Progress 1 Spindle(?) : I bent it :(

  1. daedalusminos Member

    Messages:
    894
    Location:
    Norwich
    Bend it, rotate (say) 90 degrees, bend again...this will put more of a twist than a bend
     
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  2. minimutly Member

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    1,223
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    Still only bent in one direction?
     
  3. mtt.tr

    mtt.tr Member

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    3,132
    Essex England
    Bend it

    Rotate 90 bend again. 2 bends kinda s shaped.
     
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  4. minimutly Member

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    There we are, like I said, bent in two places. This I understand
     
  5. WorkshopChris

    WorkshopChris Forum Supporter

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    Straightening will be a pig of a job with the taper as you can only measure in any given spot at 360deg you cant work along the length looking for a high or low as you would normally do with a parallel part.
     
  6. mtt.tr

    mtt.tr Member

    Messages:
    3,132
    Essex England
    But that accounts for the two bends. And equally can happed so close to one another it looks like one location!
     
  7. mtt.tr

    mtt.tr Member

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    3,132
    Essex England
    Only way is to use a tapered guage so you can hopefully measure parallel of that.
     
  8. Richard.

    Richard. Forum Supporter

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    Build it up with welding and recut

    I did one of brads bent meddings shafts for him wasn’t a particularly difficult job
     
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  9. mtt.tr

    mtt.tr Member

    Messages:
    3,132
    Essex England

    very good solution pretty simple to achieve
     
  10. Brad93

    Brad93 M J B Engineering

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    Location:
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    You can’t cut a precise enough taper on most hobbiest lathes to mate together.

    You’ll have to recut the taper as near as you can, then use blue and emery tape, till it’s spot on.

    If you’ve got a junk chuck with the right taper you could use lapping compound.
     
  11. Screwdriver

    Screwdriver Member

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    6,394
    UK London
    I generally find with single bends in shafts/spindles, you get one shot at getting it right on the flypress. For say a vice handle, it's pretty easy since they're not that thick and the result demands no great precision. I put a fair bit of effort into working out exactly where then bend is and can usually get a decent straightening in one good bonk. Flypress is a great tool for this because you have amazing control over exactly where and how much force to apply.

    The morse taper spindle looks tricky but I reckon you might get a good amount of bend out of it fairly easily. Getting it good enough for use as a spindle again... well that's probably a job for flame straightening and you'd still have to massage the taper if it has suffered any damage.
     
  12. WorkshopChris

    WorkshopChris Forum Supporter

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    Unless I am mistaken from the picture I think most of the damage will only be in the last 20 odd mm's and that's the jacobs tapper. The rest should be ok due to its larger diameter and that the majority was inside the machine held tight by the bearings.
     
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  13. Screwdriver

    Screwdriver Member

    Messages:
    6,394
    UK London
    Yep, needs careful measurement but it looks doable. Just saying even if it is a simple bend, you generally get one shot at putting it right and if you don't, there's a ton of faffing about to take out the compound bend(s) you just created!
     
  14. Richard.

    Richard. Forum Supporter

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    You can mate. If the angle set is spot on and the part clocked true there is no reason an accurate lathe won’t cut a quality taper. I don’t think I’d have any trouble cutting that taper to perfection simply using my top slide.
     
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  15. Brad93

    Brad93 M J B Engineering

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    Location:
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    I very much doubt the taper would mate with the female taper on the chuck and hold to the full required torque.

    @doubleboost has blued most of his taper projects in, perhaps he could explain further.
     
  16. mtt.tr

    mtt.tr Member

    Messages:
    3,132
    Essex England
    Ive managed it on a my dads clappy super 7

    Ive equally cut plenty on my lathe.
    To be fair my personal lathe is/was well set up

    Yes you would have to blue it and finish it by hand as long as the initial cut is concentric its not really a problem.
     
  17. rockweasel Member

    Messages:
    996
    Location:
    none
    Update: I fixed it! (TBC)

    Apologies if I mess up the terminology when describing this.

    I removed the spindle/quill assembly from the drill. Only the tapered end of the spindle was bent. "Only". I made a couple of half hearted attempts at straightening it, but thought it best to leave it before I did more harm than good. I took the offending item to my local tool store who happened to have a workshop (first I heard of it.) Gent behind the counter couldn't help but recommended an old school engineering firm that he was sure would be able to sort it out. The following day I took a trip along and presented my greasy quill to the receptionist. She called someone from the shop floor to have a look. After a few sharp intakes of breath he disappeared with it. He returned a few moment later with it swaddled in blue cloth.

    "It's only out by a few thou" he said.

    "Cool - what did you do?" :p

    "Nothing. We could try to straighten it, but we'd be liable if it broke and our rate is £50-£60 and hour just to hit it with a hammer. By the time we made a new one you'd be cheaper buying a new drill."

    He then suggested a few methods that I'd already tried (and a few that I didn't have the tools or expertise to attempt.) I thanked him anyway and went back home.

    I don't know what he used to measure it with, but this thing visibly wobbled like the teacup ride at the fair. I don't have any gauges or anything to take measurements, so I stuck a drill bit (for wood-with a sharp pointy tip) in the chuck. I painted a bit of whiteboard with engineers blue and spun the spindle by hand, tracing a circle about 6mm diameter in the blue with the end of the bit. My aim was to straighten the spindle so that there was no circle, just the point of the drill turning on the whiteboard.

    More engineers blue painted onto the spindle this time. When the tip of the drill bit was at its highest point tracing the circle I made a corresponding mark on the spindle. I had to bend the spindle in the opposite direction to the mark.

    Leverage was required. Bolt welded to a steel plate welded to a steel tube which was the right diameter to accept a 1" steel bar for even more leverage. The bolt fit into the chuck. After a half dozen attempts I managed through sheer chance to get the thing running straight. No hint of a wobble as far as I can see. Once it's back in the drill and running I'll consider it fixed, but the gods of ignorance and dumb luck were on my side tonight. :thumbup:
     
  18. slim_boy_fat

    slim_boy_fat Forum Supporter

    Nice one,and a very simple process. You're to be congratulated on the lateral thinking!! :thumbup:
     
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  19. minimutly Member

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    1,223
    Location:
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    Lateral thinking - I thought it was obvious?
    Well done simplest is easiest.
     
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  20. rockweasel Member

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    996
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    I had your comment ("If it bent, it can be unbent") running through my head to give me a bit of confidence. Sometimes easier said than done, but I got lucky. It certainly wasn't skill on my part.
     
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