Repivoting

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  • #48990
    bernie weishapl
    Participant
    • Topics Started: 58
    • Total Posts: 1218

    Here is a wheel that I repivoted due to a badly worn pivot. Hadn’t polished the wheel yet. Sorry for the bad pic’s as I took them with my phone. I try on these as Bob said to make them so you can’t tell it has been done. I am getting better at it every one I do. I used one of the flags that I made from Bob’s lathe course. I have a idea how to make one for my Taig. I will post when I get it done. Hopefully it will work like I want.

    #57219
    mahlon
    Participant
    • Topics Started: 28
    • Total Posts: 215

    well done Bernie, I haven’t tried repivoting yet. If I can get one to look like that I will be satisfied. Mahlon

    #57220
    bernie weishapl
    Participant
    • Topics Started: 58
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    Thanks. I was always told make it look so no one knows it was done. I think I am finally getting it after 30 yrs. 😆

    #57221
    david pierce
    Participant
    • Topics Started: 90
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    Bernie,
    What were the shaft and hole diameters of the pivot and staff? Was the hole drilled and reamed or just drilled? Was the part machined in the Taig with the ER collets or in the Boley?
    If you make a new flag and the two parts are brass it might save a lot of time if you solder the two parts together with soft solder (you can use a torch) instead of making rivets. The process should be similar to soldering copper plumbing pipe.
    david

    #57222
    willofiam
    Moderator
    • Topics Started: 75
    • Total Posts: 1437

    Hey Bernie, I was just thinking about a thread like this, I have photos documenting the process, I can wait to post them or add them in with yours, maybe we have some different ways of going about it? Talk to yah later about it, William

    #57223
    arutha
    Participant
    • Topics Started: 85
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    Nice job Bernie, I still remember doing my first re-pivot job, it was quite nerve wracking. I have done enough now to be confident but that didnt stop me drilling a hole off centre the other day while doing one :(
    Paul.

    #57224
    bernie weishapl
    Participant
    • Topics Started: 58
    • Total Posts: 1218

    Paul I have been there done that. :D The very first one I did I tapped it in and split the arbor. I wasn’t a happy camper. At the time I didn’t have my Boley or any lathe so had a friend of mine make one for me.

    #57225
    bernie weishapl
    Participant
    • Topics Started: 58
    • Total Posts: 1218

    Forgot to add I did have a cheap small lathe at the time and accuracy wasn’t one of it’s strong suites. After that mess I bit the bullet and bought the Boley and started adding components for it.

    #57226
    daryn
    Participant
    • Topics Started: 2
    • Total Posts: 97

    I’ve still got the very first wheel I re-pivoted whilst at college, sitting in drawer somewhere, think it’s the 3rd wheel from a Smith’s alarm clock :-)

    #57227
    daryn
    Participant
    • Topics Started: 2
    • Total Posts: 97

    I remember my master re-pivoting a French clock wheel without a lathe, just to show me it could be done, he took a centre punch to the side of his vice to stop the wheel slipping then filed the end where the pivot needed to go , also punched that then filed up a spade drill in a wooden block with a pin vice and then used an old bow driven drill restingthe wheel against the side of the vice , took him about ten minutes for the whole job and it was perfect !
    R.I.P. Bill . . . .

    #57228
    bernie weishapl
    Participant
    • Topics Started: 58
    • Total Posts: 1218

    Daryn I know what you mean. My old mentor God rest his soul always told me it isn’t the machine it the person behind the machine. I saw him do things with hand tools that we today use lathes, mills, etc. to do the same job. Some of the work he did amazed me. I watched him bush clocks by hand when he had a Elma bushing machine sitting right behind him.

    #57229
    bobpat
    Participant
    • Topics Started: 14
    • Total Posts: 97

    😡 . Ok. I need help..talk about frustrated, Got my new lathe, I have been practicing turning pivots. first with brass and some other soft metal, I can turn it down as small as a needle, but when I changed to blued pivot wire, than the whole deal changes 😯 it won’t cut, it almost scrapes, bit gets dull very fast, and I mean fast, it’s hss ,came with the lathe,I just can’t get the right combination. Should it get dull so fast. ? I oil it, I cut with just the point of the bit. So what am I doing wrong???. I’ve been woodturning for for about 15 years and am quit good at that but, this isn’t even close to that.. Oh. I have a cross slide on my lathe. tool rest and gravers will come later , IF I ever master this .The height of the bit changes a lot too, as the pivot gets smaller and smaller, sometimes the pivot rides over the top of the bit,, too low.. but anyways, it just doesn’t cut, if it does, than it not for long, just squeaks a lot and scrapes.. HELP

    #57230
    demewill
    Participant
    • Topics Started: 5
    • Total Posts: 36

    I suspect you have a combination of issues working against you. First I suspect your tool is without proper side and back rake. Go to YouTube and search for “tubalcain tool bit grinding” and you will find a great tutorial on proper tool geometry. the geometry for brass and steel are very different. Brass cuts best with negative rake,almost scraping, and steel cuts best with positive rake. Second, your bit may not be right on center and this is very important especially with small diameter turning. Another personal observation is that soft steel of small diameter is difficult to turn because it tends to bend. Make sure you have not let down the temper of the blue steel.
    Last,but not least,make sure you are starting with a very sharp HSS bit. Dullness is a progressive problem and takes off quite fast. As soon as your bit gets the least bit dull, you needs to sharpen it. If you are a woodworker, I am sure you have the skills to keep tools sharp.

    Keep playing and adjusting tool bit angles until you get comfortable with it all.

    Dan

    #57231
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Just recently I had a re-pivot job in and the pivot steel I had was incredibly hard. If you are running a tool against it and it is not cutting you are more than likely burnishing the steel which will infact make it even harder to cut. The only way I could cut the steel I had was with a carbide graver. Try a carbide tool bit or graver, it is very brittle and you will need a diamond lap or plate to re-sharpen it.
    Paul.

    #57232
    bernie weishapl
    Participant
    • Topics Started: 58
    • Total Posts: 1218

    I use carbide on blue steel and steel. HSS works with brass and Aluminum. Make sure you have a sharp tool with the proper rake and angle for your tool as Dan said. Make sure you only have a very short length sticking out of your collet as the steel can bend and flex which will mess with you cutting.

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bernie weishaplRepivoting