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Thread: Some new articles featuring Rambold

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  1. #1
    Join Date
    Dec 2003
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    Palo Alto, California
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    1,300

    Default Some new articles featuring Rambold

    Lately I've gotten around to posting some new stuff on my Web site. Here are four pictorials featuring my (rebuilt at last) Rambold turret lathe:



    Adapting a small chuck to "Set-Tru"

    Turning a special step pulley

    Making a set of collets

    First "production run"
    Cheers,

    Frank Ford
    HomeShopTech

  2. #2
    Join Date
    Aug 2002
    Location
    Topeka, KS
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    467

    Default

    Looking good, Frank. I'm going to park the design of the "parting tool arm" in the back of my head. I can't afford the Hardinge ones off Ebay . I've devolped a fetish for 2nd OP lathes. They sure are fun to run. I haven't come up with a need to do a complex sequence of operations yet but I'm building the tooling in case I ever need to. (I guess I'm a collector of capabilities. I have yet to see an accessory I don't want. I don't need the best or oldest or multiple versions but I like to have "it" in case I need it.)
    Jon Bohlander
    My PM Blog

  3. #3
    Join Date
    Dec 2003
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    Palo Alto, California
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    Default

    That cutoff tool was designed and made by a previous owner, who ran a shop in the Midwest.

    I've been having fun with the turret lathe, but mostly so far it's been in rebuilding and setting it up. Still learning as I go.

    Yesterday I visited my pal, Lloyd who'd recently moved into a new job at a tiny startup shop in Mountain view. He had called me to visit his shop, and to ask if I had a 13/32" 5C collet his neighbor could borrow. When I got there he introduced me to his neighbor, Tibor, a big stout fellow with what seems like a strong Hungarian accent.

    Tibor runs a one man operation, and Holy Moly does he have cool tools! He make the teeniest little parts for watchmakers and high tech outfits. Most of his parts are 1/8" diameter or less, and under 1/4" long.

    He ran one of his FOUR all mechanical Strohm Swiss screw machines for us, and gave a blow-by-blow description of the action as it turned out these barely visible little locating pins for chip making fixtures. Three are 1/2" capacity and one has a 1" maximum. Two are set up with bar feeders for long production runs.

    Two good size CNC lathes, two Hardinge chuckers, a big CNC mill specially outfitted for small work, tool grinders, optical comparator, microscope, and a regular Bridgeport are some of the others I recall seeing there.

    With all that, he didn't have a 13/32" 5C collet, and I was mighty glad I'd agreed to bring it along.

    I think I'll offer to pick it up when he's finished with it and maybe he'll let me take a few pictures of his gear. . .
    Cheers,

    Frank Ford
    HomeShopTech

  4. #4
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    Mar 2008
    Location
    Portland OR
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    82

    Default

    Frank,
    excellent work as usual, I've really enjoyed going through your site.

    Have you ever thought of adapting on of these to go on the Cross slide? You might only be able to put a few tools in it but it might buy you two more ops.


    - Scott

  5. #5
    Join Date
    Dec 2003
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    Palo Alto, California
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    1,300

    Default

    Scott -

    Interesting. I have one of those - maybe I'll take a look. . .
    Cheers,

    Frank Ford
    HomeShopTech

  6. #6
    Join Date
    Nov 1999
    Location
    SE OZ
    Posts
    1,966

    Default Bravo!!

    Thanks Frank.

    It is always a joy to see your work, the way you plan and do it, as well as the way you present the processes on your web site.

    This is truly great "how it should be done" stuff - on all counts.

  7. #7
    Join Date
    Jan 2006
    Location
    Lamoine Maine
    Posts
    356

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    That parting tool was the first thing that caught my eye.

    Quote Originally Posted by moldmonkey
    Looking good, Frank. I'm going to park the design of the "parting tool arm" in the back of my head.

    Very nice machine Frank. Thanks for the site updates.
    Brett Jones...

  8. #8
    Join Date
    Aug 2004
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    Sunny So Cal
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    Default

    Hey Frank, thanks for the new pictures, I love all yer work...

    Ahh, the keyway for the pulley. Oh, how deep is that? Looks between .125 and .250" Thats a couple hundred strokes at .001" each.. Patience...

    And on the collet making post. You checked concentricity of the hex rod after you turned it. How did you do that?? Always looking for new ideas. Did you check it against the collet chuck nut and compare? Like check the collet nut then move over to the turned section?

    So anyway, I love that lathe and I want one!!! Wanna sell her??? Cash in hand...

    Oh, and that large black fixture?? Did you make that? Is it only for parting?? Ill take that too LOL Oh, 7500 rpm!!! Thats cookin....

    Great work Frank, as always... JR




    Quote Originally Posted by Frank Ford
    Lately I've gotten around to posting some new stuff on my Web site. Here are four pictorials featuring my (rebuilt at last) Rambold turret lathe:



    Adapting a small chuck to "Set-Tru"

    Turning a special step pulley

    Making a set of collets

    First "production run"

  9. #9
    Join Date
    Dec 2003
    Location
    Palo Alto, California
    Posts
    1,300

    Default

    Ah, I forgot to mention - I checked the concentricity of the hex collet by turning a round section on a bit of 1/4 hex brass in a Hardinge 1/4" collet on my Sharp lathe, then sticking it in the collet on the Rambold.

    That cutoff fixture was shop made by a previous owner, the one who supposedly "rebuilt" Rambold.

    Unfortunately, I got myself buried in this small lathe, having spent $1600 for it on eBay, including transport from the Midwest. I have absolutely no doubt that the seller represented it as well as he knew it, although he admitted never having run the lathe.

    The rest of the saga goes like-a this:

    Dateline, November 2007,

    I first inspected the motor and drive preparatory to getting a rotary converter. Palo Alto Electric Motor Shop wanted me to bring the motor in for testing before they would order a nonreturnable converter for it.

    FIrst thing I noticed when I got the motor off was that there was an interesting crack in the unique stepped pulley. As I looked more closely, I saw that a big hunk had been broken off and epoxied back on. The pulley was a press fit, so I suspect that the “rebuilder” tried a gear puller and broke the pulley trying to get it off. No problem - I set it up on the mill and milled a deep groove in the heavy end of the pulley, right down to the keyway so it came right off.

    I borrowed some time on a nice Clausing Colchester lathe to make a new identical pulley from cold rolled steel, since there was no hope of finding a stock on with those size sheaves.

    Got the clean bill of health on the motor, bought the converter, put everything together, and it would NOT run on high speed. Took it off, and it ran fine. Back on, no go. Turns out that at high speed the motor had literally not enough torque to turn the lathe spindle up to speed. Brought the motor back to the shop, and they were embarrassed enough to give me the refund even though they were still stuck with the converter.

    No problem - I ordered a VFD drive and three phase motor to replace the whole system. Only cost $950. Oops, one problem. The new pulley wouldn’t work on that shaft, so I had to make another one, this time calculating a different series of diameters to accommodate the range of RPM on the variable drive.

    OK, time to get ‘er runnning. Zipped right up to speed and seemed fairly smooth, but maybe just a teeny bit noisy at high RPM. Ran it for 7-8 minutes, turned it off and laid my hand on the headstock. Wow! HOT! Must have been about 175 degrees. Time to look at the bearings.

    Removed the headstock bearing retainers, and noticed that the oil holes were oriented 180 degrees away from the external oil fittings so lubrication would have been impossible. Everything was potted in heavy black auto wheel bearing grease, or something like that. One possibly original bearing remained, and two were replaced by double sealed ones. The front one had completely deformed seals from the heat.

    Time for new bearings. ABEC #7 bearings - took a while but found a deal on a set for only $388, including a rear bearing. They’re open angular contact bearings, rated for high speed, and lubricated by oil, of course.

    Took apart the turret and found that same grease everywhere in there along with completely clogged lubrication fittings, so I replaced all the old lube fittings with Zerks, so I could use my regular oil gun.

    I made a deal with my old pal in, of all places, Seldovia, Alaska (look it up - it’s REALLY remote) for a double cross slide off an old Hardinge Cataract. Took a bit of doing, but I milled it from the bottom to reduce the height and fit it to the small inverted dovetail way on Rambold. I made a pair of tool holders and was just about ready to start work.

    During the time I spent waiting for parts, working on the rebuild, etc., I made a goodly set of collet blanks so I’d be prepared when I was able to run this old critter. Using a Slater rotary broach, I made some hex collets. My immediate aim was to start with some runs of vintage style nuts for rather exotic old banjos.

    May 9: Finished making the form tools, setting up lathe and actually made a pile of brass chips. After this long fight, it’s great to have ol’ Rambold working well - very well, indeed. Together Rambold and I cranked out 200 of these nifty fancy nuts right quick, with nary a hitch in the process.
    Cheers,

    Frank Ford
    HomeShopTech

  10. #10
    Join Date
    Apr 2004
    Location
    Collierville, TN
    Posts
    2,579

    Default

    Man, what a great lathe and the story of bringing it up to snuff! I can read your stories and look at your pictures for hours! Thanks for taking the time to put it all together so well.

    It's so great to read a thread about how you restored a fine piece of equipment rather than a bitter diatribe about how you got screwed on Ebay, what's going to happen to the slob that sold it to you when your lawyers get ahold of him blah, blah, blah...ad freakin' nauseum.

    This is the kinda stuff we need more of on the forum!

    ps: That's how you paid me to say it, right?
    Milton

    "Accuracy is the sum total of your compensating mistakes."

    "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

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