Southbend Leadscrew Nut Won't Fit, Tool Tuesday Ep.16

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  • เผยแพร่เมื่อ 27 ก.ค. 2024
  • I was sent a new lead screw nut that won't fit the lead screw. This can be repaired by simply running the correct size tap through it to chase the threads. I'll attempt this with an inexpensive tap I purchased off Amazon. #acmethreads #manualmachining #machineshop
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ความคิดเห็น • 211

  • @RobertGracie
    @RobertGracie 18 วันที่ผ่านมา +7

    These midweek episodes are awesome keep them coming Adam!!

  • @1956Taz
    @1956Taz 17 วันที่ผ่านมา +5

    Hi Adam! What I think the supplier does, that nut is is supplied undersized, so you can take a dust cut across the screw because you have worn Center sections and therefore fitting the screw to the nut that's what I would have done. Also check the screw across wires top bottom and middle and you can determine how much wear you have in the pressure angle.

  • @TgWags69
    @TgWags69 18 วันที่ผ่านมา +4

    There used to be a seller on ebay that sold the crossfeed nuts that had a partial saw cut through one end with a set screw installed. This allowed you to tighten the set screw which spread the last thread or two apart allowing you to tighten the backlash. I bought one for mine and it worked very nice.

  • @aquilamachine
    @aquilamachine 16 วันที่ผ่านมา +8

    Might not have been the case with this nut. Every time I've replaced a lead screw nut with a new one from the mfg, I was never able to screw it through the nut by hand. I had to grease the lead screw and run the lead screw through nut with a drill. Always tight and smooth after the first two runs throughs.

    • @nicholassmerk
      @nicholassmerk 15 วันที่ผ่านมา

      I think you are correct. They cut it undersized for a reason. I have a feeling the seller was supposed to state it was undersized (they probably didn't know).

  • @Awegner176
    @Awegner176 18 วันที่ผ่านมา +5

    Very common new lathe owner concern- minimal cross slide backlash like that is virtually meaningless. I think lathe owner at one point or another has wanted to replace their cross screw/ nut. I've made several for smaller lathes but I usually tell people not to agonize over it now. Best not to sell something to someone that they don't need. Good video regardless! Nice to see that the tap worked out

  • @johnwilliams2660
    @johnwilliams2660 17 วันที่ผ่านมา +2

    I've just been through the identical exercise with my Hercus (South Bend ) lathe. Had the same problem with the replacement nut. Thanks Adam, I enjoy your posts.

  • @Skyrmir
    @Skyrmir 18 วันที่ผ่านมา +9

    You said it was a left hand thread, you showed it was a left hand thread, and yet my brain still yelled 'Yer doin it backwards' when you started threading in that tap.

    • @davidcat1455
      @davidcat1455 18 วันที่ผ่านมา

      😃👍Same here

  • @TgWags69
    @TgWags69 18 วันที่ผ่านมา +9

    The problem with cheap tap suppliers is that you can't choose your H limit. That's probably an H3 or H4 tap which means it is probably 3 or 4 thou over nominal. Using it on a worn thread means you'll have a lot of back lash. You needed an H0 tap to be right on nominal size. A hack to get around it, is to not go all the way through, but leave the last couple of threads still in the taper portion of the tap. Keep goong back and forth checking it till the lead screw will go through but it is nice and snug.

  • @randallcarpenter5313
    @randallcarpenter5313 18 วันที่ผ่านมา +4

    Adam, I ordered a tap from that same company. I needed a 12-16 acme to make a shaper spindle nut. It worked out fine for $16.

  • @tomc6678
    @tomc6678 17 วันที่ผ่านมา +6

    You measured the original nut with far less thread engagement.

  • @ADBBuild
    @ADBBuild 17 วันที่ผ่านมา +5

    I've had luck on small nuts like this, cutting a slot in the center of the nut, then squishing the slot closed slightly. Not a perfect fix, but a free/easy one.

  • @mitchalsup5607
    @mitchalsup5607 18 วันที่ผ่านมา +9

    Adam, when I do a positioning nut, I run the tap in half way from both sides, leaving a semi-uncut middle to minimize end-play.

  • @secondwindmusicproductions
    @secondwindmusicproductions 18 วันที่ผ่านมา +6

    Two comments:
    1. It looks like someone did some peening on the old nut with a center punch to try and shrink the threads.
    2. I would consider making a jam nut to fit against the original nut perhaps with a bellevue spring washer between them. That would load the nut to one side of the threads and take out the slop except for loads that exceeded the spring strength.

  • @Xris-FJ1200
    @Xris-FJ1200 18 วันที่ผ่านมา

    Thank you Adam for this new video.
    My metal lathe, and my milling machine too, are old machines, they are around 80 years old.
    I was given the lathe as a gift, but I had to completely restore it.
    In particular, I redid the controls and the two control screws with left-hand thread.
    I managed to remove play from the small carriage control using two lapped nuts one on top of the other. I didn't want to use a screw or spring system.
    The assembly works very well and is very smooth along the entire length of the screw.
    I changed everything because the mechanism was too worn to repair.
    I couldn't reuse the bronze nut which was too old and too worn.
    Thank you again for this brilliant work and good advice.
    Christophe

  • @DorosAngeli
    @DorosAngeli 18 วันที่ผ่านมา +3

    great job Adam

  • @jameyodau
    @jameyodau 17 วันที่ผ่านมา +5

    looks like prior owner tried to make it fit tighter by using punch. Brass pc. has a # of punch indentations. You could have machined the spline with new threads 2-3 thousands Then a super tight connection.

  • @richb419
    @richb419 18 วันที่ผ่านมา +2

    Hi, I purchased a couple of Chinese Acme taps, the first one was cutting very large and causing excessive slop between the nut and rod, I finally bought a used one made in USA. that one was very a nice fit.
    After that experience I would test the tap first on something that doesn't matter.
    Rich

  • @greasydot
    @greasydot 18 วันที่ผ่านมา +2

    I've staked mine in my 1933 south bend 9 inch just to get by until I can built a new one.

  • @Csharpflat5
    @Csharpflat5 17 วันที่ผ่านมา +5

    Worn tap would work better and only use halve of the taper too, and back out otherwise cuts too much meat. Then use fine lapping paste, too fit

  • @MarcErkens
    @MarcErkens 18 วันที่ผ่านมา +6

    Ow please can we have the old intro tune back?

  • @markschweter6371
    @markschweter6371 18 วันที่ผ่านมา +14

    @abom79 do you think someone tried to "tighten" the original nut with those punch marks?

    • @user-ev1bi3jh2f
      @user-ev1bi3jh2f 18 วันที่ผ่านมา +4

      I’d wondered the same thing.

    • @JimWhitaker
      @JimWhitaker 17 วันที่ผ่านมา

      Or was that a way of "fitting" the nut to the lead screw during manufacture?

  • @waynegalvin4639
    @waynegalvin4639 17 วันที่ผ่านมา +3

    I have a vintage Southbend lathe and it has the same amount of play in the feeds.

  • @billtimmann338
    @billtimmann338 18 วันที่ผ่านมา +4

    If you need to tighten up the threads could you dress down the tap thread to reduce the width would you not cut as deep to take up some of the wear?

  • @Ogrûche
    @Ogrûche 17 วันที่ผ่านมา +2

    🎉🎉If you had another nut, you could remove just a little material on the tap. and the lead screw will be less loose, I guess😉

  • @mikebroom1866
    @mikebroom1866 18 วันที่ผ่านมา +1

    I did the same thing for my small lathe. Amazon tap worked brilliantly in brass. Steel? I wouldn't chance it, but you can't argue with 2 day shipping and results.

  • @pauldorman
    @pauldorman 18 วันที่ผ่านมา +19

    I notice that the nut was tipping up and down when you were checking for backlash, which won't be possible when it's installed. Backlash might be better than the measurements would "indicate" 😁

    • @lerkzor
      @lerkzor 18 วันที่ผ่านมา +2

      Agreed. I was surprised that Adam didn't clamp the nut in the vice, thread the screw through to midpoint, and measure the lash at the tip of the screw.
      That being said, Adam has at least 5 hours more time as a machinist than I do, so I'm gonna assume that his method was good enough for the task at hand :)

    • @BeenThrDunThat
      @BeenThrDunThat 18 วันที่ผ่านมา +2

      He wasn't trying to get a super precise measurement. Just something to do a simple comparison of before and after.

    • @zorbakaput8537
      @zorbakaput8537 18 วันที่ผ่านมา +2

      Correct the armchair guys always know a better way!

    • @ellieprice363
      @ellieprice363 17 วันที่ผ่านมา

      I think he wanted to test the backlash in the nut. Checking in the middle of the screw would have shown the combined backlash. .015 is not that bad for a lathe. A new nut wasn’t necessary.

    • @melgross
      @melgross 16 วันที่ผ่านมา

      @@ellieprice363true. But there’s nothing wrong with trying to get backlash out as much as possible.

  • @angelramos-2005
    @angelramos-2005 18 วันที่ผ่านมา

    Excellent work,Adam.Thank you.

  • @KBLIZZ333
    @KBLIZZ333 18 วันที่ผ่านมา +2

    My original cross slide lead screw nut is cast iron ( 9" Logan model 400) I thought that was weird. I wound up brazing the internal threads and ran the tap through that. Not perfect, a little tight at first, but worlds better than it was. I'd like to make one out of brass. I have plenty of brass stock, just not confident enough in my abilities. Only have the small lathe and a 1/2 hp drill press.

  • @DavoShed
    @DavoShed 14 วันที่ผ่านมา

    Nice work.
    I did the same thing, bought a tap and made a new nut from scratch. My old nut was nearly worn through.
    My Atlas lathe which is very similar to the south bend has two nuts securing the cross feed handle.
    If those nuts aren’t adjusted correctly it gives the feeling of having more backlash than there actually is.
    I hope the owner takes his time and adjusts those nuts carefully.
    (Same thing on the compound slide)

  • @reinoaalto9941
    @reinoaalto9941 18 วันที่ผ่านมา +4

    well... have to to wonder why that old brass has dents at "top". i would say thats for adjusting the screw ?

    • @jameslong3351
      @jameslong3351 18 วันที่ผ่านมา

      They were trying to tighten up the threads by compressing the metal. When it's worn the best temp fix is to slot the nut an hammer it closed a little, just temporarily.

  • @terrycannon570
    @terrycannon570 17 วันที่ผ่านมา +1

    Adam I would suggest trying the tap in a virgin hole the right size and then measure the back lash. Also the other variable is the male thread. Using the thread gage how much slack is in the gage and male thread when measured by feel. I have also used the Acme taps from Amazon and had good results making my own nuts for my Clausing cross slide and Clausing half nut.

  • @jerrypeal653
    @jerrypeal653 18 วันที่ผ่านมา +3

    I’d like a good mix of both . Production runs and one offs . But hey it’s his business venture not mine .

    • @manifold1476
      @manifold1476 18 วันที่ผ่านมา

      "off" WHAT?

  • @floridaflywheelersantiquee7578
    @floridaflywheelersantiquee7578 18 วันที่ผ่านมา +2

    Thanks for sharing

  • @peteengard9966
    @peteengard9966 18 วันที่ผ่านมา +1

    Some of the old SB lathes have a bronze tip set screw or screws that you can turn to take up the backlash.

  • @edwardaloftis6705
    @edwardaloftis6705 18 วันที่ผ่านมา +1

    I get my taps from Kodiak cutting tools coated they are sharp and good.

  • @Ham68229
    @Ham68229 17 วันที่ผ่านมา +6

    Since I'm not a machinist but, been around such machines and living, working on a farm, if the nut is worn, so is the shaft, either replace with new or make new one's yourself. I'm sure my comment doesn't mean diddly but, it's common sense.

    • @utidjian
      @utidjian 17 วันที่ผ่านมา +4

      The shaft (or lead screw) is, in this case, made of steel. Often lead screws are also hardened and ground to final size and finish. The nut is, in this case, made of brass or bronze which is far far softer than steel. It is much smaller and MUCH simpler to make a new nut than a new lead screw. The nut is what one might call a "wear part"... in the same way you replace your brake pads with new ones but not always your brake rotors (not the best analogy but the only one I could think of.)
      It is the same thing for the longitudinal lead screw on a lathe. Damned expensive to buy a new one every time you replace the half-nuts for threading.

    • @Ham68229
      @Ham68229 17 วันที่ผ่านมา +2

      @@utidjian I fully understand that however, what we don't know is, how old is the southbend, what kind of abuse has it had in it's life, what's the condition of said machine, even hardened steel will wear. Just only speaking from experience on the farm. :)

    • @ellieprice363
      @ellieprice363 17 วันที่ผ่านมา +1

      @@Ham68229Lathe and milling machine screws are tough but not hardened. Moore jig borers and grinders and a few other high precision machines would have hardened and ground screws.

    • @Ham68229
      @Ham68229 17 วันที่ผ่านมา

      @@ellieprice363 Not disagreeing, only stating my experience and I know everyone's experience is different. :)

    • @ADBBuild
      @ADBBuild 17 วันที่ผ่านมา +1

      He said at the beginning of the video he measured the screw and it wasn't worn.

  • @brandenoconnor7299
    @brandenoconnor7299 18 วันที่ผ่านมา +4

    Why was the new aftermarket nut undersize to begin with? I would have then machined the thread on the shaft again, just enough so that the new nut fit nice and snug. This way there will be no play along the entire length of travel. It'll be like new!! The pitch stays the same. Yes they are not to spec anymore, but the next time they wear this bad, its time to get or make a new shaft and nut anyway. I think this is why the nut was actually undersize???🤔🤔🤔

  • @ryanpeterson5239
    @ryanpeterson5239 17 วันที่ผ่านมา +1

    In my experience the Chinese taps cut pretty well as long as they are high speed steel. I believe it is because HSS has to be ground which leaves a nice sharp cutting edge vs high carbon steel taps which are probably machined some other way. I'm sure a USA made tap will last a lot longer but for us home gamers who will probably only use an odd size like this once the Chinese one is usually going to be fine

  • @theessexhunter1305
    @theessexhunter1305 18 วันที่ผ่านมา +4

    the person with the lathe will have a Vernier not
    sure how much measuring they must do lol
    3/8 v 7/16th lol

  • @jackcurrence263
    @jackcurrence263 15 วันที่ผ่านมา

    I just went through a VERY similar exercise, except my issue was a tailstock feed screw bushing that was boogered internally. Ordered a 5/8-10 LH Acme tap from everyone's favorite online purveyor of... well, everything, and ran it through the nut. Sure enough it cleaned things up (I used Anchor Lube, as well), but as was Adam's experience, the fit to the threads on the feed screw wasn't what one would call precise/tight. Fortunately, this was one nut of two, in a backlash-elimination type setup and I was able to get things adjusted such that the endplay was minimized. Thankfully, radial play/misalignment is controlled by a separate bearing (which was also replaced), so the whole shebang feels like buttah now.

  • @user-on2cm3ug6i
    @user-on2cm3ug6i 18 วันที่ผ่านมา

    I bought a 1/2-10 acme tap on eBay to make my atlas lathe lead screw nuts. Description said it was a lead screw tap. $17.00 and for a Chinese tap it worked great with zero backlash.

  • @Brian55126
    @Brian55126 16 วันที่ผ่านมา +2

    Hi I'm also trying to tap a 7/16ths with a 3/8ths thanks for the info

    • @tates11
      @tates11 16 วันที่ผ่านมา

      🤣

  • @apollorobb
    @apollorobb 13 วันที่ผ่านมา +2

    Would have been way cheaper for him to just get the correct tap and do it himself lol

  • @user-ho7km2ru6k
    @user-ho7km2ru6k 18 วันที่ผ่านมา +2

    Chasing perfection on old machines is always a case of hope over expectation. How many parts does one change?

  • @campbellmorrison8540
    @campbellmorrison8540 18 วันที่ผ่านมา +2

    I rather suspect if the thread was that bad to begin with there is no telling if the actual hole was the right diameter and so running a tap through, no matter how good it is would not fix a sloppy hole. I would remake the leadscrew and use the tap to do the thread and I'll bet its works just fine. I'm a home a home machinist and I buy quite a lot of tooling from China and for the amount I use it its brilliant, there is no way I could have the tooling selection I have at professional prices. When I find a good supplier of say gear cutters I tend to stick with them for other sizes same goes for milling cutters, I have never bought taps from China but would if I needed something like an acme

  • @keithkrueger1609
    @keithkrueger1609 18 วันที่ผ่านมา +2

    People put to much worry in the lead screw for the cross slide for the lathe. 99% of the time when your turning the pressure is pushing back. now leadscrews on mills backlash is something to worry about.

  • @PaleoWithFries
    @PaleoWithFries 18 วันที่ผ่านมา +4

    That old one was peened a bunch to try to get it to tighten up, I see

  • @ÁREAJ27
    @ÁREAJ27 18 วันที่ผ่านมา +2

    Olá amigo Adam muito bom trabalho!!!

  • @KBLIZZ333
    @KBLIZZ333 18 วันที่ผ่านมา

    My Logan 400 is 7/16x10 tpi I actually bought a tap off Amazon as well mine was I think Nitride coated though. Worked great for me

  • @RustyInventions-wz6ir
    @RustyInventions-wz6ir 15 วันที่ผ่านมา

    Very nice work sir. Not easy to make a lead-screw on nut.

  • @briangarbin8404
    @briangarbin8404 11 วันที่ผ่านมา

    you can always get a tap that is certified and of hi quality to ensure exact fit and perfect geometry.

  • @KSMechanicalEngineering
    @KSMechanicalEngineering 18 วันที่ผ่านมา

    Very nice❤

  • @semperfidelis8386
    @semperfidelis8386 17 วันที่ผ่านมา +8

    this guy must have stock in Anchorlube

    • @superdavett2
      @superdavett2 17 วันที่ผ่านมา +7

      I think he must have stock in a lot of sponsors. At this point the whole channel is highly commercialized.

    • @jerrydemas2020
      @jerrydemas2020 17 วันที่ผ่านมา +1

      @@superdavett2 But it is free to watch!

    • @tates11
      @tates11 17 วันที่ผ่านมา +1

      @@jerrydemas2020 Lots of people pay the youtube subscription.
      Put the Anchorlube in the hole instead of on the tap. It always stays at the front of the tool where it is needed so lots of holes can be prepared without having to coat the tap every time.

    • @charlesgibson4184
      @charlesgibson4184 17 วันที่ผ่านมา

      Is anchor lube a bad product?

    • @WaDahDahDang
      @WaDahDahDang 16 วันที่ผ่านมา

      @@charlesgibson4184 Not a bad product - if it was he wouldn't use it. Just sponsored so he gives it more camera time. Blondie Hacks also uses it (I believe not sponsored), so for me, that tells me it is good.

  • @robjaimiehickford4559
    @robjaimiehickford4559 18 วันที่ผ่านมา +1

    I think theres too much slop, ether id or OD was made oversize. I was able to replace a cast iron nut in my nuttell lathe with ally bronze in the same lathe. All was made in same lathe except for alittle vice work for the radius with file. I made a male thread gauge first to my calc's of standard thread LH Acme form. Squared off bronze block in lathe, yes a pain but had no access to mill or another lathe. Bored hole and cut thread to form a good/slightly tight fit, then turned stub and tapped hole thru it. Worked out well, been in use for 6 yrrs now.

  • @wh1zzzy
    @wh1zzzy 18 วันที่ผ่านมา +1

    I’m wondering weather the new t-nut was 3/8”and not 7/16”. Also before I’d condemn the cheap tap for cutting oversize I’d check the resized t-nut with a go-no go gauge.

  • @mrkevinp70
    @mrkevinp70 18 วันที่ผ่านมา +1

    That was boring AF... BUT you somehow made this exciting 🙂

    • @stephenk79-rc1il
      @stephenk79-rc1il 18 วันที่ผ่านมา

      He is very talented at that.

  • @gregdawson1909
    @gregdawson1909 14 วันที่ผ่านมา +1

    You can see someone peened the original nut to "improve" the thread fit, sort of like you might peen a shaft to make a bearing fit tighter. You can bet that nuts been worn out a long time.

  • @marceloiannini8199
    @marceloiannini8199 17 วันที่ผ่านมา +3

    I have seen quality improving steeply on chinese cutting tools in the last years. I cannot point obvious difference between name brands (OSG, Dormer, Magafor) in the last two years. Things are very different from 10+ years ago, when they were really poor.

    • @nils1953
      @nils1953 17 วันที่ผ่านมา +2

      It's still very hit or miss I feel.
      Sometimes you get actual razor sharp carbide tools and other times, it says carbide but turns out to be softer than lead.
      But all in all I'd agree, that they've been producing very decent tools, taps and endmills, especially for the home/hobbyist shop.
      I've only had bad luck with inserts for the lathe or mill though.

    • @RobertBrown-lf8yq
      @RobertBrown-lf8yq 15 วันที่ผ่านมา

      @@nils1953
      I’ve found that cutting tools, collets, Toolholders from India to be superior quality than most of the Chinese stuff.
      Robert

    • @nils1953
      @nils1953 15 วันที่ผ่านมา

      @@RobertBrown-lf8yq that's very interesting! Where do you buy tools from India? I don't think I've ever used any tools made from there.

    • @RobertBrown-lf8yq
      @RobertBrown-lf8yq 15 วันที่ผ่านมา

      @@nils1953
      I got onto it via Google. Got some 5C collets from them.
      Bloody first class….. not one burr 😱
      So ordered some square and hex collets.
      Delivery was about six-seven weeks ( probably a special order ??).
      Ditto for some BT30 ER32 toolholders.
      I’ll see if I can find their details again and post here.

  • @andreabennett
    @andreabennett 18 วันที่ผ่านมา +3

    Nice job, Adam.

  • @duaneohall
    @duaneohall 17 วันที่ผ่านมา +2

    One other option would have been to use the 3/8" tap he bought like a boring bar in the lathe to widen out the threads. You could have also optimized the thread depth for minimal backlash while doing this.

    • @utidjian
      @utidjian 17 วันที่ผ่านมา +1

      Why do that when he can get the correct tap for $27?

    • @duaneohall
      @duaneohall 17 วันที่ผ่านมา

      @@utidjian $27 plus wait for Amazon. Any time I can save time and money and get the job done correctly, why would I not go that route?

    • @utidjian
      @utidjian 17 วันที่ผ่านมา +1

      @@duaneohall Sure... I could see trying what you suggest if I was in the middle of the Indian Ocean on an aircraft carrier and for some reason I had to get the crossfeed screw nut that was in spares working... but that isn't my situation. Nor, I would guess, is it Aboms (Jacks) situation either. I value my time far more than $27 times however long it would take janking around with the wrong sized tool. With the right tool it takes less time to cut the thread correctly than it takes to compose this reply.
      Anyhow plenty of ways to skin a cat or win our own battles. We are fortunate to each have the choices on how we want to do it.

    • @rufustoad1
      @rufustoad1 16 วันที่ผ่านมา

      Agree. Not sure why Abom did this but a great video would have been to do what you suggested. I might have learned something.

    • @Brian55126
      @Brian55126 16 วันที่ผ่านมา

      Not

  • @tates11
    @tates11 18 วันที่ผ่านมา +5

    I whinced when he put the tap all the way through without checking the fit as he went. It's now almost scrap.

    • @tmmtmm
      @tmmtmm 18 วันที่ผ่านมา +3

      If you back it out, it'll cut even more off and become looser. This is a one and done deal.

    • @bertblankenstein3738
      @bertblankenstein3738 18 วันที่ผ่านมา

      It originally wasn't working, so things could only improve.

    • @tates11
      @tates11 18 วันที่ผ่านมา +3

      @@tmmtmm There are many variables to make your statement universally true, too many to list here. One in particular is worth mentioning and that is a skilled operator will have been taught to avoid this and have the feel to prevent backcutting.
      The point I was making is that if the tap is inserted at increasing depths all of which are before the parallel finishing teeth engage. When the tap is reversed to back out, the tapered teeth are in a larger threaded hole so they can't cut what they are not touching. Repeat cautiously and gradually from each side of the hole until the male thread goes in.
      In this case the subject was a leadscrew with a worn center section and virgin threads on the ends. If the nut is opened out to suit the unworn threads on the ends it will always be even sloppier in the middle. In this video he managed to get it sloppy on the full size threads on the end, he never showed the increased play in the center of the leadscrew!
      I suspect the nut thread was deliberately made to a slightly tighter spec for a closer engagement on the worn area of the leadscrew. My first operation would have been to see if the nut could be forced over the virgin threads and onto the worn area to see how it fitted in the working area. If it was too tight to thread over the full size thread on the end I would consider relieving the end of the leadscrew thread to help, as this portion is not used.

    • @leybraith3561
      @leybraith3561 18 วันที่ผ่านมา +2

      @@tates11 ...Agree. I was rather surprised he didn't begin to tap, back it out and check screw fit, when eventually it begins to fit, tap in the other direction doing the same. Likely to have ended up with a far superior fit.... Not conventional, just being practical...

    • @tates11
      @tates11 18 วันที่ผ่านมา

      @@leybraith3561 A bit gung ho.

  • @Grantherum
    @Grantherum 17 วันที่ผ่านมา +1

    makes me wonder if the internal threads there were cut with a 3/8-10 acme to begin with... considering it was cutting nearly from the start.

  • @alewis8765
    @alewis8765 18 วันที่ผ่านมา +1

    I think the only way to get the slop out, or get it down to 0.001 would be to replace the acme lead screw with a ball screw.

    • @car9167
      @car9167 18 วันที่ผ่านมา

      There are disadvantages with ball screws on this configuration. Left hand ball screws tend to be more expensive. The nut size will be much bigger. The max thrusting force is smaller since ball contact surface is much smaller. The smaller the thread pitch the smaller the balls. 10TPI si about 2.5mm thread pitch. It's hard to have a ball screw with this small thread pitch.

    • @car9167
      @car9167 18 วันที่ผ่านมา +2

      A better solution which I implemented on my lathe (although metric thread) is a split nut. Actually two nuts. One is fixed to the top slide and one is floating. One face of the floating nut is milled at 2 degree angle in relation with the nut axis. The fixed nut has 4 dowel pins in the corners which goes into the floating nut to keep it aligned. Between the two nuts it's a wedge which is adjusted with a set screw from above top slide. The bottom of the wedge is pushed up with a leaf spring mounted on the fixed nut. You adjust the backlash from above - no need to dissasemble anything - by adjusting the set screw. It will push the wedge down against the leaf spring and spread apart the two nuts creating pressure on the opposite thread flanks. I have 0 backlash on my lathe for the reason I put a 1 micron glass scale and DRO

  • @cyclebuster
    @cyclebuster 18 วันที่ผ่านมา +2

    have you considered trying a "Chicago Fit"? it looks like the old one had a bunch of them...

    • @user-ev1bi3jh2f
      @user-ev1bi3jh2f 18 วันที่ผ่านมา

      I thought the same.

    • @donsfromnz6515
      @donsfromnz6515 18 วันที่ผ่านมา

      even applying a measured force on the old nut in the press would have been better than cutting the new nut to fit the non worn part of the screw

  • @willynebula6193
    @willynebula6193 15 วันที่ผ่านมา

    Would've been cool to see you try tapping a blank piece of stock for reference, oh well.

  • @emilgabor88
    @emilgabor88 18 วันที่ผ่านมา

    Nobody is buying lathe ,” first thing changing all the nuts and screws”
    Experimented machinist , “if it didn’t strip, it’s perfectly fine”

  • @ronnydowdy7432
    @ronnydowdy7432 18 วันที่ผ่านมา +3

    You could always make a new lead screw too for a long time viewer.
    Just saying. It's hard to find these old parts.

    • @TheMoody876
      @TheMoody876 18 วันที่ผ่านมา +3

      Got that right I need it for my old atlas 10in lathe

    • @ronnydowdy7432
      @ronnydowdy7432 18 วันที่ผ่านมา +1

      @@TheMoody876 Made Adam will have time to work on it. Never hurts to ask.

    • @TheMoody876
      @TheMoody876 17 วันที่ผ่านมา

      @ronnydowdy7432 to me it would be more cost effective to sell the atlas and buy something larger and more accurate

    • @ronnydowdy7432
      @ronnydowdy7432 17 วันที่ผ่านมา

      @@TheMoody876 okay. Then you should do that if you can.

  • @brucepratt7716
    @brucepratt7716 18 วันที่ผ่านมา +3

    Could you put the nut in a hydraulic press to compress the pitch?

    • @LuggageStardate
      @LuggageStardate 18 วันที่ผ่านมา

      Soon as he stuck it in a vise I was thinking I would crush it.

    • @SeeSaw72
      @SeeSaw72 17 วันที่ผ่านมา

      @@LuggageStardate Use a hydraulic hose crimping machine with the appropriate die, it might help. Just a thought.

  • @billgilbride7972
    @billgilbride7972 18 วันที่ผ่านมา +1

    Nice video, just too many variables that cant be answered without making mult parts to find out the 'why'. I noticed his stock nut was 'measled' (my term) in hopes of tightening things. Did he do that or the prev owner? The lack of backlash adjustment saddens me.... bc I have a 13 and it probably will/does suffer the same issue of design. Some slice thru the nut and add the adj bolt. But on a SB? Demz nuts aint big enough for Ken's scale Winnebago. A custom SB nut might be the solution. Why doesnt that get made instead of the generic nos looking nut?

  • @edwardaloftis6705
    @edwardaloftis6705 18 วันที่ผ่านมา

    They make tighter cutting taps.

  • @edwardaloftis6705
    @edwardaloftis6705 18 วันที่ผ่านมา +2

    I use it diluted with water.

  • @ConcertLD
    @ConcertLD 18 วันที่ผ่านมา +2

    Can i send you my Southbend leadscrew and you rebuild mine for me lol

    • @ConcertLD
      @ConcertLD 18 วันที่ผ่านมา +3

      My Southbend lathe has some cool history it was originally built and sold to the Keebler cookie company

  • @edwardaloftis6705
    @edwardaloftis6705 18 วันที่ผ่านมา

    My x,y table has a 1/4-20 leadscrew. Right hand.

  • @johnfriend240
    @johnfriend240 18 วันที่ผ่านมา +6

    Backlash on lathe cross feeds is pretty unimportant. So easy to compensate for. Most do it without having to even think about it.

    • @fearlyenrage
      @fearlyenrage 18 วันที่ผ่านมา +2

      😂 It is annoying so it has to been fixed. Maybe you should fix yours to.

    • @swedishpsychopath8795
      @swedishpsychopath8795 18 วันที่ผ่านมา +2

      @@fearlyenrage Clearly he has some loose nuts, but as long as he is happy we'll accept him as he is.

    • @donsfromnz6515
      @donsfromnz6515 18 วันที่ผ่านมา +1

      try relling that to a carbide parting tip while cutting something gummy!

    • @johnfriend240
      @johnfriend240 17 วันที่ผ่านมา +1

      @@donsfromnz6515 That's a South Bend 9 inch cross feed nut, pretty sure he's not parting with carbide inserts, gummy or not...

  • @raypearre724
    @raypearre724 18 วันที่ผ่านมา +2

    Adam, I have that same lead screw on my South Bend. I cannot find a source for a 7/16-10 LH ACME rod to replace mine which is severely worn. Top of thread is sharp enough to cut. Can you help me?

    • @mikewilliams5873
      @mikewilliams5873 18 วันที่ผ่านมา +2

      Could you upsize to 1/2-10 LH ACME and tap out the nut to match?

    • @DonMason-cv6og
      @DonMason-cv6og 14 วันที่ผ่านมา

      Have done that on at least four leads crew repairs. Worked just fine. Found and used half ten precision ground acme. Lh stock. More readily available than the 7 sixteenth ​@@mikewilliams5873

  • @MikeBaxterABC
    @MikeBaxterABC 18 วันที่ผ่านมา +5

    I stopped at 6:07 ... How i would tap this is from each end 1/4 of the way in .... then just half way in from each end ..... etc .. until it had nive zero backlash and is not to tight ....
    In my opinion THAT is why Acme Taps are made this way ... so you can adjust the fit by making a custom cross feed nut, not a general use standard size nut.
    OK I continue watching :)

    • @specialks1953
      @specialks1953 18 วันที่ผ่านมา +3

      I think the lead screw is worn causing the slop also. I think in the end, the few tight threads in the middle would snug the backlash. It would be temporary but if he does not use it much, that may get him far down the road with tighter tolerances. If tolerances are that important to him he can buy more Nuts to do the same with.

    • @cdrive5757
      @cdrive5757 18 วันที่ผ่านมา +1

      Isn't that contrary to the "Never back out an Acme Tap" rule?
      Wakodahatchee Chris

  • @batmanacw
    @batmanacw 18 วันที่ผ่านมา

    I think it's safe to say that a new screw would have had less play as well. 0.015" wouldn't have bothered me. Not my call though.

  • @ghostdog662
    @ghostdog662 18 วันที่ผ่านมา +1

    Which tap holder are you using?

    • @kindablue1959
      @kindablue1959 18 วันที่ผ่านมา +1

      Hes says at 7:35

    • @tates11
      @tates11 18 วันที่ผ่านมา +2

      Lol

  • @davecreer9
    @davecreer9 18 วันที่ผ่านมา +2

    Its only backlash

  • @wdhewson
    @wdhewson 18 วันที่ผ่านมา +1

    Is it an advantage or disadvantage to run a tap through both directions ??

    • @firesurfer
      @firesurfer 18 วันที่ผ่านมา +1

      It really shouldn't matter, but it depends on the size of the object and whether you were able to completely pass the full threads. You risk reaming the threads a tad by repeated passes.

  • @donaldcallahan450
    @donaldcallahan450 18 วันที่ผ่านมา

    hey Adam whats the difference in right hand taps an left handed isw it the cutting edge

    • @michaelleskoske7723
      @michaelleskoske7723 18 วันที่ผ่านมา +2

      The difference is also in the direction of the threading. Regular thread "right tighty, lefty loosey".
      Left hand thread is just the opposite.

  • @RonSales
    @RonSales 18 วันที่ผ่านมา +3

    I think if he's rebuilding it , he would have also replaced the main threaded screw for the machine also to ensure it was right. He could of gotten a nice one built by you.

  • @federiconiedenthal4180
    @federiconiedenthal4180 18 วันที่ผ่านมา +3

    Long live the Monarch Leath

  • @user-yj7sn2xs8w
    @user-yj7sn2xs8w 16 วันที่ผ่านมา +1

    Leadscrew? Isn't that the crossfeed screw?

  • @erichoff7926
    @erichoff7926 17 วันที่ผ่านมา +2

    Adam I bet the lead screw was threaded with the step one tap which cuts most of the Acme thread and you used the finishing or full thread depth tap to clean it up. I ran into this some years back.
    Best wishes
    Eric

  • @user-qb7vv8xn3y
    @user-qb7vv8xn3y 18 วันที่ผ่านมา

    Do you think a more expensive tap would have been a better fit

    • @tristansimonin1376
      @tristansimonin1376 18 วันที่ผ่านมา +1

      When you tap something who already has a thread it will be bigger than the first time you tap it, if he made a new nut and tap it with this tap I'm pretty sure there will be much less play

  • @sotm6078
    @sotm6078 12 วันที่ผ่านมา

    Was that a left handed thread really?

  • @lonwillis783
    @lonwillis783 18 วันที่ผ่านมา

    😀😁😊

  • @davidcahan
    @davidcahan 16 วันที่ผ่านมา

    New intro music....🤔

  • @tomoakhill8825
    @tomoakhill8825 18 วันที่ผ่านมา

    This video shows why. I like this channel. Adam _correctly_ measured the diameter, doing it as though there was nothing to it. Assume the lathe owner is ordinarily competent, and his mismeasure demonstrates that it takes _high_ skill to get that diameter correct.

    • @Spectrum184
      @Spectrum184 18 วันที่ผ่านมา +4

      Measuring an OD with calipers is trivial. Any machinist should be able to do it drunk and blindfolded while in their sleep.

  • @myquartknee
    @myquartknee 17 วันที่ผ่านมา +2

    I am a furniture maker and a novice machinist. I have been watching your channel for a long time and I learn a lot about tight tolerances from you. I do know that leadscrews need some backlash, so what is acceptable backlash and would a better known brand of tap cut the thread with less backlash or would cutting the threads on a lathe be the only way to manage the backlash?

    • @joansparky4439
      @joansparky4439 14 วันที่ผ่านมา

      backlash is inherent to threads, otherwise they bind and can't be 'threaded'.. to get backlash out of this mechanism it requires a 2nd nut that is being put under adjustable tension / pressure axially to get backlash minimized to near zero and to be able to readjust once things have worn and get sloppy again.. the cheap version of this is to cut perpendicular into the nut without parting it off and using that as the 2nd nut (needs a way to bend it slightly then, usually with a set screw pushing into the cut).

  • @StephenYoung-tb1pc
    @StephenYoung-tb1pc 18 วันที่ผ่านมา +2

    I am thinking along the same lines as @joeromanak8797. I bet the drill size may have been oversized, ?? ( Cool video though. )

    • @Bob_Adkins
      @Bob_Adkins 18 วันที่ผ่านมา

      Undersized, right?

    • @cameronjohnston5748
      @cameronjohnston5748 18 วันที่ผ่านมา

      I don't think the drill has anything to do with it on those type of threads, a square thread is designed to take the force on the face of the thread not on the outside or inside diameters. On angled threads a totally different matter.

    • @Ben.last.name.
      @Ben.last.name. 18 วันที่ผ่านมา

      Acme threads are a tapered threadfrom (14.5* per side, 29* inclusive) ​@cameronjohnston5748

  • @Da5idc
    @Da5idc 18 วันที่ผ่านมา +2

    Won't clamping it like that risk distort the inside of the nut - surely it would be safer to clamp on the pin?

    • @boothbytcd6011
      @boothbytcd6011 17 วันที่ผ่านมา +1

      He isn't using a hydraulic press. It's just hand tight.

    • @Da5idc
      @Da5idc 17 วันที่ผ่านมา +1

      @@boothbytcd6011 how difficult would it be to clamp it on the pin?

  • @inkman996
    @inkman996 18 วันที่ผ่านมา +3

    There was nothing gained at all. Lead screws and nuts should be fairly tight when fresh and allow them to wear in. A better approach would be a quality sized tap or manual threading. Measuring the backlash should have been done with the nut static and pushing on the lead screw.

    • @Drottninggatan2017
      @Drottninggatan2017 18 วันที่ผ่านมา +1

      Yes, maybe the new nut was high quality and made in such a way to be a tight fit, and now it is ruined?

  • @Michel-Uphoff
    @Michel-Uphoff 18 วันที่ผ่านมา +10

    Too bad you didn't measure the backlash at the center of the axle. There the wear is usually maximum. And if that were the case, I would first clean up the lead screw threading by removing a few microns. The nut may then fit without having to use the tap. I still think the backlash is much too high, especially because you only measured it at the unused end of the lead screw.

    • @reinoaalto9941
      @reinoaalto9941 18 วันที่ผ่านมา +1

      yup theres always worn part somewhere depending of use case...

  • @patheron7812
    @patheron7812 10 วันที่ผ่านมา +2

    Not your best video; buy a tap, run it through a pre-made part, see what happens... Maybe you should have engineered a split nut to replace the stock nut.

  • @susannovotney1903
    @susannovotney1903 12 วันที่ผ่านมา

    That nut was made to be tight. n You machine the leadscrew to match the nut. Machining the leadscrew will make the whole screw the size of the worn area. The nut will then work with zero backlash the whole length of the screw!!

    • @tates11
      @tates11 11 วันที่ผ่านมา

      That makes perfect sense. New to me, but obvious when you think about it. Great comment.

  • @arkansas1336
    @arkansas1336 14 วันที่ผ่านมา

    The new tapped hole might have been M12

  • @passenger6735
    @passenger6735 17 วันที่ผ่านมา +4

    Old music please.

    • @Kalumbatsch
      @Kalumbatsch 17 วันที่ผ่านมา +1

      Or some steel guitar while we're at it. High speed steel guitar!

  • @alevgsid
    @alevgsid 18 วันที่ผ่านมา +2

    Забавно, что у амертканцев нормальной точностью изготовления резьбы является 0.007", а у нас бы любого техно-блоггера говном бы закидали за осевой люфт резьбы в 0.2 мм. Надо понимать, что осевой люфт на таких винтах мультиплицируется, и в итоге получается ни на что ни годный винт.

    • @rsxjackal
      @rsxjackal 18 วันที่ผ่านมา +1

      Я вот тоже не понимаю этого прикола, я спрашивал у Адама в его инстаграме насчёт точности изготовления деталей, но чёткого ответа так и не услышал. Меня очень смущает тот факт, что я на 1К62 '59 года выпуска, шабрил направляющие, изготавливал на заказ новый винт поперечной подачи, сам точил гайку безлюфтовую сборную и заполненную маслом, чтобы избавиться от свободного хода, стараюсь обкатывать СТАРЫЕ детали при установке в пределах погрешности установки патрона (ДО 0.04мм) и точить с разбегом размера +-0.02мм, если в плюс то можно либо шлифовать либо выглаживать алмазом, что относительно затратно по времени, но иначе смысл от таких станков? А тут хлоп хлоп, разбег 0.2мм+ и пойдёт, я конечно понимаю что данная работа может быть вполне за бесплатно ибо для подписчика, но маловероятно, да и если на публику, то я всегда стараюсь близко к идеалу работу выполнить.