Page 1 of 2 12 LastLast
Results 1 to 15 of 20
  1. #1
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default 5C Spin Indexer Modifications

    I purchased an indexer from forum member Rod Mell and to render it usable on my little mill it required a few alterations. As supplied the front and rear faces of the main body casting are machined but the sides of the base are left as cast. Great for a magnetic chuck and probably useable if held in a large vice but pretty much useless on my mill.

    So I machined the edges parallel with and centred on the spindle centreline.

    IMG_20191003_163417266 (Large).jpg IMG_20191004_102245821 (Large).jpg

    Then I machined and spot faced a pair of hold down slots. Some of the paint and filler chipped off during the spot facing so I removed all the paint and most of the filler.

    IMG_20191005_105432858 (Large).jpg IMG_20191006_150341815 (Large).jpg

    The front and rear faces and their counterbores were not very accurate so I used my boring head for both flycutting and facing to improve those surfaces.

    IMG_20191007_160335319 (Large).jpg IMG_20191007_162537538 (Large).jpg IMG_20191022_102627602 (Large).jpg

    I then machined a keyway and made a pair of keys to suit the mill's 12mm wide tee slots.

    IMG_20191009_150124565 (Large).jpg IMG_20191009_162336027 (Large).jpg IMG_20191020_084650806 (Large).jpg

    The indexing plate threaded lock ring was poorly made, the internal diameter of the ring was the same as most of the spindle's thread OD with engagement of one thread when the ring was screwed up against the plate. A replacement was made from 4140 with holes to facilitate the use of a proper pin spanner for tightening. I also made a replacement rear ring. The original was a loose wobbling fit and its role is to set the end play in the spindle. The new ring has a few tenths clearance and end play is easily set.

    IMG_20191014_161756260 (Large).jpg IMG_20191015_133747049 (Large).jpg

    And then there is to my mind the most important modification, a spindle lock. Having come unstuck before when a workpiece rotated while milling with disasterous results, there was no way that an M12 threaded aluminium thumbscrew was going to cope with two horsepower. I toyed with the idea of some sort of split clamp that bolted to the rear of the casting then decided on the simple solution of using a split cotter. Machined from 4E cast iron and secured with an M8 cap screw, it locks the spindle solid.

    IMG_20191023_140702767 (Large).jpg IMG_20191024_144918981 (Large).jpg IMG_20191030_133623400 (Large).jpg

    And finally, the reason for all this fooling around....

    IMG_20191008_140244390 (Large).jpg

    Bob.

  2. #2
    Join Date
    Sep 2008
    Location
    Riddells Creek, Vic.
    Posts
    831

    Default

    Nice work Bob, I might add the spindle locking idea to my spin indexer.

  3. #3
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default

    Quote Originally Posted by Techo1 View Post
    Nice work Bob, I might add the spindle locking idea to my spin indexer.
    Thank you Lex.

    There are undoubtedly many ways of skinning this cat but here's how I machined the radius in the cotter. I centred a good fitting bore sized plug using one scope then used another to align the boring head's cutter with the edge of the plug. Worked out well enough.

    IMG_20191024_075047647 (Large).jpg IMG_20191024_093010129 (Large).jpg IMG_20191024_120910331 (Large).jpg

  4. #4
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Bob, Guys,

    Nice work there !

    I've looked at buying a spin indexer several times, but never been happy with the appearance and the slop in them. Your work answers all those issues.
    Best Regards:
    Baron J.

  5. #5
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default

    Nice work !!

    Steve

  6. #6
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default

    Quote Originally Posted by BaronJ View Post
    Hi Bob, Guys,

    Nice work there !

    I've looked at buying a spin indexer several times, but never been happy with the appearance and the slop in them. Your work answers all those issues.
    Thanks John,

    I would never have gone out of my way to buy one but Rod offered me his at a bargain price so I thought why not. Little did I know the extent of the work involved in rendering the thing useful!

    I also bought the tailstock. It's a big awkward looking thing and takes up way too much room on the mill's little table so I'm seriously considering adapting the home made tailstock of my 3 1/2" Hercus dividing head to suit the 70mm centre height of the spin indexer. The pretend Hercus tailstock is adjustable vertically.

    IMG_20191110_144703902 (Large).jpg IMG_20191110_172302774 (Large).jpg

  7. #7
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    Quote Originally Posted by Anorak Bob View Post
    ...so I'm seriously considering adapting the home made tailstock of my 3 1/2" Hercus dividing head to suit the 70mm centre height of the spin indexer. The pretend Hercus tailstock is adjustable vertically.
    My dividing head tailstock is vertically adjustable too, but for some reason no manufacturers have devised a controlled way of making that adjustment - when trying to get the centre heights level that can be a right pain. In the past I've used bits of clamping kit as a screw jack.
    I'll be very interested if you can come up with a way of integrating a vertical adjustment. Currently it's one of those 'adjust at last resort' things because it is so fiddly to get back to parallel.

    Michael

  8. #8
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default

    Quote Originally Posted by Michael G View Post
    My dividing head tailstock is vertically adjustable too, but for some reason no manufacturers have devised a controlled way of making that adjustment - when trying to get the centre heights level that can be a right pain. In the past I've used bits of clamping kit as a screw jack.
    I'll be very interested if you can come up with a way of integrating a vertical adjustment. Currently it's one of those 'adjust at last resort' things because it is so fiddly to get back to parallel.

    Michael
    Michael,

    If I position an adjustable parallel set to 1.656" between the TS base and body I achieve parallelism, alignment horizontally with the headstock centreline and repeatability. Hercus used a small removable locating dowel to provide alignment of the body when the tailstock was used in the horizontal position. These photos were taken prior to me making and fitting the dowel.

    IMG_20191110_172318890 (Large).jpg IMG_20191115_151616513 (Large).jpg IMG_20191110_172158495 (Large).jpg IMG_20191115_155307421.jpg

    I will need to make a spacer to offset the body of the tailstock for it to align with the spin indexer's vertical centreline when it's keyed into the 13's table. I will probably make a simple cylindrical spacer to facilitate the setting of the body at 70mm centre height though an adjustable parallel would do the same job.

    Easy peasy.

  9. #9
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    Why not just make packers that fit under your Tailstock to suit the centre heights of your rotary table/dividing head to suit.

  10. #10
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default

    Quote Originally Posted by pipeclay View Post
    Why not just make packers that fit under your Tailstock to suit the centre heights of your rotary table/dividing head to suit.
    Peter,

    I had to lower the centre on the Hercus tailstock to suit the spin indexer. My 6" Hercus rotary table won't stand on its side like say a Vertex but it could be mounted on an angle plate and in that case a packer under the tailstock base would be the answer.

    Bob.

  11. #11
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default Adapted...

    Today I made a spacer to offset the tailstock body the 9.25mm I established I would require using the centring microscope. I started using 1020 and finished using a piece of cast iron. The former detached itself from the chuck when I crept in just a little bit too hard. Often the way....

    IMG_20191121_101212718 (1) (Large).jpg IMG_20191121_152957562 (Large).jpg IMG_20191121_154732240 (Large).jpg IMG_20191121_154748029 (Large).jpg IMG_20191121_162045505 (Large).jpg IMG_20191121_162109915 (Large).jpg
    IMG_20191121_162204745 (Large).jpg

    The TS centre is on the left, the scope reverses the image.

  12. #12
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Bob,

    Daft question ! What is the angle on the adjustable parallels ?
    Best Regards:
    Baron J.

  13. #13
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    Quote Originally Posted by Anorak Bob View Post
    If I position an adjustable parallel set to 1.656" between the TS base and body I achieve parallelism, alignment horizontally with the headstock centreline and repeatability...Easy peasy.
    Hmm. All I need now is the adjustable parallel...
    (Shaper gauge?)

    From memory (the tailstock is in a cupboard several wheeled storage cabinets deep), mine has a rough base and rounded bottom piece but it could be done if I cleaned up the surfaces. I could possibly
    use one of my machinist's jacks set to the right height as well.

    Quote Originally Posted by pipeclay View Post
    Why not just make packers that fit under your Tailstock to suit the centre heights of your rotary table/dividing head to suit.
    A packer would do it, but I have a habit of losing small undistinguished pieces of metal made expressly for purposes like that. I was also hoping to uncover a way to vary the tailstock height so that if the dividing head is on an angle or raised up on some parallels (I had to do that for an 11" gear I was cutting once), I could get the TS to adjust readily.

    Bob's solution is a neat and elegant one, but does not have the flexibility and ease of adjustment that I would prefer. It has however provided a few things to think about and potential solutions to investigate.

    Michael

  14. #14
    Join Date
    Nov 2008
    Location
    Perth WA
    Age
    71
    Posts
    6,458

    Default

    Quote Originally Posted by BaronJ View Post
    Hi Bob,

    Daft question ! What is the angle on the adjustable parallels ?
    It appears to vary John. I just had a look at a couple of my Starretts. The larger 154F looks like 10 degrees and the smaller 154C, 8. Probably different vintages.

  15. #15
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Bob,

    Thanks for that info ! So anything around 8 to 10 degrees will work OK.

    I'm assuming 6 to 8 mm steel plate would be fine to use to make a pair.
    Best Regards:
    Baron J.

Page 1 of 2 12 LastLast

Similar Threads

  1. Bearing spin
    By phaser in forum METALWORK GENERAL
    Replies: 7
    Last Post: 4th Apr 2019, 02:42 PM
  2. X2 Modifications
    By KBs PensNmore in forum METALWORK GENERAL
    Replies: 9
    Last Post: 23rd Jan 2015, 06:35 PM
  3. Frozen Spin Index Spindle
    By electrosteam in forum METALWORK GENERAL
    Replies: 7
    Last Post: 16th May 2013, 02:36 PM
  4. Spin Test
    By Stustoys in forum METALWORK GENERAL
    Replies: 17
    Last Post: 18th Apr 2013, 11:58 PM
  5. Scraping, the spin test.
    By Ueee in forum METALWORK GENERAL
    Replies: 10
    Last Post: 5th Mar 2013, 11:07 AM

Posting Permissions

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