                Then just a twist of a chuck wrench loosens or holds the part, the limit
                being the diameter of the through bore of that chuck.

                Hum......I have a couple of 4 jaw small scroll chucks for my wood lathe that just might be the ticket, I'll have to look into that.

                Now you've sparked my interest!
                Mike Green
                Mike Green

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                • #9
                  Originally posted by TGTool
                  Four is my suggestion. I know that just three is enough to hold a part in position, but if you have to actually dial in something, my experience is that three is a PITA. You have to loosen two on the opposite side and I can never get them backed off just the same amount, so it's another round of screw adjustment. Of course four isn't immune from having one plane affect the other, but it seems more tractable to me.
                  I will agree with that, as the cathead is frequently used to center work as well as stabilize it.

                  Unless a very critical operation such as chamber reaming is being done, the cathead can be left a tad loose to permit feeding work through without the need of loosening and readjusting each time.
                  Jim H.

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                  • #10
                    Crap...I just drilled and tapped it for three. I knew someone would say why it should be four setscrews...never thought of the setup issues with three.
                    Oh well...I left lots of room for four...I can drill them later.
                    Mike, good call on the four jaw. That'd work well on my lathe. There's plenty of thread sticking out the back for a backing plate to screw onto.
                    Oh ya...the stores will be closing soon and I don't have any 5/16" sewtscrews...gotta go. Will snap a pic later!
                    Thanks for your time!
                    Russ
                    I have tools I don't even know I own...

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                    • #11
                      ...sorry Russ...but I think catheads always have four...for setup as stated above.

                      THAT OLD GANG 'O MINE

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                      • #12
                        Yep...you guys where right! Do not make one with three setscrews. Three works but like Mike said...it's a lot of fooling around to adjust with three.
                        Oh yes...LOL! After I made this my wife picked up a couple of my magazines I had laying around. She handed them to me. The top one was a MW Feb/March 2005(Thanks D!). On the cover is a Cathead...cept they called it an "Offside Chuck" Either works for me! Thing was easy to make and very handy! Highly recommended!

                        Russ
                        Last edited by torker; 04-15-2007, 01:42 AM.
                        I have tools I don't even know I own...

                        Comment


                        • #13
                          I ruined a good piece of 3/8" drill rod and banged up an open drawer on my lathe. I was turning along fat, dumb and happy when I thought somebody was taking shots at me. It wasn't until the stock started squealing in the chuck that I figured out what happened. I don't think the cat would have helped though. If you'll have long stock hanging out of the end, be sure to support it at the other end! I have the piece hanging on the wall behind the lathe as a reminder.

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                          • #14
                            I use a cork or plug of wood in mine, depending on the rod size. I've also been known to use a push broom handle and a pair of c-clamps. There's lots of ways to keep that stuff from whipping. I once stuffed a piece of PVC into the bore and it was a good fit on my little lathe. It added just enough tension to keep the rod from helicoptering.

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                            • #15
                              Originally posted by torker
                              Yep...you guys where right! Do not make one with three setscrews.
                              On the cover is a Cathead...cept they called it an "Offside Chuck"
                              That's usually called a "spider" when you use a cathead-like device on the backside of the spindle to stabilize long stock. For that, three setscrews is fine, since you're using it like a steadyrest.



                              Since you've already tapped 3 holes at 120°, why don't you add 3 more holes that are 90° from one of the three you already have, and then you can switch between 3 and 4 set screws? Then you can use it with 3 set screws as a spider, and with 4 set screws as a Cathead.

                              Like everyone else said, aligning the work in a cathead is alot easier if you have 4 set screws (you align it with an indicator like a 4-jaw chuck).

                              HTH,

                              Robert
                              Last edited by lazlo; 04-15-2007, 01:35 PM.
                              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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