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Advice on Kao Ming KM-40S (Maybe same as Makino C40)

What should I do?

  • 3" / Ft

    Votes: 0 0.0%
  • 4.5" / Ft

    Votes: 0 0.0%
  • Don't Regrind

    Votes: 0 0.0%
  • Some other Angle

    Votes: 0 0.0%

  • Total voters
    0
  • Poll closed .

abakker

Plastic
Joined
May 30, 2017
Location
SF, CA
I recently came into possession of a nearly unused Kao Ming tool and cutter grinder. It had some of the fixtures, but not all and mostly had been slathered in grease once, 40 years ago, and never really run. (previous owner had wired it incorrectly, using one of those phase-a-matic things, and I don't think ever got it to run).

I took it apart and cleaned it up recently, and got a VFD installed on the main spindle motor. All of that is working great now, so i'm almost ready to run it. Here's the problem: Kao Ming/Makino used a "non-standard" spindle taper, and wheel adaptors for this taper are not really available. William Sopko and sons would make custom ones, but the price of those is more than what I paid for the machine.

It looks like my best option is to regrind the spindle. The large diameter end of the taper is the same as the Cincinnati #2, which used a 4.5"/Ft taper. (looks like about 2 degrees different from what Kao Ming chose to use...). The folks at William Sopko recommended I regrind to 3"/Foot because that is the standard. So, I'm asking the hive mind here, should I regrind 3"/ft or 4.5"/ft or do something completely different?

Also, I am a hobby machinist. I want to hold good tolerances, but, I also don't want to break the bank. I think that leaves me with doing the spindle regrind myself. I figure that means I need to indicate the grinder head in very carefully to the table in all dimensions, then set the head to the taper angle. I have a good condition Dumore Tool Post Grinder which I could mount to the T slot in the table and then basically run the spindle in reverse and grind it with the tool post grinder. Does this sound like an adequate method?

I'm open to all advice/any ideas.
 
Following up in case anyone else needs to see this - what I ended up doing was buying several Shars 505-1008 arbors and then boring them out. They are reasonably soft metal and bored easily. While Sopko lists the angler as 18* 54', mine didn't measure out that way - by my math the taper should have been .331" in/in or 3.972/ft. The taper that blued well and made good contact was .334in/in or just a tad over 4in/ft. The wide end of the taper is just under .875. I guess that these machines were made with an odd reference or maybe my lathe DRO can't be trusted...but anyway. This post is here for posterity. The Shars parts are $30 each and only come in right hand thread, so I bought 10 and made a secondary washer that locks the arbor bolt closed with the taper screw so that the holders don't unwind themselves.
 
I never saw the post when first up, but reading through it today, at the point when you were asking about grinding the arbor, my immediate thought/advice was "just buy 1/2 dozen cheap adaptors on ebay or imports, and grind or hard bore them"

Relieved you worked it out that way.

Plus it's a good practice project.

:)

smt
 








 
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