Thanks Thanks:  0
Likes Likes:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Page 1 of 2 12 LastLast
Results 1 to 15 of 18
  1. #1
    Join Date
    Sep 2012
    Location
    Bomaderry NSW
    Posts
    46

    Default OK got that out now how do I get this off?

    Gents.

    You may remember a short time ago I was having all sorts of difficulty getting the morse taper fitting out of my mill? And you may remember that after some struggle I managed that?

    Well now its time to get the backing plate for the chuck off my Mars lathe.

    I have a chuck which bolts via three bolts onto a face place which in turn is threaded onto the lathe spindle. The chuck comes off easy. The backing plate doesnt/wont. Its been there since Adam was a boy. It appears that someone else has tried to get it off judging by the damage around the back of the collar.

    I do NOT want to engage the back gears and hammer the #### out of the plate for fear of doing more damage to my back gears.

    I am thinking of making up a dog that I can mount onto the plate and which I can hit with a substantial hammer without damaging the plate (which is cast by the way)

    1: Is this acceptable (Hitting the plate like that)

    2: Is it acceptable to warm the plate with my LPG torch (a big one), maybe packing the inside of the spindle with ice or something and then giving it a touch up with the hammer.

    3: Is there any other suggestion (apart from machining the plate off the bloody lathe!)

    yours in frustration

    Old Hutcho

  2. #2
    Join Date
    Aug 2007
    Location
    Melbourne
    Age
    68
    Posts
    1,410

    Default

    Read all of this. Then decide what you want to try first.

    Lathe - Stuck Chuck

  3. #3
    Join Date
    May 2010
    Location
    rural s.a.
    Posts
    120

    Default

    Hi Old Hutcho, My face plate (not chuck back plate) locks up fairly tight on the spindle nose. My method isn't in agreement with you, but I engage the back gear, pull the face plate around to take up any backlash in the back gear & use a brass drift & club hammer to tap the faceplate loose. I have used this method ever since I have had the lathe (about 38 years) & to date there is NO damage to either the back gears or face plate. I always place the drift on the front of the plate (if it's free) as I am concerned that I will break some of the lip around the slots if I hit from the back. I use lots of moderate taps with a heavy hammer, not one all-mighty bang, this acts more like an impact wrench to loosen the plate. In your case I would give it a drink of WD40 the day before & I like your idea of some heat, not enough to damage seals but enough to expand the backing plate. I would go for just enough that you can't leave your hand on it. I don't know if your chuck back plate has slots in it but if so, the further out you can tap it the better. Hope this helps & good luck.
    tinkera

  4. #4
    Join Date
    Aug 2010
    Location
    Near Bendigo, Victoria, AUS
    Age
    72
    Posts
    3,102

    Default

    Could you take photo of your headstock with the backplate please? A nice close-up toud be good.
    I've had such an issue once an made a 6 foot long lever bolted on the flange I needed to unscrew. It came off without much strain and more importantly without impact on any bearings.
    Your particular problem is going to be holding the spindle. Maybe you can key or shrink a solid bracket to the other end of your spindle and bolt that to the headstock somewhere?
    With photos we may be able to offer some non-violent suggestions....
    Cheers, Joe
    retired - less energy, more time to contemplate projects and more shed time....

  5. #5
    Join Date
    Jan 2011
    Location
    Far West Wimmera
    Age
    63
    Posts
    4,049

    Default

    The best penetrating oil based on a Motoring Magazines not exactly scientific, but still relevant tests are a mix of auto transmission oil and acetone. This has been discussed before. The acetone has low surface tension and draws the oil into gaps and then evaporates.

    I am with Joe re the pictures, but as it would seem that the use of the gears would be risky, maybe also pictures of the other end of the spindle. You are going to need some method to stop the spindle from turning whilst applying force on the back plate.

    Dean

  6. #6
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    After looking at some photos of this type of lathe,it appears that you may have reasonable access to the bull gear.

    You may be able to wedge a piece of soft material between the bull gear and the headstock casting,this may allow you to lock the spindle enough to release your backing plate.

    If you think that it would be better to heat the back plate 1st I would be tempted to try heating only in one spot 1st rather than heating the whole plate,I would concentrate on an area fairly close to the spindle thread and try and get it cherry red,hopefully your torch can produce enough heat quickly.

    Another alternative would be to make something up that would fit over the rear spindle gear that you can clamp tight to stop the spindle turning.

  7. #7
    Join Date
    Jun 2012
    Location
    SA
    Posts
    1,649

    Default

    In a situation where it's unsafe to lock the spindle/shaft for fear of damage, a method to unscrew the chuck is to use a big rattle gun (air impact wrench) on it. This works against the mass of the object, even though it's free to turn. I've seen this method unscrew nuts on free turning camshafts without an issue.

    For a lathe, you will need to make up an adpter or mount a big hexi shaft in the chuck.

    Rob
    The worst that can happen is you will fail.
    But at least you tried.



  8. #8
    Join Date
    Sep 2012
    Location
    Bomaderry NSW
    Posts
    46

    Default Pictures.

    Right guys I have read the stuff above and I am grateful for the suggestions. I like the idea of the long bar bolted to the plate and I also like the idea of jamming some wood or something soft in between the gears. Aurely that wont hurt the gear teeth. In the meantime, I have provided some pics which may set your imagination free.

    regards


    Old Hutcho

    DSC00657.jpgDSC00653.jpgDSC00656.jpg

    DSC00654.jpgDSC00655.jpg

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

    Default

    If you happen to go with the method of jamming the gear ONLY PLACE THE MATERIAL UNDER THE BULL GEAR NOT BETWEEN GEARS.

  10. #10
    Join Date
    Jul 2008
    Location
    near Warragul, Victoria
    Posts
    3,718

    Default stuck

    I had to resort to butchery to remove the HENDEY back plate............cut it off with cut off discs and a angle grinder .........Mike

  11. #11
    Join Date
    Sep 2012
    Location
    Bomaderry NSW
    Posts
    46

    Default

    Well. It's off! Tucked my heart firmly in my mouth and used the long bar while the back gear was engaged method. Came off surprisingly easy all things considered. Many thanks to all the guys who offered advice. The spindle thread has 4 threads and only half an inch long. So I guess I have a 8 thread per inch jobbie. Anybody like Ewan care to guess what thread it is. Might look for a new back plate to fit my drive dogs into rather than using the old one.

    Regards

    Old Hutcho

  12. #12
    Join Date
    Aug 2011
    Location
    Melbourne
    Posts
    4,779

    Default

    Quote Originally Posted by Old Hutcho View Post
    Anybody like Ewan care to guess what thread it is.
    Complete stab in the dark…… UNF?

    Edit: Well done by the way! I bet that is a load off your mind….

    Simon
    Girl, I don't wanna know about your mild-mannered alter ego or anything like that." I mean, you tell me you're, uh, super-mega-ultra-lightning babe? That's all right with me. I'm good. I'm good.

  13. #13
    Join Date
    Sep 2012
    Location
    Bomaderry NSW
    Posts
    46

    Default

    Thanks Simon. It is. The thread is fairly coarse and the I/ s dia of the thread is 1.5". So it will be something like 1.5 x 8?

    regards

    Old Hutcho

  14. #14
    Join Date
    Oct 2008
    Location
    blackburn vic
    Posts
    297

    Default Lathe thread

    My guess is 1 5/8 BSF

    Roger

  15. #15
    Ueee's Avatar
    Ueee is offline Blacksmith, Cabinetmaker, Machinist, Messmaker
    Join Date
    Dec 2011
    Location
    Canberra
    Age
    39
    Posts
    4,515

    Default

    Hi Hutcho,
    Mine is 1 1/2" 8tpi 55deg, so i guess that makes it BSF.

    Well done on getting it off. I think my spindle would be the same, about 4 threads and maybe 3/8" of register.

    I think you will have to make the drive plate, please correct me if i'm wrong but the Hercus/southbend noses are UNF, 60 deg, not 55deg.

    Cheers,
    Ew
    1915 17"x50" LeBlond heavy duty Lathe, 24" Queen city shaper, 1970's G Vernier FV.3.TO Universal Mill, 1958 Blohm HFS 6 surface grinder, 1942 Rivett 715 Lathe, 14"x40" Antrac Lathe, Startrite H225 Bandsaw, 1949 Hercus Camelback Drill press, 1947 Holbrook C10 Lathe.

Page 1 of 2 12 LastLast

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
  •