Announcement

Collapse
No announcement yet.

What did you screw up today?

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

  • #61
    Originally posted by nc5a View Post
    /QUOTE]

    Ditch the high rake on the tool, small wonder it chattered.
    I bet it was loud (-:
    If you do a lot of such work Kaiser/Thinbit make excellent modular insert tooling.
    http://www.thinbit.com/products/face-grooving/index.php
    Hey, thanks for the tip Bented. I had no idea there was such a selection of trepanning tools. I didn't check prices yet but I'm certain they would be quite spendy and very likely out of my price range but I will check just in case.

    With regard to the high rake and chip breaker trepanning tool I made. The one shown in the photo was my last attempt at tool profile to minimize the chatter and it actually worked quite well. It still chattered a bit but much less than my other profiles. Thanks for the link to Thinbits.

    [/QUOTE]

    If you ever try it again, keep the top rake and instead of getting rid of that, reduce the end clearance a bit. The top rake will reduce cutting forces but tend to make the tool bite in and self feed; the reduced end clearance will prevent it from getting too much of a bite so that it doesn't want to bounce.

    Comment


    • #62
      well. my hss trepanning tools have a rake of 25° and a relief of 10°. i think the trick is to have a draging setup.

      Comment


      • #63
        Sorry to be ignorant but what is a draging setup?
        I have trepanned several times, with some success, but it was never an enjoyable experience, just something to be endured.
        'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

        Comment


        • #64
          Originally posted by The Metal Butcher View Post
          I was doing some more work on my senior design project and blew the dimension on a 1" diameter of a 4.5: part. I will blame it on being distracted helping others. :P

          I decided to try to weld it up to save the piece. Well, I was woefully unprepared for how much heat it took to puddle 1" aluminum. I was at 60% of the dial in high range on the 330A/BP, so that's somewhere north of 300 amps. I got most of it built up when everything went quiet and my tungsten caught on fire. I'd popped the 50 amp breaker. I knew that would be an issue, but dad wasn't going to do anything until it happened. Well, it has now. I tried again after letting it cool a bit, but didn't make it far before it popped again. I went ahead and roughed out a 6th part as I don't know if my welding will be successful and a 2nd spare doesn't hurt. Took less time than the welding did...

          Any recommendations for keeping fumes away? Even just aluminum I felt kinda weird afterwards. Part of it is that I just get so damn nervous tig welding. I need to do it a lot more to calm my nerves. Or use the Russian approach...

          No pics as my welds look like crap.
          Back in the early 80's I knew a profession aluminium welder who almost died from breathing the fumes. He did a LOT of welding and I don't know if he eschewed wearing a proper mask or if he just thought it was no big deal to not wear one. Either way, he breathed in lots of fumes with the resulting problem. It's one of those things to be very careful of.
          Location: Saskatoon, Saskatchewan, Canada

          Comment


          • #65
            Originally posted by Richard P Wilson View Post
            Sorry to be ignorant but what is a draging setup?
            I have trepanned several times, with some success, but it was never an enjoyable experience, just something to be endured.
            cutter slopes down from above centerline to give it some flexibility.. similar to a "goose neck" parting tool holder.

            Comment


            • #66
              There is metal fume fever, trust me it’s real, not a made up thing, can lead to heart problems, ( I had 3 heart attacks before 50),
              get an air fed shield, it really helps
              plus I found a bit of music helps, the Hf buzz can cause nausea and dizziness
              mark

              Comment


              • #67
                A run of 20 parts today, 410 stainless.
                The small diameters are .1969" +.0000 -.0005, the first two came out small before I got the set up tweaked.
                For small parts always have extra material before you start as the first or second part will not likely be correct (-:

                Comment


                • #68
                  Is the bladed mic for getting into the lands by the shoulders? Were these done manually? Nice work.
                  Btw, I have trouble calling these screw ups. I'd call them "warm ups😁"

                  Comment


                  • #69
                    I have a paslode trim gun that I've been repairing. In this journey I broke the blade. It's the small piece that does the actual driving of the trim nail. It is a very thin piece of hardened steel and I figured I'd try to torch weld it. Wasted 2 hours until it went into the round file. I had not much else going on but a rare win sure would have been uplifting.

                    Comment


                    • #70
                      Story of my life. Just look at the number of my last post.....

                      Comment


                      • #71
                        Originally posted by challenger View Post
                        Is the bladed mic for getting into the lands by the shoulders? Were these done manually? Nice work.
                        Btw, I have trouble calling these screw ups. I'd call them "warm ups😁"
                        For measuring the under cut that has a 3 decimal diameter and a .020" radius. The blades are .015" thick carbide and are frighteningly easy to break, bought it from MSC last year for about $225.00
                        A CNC lathe. Someone else has to drill and tap each end M3-.?? so I made a few extra (-:

                        Comment


                        • #72
                          I don't even know where to start. I spent HOURS putting together a press for squeezing cured silicone through a die so I could cut it into bits and recycle it. WAY TOO much time was spent chasing the problems with a cheap 2 ton bottle jack. The final straw came from hydraulic oil spraying my entire front quadrant. It was a terrible day from a, "one step forward", standpoint. Click image for larger version

Name:	PXL_20210207_163954088.jpg
Views:	355
Size:	3.77 MB
ID:	1926790 Click image for larger version

Name:	PXL_20210207_163947753.jpg
Views:	341
Size:	3.96 MB
ID:	1926791

                          Comment


                          • #73
                            The bull gear on my 14" Logan uses two pins, but only came with one. Awhiles back, I bought a second pin from Logan and some .026" spring steel wire from McMaster, and yesterday I decided to install the new pin.

                            Removing the bushing that houses the pin took a soaking in Kroil (through the set-screw hole in the handwheel), then driving a tapered (well, OK, chamfered) oak dowel into the bushing and using a tommy bar through the dowel to pull it and the bushing out. It took a few tries (and about 2/3 of a foot of the wire) to figure out how to get the wire through the slot in the bushing with the pin in the bushing. Got the spring and the pin in, put the bushing back in its hole in the handwheel, tightened the set screw ... and the pin doesn't move. Aligned the working pin with the bull gear, and tapped the new pin with a punch. That got it to engage the bull gear alright, by driving the bushing in further. Now neither the pin nor the bushing can be pulled out, even with the sinful use of vise-grips.

                            Going to fabricate a puller when I am in the shop later. Hoping I can get the pin and bushing out without having to destroy the pin. Until I do, it's high-gear only.

                            Comment


                            • #74
                              While successfully changing the drive belt on my ENCO 13x40, I decided to enlarge the rear spindle opening in the end cover so I won’t have to take of the 5C draw bar detent piece from the spindle just to do gear changes. The cover is 1/4 aluminum and I used a 4” bi metal hole saw in a 1/32 > 5/8 Chinese keyless drill Chuck. As I was cutting in back gear on the mill I noticed the saw hesitating a few times and wondered if I was possibly spinning in the R8 mill spindle. That was tight and OK. I started cutting again and saw a few more pauses but I got through and was happy with the cut. When I tried to remove the 1/2”, 6 sided, hole saw adapter from the drill chuck it was very tight and I put a 14” pipe wrench on it and held the spindle brake while still in back gear. It seemed to loosen up easily enough but then the saw adapter was still held tight in the Chuck jaws.

                              Long story short...the left hand screw piece in the chuck, separated from the slotted flange that holds and moves the 3 jaws. After I disassembled the Chuck I saw it was so twisted up in there I just took it off the R8 shank and tossed it. I ordered a Taiwanese chuck from Discount_Machine on Ebay.
                              Illigitimi non Carborundum 😎
                              9X49 Birmingham Mill, Reid Model 2C Grinder, 13x40 ENCO GH Lathe, 6X18 Craftsman lathe, Sherline CNC mill, Eastwood TIG200 AC/DC and lots of stuff from 30+ years in the trade and 15.5 in refinery unit operations. Now retired. El Paso, TX

                              Comment


                              • #75
                                Click image for larger version

Name:	02299986-E6E8-4AE5-8E9E-0A2811715523.jpeg
Views:	416
Size:	879.2 KB
ID:	1928407 I really don’t want to talk about this........
                                I cut it off twice; it's still too short
                                Oregon, USA

                                Comment

                                Working...
                                X