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Benchmaster progress

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  • #61
    Had a go at it again, and the taper pin is not coming out of there easily. That's the same as last time. In fact, a previous owner had bunged up the small end (I think) of the pin so badly that I could not even find it. Still cannot, even after filing the bumpy surface, hoping to find a thin dirty line showing the pin.

    Not sure what I will do there. I have it partway apart, but it is not going to be fun. I "think" the end that sticks out is the big end. It is, of curse, down in a hole, so many approaches are just not going to work. Might have to make a slide hammer, don't have one.

    CNC machines only go through the motions


    • #62
      They make slide hammers for pulling dowel pins in flywheels. The pins that locate the pressure plate. The set comes with different size collets.
      You can probably rent one . Around my way Autozone or Advanced Auto have a loaner system. Leave a deposit, use the tool, return for your deposit back.


      • #63

        I bagged that as not worth my time at present, lubed the parts, and put it together again. The entire "quill" with shaft, bearings, gear and all is supposed to come out, but does not. The pin is supposed to come out, but does not. And the pin is about 0.140" diameter at what I think is the fat end. I decided it was not productive to drill, tap, and install a #5 puller screw. It would likely break, and I do not even know that the visible end really IS the fat end.

        Worked on other things instead.
        CNC machines only go through the motions


        • #64
          Looking it up, the pin is a #0 x 0.75, and for a #0, the small end of a 0.75" pin is 0.140" diameter. So the part sticking out is the small end, unless it is just beaten up enough to be that size. The big end is 0.156". So there is a chance that the exposed end is the small end, and if so, someone may have welded the other end in, or just beaten it until it is wedged and burred over to the point it is nearly welded.

          If I could remove the whole quill, I could get some backing and smack that pin harder, but that's a no-go also. It's been in there 70 years, and it likes where it is just fine.

          So I moved onward to planning oil holes for the table, and improving those ugly handles (see last picture above). The handles bug me, because not only do I not like them that much, but also they are things I would be grabbing, and so the finish being rough on the lever part is likely to be scratching me up.

          .That Cubitron belt is still very aggressive even though it seems less rough than when I first put it on some months ago. I was barely able to hold it back, it was eating cast iron fast.I got the handles rapidly to this point, having to be really careful with the edges so as not to eat them away too far.

          I think this looks better than the pic above......

          Painted, they look like this one:

          I do have a plan for the table lube points. I will put holes in from the top, filled with set screws for use, and removed to oil. That's a nuisance, but I did not think ball oilers would be tough enough, even in a recess, and they would collect almost unremovable dirt that might get in. I am putting in discs of F1 felt as a filter, but......

          Another choice would have been ball oilers in the bottom of the t-slots, which I have seen, but I figured that would be just as dirty down there, if not more so, and considerably harder to clean, down in the slot.

          More on that when it is done.

          At least I got it re-assembled to where it was before I took it apart to get at the &^%$#@! bevel gear and its taper pin.
          Last edited by J Tiers; 12-27-2020, 11:05 PM.
          CNC machines only go through the motions


          • #65
            Next was drilling the oil passages, fitting them out, and assembling the table onto the rest of the parts.

            Status so far:

            I put the oiling ports in the middle of the table as far as the table travel (X axis). That way, they are only exposed in the open at the most extreme table positions. They were going to be exposed at some point n the table travel, so that seemed the best place.

            The oil passages were drilled in two different ways. If you look back at post 52, there is a view of the end of the table. The front has a t-slot, the back is plain. So in the back, I drilled straight down through. The top part was made 0.187 diameter, with the last bit 0.106". That gives a sort of oil reservoir, which can be filled up and then capped, letting the oil drain through the felt filter and to the way.

            The front was more trouble. I drilled up a short distance, then drilled through from the bottom of the front-side t-slot back intersecting that hole, to reach past the first top-side t-slot. Another hole was then drilled down to meet that from the top surface, all with a #6-32 tapping size drill. Again, a larger diameter vertical hole was made down to meet the hole drilled from the front. The front hole was tapped in a short distance for a 6-32 setscrew to plug it.

            The tops of the "reservoirs" were tapped 1/4-28, for set screw plugs. (I had some short 1/4-28 slot head set screws).

            Felt plugs were installed at the bottom of the reservoirs, and a the 6-32 set screw put int he front to block oil escaping that way.

            The table was installed, oil was put in the reservoirs, and allowed to drain through to the ways, being refilled several times. Oil seems to be reaching all points that it should.

            The felt plugs, cut with a Roper-Whitney #5 punch from 1/8" "F1" felt.

            The table top, with set screws installed to close the holes I decided that slot-head screws would be easier to clean of swarf so they can be removed to oil the table.

            The front set screw plugging the drill hole at that point. It got loctite on it to seal it.

            Now I need to sort out the drive parts, see about the front pulley cover, electrical stuff, and generally get it running. I do not particularly like the stand, it is an HF stand, acquired for maybe $5 at a sale, and it rings like a bell, even with the moll on top. I could install a shelf, and some sides, which would probably damp the ringing down a bit, unless I just put the mill on a different base. The stand rings if you just stand nearby and clap your hands..... I expect it to be stupidly noisy unless thoroughly damped somehow.

            I will probably find some things which I do not like, and may have to disassemble to fix them. I still need to sort out the matter of a piece of rubber for a shield at the back of the table. Works on the other mill, but despite limited "daylight" under the head, this mill has taller column and ways, so there is a lot of rubber to go somewhere when the knee is up at the top of its travel.
            Last edited by J Tiers; 12-28-2020, 09:34 PM.
            CNC machines only go through the motions


            • #66
              here is a view from the back of the table You can still see some marks, either from scraping, or from planning the oil passages.

              And that reminds me that some paint would not hurt parts of the mill......

              I still have a good bit to do, electrically, and also just getting the thing checked out in use, getting the table and other slides working smoothly, etc. Also getting the drive to not be so ugly. The motor mount is actually a steel cover from some scrap electrical wiring channel. It needs to be at least painted, if not replaced eventually.

              It probably needs some way wipers for the saddle, especially in front, as well as the swarf shield, etc that I am still considering. I also had a "brilliant idea" for a lubricator to easily lube the table screw, which is always hidden from view. I have to see if it will work.

              But the big job, the "stopper", getting the ways scraped and all the table parts installed is done, the rest is cleanup. I have to go out of town, and may not get to that for a while.
              Last edited by J Tiers; 12-28-2020, 09:47 PM.
              CNC machines only go through the motions


              • #67
                I have my drill press on one of those HF stands. It buzzes like a bastard. I put a tight fitting plywood shelf in, that made the buzzing worse. I cut the corners off the shelf and that helped a little bit.


                • #68
                  well, THAT is not encouraging. But I was also going to put side pieces on it, which seemed to do more toward damping the ringing when I just held stuff up against the legs. That may do oit

                  I have another stand, that is of welded steel, and currently has a shaper on top of it. I have a wood base for the shaper, which needs to leave anyhow, so I might need to set up a shop gantry and get that shaper lifted off the stand. I have a half ton chain hoist, but have not set up a frame yet. Then that stand would be an option for the mill.

                  We'll see about that.

                  Since putting it all together for checking, I had a bit of fun (??) looking the thing over and getting all the gib screws set up. The knee-to-column gib screws are too short, they need another 1/16" at least to let the jam nuts be correctly fitted. I checked around with all the other screws, and found that I already had the longest ones in place. I was having a problem with what the dickens was going on.....

                  Then I realized the problem.

                  I had scraped the slides, and I did quite a bit of adjustment on the knee and column. I will need to get some longer screws, the missing length is taking up the scraped material! A little scraping on a dovetail means nearly half again the distance across the two dovetails. I scraped three dovetail surfaces (#4 is a gib), so I have three worth of dimension change, plus scraping the two contacting flat ways as well, which also adds extra space, as it moves the dovetail surfaces apart.

                  Actually, the better approach would be to make another gib that is somewhat thicker. That would probably be a bit more elegant, as well as being more secure.
                  CNC machines only go through the motions


                  • #69
                    looking over the thread, there are things that need to be filled-in.

                    For instance, it appears I failed to show the X and Y-screw bearings. These bearings are pretty simple.There is a collar on the screw, which appears to be a separate piece threaded on, which is steel and rides on the inside of the casting in a recess.

                    This is the table bearing plate, but both are similar:

                    The collar at left on the screw, fits into the recess shown in the plate, but is not a close fit in the recess. The smaller diameter on the bearing part to the right, fits a similar recess. It is adjusted by turning it, as it is screwed onto the mounting threads of the screw. But it takes radial forces on the ground smaller OD, and thrust on the face of the larger OD portion. The screw collar takes outward thrust forces along the screw. It is steel on cast iron for all bearing surfaces, and there is no provision for lubrication other than the "drip and hope" method.

                    The separate bearing part has a set screw (visible), which tightens down on the screw threads to hold the bearing adjustment. You want to put in a piece of brass or copper under the set screw to keep from chewing up the threads.

                    I decided to add bronze thrust bearings and oilers. But the available sizes were too big on the OD, so I got ones at a local hardware store (not having them shipped at Christmas), and cut them down.

                    Mandrel, stock size bearing, and trimmed down bearing:

                    Bronze in place for the screw collar. I put another one on the outside, under the separate bearing piece for the X screw bearing, to ride on the outside face of the plate, but did not do that on the Y, there was not enough room on Y, where the bearing is in the knee casting, and not in a separate piece.

                    The oil hole inside the bearing for the X-direction screw bearing. The one in the casting is similar. In each case, I drilled the hole to a larger size on the OD just deep enough to take the ball oiler, which is visible for both positions in photos above. The ball oilers I used were 3/16" OD, and about 0.3" long. Just barely fit in the plate.

                    Last edited by J Tiers; 12-29-2020, 02:25 AM.
                    CNC machines only go through the motions


                    • #70
                      The plate assembly, seen from the bottom, without the bronze for the outer bearing. The dial has to fit between the hole in the shaft and the face of the plate. The skirt of the dial goes over the bearing and set screw. I could cut the dial down to fit for the plate (X direction) but not for the Y.

                      The bronze fit between the collar with the set screw, and the extended part of the plate, but was not in place for this photo.

                      The hole takes a #000 x 0.75 taper pin. One of them I had to ream for a #00, since I had no 000 size, and the old one was very bunged up. The pins double as the dog clutch for the cranks.

                      A typical slug of soft metal (looks to be copper) to protect the threads. Goes under the set screw, you can see that the threads have cut into it a bit.

                      Last edited by J Tiers; 12-29-2020, 02:25 AM.
                      CNC machines only go through the motions


                      • #71

                        In your discussion of a rubber shield behind the table, it sounds like you're thinking of a long piece to cover the front-to-back and top-to-bottom at the lowest and furthest forward positions.

                        Have you considered just a short piece for front-to-back with the back edge clipped to the back end of the knee? The vertical expanse won't collect chips as badly, except for what sticks with oil, and the vertical ways could be protected with wipers.
                        "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill


                        • #72
                          I really had not considered that. It could be done, and wipers would be good, I might have put them on even with the rubber piece. Might also put them on the front of the saddle, I did with the other mill, which has a rubber strip to the top of the column ways.
                          CNC machines only go through the motions


                          • #73
                            I have been pleased with this type of cover on my mill:

                            Don't take up much space when compressed.



                            • #74
                              Do those default to retracted? That's the issue with most things, they need to be forced to compress, and always seem to get pouched up.

                              Also, when they DO retract, they might tend to block movement, being that they are then pretty much a block of material. Like at top of travel, and all the way toward the column.

                              Might be good, though
                              CNC machines only go through the motions


                              • #75
                                Had a fun time today when I noticed that just about all of my t-nuts for that size slot would NOT move freely in the Benchmaster slots. They work everywhere else that I use them, but not in the Benchmaster.

                                It seems that the slots were cut a bit roughly, and have burrs that catch on the t-nuts if they are at the 0.375" nominal size. Even after a fair bit of filing to clean them up, there were spots that would pass 0.372", but jam hard at 0.375". Still not right, I decided it was easier to file down some half-hard t-nuts a couple thou than to get the "fat spots" off 42" of total slot length.

                                Also re-checked the table alignment. It is showing to not be quite as good as it measured on the knee, when the column ways are the reference. At some point I will check into that.
                                CNC machines only go through the motions