Page 1 of 2 12 LastLast
Results 1 to 15 of 17
  1. #1
    Join Date
    Jun 2014
    Location
    Seattle, Washington, USA
    Posts
    1,857

    Default Off-sized spindle mount

    I've been rehandling my (joinery) chisels recently. The ideal size for a spindle for these is 35mm squared and ~160mm in length.

    I need to mount the end in a scroll chuck with the live center, turn a dovetail, remount, shape the handle, remove the live center from the equation, and then turn the rest of the piece while it's freely spinning so that I can test fit the socket. Similar to how you would have something mounted that you were boring out.

    I've been finding that, at 35mm, there is a very small margin for error when turning my dovetail, and it is easy to get it too small. Not a crisis, it just means I have to turn it back around, turn another one, and try again. The woods I'm using are figured and pricey, so I don't want to increase the size unnecessarily. The problem is that my standard sized jaws are minimized at around 31mm. Beyond this, it seems that you get down into the Pin Jaw sizes, which are inadequately small.

    So I have two questions...

    1. How does everyone feel about having freely-spinning spindles which are mounted on a square end in round jaws. I am of the school of thought that this is unsafe, but I'm open to being told otherwise. Mounting square would solve the problem.

    2. Does anyone have a simple jig or otherwise means of decreasing the minimum diameter which a standard sized scroll chuck jaw set can safely clamp? I would need to "chock" the chuck about 3-5mm on each jaw to adequately downsize.

    I hope that's not too difficult to understand...

    Thanks a lot,
    Luke

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #2
    Join Date
    Apr 2005
    Location
    Nerang Queensland
    Age
    66
    Posts
    10,766

    Default

    Why aren't you just turning between centres?
    Neil
    ____________________________________________
    Every day presents an opportunity to learn something new

  4. #3
    Join Date
    Jun 2014
    Location
    Seattle, Washington, USA
    Posts
    1,857

    Default

    Quote Originally Posted by dai sensei View Post
    Why aren't you just turning between centres?
    The chisels are socket-style chisels and I have to make multiple test fits of the socket taper in order to ensure a proper fit.

  5. #4
    Join Date
    Apr 2005
    Location
    Nerang Queensland
    Age
    66
    Posts
    10,766

    Default

    Still a between centres job, you can remount spindles between centres to enable trial fits.
    Neil
    ____________________________________________
    Every day presents an opportunity to learn something new

  6. #5
    Join Date
    Feb 2008
    Location
    Nth of Newcastle
    Age
    77
    Posts
    811

    Default

    Before scroll chucks they would have used a cup chuck, quick, simple and safe. Phil

  7. #6
    Join Date
    Jun 2014
    Location
    Seattle, Washington, USA
    Posts
    1,857

    Default

    But in order to do that, I would have to make a divot in the end of the socket taper in order to secure the live center end. This seems likely to split the taper and make me lose the (aforementioned expensive) blank. I definitely won't be going this route.

    Either way, maybe just forget I described the project.

    New description:

    I need to bore a spindle that is 35x35x160.

    Now see questions 1 and 2 from original post.

  8. #7
    Join Date
    Apr 2005
    Location
    Nerang Queensland
    Age
    66
    Posts
    10,766

    Default

    You could use pin jaws in your chuck but I would still be using tailstock support, so you would still have a divot as such, the trick is not doing up the tailstock to tight.
    Neil
    ____________________________________________
    Every day presents an opportunity to learn something new

  9. #8
    Join Date
    Jul 2012
    Location
    Minnesota USA
    Age
    64
    Posts
    150

    Default

    do you use a steady rest? you could chuck the square in the chuck no trouble then shape the handle and remove the tailstock center and use a steady rest to finish the socket end. Then take your time with the final shaping of the butt end and part off. sand the nubbin to finish the way you like.

  10. #9
    Join Date
    Jun 2014
    Location
    Seattle, Washington, USA
    Posts
    1,857

    Default

    Quote Originally Posted by oreos40 View Post
    do you use a steady rest? you could chuck the square in the chuck no trouble then shape the handle and remove the tailstock center and use a steady rest to finish the socket end. Then take your time with the final shaping of the butt end and part off. sand the nubbin to finish the way you like.
    That's similar to what I've been doing, only in lieu of the steady I just make sure I've got a super solid dovetail mount and I just turn it freely spinning.

  11. #10
    Join Date
    Oct 2007
    Location
    Horsham Victoria
    Posts
    901

    Default

    In answer to your first question; is it unsafe? Well, whats the worst that can happen? The wood can come out of the chuck and hit you in the face. Not too much of a problem if you are wearing a facesheild. So, if you are doing it this way already why not keep going.

    However, I agree with Dai Sensei. I would turn most of the shape with chuck and live centre in tail stock and take the tail centre away for the final shaping of the end. The live centre wont split your wood unless you over tighten it into the end. And to do this you would have to be applying a bit of pressure. I would confidently do this no matter how special the timber, especially 35 sq.

    To your second question; sorry I don't quite follow what you are asking.

  12. #11
    Join Date
    Jun 2014
    Location
    Seattle, Washington, USA
    Posts
    1,857

    Default

    Quote Originally Posted by brendan stemp View Post
    In answer to your first question; is it unsafe? Well, whats the worst that can happen? The wood can come out of the chuck and hit you in the face. Not too much of a problem if you are wearing a facesheild. So, if you are doing it this way already why not keep going.

    However, I agree with Dai Sensei. I would turn most of the shape with chuck and live centre in tail stock and take the tail centre away for the final shaping of the end. The live centre wont split your wood unless you over tighten it into the end. And to do this you would have to be applying a bit of pressure. I would confidently do this no matter how special the timber, especially 35 sq.

    To your second question; sorry I don't quite follow what you are asking.
    I think we interpreted Dai differently. When he said "between centers" I was thinking both a drive and a live center. I wasn't thinking about the chuck being on the drive end. I guess this makes sense though. The live center adds some stability to the potentially unstable "square in a round chuck" mount. If that's what he meant then I now understand and think that's a very good idea.

    As far as question two, the problem I'm facing is that my standard jaws are JUST too big and the next size down is too small, so is there some way to "step down" the minimum diameter which can be clamped by standard jaws. Like a jig or a trick of some sort.

    Cheers,
    Luke

  13. #12
    Join Date
    Oct 2011
    Location
    Langwarrin
    Age
    44
    Posts
    952

    Default just a thought

    I may not be following the questions correctly, but if you wish to hold a square spindle in your jaws to work on an open end, what about pen jaws for your chuck?
    they are designed to hold a square timber (and 35mm would fit fine) for drilling one end. I know the forces exerted would be different but they're pretty bloody sturdy. Maybe start by turning your tenon with the 'to fit' size, then make a jamb chuck of similar size to the socket in the chisel to attach to a live centre, then finish the handle between centre's?

    If the size of your chuck is an issue, they have a pen jaw set from psi (I got mine from pops shed) that is a just for this purpose and only about 60mm diameter.

    http://www.pennstateind.com/mm5/merc...rilling-chucks


    Just a thought, if I understood the question properly.

    Good luck with it. ....

    Cheers
    Gabriel
    "All the gear and no idea"

  14. #13
    Join Date
    Oct 2006
    Location
    Tallahassee FL USA
    Age
    82
    Posts
    4,650

    Default

    Quote Originally Posted by Luke Maddux View Post
    I think we interpreted Dai differently. When he said "between centers" I was thinking both a drive and a live center. I wasn't thinking about the chuck being on the drive end. I guess this makes sense though. The live center adds some stability to the potentially unstable "square in a round chuck" mount. If that's what he meant then I now understand and think that's a very good idea.

    As far as question two, the problem I'm facing is that my standard jaws are JUST too big and the next size down is too small, so is there some way to "step down" the minimum diameter which can be clamped by standard jaws. Like a jig or a trick of some sort.

    Cheers,
    Luke
    You don't need to step down the jaws; just step up the workpiece - by many wraps with masking (or other) tape. Make the final size large enough to engage the corners of the jaws. In effect, you have very stable square mounting in "square" jaws.

    And plus one for the steady rest.

    Cheers,
    Joe
    Of course truth is stranger than fiction.
    Fiction has to make sense. - Mark Twain

  15. #14
    Join Date
    Jan 2010
    Location
    Melbourne
    Posts
    2,636

    Default

    In situations like this I've used hot melt glue to mount the timber to a piece of pine mounted in a chuck with a live centre at the other end. That's if you're concerned about your fingers. You could also use a collet chuck once you've rounded up your work and have enough to hold onto. There are an infinite amounts of ways to mount your work but at the end of the day the best way is what you feel comfortable with (as long it's 'safe').
    -Scott

  16. #15
    Mobyturns's Avatar
    Mobyturns is offline In An Instant Your Life Can Change Forever
    Join Date
    Jul 2012
    Location
    "Brownsville" Nth QLD
    Age
    66
    Posts
    4,435

    Default

    Q1. - many turners do this regularly. I agree not the best or safest method however it can be done at a pinch if you are aware of the hazards.

    Q2. - depending upon the final tool handle diameter there are a few options.

    One of the safest chucks for small dia spindle work is a collet chuck similar to the Vermec ER25 or ER32 http://vermec.tripod.com/PDFs/ER32_Page.pdf.

    The ER32 is more flexible as it covers 2 mm to 20 mm collets. To make a chisel handle it is a simple process of first mounting the blank between centers and then turning a temporary tenon to suit the 19-20 mm collet. Mount the blank tenon in the ER collet chuck. Turn to suit the ferrule using the tail stock for support between chuck & live center. The tail stock can be withdrawn to test fit then put back in place. This method will require sacrificing some 20 or 25 mm of blank length.

    Another option if you do not wish to purchase a collet chuck is to use a sleeve of PVC - a 12 - 15 mm high ring from 35 mm PVC pipe with a small section of the circumference removed. Place the sleeve between the round work piece & chuck jaws & bring up the tail stock and turn using the tail stock. You cannot use a tenon dovetail with this method.

    Make a temporary dovetail disk from a waste wood blank to fit the chuck jaws, as you would for a glue on tenon for a bowl blank. Make it so that it sits proud approx 10 mm or so from the face of the jaws. Use a suitable size forstner bit to drill a socket into the disk to make it into a donut ring. Then make a radial cut with a bandsaw so that the ring can clamp down (close up) on a turned tenon on your chisel handle blank when the chuck jaws are tightened.

    I'm not a fan of using pin jaws in compression mode especially any pin jaw set with only one cap screw on the outer rim. The two cap screw pin jaws are a little safer.
    Mobyturns

    In An Instant Your Life CanChange Forever

Page 1 of 2 12 LastLast

Similar Threads

  1. King sized bed
    By Simo79 in forum WOODWORK PICS
    Replies: 3
    Last Post: 9th October 2014, 02:48 PM
  2. Best way to cut various sized holes?
    By blue in forum WOODWORK - GENERAL
    Replies: 9
    Last Post: 9th January 2014, 12:39 PM
  3. Spindle motor mount drawings
    By Bob Willson in forum CNC Machines
    Replies: 10
    Last Post: 6th May 2010, 12:27 AM
  4. Queen sized bed
    By dan_tom in forum WOODWORK PICS
    Replies: 12
    Last Post: 29th January 2007, 03:13 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •