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Cylinder square now with more lathe

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  • #16
    Have you thought of setting the stone in the lathe toolpost and very gently honing it that way?

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    • #17
      Originally posted by old mart View Post
      Have you thought of setting the stone in the lathe toolpost and very gently honing it that way?
      Yes I did think of that but I'm not sure I want to risk the work I've already done -- -- The lathe setup is pretty marginal with this workpiece, not a good grip and not very true... I suppose I could use the tenths indicator on the OD but frankly I just don't trust the lathe enough for that. The chuck jaws barely grip on the ID... the cross-slide is nice and solid though... will have to think about it. The faces of the chuck and jaws etc are in no way square, so I can't count on them for anything.

      EDIT: Nope, that was an exercise in frustration. Will go back to the old method of lapping and checking on the surface plate.
      Last edited by nickel-city-fab; 02-23-2020, 04:51 PM.

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      • #18
        Originally posted by RB211 View Post

        Cool
        ... and just for you, Things are getting interesting again... Finally! Pics show my "roughing in" setup. I put sharpie marks every 90 degrees along the top of the cylinder. The indicator does not move between 0 and 180 degrees, about halfway up the height of the cylinder. HOWEVER, at 90 degrees to this plane, it is off by a thou. SO, I will rotate the cylinder 90 degrees and lap it in that direction and continue.

        As soon as this indicator reads zero all around, I will switch to the test indicators and start chasing tiny numbers. Pics: Click image for larger version

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        • #19
          Coolness! I just got it to where the indicator reads the same all around! (Whew, that was a lot of work...) my main motivation was saving the money over buying one... now its time to switch to a finer indicator, say .0005. I think I'll stick with the Federal indicators for now and get out the Compac DTI later.

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          • #20
            Well DONE! I bet you get that .0005 indicator out within days, just to see how good it really is.

            Dan
            At the end of the project, there is a profound difference between spare parts and extra parts.

            Location: SF East Bay.

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            • #21
              That's some really nice work you've done on it. I think it was Suburban tools or Tom Lipton that lapped stuff like this with a weight on the high side to bias the lapping. Something to consider. That way you can focus on doing nice smooth pushes around the paper from down near the bottom of the cylinder.

              Of course it's actually usable now. But it's nice to play with and get it really close just to impress the ladies....
              Chilliwack BC, Canada

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              • #22
                what wrist pin is it and how tall?

                newer mind, i found the other thread. but Fairbanks-Morse Z-series seems to be a 6 hp engine? such a big pin?

                i have frequently searched ebay for wrist pins, but i never know how big they are. is there a good one out there now?
                Last edited by dian; 02-26-2020, 01:58 AM.

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                • #23
                  Originally posted by BCRider View Post
                  That's some really nice work you've done on it. I think it was Suburban tools or Tom Lipton that lapped stuff like this with a weight on the high side to bias the lapping. Something to consider. That way you can focus on doing nice smooth pushes around the paper from down near the bottom of the cylinder.

                  Of course it's actually usable now. But it's nice to play with and get it really close just to impress the ladies....
                  Yep, that is exactly what I've been doing. I found out that the job goes a bit faster with diamond stones because this pin is so hard. So I got the set of 3 diamond plates at Harbor Freight an push down on the high side, using the other hand on the bottom, and lots of honing oil.

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                  • #24
                    Originally posted by dian View Post
                    what wrist pin is it and how tall?

                    newer mind, i found the other thread. but Fairbanks-Morse Z-series seems to be a 6 hp engine? such a big pin?

                    i have frequently searched ebay for wrist pins, but i never know how big they are. is there a good one out there now?
                    Yes, the same seller has a bunch of them , they are for an 18 HP engine. They are about $20 each and they weigh about 2 lbs (1 kilo) Here's the listing: https://www.ebay.com/itm/Sealed-Powe...-/184067517657
                    Last edited by nickel-city-fab; 02-26-2020, 04:35 AM.

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                    • #25
                      Originally posted by danlb View Post
                      Well DONE! I bet you get that .0005 indicator out within days, just to see how good it really is.

                      Dan
                      Actually got it out now, chasing 0005. Couldn't sleep, it's been too warm lately (45F).

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                      • #26
                        thanks. they seem not to be shipping overseas. do you think this is any good:

                        WRIST PIN Pt# 7N-9803 CATERPILLAR

                        https://www.ebay.com/itm/CATERPILLAR...AAAOSw6eleIyF7

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                        • #27
                          I've got the Fairbanks-Morse pin from the same seller on Ebay. It is 2.5" in diameter by 6" long. Both ends are not ground and it needs to go on my 12" lathe to form a relief at the ID and true the face up. Unfortunately this setup would require a steady rest and its current fingers are too long to accept a 2.5" diameter part. Now I have to make new shorter fingers. It is a never ending process...

                          I may also decide to try lapping the OD of the pin before going to the face. Never did the OD lapping, should be interesting.

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                          • #28
                            Originally posted by dian View Post
                            thanks. they seem not to be shipping overseas. do you think this is any good:

                            WRIST PIN Pt# 7N-9803 CATERPILLAR

                            https://www.ebay.com/itm/CATERPILLAR...AAAOSw6eleIyF7
                            I looked it up, and it says its 1.5" (38mm) dia and 3.2" (80mm) long. Cat parts tend to be premium quality. Your call if its a large enough size.

                            Maybe you could also search for "Detroit Diesel series 60 piston pin" those are about 38mm dia (1.5 inches) but they are around 4" long (100mm). The Detroit pins have a row of holes tapped on one side and the ends are very non-square, but the OD is very straight and true. The Detroit pins were very common in e.g. marine engines so they should be easy and cheap to find.

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                            • #29
                              Originally posted by mikey553 View Post
                              I've got the Fairbanks-Morse pin from the same seller on Ebay. It is 2.5" in diameter by 6" long. Both ends are not ground and it needs to go on my 12" lathe to form a relief at the ID and true the face up. Unfortunately this setup would require a steady rest and its current fingers are too long to accept a 2.5" diameter part. Now I have to make new shorter fingers. It is a never ending process...

                              I may also decide to try lapping the OD of the pin before going to the face. Never did the OD lapping, should be interesting.
                              Yeah I thought about doing the OD and decided it wasn't necessary, mine is extremely true and round and it shines like a mirror -- so I decided to leave well enough alone. Turning it in the lathe required a new solid carbide boring bar because they really hardened them.

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                              • #30
                                thanks, 6" would be the minimum to look at, i guess. i wrote the seller if he will ship it anyway, so well see. (i have bought writs pins before, but they always turned out smaller than i thought.)
                                Last edited by dian; 02-26-2020, 11:29 PM.

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