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Thread: Advice needed

  1. #1
    Join Date
    Mar 2012
    Location
    Hugo, MN
    Posts
    111

    Advice needed

    I have been trying to learn how to turn hollow forms. I have two hollowing systems, both of which I have picked up used and have a variety of parts some of which have been modified. I haven't really had any instruction which has led me to the door step of frustration.

    The two hollowing systems area a captured (Jamieson) style and an articulated arm (Monster) style. Both have 3/4" boring bars. I have one round carbide cutter (~5/16 inches in diameter?), and some round and teardrop cutters (high speed steel?), and some 3/16 square cutters (high speed steel or carbide?). I have found the round carbide cutter to be very aggressive and hard to get a small controlled cut without being grabby and causing vibration. I am turning on a Jet 1642 lathe. I have several tool holders for the 3/16 cutters and they are the ones that I am trying to understand and use for removing the majority of the material. I have a straight tool holder, and two curved holders with one being more curved than the other.

    I understand that I should have the cutter on or maybe very slightly above center. That leads to another problem, my tool rest that came with the lathe sits higher than I really want, even when bottomed out on the banjo. In both systems, it seems like to get the cutter on center, the hollowing system support is slightly higher than my tool rest. I have sharpened the cutter on my grinding wheel to get a burr.

    My biggest misunderstanding seems to be around the orientation of the cutter. I have attached two photos. The end of the tool holder has a bevel that orients the cutter in a downward angle. Then, depending on the angle that I have the cutter directed depending on the slope of the surface I am cutting seems to cause that angle to be variable as well. There is a set screw on the tool holder and also the boring bar so there seems to be a lot of adjust ability. I do not know what is the correct orientation. Rather than cutting chips, I am creating dust and I know that is not correct. I do not believe the cause of the 'dust' is an unsharp tool but rather the presentation of the tool to the surface.

    Can someone more experienced provide some advice on adjusting the cutter and tool holder for hollow cutting? My next step is to rough out a bowl and try using the hollowing cutters on a bowl interior just so I can see better what is going on. I'm tiring of the trial and error and looking for some direction. I have watched many videos done by skilled hollow former turners but can't seem to find anyone who discusses this or shows the tool orientation.

    Thanks in advance for any help you can provide.
    Attached Images Attached Images

  2. #2
    Join Date
    Jan 2015
    Location
    Lake Burton, Northeast Georgia
    Posts
    107
    I'm also a beginner at hollow form, so don't take this as gospel.

    All of my tools (also acquired used, a Jamieson system with some other compatible tools) present a 3/16" HSS cutter with the top of the cutter flat (parallel to the earth). None of my tools angle the cutter down, as shown in your photos. The standard Jamieson swivel assembly (both straight and curved versions) present the cutter flat, as well. Might be $55 well spent to acquire this, to replace the cutter holder you now have.
    straight-swivel-assem-img-300x300.jpg
    Robert

  3. #3
    Join Date
    May 2010
    Location
    Ambridge, PA
    Posts
    938
    I've not seen a cutter head like this before but it appears to have some type of shear scraping orientation. Maybe someone else has seen this before but appears to me to be some type of home brew creation. Hunter makes a small round cutter assembly for shear scraping that works great on all the major hollowing systems. On wet wood, I'll usually use it from start to finish but use the flat style scrapers for most of the hog out work on dry wood and do the final few passes with the Hunter.
    Member Turners Anonymous Pittsburgh, PA

  4. #4
    Join Date
    Dec 2013
    Location
    Greenbush, Wisconsin
    Posts
    38
    It has been awhile since I have used my monster system, but...
    1. I think you are getting the dust because your cutter is too high
    2. I'm pretty sure I don't allow my cutter to extend as far away from the round cutter holder as is shown in the pictures.
    3. I'm pretty sure my tool holder is more enclosed (inside) my boring bar (maybe fully enclosed). My boring bars are 3/4" and 1" and they can extend over my tool rest quite a ways but having the cutter holder which is maybe 1/4" extend so far out is inviting excessive vibration.
    4. I believe the angle that my cutter is presented at would be about 8:00 or 7:30.

  5. #5
    Join Date
    Oct 2006
    Location
    Harvey, Michigan
    Posts
    20,432
    Jenny, I have a few carbide cutters but prefer using HSS for hollowing. Your cutter should be almost flat but needs to have a slight downward cant to it so that the burr will cut. Having the tip of the cutter rotated too far down would result in the burr being quickly removed and then you are not presenting any cutting edge to the wood at all - hence the dust.

    When hollowing, cutter presentation is constantly changing because of the shape you are hollowing. Remember that the cutter should be slightly higher than center but also needs to be perpendicular to the wood surface. That means that you get to hollow a small sections at a time, then change the cutter orientation to cut the next section. Also, when hollowing, remember that you are basically hollowing two bowls (think 2 bowls held rim to rim) and need to follow the cutting direction (larger surface to smaller surface) to prevent catches. Light cuts, smooth body movements make all the difference when hollowing but it does take time to perfect.
    Steve

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  6. #6
    Join Date
    Feb 2008
    Location
    lufkin tx
    Posts
    2,011
    Jenny, I appreciate your problems here--went through that 30 years ago when I decided to make urns and deep vases. Very few tools available then. Made a homemade jamison type tool and finally discovered a cutter made by Master cut in NZ. It has a limiter like a safety razor which simply eliminates catches way down deep! It is heavy made and lasts for many years. Have done hundreds of pieces to 20" deep and 125 #--green wood and returned after waxing and curing. Rarely gums up and only on soft very wet woods--simply dry them for a week. It really is the final answer to deep hollowing in wood. Old Forester Ps--also leaves a very smooth surface due to the hook shape.

  7. #7
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    8,058
    Quote Originally Posted by Jenny Trice View Post
    ...my tool rest that came with the lathe sits higher than I really want, even when bottomed out on the banjo....
    You can cut a bit off the bottom of the tool rest post. I've shortened several that way. A hacksaw will work but that takes a bit of effort. I prefer to use a bi-metal metal-cutting blade in a reciprocating saw (sawzall).

    JKJ

  8. #8
    https://www.youtube.com/watch?v=llFMhrKNziA

    Lyle Jamison has a DVD series on hollowing and will answer questions if you contact him. The cutter meeting the wood is the critical element no matter what mechanical system you attach it to I would think.

  9. #9
    Join Date
    Mar 2012
    Location
    Hugo, MN
    Posts
    111
    Thanks Robert. Is the Master cut a ring tool? I did some looking and couldn't find either of your references.

  10. #10
    Join Date
    Jan 2007
    Location
    Ottawa, ON Canada
    Posts
    1,246
    Jenny: Is this something like you are looking for?

    http://www.packardwoodworks.com/Merc...ode=tools-munr
    Grant
    Ottawa ON

  11. #11
    I cut one off really easily with a zip cut blade in a a small disc grinder.
    Quote Originally Posted by John K Jordan View Post
    You can cut a bit off the bottom of the tool rest post. I've shortened several that way. A hacksaw will work but that takes a bit of effort. I prefer to use a bi-metal metal-cutting blade in a reciprocating saw (sawzall).

    JKJ
    Pete


    * It's better to be a lion for a day than a sheep for life - Sister Elizabeth Kenny *
    I think this equates nicely to wood turning as well . . . . .

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