Announcement

Collapse
No announcement yet.

bought a new part, but wait! I have to machine it??

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

  • bought a new part, but wait! I have to machine it??

    Ok everyone,

    Have you had this happen to you?

    I bought a replacement input shaft for a gear box. A little 19-1 gearbox that handles 0.50 HP. Not a paticularly big one. I call GBS and Motion Canada. They both can get me the part. GBS could get the part one day sooner. So GBS it is.

    Pick up the shaft, check the diameter of the shaft landing and OOPS. It is an oddball size? We all measure, and the manager tells me,

    "Nope, we don't have that bearing, and i have never seen it!"

    What? Call the supplier and the tell us it is even smaller then the bearing we think it is.

    To be exact. The outside of the bearing was 1.875. The inner race measured 0.787 (20 mm). Well the shaft measured 0.800 (20.32). The supplier said it was a 0.669 (17mm).

    Drive back to my shop and machine off 0.012. Here i was thinking i was getting a replacement part. A little frustrating. If i had had everything delivered directly to my customer i would have looked like an idiot trying to press this all together.

    Has stuff like this happened you?

    Rob

  • #2
    I'm a TV engineer in real life, not a machinist. But we buy parts too.

    I worked at a UHF station in Florida some years ago and they used tubes called klystrons in the transmitter. They are about five feet high and operate at about 5,000to 10,000 Volts and 5 to 10 Amps. (25 KW). Each one would last a year or two and then had to be replaced or moved to lower power service. I ordered one one fine day - oh did I say they cost about $20,000 each. It came in and I installed it in the transmitter. Turned power on and POW, instant 25 KW short. Check everything very carefully and try again. POW again.

    Major sweat factor as I am wondering what I may have done wrong to destroy a brand new tube. And how/what am I going to tell the station manager.

    Long story short, I called the manufacturer and they have me perform a very simple test with an Ohm meter. Sure enough, it is shorted. They send another one out and it works perfectly. I return the bad one and they open it and find a washer that dropped inside it during manufacture. The washer probably sat in a harmless position during factory tests and tuning and was bounced around during shipping to cause a short. But like I said, major sweat factor until I found it was a factory mistake and not mine.

    I shouldn't have worried about the station manager. But that's another story and you'll have to get me very drunk to hear it.
    Paul A.
    SE Texas

    Make it fit.
    You can't win and there is a penalty for trying!

    Comment


    • #3
      Paul - reminds me of when I used to work on shipboard radar systems. The craziest little things can cause those high voltages to wander around the chassis. I do miss it, though

      Comment


      • #4
        I helped a friend wire the house he was building on the beach in SC. I was amazed at how quickly anything made of copper turned green and slimy in the salty air, even with the house dried-in and closed up.

        I can't imagine how you can maintain anything electrical or electronic on board a ship without going nutso.

        I suspect they have special clean rooms for some work, but how do they cope with it where they can't control the environment?

        Roger
        Any products mentioned in my posts have been endorsed by their manufacturer.

        Comment


        • #5
          Purchased a part from International Harvester several years ago. Hydrualic pump coupling. cost $495. Four inch OD 5/8 thick 1-1/2 ID with splines. Three 5/16 mounting holes 120 degrees apart. One hole miss drilled bolt would not in....returned to dealer (160 miles round trip) they had 4 in stock. All had the same flaw...It took seveal gringing stones to get the bolt to go in. Had been doing business with this dealer for over 20 years...Think i got a discount on that part...HA!!!!
          Gary Davison
          Tarkio, Mo.

          Comment


          • #6
            It is not at all unusual for a manufacturer to have nonstandard bearings manufactured for them. An oversized bore is the usual modification.
            Jim H.

            Comment


            • #7
              "I shouldn't have worried about the station manager. But that's another story and you'll have to get me very drunk to hear it."

              Yes, must be typical in the industry.

              My chief (engineer) constantly sipped malox from a small
              bottle he carried on him at all times. He refilled it from a large
              gallon size he kept in his desk.

              My t.v. friend (I ran the radio side) came in one morning, same
              as always for 30 years, warmed up the tube (3.5 mwatts uhf)
              at 5:30....6:00 rolls around, same as every other day...
              Look in the window at said big tube...lean in to push
              the plate on button (have to push quite hard and hold it while
              3 separate contactors slam in).

              BBBZZZPT....

              Some one the night before left the grounding hook on the
              plate supply (in the tube chamber) while working on the xmitter.

              Apparently this was flying 'round inside...

              There was shortly installed a microswitch for said grounding hook,
              registering if/if not the hook was put in it's holder.

              Ah yes fun at $5.00 an hour (1985)

              Comment


              • #8
                Once had to pay three times the normal cost for some Torrington "Needles", the usual bearing store would have had to order 3000 "Specially", only wanted 120, so I was forced to go to the Mercury spares supplier. They were in the catalogue and didn't have an X in the ref.

                Regards Ian
                You might not like what I say,but that doesn't mean I'm wrong.

                Comment


                • #9
                  You Guys haven't lived untill you get involved in building hotrods and buy an aftermarket "Bolt on" part.--True, they might bolt onto something, somewhere, ---but they sure as Hell don't "bolt on" to the things they were advertised to bolt onto.---Brian
                  Brian Rupnow

                  Comment


                  • #10
                    Oh but Brian,

                    That is where i startred. Drag racing and tuning my engine at the track. Should we talk Headers or tansmition flanges? How about flex plates? Clutches? Any my favorite....carburator lines and cables!

                    It would proabably be easier for you to design what you need and get it made!

                    Rob

                    Comment


                    • #11
                      Originally posted by brian Rupnow
                      You Guys haven't lived untill you get involved in building hotrods and buy an aftermarket "Bolt on" part.--True, they might bolt onto something, somewhere, ---but they sure as Hell don't "bolt on" to the things they were advertised to bolt onto.---Brian
                      Custom bike accessories,you know the aftermarket "billet" crap.

                      Chrome plated parts where the threads have closed clearance and now the threads won't fit.

                      Chrome parts that need re-chroming out of the box cause it's flaking off.
                      I just need one more tool,just one!

                      Comment

                      Working...
                      X