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Thread: New tool

  1. #11
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    Mar 2017
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    Quote Originally Posted by Steve Little View Post
    Hi Ryan.
    Thanks for contributing with your knowledge.
    I usually keep the material close to the jaws because my 3 jaw chuck has 007” (I think the term is concentric run out). But on this occasion I was going to be brave and try to do all the turning in one set up. But I ended up wimping out half way through, and parted off and turned the job around.
    It didn't matter to me because I just needed the tool to check the distortion of the front, and rear, brake backing plate but in truth...I err... well you see... umm... I don't know what I'm doing.
    But I'm the only person here these days, so I get away with it. Until now!

    I used to employ Tool room machinists, who I can say, are a testy funch of buckers.
    They turned their noses at this Chinese 3 jaw which is 9 1/2” diam. They mostly used the four jaw chuck. But it is 12” diam and I cant lift it in and out of the lathe these days, so I leave the easy one in.

    Shortly after buying this Mazak, I remember a machinist was turning up some parts on the 3 jaw and I heard him swear and turn off the lathe. I went over to see if I could help, and he just waived me away. I dropped my head and shoulders and dragged my toes back to the office.
    Much to my angst he proceeded to take parts off the lathe, even though we were trying to get an order finished.
    He pulled the 3 jaw apart, at which point I weaseled my way back into the operation by offering to clean the parts in the parts washer (as you know I did the most important part of the job) while he reconnected the 3 jaw face plate to the lathe and checked it for run out.
    It was running out 003” on the face at 9” diam. He refaced it, then lubed all the parts and put it back together.
    He then put the 4 jaw chuck on the machine and put a long piece of ground round bar in the chuck and drilled a center in both ends.
    As long as I kept my manic breathing under control I was allowed to stay and help.
    He removed the 4 jaw and put the big dead center in the quill of the head stock, and another one in the tail stock and then put the round bar in and dialed the tail stock to the head. When all this was done, he refitted the 3 jaw and checked it. The teeth were...and still are, running out at 007”
    We didn't have a tool post grinder to fix the jaws.
    I do now, so I will do it soon.
    Thanks again.
    Regards Steve
    Steve,
    Again, I was not trying to shoot down your process. I was a mold maker at one time. Please let me know when you decide the grind in your jaws, I can explain the correct procedure. All I see on YouTube only have the process half right and come out worse than they started.

    Take care,
    Ryan

  2. #12
    Join Date
    Apr 2003
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    Seaford, NY
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    Ryan, I'd be curious as to your method of grinding jaws as well. The tricky part is for the jaws to be in position as to a mimic as if the jaws are closed down on a piece of round stock. I've seen a few methods and I'd like to hear yours. Thanks.

  3. #13
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    Mar 2017
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    The people are using the jaw threads to locate instead of using the jaw itself to locate off of. There is play or clearance in the bolt hole threads that bolt the jaw on. The threads do not locate the jaw itself, causing everything to go out of whack. There is a tool called an anti-backlash ring or a jaw boring ring that locks into the counterbore of the jaw itself, this will keep the jaws true going in both directions, clamping on the o.d. of the stock and clamping on the I.d. of the stock.

    There are some inexpensive ones out there, so do not panic, I will help look for some as well.
    Take care
    Last edited by ryan; 04-17-2017 at 09:50 PM. Reason: Added material

  4. #14
    Join Date
    Apr 2008
    Location
    Upper Yarra Valley, Victoria. Australia
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    Hi.
    Seems like there are a few interested machinists on the forum, so here is a little wall break in the thread with some ideas for your deliberation and discussion:
    I've been trolling through You tube for fix it ideas on 3 jaw chucks.
    Here are some methods that might have plausible merit:

    Method 1.
    Thick machined ring placed over external steps on jaws. Open jaws onto ring for uniform outward pressure.
    Grind face of teeth to achieve a uniform face.
    My question on this method is: Does this method (pressure on jaws is reverse to working action)) invite error because slop in scroll might cause jaw misalignment?





    Method 2
    Place small precision V plates between each jaw and screw down jaws to capture plates between the jaws to trap the plates at the end and cause pressure. The V in the plates creates clearance for the grinder tool to pass through. This method has a downward pressure on the jaws.




    Look forward to reading the discussion.
    Regards Steve
    Steve Little
    Upper Yarra Valley. Victoria.
    Australia.
    AMCA member 1950

  5. #15
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    Apr 2008
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    Upper Yarra Valley, Victoria. Australia
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    Hi Ryan.
    Terms or job references mean different things in different countries. I'm making a guess that (Mold Maker) may not mean the same thing over here as it does over there. It reads like you are making a reference to machining.
    I think a mold maker over here means a guy working in a foundry who boxes up patterns and fills them with sand to make a mold.
    To help cross the international divide, what does a Mold Maker do in the States?

    Not making any disrespect for your job. Just like to learn different terminologies in different countries
    Regards Steve
    Last edited by Steve Little; 04-18-2017 at 09:24 PM. Reason: Note at end. :No disrespect.
    Steve Little
    Upper Yarra Valley. Victoria.
    Australia.
    AMCA member 1950

  6. #16
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    Apr 2008
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    Upper Yarra Valley, Victoria. Australia
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    Found it in Google. I think your relating to Tool room machinist.
    Steve Little
    Upper Yarra Valley. Victoria.
    Australia.
    AMCA member 1950

  7. #17
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    Mar 2017
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    Quote Originally Posted by Steve Little View Post
    Hi Ryan.
    Terms or job references mean different things in different countries. I'm making a guess that (Mold Maker) may not mean the same thing over here as it does over there. It reads like you are making a reference to machining.
    I think a mold maker over here means a guy working in a foundry who boxes up patterns and fills them with sand to make a mold.
    To help cross the international divide, what does a Mold Maker do in the States?

    Not making any disrespect for your job. Just like to learn different terminologies in different countries
    Regards Steve
    Hello Steve,
    A plastic injection mold maker is a highly precision tool and die maker that builds plastic injection molds. I had to work under a senior mold maker for 5 years. The senior mold maker has to have at least 30 years experience to be able to train the journeyman mold makers.

    After about 7 years, I worked myself in an office and started to program cnc mills to mill the the base work and injector plates, I then work up to high speed milling of highly precision carbon machine EDM electrodes and high speed cavity details. EDM means electrical discharge machining, meaning it burns the metal away. Again after more time, I got into high speed milling hardened tool steel. I also programmed, setup and ran a wire EDM during downtimes.

    Even after ten years of learning and training I still wasn't a pimple on the fanny of the senior mold makers.

    Then almost right at the ten year mark of working, the infection came back in my leg (which is what I am dealing with yet again), so I went to grad school to get my Masters in Industrial Engineering which also consisted of engineering management. I have then been working as engineer ever since.

    Sorry for my rambling, but I learned more as a machinist than I have ever learned anywhere else. I love to machine. I know if we put all our experience and resources together, we can make about anything. I want to repo an Indian four engine.
    Last edited by ryan; 04-19-2017 at 08:00 PM.

  8. #18
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    Apr 2008
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    Upper Yarra Valley, Victoria. Australia
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    Hi Ryan.
    No need for apology. I enjoyed the read on your background.
    I have seen the term (Journeyman) written before, and guessed at the meaning.
    The Australian equivalent of a Journeyman is a Qualified Tradesman.
    A business would screen a bunch of kids and pick the most suitable for a 4 year apprenticeship.
    An apprentice would work under the guidance of a Tradesman and also attend Trade school once a week. Teachers at Trades schools are Tradesman who have been lured back to teach the apprentices.
    When I started my apprenticeship back in 1975 I took home $18.50c a week. Yep it sounds sh!t, and it was, compared to my mates who were getting $80 for unskilled jobs.
    After completing the apprenticeship, my Tradesman wages was pretty darn cool.

    Come on you guys.
    I need suggestions on 3 jaw chuck truing methods.
    I got Ryan paying me $18.50 a week and I wanna feel like a Tradesman again.
    Steve Little
    Upper Yarra Valley. Victoria.
    Australia.
    AMCA member 1950

  9. #19
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    Mar 2017
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    Steve I will answer your questions on your two posted methods and firstly go over checking the 3 jaw to see if it even needs to be ground in the first place.

  10. #20
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    Upper Yarra Valley, Victoria. Australia
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    Excellent idea!
    Steve Little
    Upper Yarra Valley. Victoria.
    Australia.
    AMCA member 1950

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