Announcement

Collapse
No announcement yet.

Back to Steam--

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

  • Originally posted by brian Rupnow View Post
    Bob_s--I may try that. I have a couple of spray cans of silicone for waterproofing leather coats. I wonder if that would work?
    I think that stuff is more of a sealant like clear RTF than a lubricant.

    The stuff that I'm using is marketed by the makers of WD40/3in1.

    Test it by taking an o-ring and a piece of scrap aluminum sheet, spray and allow to dry. Then check to see if the o-ring is stuck or not.

    Comment


    • I have reached the limit of what I can do in my milling set-up. The remainder of material to be removed will be done with bandsaw and file.
      Brian Rupnow

      Comment


      • So---we have one reversing link finished. All of the holes and centers of radii are exactly where they should be. The arc is exactly where it should be. Sid was right, cutting the 0.156" wide arc with a 0.156" endmill held in a drillchuck is not accurate---The slot ended up at 0.165" wide. This does not pose a problem for me, as I am the one who makes the "follower" that runs in the slot. When I do the second link, I will hold my 0.156" endmill in a collet and see if that yields anything different.
        Brian Rupnow

        Comment


        • Usually, it is not good to try to cut an on-size slot with an exact size end mill. It rarely works out as expected, although it is possible to get lucky.
          1601

          Keep eye on ball.
          Hashim Khan

          Comment


          • For what it's worth---I cut the arced slot in the second part with my 0.156" four flute endmill held in a collet. The slot measures 0.161" wide. When I cut the slot in the first part with the same endmill held in a chuck, the slot came out at 0.165" wide.
            Brian Rupnow

            Comment


            • And now there ate two. Not nearly as much drama with the second one.
              Brian Rupnow

              Comment


              • They look good.

                I'm not surprised they are that close in size (0.161 vs 0.165). That is an off-center of a couple thou. Despite the dire comments, drill chucks of a decent make are rarely out very much, especially if they are ones made to take a range including small (1/16") drills.
                1601

                Keep eye on ball.
                Hashim Khan

                Comment


                • Originally posted by brian Rupnow View Post
                  For what it's worth---I cut the arced slot in the second part with my 0.156" four flute endmill held in a collet. The slot measures 0.161" wide. When I cut the slot in the first part with the same endmill held in a chuck, the slot came out at 0.165" wide.
                  I have read many times that cutting a slot with a on-size endmill should be done with a 2 flute endmill because it will come out oversize otherwise.

                  Comment


                  • I have heard most of the conventional wisdom about two flute versus four flute, holding endmills in chucks, etcetera. I believe 99% of it, unless personal experience shows me something different. Some of the things I've heard, I haven't yet had the opportunity to verify.
                    Brian Rupnow

                    Comment


                    • Originally posted by brian Rupnow View Post
                      I have heard most of the conventional wisdom about two flute versus four flute, holding endmills in chucks, etcetera. I believe 99% of it, unless personal experience shows me something different. Some of the things I've heard, I haven't yet had the opportunity to verify.
                      As with most of everything in this trade, there is a "theoretically perfect" way of doing everything. There are also about 10-30 OTHER ways of doing it that will also net acceptable results. Sometimes you just work with what you got, and give it your best shot. It looks to me like you're doing that. Nice job. I enjoy watching your projects come together Brain, thanks for sharing.

                      And by the way, while not "proper" and under the category of "your really shouldn't do this if you can help it". Holding endmills in drill chucks has been done, and will continue to be done for years. Sometimes it's all you got, sometimes, it's just not worth cranking the knee up/down to change tooling when space is tight. Even more so with smaller cutters down in tight pockets. It's not like you're hogging a channel out with a corncob.

                      Another handy trick is to keep an assortment of undersized endmills around. A 0.480 end mill is pretty handy for cutting a 0.500 slot.

                      Comment


                      • This is a very well done assembly video of the engine I am building. The reverse mechanism has a few minor differences, but the video is amazingly well done.
                        https://www.youtube.com/watch?v=M9r7gw-XxIc
                        Brian Rupnow

                        Comment


                        • Okay, it's time to ask for an opinion. I am going to require a total of four eccentric strap assemblies. Two with straight rods connecting the ends and two on which the rods have a 1/4" offset. In the normal course of affairs, I would thread everything and screw all the pieces together. Although they look huge in this picture, they are only 1.646" center to center. I have a fixture to mount everything on at the exact centers required, and it is imperative that all four center to center distances are exactly the same. I'm thinking to myself "Why not set them up one at a time in the fixture and silver solder the rods to both ends?" The only adjustable thread required would be on the rod which passes thru the valve nut, to center the valve for timing the engine correctly, and the rotational position of the eccentrics on the crankshaft. Opinions please.---Brian
                          Brian Rupnow

                          Comment


                          • Fixturing them would be the best method.
                            Jim H.

                            Comment


                            • The soldered joints will contract on cooling. You may want to make a half pin for the upper clevis that's a slip fit in the fixture hole. To solder, have the flat facing the center of the fixure, then after cooling, turn the pin 180 degrees to relieve the pressure and get the parts off more easily.
                              Kansas City area

                              Comment


                              • I really do try to make something each day. Some days it's not much. These little guys are destined to become drag links.

                                Brian Rupnow

                                Comment

                                Working...
                                X