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Thread: Metrology For the Cabinermaker - II

  1. #1
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    Metrology For the Cabinermaker - II

    This thread is a continuation of Metrology for the cabinetmaker.

    Please don't mistake the level of detail and effort as dissatisfaction, I'm very happy with this machine, it cuts a good mortise and does so very well. The reason I'm doing this is because I'm putting a mini-pallet and sine plate on this machine to handle angled mortises and everything must be tip-top for that to work out properly.

    I find it highly important to be able to reliably dial in my machine tools, check parts (of the tools) and inspect to find errors in their machined surfaces or tune. I recently purchased a Wadkin DM mortiser. Upon inspection I found some parts out of tram. My initial thought was to shim the column to bring it into tram, however I decided to inspect the table first.

    Prior to inspecting the table I setup an indicator to run across X, Y and Z across various parts of the main table. Z provided out by .007" over the length of the fence, the fence out of parallel to the travel by .012". I then ran X and Y on the main table itself, the table provided out of tram at the ends by an amount I don't recall (not zero, lol) and .005" across the major part of the table. Presumably more but I ran out of Y before I ran out of table.

    First point of inspection was the table itself, I sat my camelback straight edge on it and the straight edge revealed a bow in the center of the table. So, table must be re-ground. The table is bigger than I want to machine myself so it's off to the machine shop. What they plan to do is bring everything square to the fence and grind the bottom of the ways to remove the slight concavity there. Without recutting the ways nothing will bring the fence back to parallel but Wadkin ways are 55 degrees rather than a standard 60, so i'm debating my approach there.

    Next I decided to inspect the saddle. It's in fine shape with exception to a .002" bow in the center of the ways. I'm debating wether to mill this.

    Finally I got the machine down to the fixed ways. I inspected these ways and found the head out of tram to the ways. I worked them lightly with a hone to remove burrs and take out a very slight out of parallel situation, then sat a shop standard square on the ways in multiple places.

    I'm traveling the head the entire length of the machine's travel, which is a lot.



    .0035" tilted along the side, I was able to manage .000" along one way front to back and .001" along the other.

    I ultimately decided it would be best to shim the column, I stuck two round shims front and back along the offending side.



    The back remained slightly out still, but something I can live with



    I reinstalled the saddle after deburring everything, an important part of inspecting.

    The outer gib screw was out of proper adjustment, bringing it into adjustment allowed smooth travel and brought the surface into tram, almost. That .001" bump in the center is showing itself here. Inspection grade blocks are used to raise the square.



    Before adjustment above:

    After:



    While the table is out I will check the chisel holder to see if it is centered to the spindle and parallel to travel. I will also inspect the collet holder for runout both inside and outside.
    Last edited by Brian Holcombe; 10-14-2019 at 10:28 PM.
    Bumbling forward into the unknown.

  2. #2
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    The German blood in me loves this stuff Brian. I have the desire for "exactness" in a machine, but not the skills/training to make it so. This is one of the things that pushed me to a more hand tool approach after retiring.
    David

  3. #3
    Well done Brian.
    "Anything seems possible when you don't know what you're doing."

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    Thank you, both! David, that’s it for me as well I’ve been chasing the idea of ‘machine perfection’. I’d like to pursue scraping, so I’ve been adding stuff for that as opportunity allows. I’ve been contemplating learning to flake just for this machine.
    Bumbling forward into the unknown.

  5. #5
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    Hi Brian, Nice work!
    It's fun to chase down the demons in the search for absolute. I am also hoping to get some practice at scraping in surfaces soon.

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    I always enjoy your posts Brian and learn something every time. Thank you for sharing your methods.

    Michael

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    Thanks gents! My pleasure!

    Mark, very interesting that you’re heading this way as well, what do you plan to scrape up first?
    Bumbling forward into the unknown.

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    Hi Brian, I don't know where to begin... Everything needs tuning up. I may start with the cross-slide on my lathe.
    I did some work on my table-saw top with a disc- grinder and a die-grinder.( not as crude as you might think) the sliding top was about twenty thou out, its now within 0.002" I have since purchased a large granite, grade A surface plate, so i may get around to finishing it at some point.I have a few camel-backs up to 6'. I have been doing a bit of research on it, and its all pretty fascinating. I have to get some scrapers soon.

    1-SAM_2547.jpg

    Quote Originally Posted by Brian Holcombe View Post
    Thanks gents! My pleasure!

    Mark, very interesting that you’re heading this way as well, what do you plan to scrape up first?

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    Interesting, wow .020” is a lot! That would be pretty sweet to see that big table scraped in flat, but I’d imagine that’s a pretty time consuming start.
    Bumbling forward into the unknown.

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    Brian,
    the problem is, it's all connected once you start you petty much have to do everything.
    And really to start you need to get a verified reference surface. But without going to far down the rabbit hole, i could assume that my surface plate is more than good enough for my use, and scrape in my camel-backs. And work from that.
    It get pretty intoxicating when you start looking into it, and hard to know when to stop.

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    Exactly, it’s very hard not to dig deeper once you start looking closely at things, I mean that in a general sense since I have no experience scraping.

    I thought I might be able to just sweep and indicator over the table and then live with the results....yeah right.
    Bumbling forward into the unknown.

  12. #12
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    Yeah, good luck with that.


    p1420001.jpg


    Quote Originally Posted by Brian Holcombe View Post
    Exactly, it’s very hard not to dig deeper once you start looking closely at things, I mean that in a general sense since I have no experience scraping.

    I thought I might be able to just sweep and indicator over the table and then live with the results....yeah right.

  13. #13
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    This machine job was too big for the Bridgeport so I brought it to a local shop which did a fabulous job in my opinion. They inspected the part on a 4x8 granite with cert, moved it to a gantry style Haas then started taking measurements. The table top was like a landscape, highs and lows all over. The fence was out of square to the table and out of parallel to the ways. I was happy to see numbers very similar to what I got measuring on the machine. .007” out if square and .012” out of parallel.

    They brought it to dead on square (no change in the indicator) and parallel to .001”.

    I have more work to do to this for installing the mini-pallet. So when I setup to do that work I will reapply the main grooves in the table for posterity.



    If you’re wondering the time involved, about 5-6 hrs of setup and a few hours to cut and that doesn’t count my inspection time.

    This shop is fantastic, really care about the work they are doing and did not mind my nosing in and putting my two cents in here and there as the part was setup and measured
    Bumbling forward into the unknown.

  14. #14
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    Hi Brian, Nice work!
    Glad that you have found a great shop to do that quality of work.

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    Thanks, Mark! They will be handy to have access to, for certain, and great to work with people interested in unique work and who take pride in quality of results.
    Bumbling forward into the unknown.

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