Announcement

Collapse
No announcement yet.

Project: Building the MLA-18 Filing Machine

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by thin-woodsman View Post
    I've had an MLA-18 kit on the TODO shelf(/ves) for a couple years now. Maybe your build will inspire me to finally get started

    Also thanks for the info on the Falcon files
    I'm working at it tonight, I'll have an update sometime later tomorrow. It occurred to me, that one could also mount saber-saw blades in this. Or even jewelers blades, with a appropriate spring-loaded arm..... poor man's scroll-saw!
    25 miles north of Buffalo NY, USA

    Comment


    • #17
      The sabre-saw blades are a good idea. Modify the toolholder so it is threaded to take different accessories, like the stuff George Thomas or Tubal Cain (UK) used to make.
      Also, as much as I like the look of the smooth top, I'm considering adding some provision for a fence.

      Comment


      • #18
        OK some more (slow) updates, but progress is happening. In the previous post, I had cleaned up the base and rim of the base, and also the "spud" on the business end of the filer. I centered the business end in the 4-jaw and drilled/bored the hole thru the base for the lower bearing, for the tool holder. Since I turned the base and the spud concentric to each other, everything else that I set up from either surface should also be concentric -- I hope.

        So I turned the filer around once again in the 4-jaw and centered it to drill/bore the other bearing hole thru the spud.

        Click image for larger version

Name:	mla18-3.jpg
Views:	73
Size:	731.0 KB
ID:	1945252

        That's just a Federal group 3 indicator mounted in a "Mighty-Mag" holder, stuck to the tool post. It's fantastically sensitive for its age, and very easy to use. One of my favorite indicators. I centered the part till the needle didn't move. Drilled and bored the hole thru the spud for the upper tool holder bearing. Both bores are .875 (22mm) The kit supplies 2 pcs of bronze hollow bar for the bearing stock, with very generous over-allowance.

        Click image for larger version  Name:	mla18-4.jpg Views:	1 Size:	750.0 KB ID:	1943126

        Continued next post......
        Last edited by nickel-city-fab; 06-03-2021, 06:54 PM. Reason: replaced the pic
        25 miles north of Buffalo NY, USA

        Comment


        • #19
          Continuing on,

          Once the upper bore was done, I shortened the spud off to its final length. I actually don't think these dimensions are very critical, but the drawings call for an overall height of 5-1/4" (133mm). I left it at 5-1/2" (140mm) because I just don't feel like doing that much facing!

          There is a dust cap which has a felt in it on the completed machine. This keeps chips from getting into the moving parts. This cap is held onto the spud with 6x, 4-40 screws on a 1-1/8" dia. B.C. (say 3mm on 28mm). I used a sharp DCGT tool in the tool post to scribe the bolt circle. This bolt circle is where my lathe back plate is useful: recall how I pointed out the 60 holes drilled radially in it? I use a simple piece of brass with a small screw thru it to simple index things in the chuck:

          Click image for larger version  Name:	mla18-5.jpg Views:	7 Size:	568.0 KB ID:	1943131

          Its surprisingly accurate (I used a change gear with a similar stop to drill all those holes.) I find it good practice to go around and mark your holes with a sharpie to test your setup *first* before drilling or cutting.
          Please don't ask me how I know this.
          Next I drilled the 6 tap holes with a #43 drill (.089, or 2.2mm) to 1/2" (12mm) deep.

          Click image for larger version  Name:	mla18-6.jpg Views:	7 Size:	864.5 KB ID:	1943132

          The tool post drill fixture gets a work out. More to come....
          Last edited by nickel-city-fab; 05-16-2021, 06:37 PM. Reason: clarity
          25 miles north of Buffalo NY, USA

          Comment


          • #20
            Tapped the holes to 4-40 x 1/2" deep. This tap set is a 1950's -era GTD (Greenfield) still in good working order with all the common machine screw sizes. I was sweating on this because I have never ran a tap that small, let alone in a blind hole on cast iron! The high-quality GTD tools make the job easy. You can't see it in the photo, but I had a spring-loaded tap follower mounted in a tool block on the backside of the tool post.

            Click image for larger version

Name:	mla-7.jpg
Views:	290
Size:	817.1 KB
ID:	1943135

            Coming up next..... should I continue with the main casting, or should I start turning the bronze bearings? Let's find out!
            25 miles north of Buffalo NY, USA

            Comment


            • #21
              OK, I did the unthinkable: I read the instructions! They go into boring the motor/crank shaft hole first, followed by the rear cover. They show multiple ways to setup the job, and there's probably more that aren't mentioned. I've got it roughly centered for boring (it's a cored hole this time) BUT here is the big thing: You want this bore to be square to the other bores (just completed). It's easy to get the bore square on the vertical plane (using already-finished surfaces) but not so easy to get it square in the horizontal plane.
              I gotta think about this one. Anyone else have ideas how to square it?

              In these pics, I have removed the top slide and screwed a piece of threaded rod thru into a dovetail plug (which South Bend normally uses for their top slides and accessories). There is a machined spacer bringing the piece up to the correct height, nearly. Because everything is clamped on machined surfaces they should be square in two directions.
              The big question is when viewed straight down upon the part, how to ensure it is not rotated relative to the spindle? Or is this gonna be a case of "cut it and wing it"? Eyeball it and pray for the best?


              Click image for larger version  Name:	mla18-9.jpg Views:	0 Size:	614.4 KB ID:	1943151

              Click image for larger version  Name:	mla-18-8.jpg Views:	0 Size:	519.4 KB ID:	1943152
              Last edited by nickel-city-fab; 05-16-2021, 08:38 PM. Reason: readability wrt para breaks
              25 miles north of Buffalo NY, USA

              Comment


              • #22
                Forgot to mention, that's a MT blank stuck in the spindle, to give me a reference for centering. When I bore this, I'm going to have the boring bar held in the 4-jaw chuck since I haven't made the boring head yet.
                25 miles north of Buffalo NY, USA

                Comment


                • #23
                  Never had much use for a filing machine, but that indexing back plate on the lathe is clever. Mine is on a crank that goes into the back of the spindle. Like yours better with easyer access !! Nice.

                  Comment


                  • #24
                    what reference surfaces do you have? The top is obvious, but I can't see any others that you can use to center the bore in the part closest to the spindle. Your best shot would be to indicate off the casting bore by holding a DTI in the spindle somehow (3 jaw chuck?) to get it centered relative to the spindle and as straight as you can get it relative to the bed. How are you going to hold it to bore the other side (the big open bit with the bolt through it)?

                    Comment


                    • #25
                      Originally posted by mattthemuppet View Post
                      what reference surfaces do you have? The top is obvious, but I can't see any others that you can use to center the bore in the part closest to the spindle. Your best shot would be to indicate off the casting bore by holding a DTI in the spindle somehow (3 jaw chuck?) to get it centered relative to the spindle and as straight as you can get it relative to the bed. How are you going to hold it to bore the other side (the big open bit with the bolt through it)?
                      Well. the top surface of the spud (where it is contacting the lathe right now) is turned and faced -- that is what is holding it square in that direction. That is the surface that is blued and getting tapped in the previous photos. So far I ended up just using the casting flash line and eyeball it -- that would work if I indicated off the bore like you said. The casting flash line goes right up the middle of the thing anyway so I figured it'll be close enough. I have 1/8" (3mm) of material to remove over a 3-inch (75mm) length. It probably won't be "perfect" but it'll be close enough.Thankfully the "big end" doesn't need to be bored through. It does need to be faced off smooth and get a countersink for the cover.
                      Last edited by nickel-city-fab; 05-20-2021, 04:15 PM. Reason: typo
                      25 miles north of Buffalo NY, USA

                      Comment


                      • #26
                        Originally posted by nickel-city-fab View Post
                        ...It's easy to get the bore square on the vertical plane (using already-finished surfaces) but not so easy to get it square in the horizontal plane.
                        I gotta think about this one. Anyone else have ideas how to square it?

                        ...The big question is when viewed straight down upon the part, how to ensure it is not rotated relative to the spindle? Or is this gonna be a case of "cut it and wing it"? Eyeball it and pray for the best?
                        Unless I've missed something, the rotation about horizontal is not that critical since you still have to face the area for the crank cover, right? As long as the horizontal bore's axis intersects the axis of the vertical bore, it shouldn't matter much (assuming MLA left enough extra material for facing).
                        Location: Northern WI

                        Comment


                        • #27
                          Originally posted by Galaxie View Post

                          Unless I've missed something, the rotation about horizontal is not that critical since you still have to face the area for the crank cover, right? As long as the horizontal bore's axis intersects the axis of the vertical bore, it shouldn't matter much (assuming MLA left enough extra material for facing).
                          You may be right. I've already started the boring job. I basically had to eyeball most of it though -- as long as the axes intersect squarely, it should be OK but it still makes me nervous. Just wait till you see the setup pics, it's a screamer.
                          25 miles north of Buffalo NY, USA

                          Comment


                          • #28
                            OK, here's the boring setup I'm using. It's real dodgy, sketchy, mickey-mouse, whatever you want to call it. Less than optimal, but it *is* working. It requires a great deal of care though, to accommodate the limitations of the South Bend lathe. Specifically, the way to top slide is mounted on the cross slide is kinda weak. There is a dovetail plug that is held by a couple of screws and gibs going into the dovetail, instead of having screws coming thru the top of the cross slide. Over hang or stick out is a real bear on these machines. And yet this entire setup is pure over hang and stick out. there isn't nearly enough surface area clamping between all the parts. It works, but its a royal PITA.

                            Click image for larger version  Name:	mla18-11.jpg Views:	0 Size:	703.4 KB ID:	1943255

                            I cannot flip it around the other way on its base because that would raise the center of the bore way too high. And I do not want to chuck it by the OD of the housing even though it would be much easier. It would make it harder to center the shafts with respect to each other even if the job would be easier to setup.

                            Notice I have my boring bar mounted in the 4-jaw. This give me a way to adjust the DOC, leaving the cross-slide alone except for longitudinal feed. Notice in the next pic, I drew sharpie marks on the jaws that I need to adjust. One mark has the arrow pointing to the right, that is the one that increases the DOC. The opposite jaw has its arrow pointing to the left (loosen it). The telescopic gauges say I'm at 1-1/8 (28mm) right now, the drawing calls for 1.250 (say 32mm). The length of the bore is 3 inches (75mm). EVERY single cut requires a spring pass, and checking to measure. I've already had to re-do the setup 4 times, it gets knocked loose easily. I am considering modifying the setup a bit and re-doing it again.

                            Click image for larger version  Name:	mla18-10.jpg Views:	0 Size:	854.9 KB ID:	1943256
                            Last edited by nickel-city-fab; 05-20-2021, 04:17 PM. Reason: yet another fat finger
                            25 miles north of Buffalo NY, USA

                            Comment


                            • #29
                              good work, but I feel your pain, that must be a real drag to machine. Still, you only have to do it once hopefully! Shame you don't have a mill though, would have been pretty straight forward to do with a boring head.

                              Comment


                              • #30
                                Originally posted by mattthemuppet View Post
                                good work, but I feel your pain, that must be a real drag to machine. Still, you only have to do it once hopefully! Shame you don't have a mill though, would have been pretty straight forward to do with a boring head.
                                You actually could do the job on the SB lathe with the MLA-7 boring head. If there was some way to mount the part on the chuck or face plate I'd do it in a heartbeat.

                                I shouldn't really complain. These kits are a great way to get to know your machine, and expand your abilities. I'm currently revising the boring setup a bit to make it more stable (reducing degrees of freedom)
                                Last edited by nickel-city-fab; 05-17-2021, 08:15 PM.
                                25 miles north of Buffalo NY, USA

                                Comment

                                Working...
                                X