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  1. #2791
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Nigel,

    You should have found the the vial is supported by a cotton packing underneath it in the outer tube. Once the vial is in place and correctly orientated you can then pour the plaster into the ends. Do the seal end last. These levels normally have a "V" in the bottom.

    If the tube is too short use a piece of clear thin heat shrink tube over it to get the length needed.

    PS. I would have robbed a cheap £ shop level for a bubble.
    Best Regards:
    Baron J.

  2. #2792
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    I had an old level that I re-vialled a while back (sorry - no video) that had the ends held by what I think would have been sulphur. I got a new vial and put a sliver or two of business card underneath it to lift it up before using plaster on the ends. I bought mine from this crowd (https://caterpillar-red.com/spirit-levels-vials/) through ebay I think

    If you can identify the model number of the level, the specs on the manufacturer's website should give an idea of the precision (typically it is a height per length thing per division)

    Michael

  3. #2793
    Join Date
    Jun 2020
    Location
    Freo
    Age
    68
    Posts
    141

    Default

    Quote Originally Posted by nigelpearson View Post
    1)
    Some of the narrower vials do 1mm per meter.
    I assume that is per etched division on the vial, not full bubble deflection.

    Any advice as to the size/length/resolution of the vial?
    That seems very coarse
    My level is .02mm per Meter and not terribly expensive
    https://www.mag-pro.com.au/index/ind...ls/id/256.html

  4. #2794
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,183

    Default

    Quote Originally Posted by oldbuggermike View Post
    That seems very coarse
    My level is .02mm per Meter and not terribly expensive
    Oops. You are right. 20 microns, not 2mm:

    https://www.aliexpress.com/item/32872235091.html



    Yes, a new level would have been cheaper, but I do like the design of old equipment
    Nigel, from a cave FULL of unfinished projects and lost tools.

  5. #2795
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,183

    Default Cutting corners

    Making some large discs from sheet steel:
    IMG_4002.jpg IMG_4003.jpg

    which will become new blanks in a cam grinder,

    except that the bandsaw started leaking coolant all over the floor.
    Thought it might have been overflowing after being moved* on Saturday,
    but no, the 10+ year old hose is brittle and cracking:
    IMG_4004.jpg



    Quick trip to Pirtek for some new 8mm OD hose. Nylon this time.
    Hardest part is wrapping it back up in the protective sleeve:
    IMG_4005.jpg




    (*) Bandsaw was moved on Saturday to fit another car body in the man cave –
    an stripped Austin 7 Swallow roadster, that might look something like this:
    https://www.shannons.com.au/auctions...RFFMOQ8PE20F8/
    Nigel, from a cave FULL of unfinished projects and lost tools.

  6. #2796
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,183

    Default Motor tool weirdness, Lathe oiler, chuck jaw repair

    1) A wall chasing tool, whose motor is behaving strangely.
    It hums and vibrates on start, never spins up to speed.
    IMG_4018.jpg
    I checked resistance between each coil, and they are fairly consistent. (1.2ohms).

    Tried polishing brush contact points, changing start capacitor, no change.

    Tried bypassing electronic module (which I think gives a soft-start feature).
    No change, and field magnets got hot.

    A mystery.



    2) Based on a post a few weeks ago on making a push lathe oiler, I decided to get one from eBay.
    IMG_4042.jpg
    $37 delivered.

    After an annoying 1/2 hour removing the grease tip, and fitting the oil taper tip,
    discovered it is too large for my oilers, so:
    IMG_4035.jpg IMG_4036.jpg IMG_4037.jpg IMG_4038.jpg

    Seems to work OK. Forced some milky (water bubbled) oil out from under one side of my cross slide.



    3) There is some damage at the front of my AL336 3jaw jaws.
    I must have somehow hit them. It has made a little ridge inside, on the gripping surface:
    IMG_4043.jpg

    So, I decide to machine it off.

    Now, I have heard about putting 3 precisely sized blocks between the laws to keep them apart.
    Decide to try that.

    Look around for 3 blocks the same size. Find some rusty old chuck jaws. Surface grind them:
    IMG_4039.jpg IMG_4040.jpg IMG_4041.jpg

    and try to fit:
    IMG_4044.jpg
    Sadly, that wasn't far enough apart, and the angle on these adjacent jaws are not parallel,


    so use the "grip a ring" method. A large ER32 nut is about right:
    IMG_4045.jpg
    (checking the factory ground radius there with an indicator)


    Quickly hoed in:
    IMG_4046.jpg

    Not a perfect job, but very little light showing through:
    IMG_4047.jpg




    P.S. Also made a shelf under one lathe; https://metalworkforums.com/f65/t202...st/post1988230
    Attached Images Attached Images
    Nigel, from a cave FULL of unfinished projects and lost tools.

  7. #2797
    Join Date
    Oct 2019
    Location
    Adelaide, SA
    Posts
    1,198

    Default

    Quote Originally Posted by nigelpearson View Post
    2) Based on a post a few weeks ago on making a push lathe oiler, I decided to get one from eBay.
    IMG_4042.jpg
    $37 delivered.

    After an annoying 1/2 hour removing the grease tip, and fitting the oil taper tip,
    discovered it is too large for my oilers, so:
    IMG_4035.jpg IMG_4036.jpg IMG_4037.jpg IMG_4038.jpg

    Seems to work OK. Forced some milky (water bubbled) oil out from under one side of my cross slide.
    I bought one of these Pressol 12363 oil guns off ebay about 6 months ago and it’s holding up well.
    There are claims that Pressol products are still German made and the quality appears good but there are no brand markings on the oiler which make it seem like a generic product.
    Makes good pressure and does the job getting oil into the oil nipples.
    I like the fact that it comes with 2 nozzles, one of which works well on my Myford. There is a knurl on the nozzle and for me it came off quite easily for replacements.
    Do not over tighten the cap once you fill in oil as the rubber seal tends to move a bit and cause leakage as its only held on by a small lip.

  8. #2798
    Join Date
    Sep 2008
    Location
    Riddells Creek, Vic.
    Posts
    831

    Default

    [QUOTE=nigelpearson;2005578]1)
    I checked resistance between each coil, and they are fairly consistent. (1.2ohms).

    Tried polishing brush contact points, changing start capacitor, no change.

    Tried bypassing electronic module (which I think gives a soft-start feature).
    No change, and field magnets got hot.

    A mystery.



    I don't think there is a start capacitor in this type of motor, it is more likely some sort of smoothing capacitor and could actually be removed/bypassed if required. The problem is most likely with the armature.

  9. #2799
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Nigel, Guys,

    The capacitor you mention is most likely to be an interference suppression capacitor !

    Its quite possible that the armature has a bad winding, either open, high resistance or a partial short, using an ohmmeter across the brushes and stepping the armature by hand one segment at a time might give you a clue.

    The humming and failure to start is a clue to a short in one armature winding.
    Best Regards:
    Baron J.

  10. #2800
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,183

    Default

    Quote Originally Posted by BaronJ View Post
    Its quite possible that the armature has a bad winding, either open, high resistance or a partial short, using an ohmmeter across the brushes and stepping the armature by hand one segment

    Motor was disassembled when I got it, so I tested resistance between each adjacent segment,
    instead of 180° opposite through the brushes. No time to actually trace the armature wind geometry.

    One segment was a little higher than the others, something like 3ohms instead of 1ohm,
    but nothing broken or shorted.


    The humming/vibration occurs in any position.
    i.e if I remove the power, turn the motor shaft 20°, and pull the trigger again, same behaviour.

    It looks like a universal motor, but with two field findings separately wired to the electronic module.
    (didn't have time to trace and document the wiring).
    I did wonder if the windings are pulsed by the module for soft start and speed regulation.
    Nigel, from a cave FULL of unfinished projects and lost tools.

  11. #2801
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Quote Originally Posted by nigelpearson View Post
    Motor was disassembled when I got it, so I tested resistance between each adjacent segment, instead of 180° opposite through the brushes. No time to actually trace the armature wind geometry.

    One segment was a little higher than the others, something like 3ohms instead of 1ohm, but nothing broken or shorted.

    The humming/vibration occurs in any position.
    i.e if I remove the power, turn the motor shaft 20°, and pull the trigger again, same behaviour.

    It looks like a universal motor, but with two field findings separately wired to the electronic module.
    (didn't have time to trace and document the wiring).
    I did wonder if the windings are pulsed by the module for soft start and speed regulation.
    Hi Nigel,

    Its worth checking that if the windings have been disconnected at some time and that the windings have not being rewired out of phase.

    Though finding a high resistance is a bad sign !
    Best Regards:
    Baron J.

  12. #2802
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,183

    Default A simple stud

    ...gave up on the motor. Couldn't see anything wrong in the windings, and had already spent too much time on yet another broken 240v motor produced this century (in contrast to all the working ones that have lasted since last century!).

    Onto the next little task, a rocker cover stud for a 1952 DeSoto Hemi V8:
    IMG_4099.jpg IMG_4100.jpg
    I'm kind of proud of that – the 5/16" UNF thread perfectly blends into the 5/16" UNC?



    – although it was a rush job, so I cheated by throwing a 5/16 bolt into the lathe, parting off the excess, pushing a die to cut the UNF end, and polishing the visible end.

    The first attempt didn't go so well:
    IMG_4101.jpg
    the die just caused the job to tear around in the chuck jaws. I initially tried a few nuts bolted together, but that was way off centre for parting and threading. If I ever do a batch of these, will have to make a long threaded sleeve with a slit?
    Nigel, from a cave FULL of unfinished projects and lost tools.

  13. #2803
    Join Date
    Oct 2019
    Location
    Adelaide, SA
    Posts
    1,198

    Default

    Quote Originally Posted by nigelpearson View Post
    ...gave up on the motor. Couldn't see anything wrong in the windings, and had already spent too much time on yet another broken 240v motor produced this century (in contrast to all the working ones that have lasted since last century!).
    Its hard to walk away from a project but at times its the sensible thing to do.

    Don't junk it, just leave it for a rainy day when you have more spare time or come across someone who enjoys rewinding motors

  14. #2804
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    Motor windings don’t go high resistance from use, ever…
    Mode of failure is always excessive heat which means they fail to open (heat is so high it melts the winding), short (heat is high enough to melt all the insulation) or lower resistance than otherwise intended (heat is high enough to partially melt the insulation).
    If you have 2 windings higher than the other, you have two that have dropped turns because the insulation has likely melted between layers, not one that has high resistance.
    You may possibly get high resistance joints from green death at the ends of the windings if the tool is mistreated and allowed to be stored wet, but that is not a usage failure.
    3Ohms on one winding is not a high resistance consistent with corrosion, one ohm on two of three windings is consistent with partial failure of insulation in those windings.

  15. #2805
    Join Date
    Dec 2011
    Location
    Sydney
    Posts
    505

    Default

    Motor failures can be tricky.

    I bought an old Macson grinder. It came with a decent quality single phase motor (not old). The motor is designed to run with both windings powered up,
    so has 2 capacitors. It looked great, but would not not run smoothly.

    Looked and looked to find the problem, replaced the caps but that made no difference.
    In the end I discovered that the motor had been modified to fit the machine, by shifting the baseplate on the motor casing.
    Fine, except that when drilling new holes in the casing ......!!!!
    Yup. He drilled right through the casing and into the windings! Being a careful chap he did not drill far into the windings, so the motor kept working - sort of. But not well enough.

    Bill

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