Tuesday, April 12, 2011

No hope of Drilling to China

I decided to do a little digging into my drill press today to see if I could isolate the parts which were giving the machine a little vibration, particularly at medium and higher speeds. This drill press can crank up to 8200 rpm - thank god I have no need for that as it would probably blow itself apart if at that speed for an extended period.

Stripping the machine head down to remove the motor and pulley assembly took all of two minutes, and it was only another few minutes of wrenching and I had the quill and spindle out of the head:


Some of the parts are strewn around the work table, the spindle drive pulley at the upper left, and retainer cone just in front of the flashlight:


I only had to use the puller on one bearing - the dis-assembly was really easy to accomplish overall.

Another view, with the quill standing upright and the main spindle, which slides inside the quill, laying on it's side at front:


Now I have the thing apart, I'd discovered a couple of bearings that could use replacement. Unfortunately, they are 'special' bearings designed to work with only this machine, having their inner races extended to act as spacers and so forth. So, getting the bearings for cheap at a local bearing supplier was not really in the cards, though an extended phone call with an outfit in Boston did turn up some interesting information - for instance, the company that makes one of the bearings I pulled out from the head has been defunct for 35 years!

So, I have little choice but to go to Delta for the parts, and boy oh boy do they charge an arm and a leg for these things. A bearing, 1.375" x 0.625" is around $5.00 from a bearing house - the special one from Delta is $70.91. I need two of those, and there's no way around it.

Then there's the spindle, pictured above at the front edge of the table. Hardly a sophisticated piece of machining, yet Delta wants $537.02 for that part. Mine has some damage in a couple of spots, but I think a machine shop will be able to repair it relatively inexpensively. I'm thinking that no more than $60 should get it right.

It's a shame the parts are so expensive because it really puts a damper restoring/rebuilding the machine. At least the parts are available, well, most of them anyhow. And, lucky for me, most of the machine is in good shape - if I needed a new head casting, for instance, I would be looking at more than $2500! Of course, since I'm just the next guy in a long succession of people who have owned this machine and have worked on it, I get to see which parts that have been replaced (or not) when getting into the guts of it. Usually, when a dude is faced with dropping hundreds of dollars on the correct factory parts, or getting some inexpensive generic parts that only sorta fit, or not replacing the part at all, well, most of the time the outcome is anything but the replacement with the correct part. And of course that just accelerates the wear pattern on the machine as the not-quite-right parts in concert with heavy use leads to premature wear and worse. By the time I'm getting to my turn with this machine, it needs extensive work to put everything right, and like the previous mechanics, I struggle with the cost of the parts. Same thing of course for lots of products out there, cars being a prominent example coming to mind right away....

It goes to show that while it is really ideal to have equipment that is fully repairable and re-buildable, and even nicer if the parts for old equipment are stocked by the manufacturer, sometimes the cost of those parts is so prohibitive that maintenance suffers, or is simply not done at all.

Reminds me of an American company, Paul Components, in the 1990's that developed derailleurs for bicycles that were fully re-buildable:


Sounds like an awesome idea, but....

.... at uh, $300 for a rear derailleur, a part which on a mountain bike which can be removed instantly by a very inexpensive branch or rock, most people, myself included, decided that a $70 Shimano derailleur made more sense.

Those Paul derailleurs are no longer made, so I wonder if the rebuild parts are still available? Stuff built to last and be re-buildable is not always as wonderful in practice as in theory, unfortunately.

Anyway, I'll get a few bearings for the Rockwell Radial, spending no more than about $300, and add a link belt and we'll see how much that improves the vibration situation. It's nothing too bad really, but I like a machine to run as it should.

Tomorrow is looking like the day to pull the jointer tables off the Oliver and take them down to Hartford CT for some re-surfacing. I'll take a few pics and post them up as the 'fun' unfolds. The table will be heavy, but there are people around to help, along with pallet jacks and so forth.

Next post will be another one in the CNC series, now that I've waded through the 400 pages of Noble's book on the history of industrial automation. Don't worry, I'll give the short version of the story!

Thanks for swinging by on your travels today.

5 comments:

  1. You may know this already, but try Lynn at Accurate Bearings. She is a well known supplier of oddball bearings the OWWM community.

    ReplyDelete
  2. Thanks so much for the tip Dan, I'll check into that tomorrow.

    ReplyDelete
  3. Here's a link to a page on OWWM that provides some guidance when ordering from Accurate Bearings. HTH

    http://owwm.org/viewtopic.php?f=1&t=93322

    -jamie s

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  4. I'm on chapter three in Noble. I can see why he might be unpopular with the command and control crowd.

    ReplyDelete
  5. Bill,

    chapter 3...ah yes, "Power and the Power of Ideas" - one of the better parts of the book.

    I'm now onto another book of Nobles', "America by Design", which I'm reading in alternation with Mumford's "Technics and Civilization". Whew! My head hurts just thinking about the volume of dense reading that lay ahead!

    ~Chris

    ReplyDelete

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