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  • Mill needs more clearance

    Has anyone comtenplated making a steel spacer for their mill to gain extra height above the table , most of the commercially available ones are cast iron .

    Have had some distortion problems with a few "new " cast items lately .

    Many suppliers dont seem to care about quality as much as quantiy.

    Just a thought as I will possible make it a permanent fixture as there seems to be a lot of jobs which require 50mm more clearance than the mill has .

    I dont want to purchase a new one as this one has only done about 2.5 years work so far.

    Michael

  • #2
    If I remember correctly I think there was a artical about building one in the HSM magazine a few years ago. Steel pipe was used with welded flanges for bolting it to the coloum and the rams female dovetail block. I've never built one, But I think welding plates to seal up the internal space and fill that up with sand to dampen vibrations might be a good idea. It would be pretty heavy tho.

    Pete

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    • #3
      Cast iron is the ideal material here - it damps the vibrations, and is in compression where it is very strong. A steel one will work, but cast iron is better.

      - Bart
      Bart Smaalders
      http://smaalders.net/barts

      Comment


      • #4
        Cast would be better

        I think cast iron would be much better for this application, steel will flex considerably more than cast iron, although possibly just a big block of steel as a spacer would show little if any flex.

        I have this problem on my mini mill. the best fix I have so far is to use a regular collet to hold tooling instead of the collet chuck it came with, which saves nearly 3 inches of vertical height.

        I also have a plan to get another 1.25 inches out of it, it involves moving the stop at the top of the dovetail column and bolting on some made extensions. This will allow the use of the entire vertical cast iron dovetail, without ever traveling the head off of it. Right now when I crank the mill head all the way up until it hits the stop, there is approximately 1.25 inches of column left unused above it.

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        • #5
          On the board "Shop Floor Talk" a fellow has just made one. He used
          a section of pipe and welded a flange on both ends for the matting
          surface. Worked very well. Of course it takes a good size lathe to
          finish it properly.
          ...lew...

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          • #6
            I've contemplated it a lot. That's as far as I have gotten on the project. www.mcmaster.com sells 2" thick cast iron disks in large diameters for fairly reasonable cost. A 2" thick by 8" diameter disk is about $51. A 2" x 6" is about $42.
            ----------
            Try to make a living, not a killing. -- Utah Phillips
            Don't believe everything you know. -- Bumper sticker
            Everybody is ignorant, only on different subjects. -- Will Rogers
            There are lots of people who mistake their imagination for their memory. - Josh Billings
            Law of Logical Argument - Anything is possible if you don't know what you are talking about.
            Don't own anything you have to feed or paint. - Hood River Blackie

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            • #7
              All carbon steels are actually more than twice as stiff as cast iron for the same section.

              Phil

              Originally posted by Iraiam
              ..... steel will flex considerably more than cast iron

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              • #8
                Yes I will do this for my little machine as I'm really struggling for headroom. Here's a link to the same mill with the riser block constructed, sorry no construction details but it wouldn't be too complicated, nothing fancy needed, just make sure it's all square.

                http://www.lathes.co.uk/hercus/page4.html

                Pete

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                • #9
                  Miker, there may be some ideas for you here.
                  http://ryanbrownracing.com/Bill_Jones_Page_10.html

                  Comment


                  • #10
                    Originally posted by Lew Hartswick
                    On the board "Shop Floor Talk" a fellow has just made one. He used
                    a section of pipe and welded a flange on both ends for the matting
                    surface. Worked very well. Of course it takes a good size lathe to
                    finish it properly.
                    ...lew...


                    Lew,

                    The guy was me, and yes it has worked fine. Below is the thread link.


                    jack


                    http://www.shopfloortalk.com/forums/...ad.php?t=28383
                    jack

                    Comment


                    • #11
                      I have an 8" tall, 12" diameter, 3/8" wall steel tube riser. No flanges, just longer studs. I used alloy all-thread. Swiveling the turret is inconvenient without the proper pilots but I very rarely swivel my turret so a non issue. The local shop I purchased it from turned the ends parallel for me within .001 for minimal extra. I selectively positioned the .001 for nod tram since my head only tilts side-to-side. Works great for me.

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                      • #12
                        Michael,
                        What kind of mill do you have?
                        Mark Hockett

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                        • #13
                          For home shop use . Steel is fine I would dare that any one of you could tell the difference running one with a steel riser are a cast iron one . People get real.
                          Every Mans Work Is A Portrait of Him Self
                          http://sites.google.com/site/machinistsite/TWO-BUDDIES
                          http://s178.photobucket.com/user/lan...?sort=3&page=1

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                          • #14
                            Mill

                            Originally posted by Mark Hockett
                            Michael,
                            What kind of mill do you have?
                            Its a HM52 which is similar to Grizzly 's offerings ,I purchased this one to save changing setups for some work that comes along .
                            Jobs which require both horizontal and vertical milling .

                            Now I have a batch of higher than normal parts to cleanup and modify for an application ,probably wont need the clearance again .

                            Making the riser and machining it is not a problem ,I just wanted to hear from others who may have already done this.

                            Comment


                            • #15
                              Get a factory made riser for your turret mill. It is the simplest solution but also one that's expensive.

                              You don't say if yours is a turret mill Is it made like a Bridgeport stye mill where a milling head bolts on the end of a horizontal ram that mounts in a dovetail across a turret that swivels atop the column?

                              Anyway, a "riser" is what you're looking for. Here's a link to a few: http://business.shop.ebay.com/?_from...r&_sacat=12576

                              You can cook up a home made riser but the top and bottom faces have to be machined parallel and there are rabbet fits so the turret turns on an axis. If you don't have access to a machine large enough to face an internally flanged ring that's what? - 18" OD? You also have to drill for the bolts so the upper and lower hole patterns line up with the turret holes. The hole are necessary to carry the bolts along as the turret swivels, If the bolts hang free thay can swing a litttle and hang up in the T slot.

                              No reason you can't make your own (save a couple hundred bucks but don't forget to figure the cost of materials) but you do have to provide the necessary features to make it work.

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