Cutting a Double Start Acme Thread

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  • เผยแพร่เมื่อ 28 ม.ค. 2025

ความคิดเห็น • 43

  • @JeremiahL
    @JeremiahL 3 ปีที่แล้ว +3

    Awesome. Do you just get the rough dimensions for your acme cutting tool from machinery hand book? How do you grind something like that, and get it close enough that you can match the thread form with confidence? Thanks for the video.

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +7

      They make thread gages for acme threads just like the ones for unified national/ISO threads (60 degree thread form). They are used in much the same way. Grind a bit, check the angle, grind more, check, get really close, check, make a small adjustment and screw it all up, curse a bunch, start over. The big difference is that acme threads have a wide flat on the end of the thread that is very different in size depending on thread pitch. Actually, UN/ISO threads have a flat too, but it is quite small and you can get away with using the same tool to cut multiple thread pitches. Not so with acme threads. The acme thread gage has numerous notches on the sides to help you grind the correct flat. If I get a chance, I'll shoot a short video on it. Great question! Thanks for watching!

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +3

      Hi Jeremiah. I put up a video showing the acme threading gage. You can find it here:
      th-cam.com/video/K0mcGgGS5m0/w-d-xo.html

    • @JeremiahL
      @JeremiahL 3 ปีที่แล้ว +1

      @@StuartdeHaro i saw it. Perfect explanation. Thank you

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +2

      @@JeremiahL you're very welcome! Thanks for the question.

  • @robertoswalt319
    @robertoswalt319 3 ปีที่แล้ว +4

    Those features on the Monarch have to be incredible to use for production runs.

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +1

      It is really fantastic.

  • @bwcordes
    @bwcordes 3 ปีที่แล้ว +5

    Another terrific video. I'm really looking forward to Mondays since you've started releasing videos once a week.

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +3

      I'm starting to feel the pressure actually. I've got one more scheduled and one being edited right now. Then I've got to start filming like a madman.

    • @bwcordes
      @bwcordes 3 ปีที่แล้ว +1

      @@StuartdeHaro I can imagine. Have you thought about doing some live streaming like Richard Holdener does? Maybe a video every other week and a live stream on the off weeks? Either way, keep the content coming. I've been watching a ton of machining videos since you have started this.

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +1

      @@bwcordes I've thought about it. I'm not sure I'm properly set up for it though. I'll look into it.

  • @joell439
    @joell439 2 ปีที่แล้ว +1

    Fascinating approach. Thanks for sharing 👍👍😎👍👍

  • @stevechambers9166
    @stevechambers9166 3 ปีที่แล้ว +2

    Nicely done 👍👍👍👍

  • @garymucher9590
    @garymucher9590 3 ปีที่แล้ว +1

    Interesting concept and great video. Thanks for the info. Thumbs Up!

  • @mchiodox69
    @mchiodox69 3 ปีที่แล้ว +1

    brilliant. Nicely done!

  • @greglaroche1753
    @greglaroche1753 2 ปีที่แล้ว +1

    Interesting video. Thanks!

  • @1SirAnthony
    @1SirAnthony 3 ปีที่แล้ว +2

    Good video.

  • @nadam35
    @nadam35 3 ปีที่แล้ว +1

    excellent video!

  • @RalfyCustoms
    @RalfyCustoms 3 ปีที่แล้ว +1

    Wonderful stuff, very well done, thanks for sharing, new sub here

  • @turningpoint6643
    @turningpoint6643 3 ปีที่แล้ว +1

    Nicely demonstrated and impressive that Monarch will cut a thread pitch that coarse. It should be mentioned that for more standard, lighter weight lathes most at the hobby level will have it's not recommended to cut any threads per inch coarser than the feed screw pitch is due to the stress put on the gearing components. It can still be done by hand or with an add on independent power feed by back driving the lathes spindle and part with the feed screw. Chaddock's book Building the Quorn tool grinder details the problem and his solution. In his case he was thread milling a part with a 1 tpi pitch using a manual lathe with an 8 tpi feed screw.

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +1

      Interesting. I've never heard that. The Monarch will cut down to 1.5 TPI with a 4 TPI leadscrew. I'm pretty sure my lathe at home will do 4 TPI and it has an 8 TPI leadscrew and it is pretty light.

    • @turningpoint6643
      @turningpoint6643 3 ปีที่แล้ว +1

      @@StuartdeHaro I've read it in a few older books written in the U.K. And those were from well respected authors so I'd assume there's something to it. And most lathes with change gearing there thread charts I've looked at never seem to list any thread pitch less than the lead screw pitch. More industrial type lathes are a different animal though. Hardened and ground helical gearing will obviously take a lot more than the light weight spur gears mine have.

    • @highpwr
      @highpwr 3 ปีที่แล้ว +1

      @@StuartdeHaro My home lathe has an 8 TPI lead screw as well and will cut 8 different threads between 4 - 7 TPI. The key words here are '_older books_'. South Bend's book "How to Run a Lathe" caused me quite a bit of grief when I first tried single pointing threads on that lathe. Following the information in that "older book" on using the threading dial was a disaster when applied to my more modern lathe. Using the chart in the owners manual however works just fine.

  • @jeffanderson4979
    @jeffanderson4979 ปีที่แล้ว

    Great video. Clean the Monarch.

  • @chrisstephens6673
    @chrisstephens6673 3 ปีที่แล้ว +4

    That worked out fine but i wonder if some no nothing will comment that you cant cut threads with the top slide parallel to the axis of the lathe and it really must be at half the thread angle because they saw it on youtube😉
    If i were doing that job i might have not cut such a deep thread relief till after the threading was complete to encourage a stiffer work piece but thank goodness we are all different.
    It's always the destination that matters never how you got there. Some folks need to be there quickly others enjoy the scenic route. I often enjoy the journey more than the final result, hence making tools but never sctually using them.😂

    • @electech3339
      @electech3339 2 ปีที่แล้ว +1

      Not necessary in brass. Mostly not necessary in steel either.

    • @chrisstephens6673
      @chrisstephens6673 2 ปีที่แล้ว

      @@electech3339 indeed, if cutting a 6tpi perhaps but more regular threads quite unnecessary.

    • @electech3339
      @electech3339 2 ปีที่แล้ว

      @@chrisstephens6673 Agreed. I generally only infeed at an angle if having trouble with finish or chip control. And try threading at 0.5 TPI... Especially for internal threading, often need to cut every thread surface separately - and sometimes split even *those* into halves!

    • @chrisstephens6673
      @chrisstephens6673 2 ปีที่แล้ว

      @@electech3339 have you seen a "clapper box" threading tool? If not take a look at my video about screw thread cutting, so you think you know an easy way, showing an up dated victorian design.

    • @electech3339
      @electech3339 2 ปีที่แล้ว

      @@chrisstephens6673 nope, had not seen that style, very neat. I have seen the spring loaded style ones that shoot back out of the cut once they're triggered. Those need to be reset after reversing back out past the end of the part. Those are pretty cool too, and don't require any relief groove.

  • @somebodyelse6673
    @somebodyelse6673 3 ปีที่แล้ว +3

    Stick the pins in styrofoam so they sit in the grooves, so much less trouble holding stuff!

  • @LCHcommunity
    @LCHcommunity 2 ปีที่แล้ว +1

    This is 4,tpi inch's??

    • @StuartdeHaro
      @StuartdeHaro  2 ปีที่แล้ว +1

      Yep. 4 TPI double start, so the machine was actually set to 2 TPI.

  • @larrysperling8801
    @larrysperling8801 3 ปีที่แล้ว +2

    very good video. i was wondering since you were only using the thread wires for a comparison why couldn't you have just used two wires and a mic to measure the thread depth?

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +1

      I could have. The thread pitch is very coarse though and I think that would have made it even harder to get a good measurement.

  • @wktodd
    @wktodd 3 ปีที่แล้ว +2

    That would have quite some pukka factor without a machine stop :-)

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +3

      Probably, but I think it wouldn't be too bad. The groove at the end gave a lot of room.

  • @sajaldebnath5804
    @sajaldebnath5804 3 ปีที่แล้ว

    Who needs micrometer sir

  • @jpsimon206
    @jpsimon206 3 ปีที่แล้ว +1

    Why no cutting oil? Brass is so grabby... Enlighten me

    • @jpsimon206
      @jpsimon206 3 ปีที่แล้ว

      And no tailstock support? And the thread relief being fully cut before threading? I feel like I'm missing some vital piece of information, what gives?

    • @jpsimon206
      @jpsimon206 3 ปีที่แล้ว

      Sorry, I just read my own comment and realized it could be misinterpreted as being nasty. I'm not critiquing, just looking to learn something I don't understand

    • @StuartdeHaro
      @StuartdeHaro  3 ปีที่แล้ว +1

      @@jpsimon206 brass is really only grabby when drilling, and just when the drill starts to break through the other side. I never use cutting oil when machining brass. It doesn't stick to the tool like aluminum. It won't wear down a tool quickly like steel or stainless. The thread relief was actually a critical feature on the part that slipped into a channel on the mating part. I could have machined it in later but honestly didn't think about it. The thread was quite short and stout so I didn't think tailstock support was necessary.