Threading - Feeding with the Cross slide vs Compound
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- čas přidán 3. 07. 2024
- A closer look at threading methods plus a little surprise! An unconventional threading tool.
Mr. Whoopee's Auto-Retract Threading Tool: Takes the Worry Out of Being Close
CZcams Channel: / @phineasj.whoopee3301
Email: autoretractthreader@gmail.com
Pricing: $280-$310 depending on model. Available in Aloris style AXA, BXA, CXA and straight-shank for other style of toolposts.
Automatic Half Nut Release on South Bend Heavy 10 Lathe:
• Automatic Threading St...
Your printed illustration was far better than any other shown before on CZcams. Great demonstration. Thanks for the video!
Thats great, Thanks
Kurtis, from CEE, Australia, cuts some huge threads in his work. He says he always uses the cross slide predominantly, never releases the half nuts, stops the lathe at the end of the thread, his machine stops instantly, and then reverses with the tool extracted. If you watch him carefully, he always advances the compound dial a few thousand before engaging the next cut, which is applied with the cross slide. His results are perfect. I've never questioned the compound movement but I surmise that it's to achieve much the same effect as cutting with the compound in that the principle cut is with the left edge of the insert while the right, if it cuts at all, provides a "polishing" action to the right edge of the thread resulting in a cleaner thread. He then follows up with a thin strip of abrasive tape and a flat file. Granted, in comparison to most hobby lathes, his are huge, but he's using the same inserts as you and I do. Just sayin'.
A big lathe makes a difference although, if his compound is set parallel to the stock advancing with both is the same as advancing with the compound only set at 30 degrees. The only advantage (in my opinion) is that you can read the thread depth on the cross slide dial.
My Dad taught me to thread with the compound set at 29 degrees almost 60 years ago. He explained the reason as you just did. i never questioned it, and always got good results. Good Video, clear, and concise.
Thanks you sir!
Good video ,Mark and specially when you question and answer yourself and not just telling the solutiom.Trial and error.Thank you.
Glad you enjoyed it. Yeah, the only absolute conclusion is that I get slightly better results feeding with the compound
A bit off topic here but here is a tip for the method I use for parts I use in my shop.
I rarely go to the bother of screwcutting a male thread on the end of a shaft. I tap the required size in the end and fix a high tensile set screw in the end.
This gives me a high strength thread that can be used up to a shoulder without an undercut that weakens the part. It is far easier, quicker, stronger & saves material.
I've done the same
I think what proved the point that using the compound at 29.5 degrees is better is when you used the "half threading tool" it couldn't cut on both sides because there weren't 2 sides !
yet the threads came out best of the lot ! it also shows that threading inserts are not always
as sharp as they could be ! a super sharp threading tool really makes a big difference !
Yes it does... good point!
Great visual with that printout 👍🏻
Thanks 👍
Loved your half thread tool👍
I was shocked that is worked so well. I need to look closely at the grind and take notes.
Your comment(around @0:45) re: "Small lathe... compound, and big lathe Cross-slide" is SPOT ON!
As a machinist(of a few years): plunge cutting of threads is great for standard series metric and imperial thread forms up to 24mm/1" dia, anything bigger(or square/ACME) is simply a case of walking the form tool into the cut to relieve stress on the tool(prevents grab and chatter on the thread form), whilst compound is preferred for high precision threads where there is no thread chasing possible(die run through/over).
I mostly use "Big machines" (1.5ton to 6ton), but I do use import machines of tiny size too for fiddly bits.
PS love the quick release threading tool(poor man's cross-slide quick retracting action as found on tool room machines(I have a Holbrook C10 with this function BTW)....
Keep up the good work.
Thanks, I think your idea of big and small and different thank mine, my lathe is super small... ha
That single side threader did a NICE job!
Yeah, I was surprised.
Thank you for sharing this informative video. I enjoy your channel very much.
For MANY years I did all of my single point threading with 3/16" square HSS tools held in an Armstrong style tool holder held in a "lantern tool post" on a 6" Atlas/Sears lathe. Side rake was ground into the tool (leading edge only) and back rake is set via the Armstrong holder. The feed was put on with the top slide set at 29.5 dgr. The look and feel of these threads was, IMHO, consistently good.
Recently I began using a genuine Aloris (wedge style) tool post with AXA tool holders and 3/8" square HSS tools with a 9" South Bend workshop lathe. The plunge feed is put on with the cross slide as suggested in many internet videos. Threading results are rather poor. I attribute this to no back rake and no side rake. In other words, the tool is basically scraping, not cutting.
I have also tried feeding with the compound set at 29.5 dgr. The results are somewhat better on the left thread flank (leading edge of tool) but finish on the right thread flank (trailing edge of tool) is "smeared and flakey" even though there is plenty of side clearance.
I plan to try treading with the South Bend lantern tool post, Armstrong tool holder and 1/4" HSS tools with this "new" lathe. I'll let you know how it goes.
For what it's worth,
F.C.
From what I have experienced I think the best approach is to grind a HSS tool with a small amount of side rake on the left side and a small amount of back rake. Then set the compound at or very close to 30 degrees. Good comment, thanks!
@@WinkysWorkshop GMTA!! (Great Minds Think Alike) 😉
I was taught to do this with the compound at 29.5 degrees for all lathes big or small and never thought to try it any other way. Very nice demo and intesting to see that I was taught what seems to be the best way.😃
To me, feeding with the compound is much easier but many feel otherwise. The first thing I realized was that I had to remember a dial setting. Going back to zero each pass avoids some possibility of error.
This is one of those things that has passed from knowledge into myth over time. Only the techniques survive and the original reasoning is lost(as has happened to a number of other things). Threading CAN be done either way, in fact there are even more ways than that which are options on CNC lathe programming. For manual work it boils down mainly to these two techniques. Is there one more "proper" than the other? Yes there is and there are reasons for it. Cutting with the compound was used , not to complicate your life needlessly but to overcome real problems in doing the best possible work.
The 29.5° compound method has these advantages.
1 The load on the tool is strongly biased against the direction of the feed, keeping the half nut securely and consistently engaged.
2 The chip load is very much reduced by not having two heavy chips colliding from 2 directions right over the weakest part of the tool.
3 The alignment of the tool can never be "perfect" and the 1/2° - 1° skew ensures the right side skims clean if slightly off.
4 The in feed per pass is twice as sensitive and precise relative to the PD because taking off mainly only one side.
5 An important reason for using less than 30° is that the chip coming off the left side of the tool erodes the surface on the right. The ~29° continually skims that side to remove that erosion damage.
Ultimately both techniques are usable in different scenarios but the 29° method is better in most cases even if you can get away with the cross slide sometimes it will pay dividends to know and use both.
Personally I use the 29° method for all critical threads, most threads in steels and reserve the cross slide method for soft metals and non critical threads. I mix and match the two, using the 29° method for the bulk of the thread then often switch to the cross slide for skimming the final clean up sizing cuts where the load is light and because of the direct 1:1 relationship of cut depth to Pitch diameter.
This is the BEST comment! It perfectly describes what I needed to say. Thanks I'm pinning this comment to the top!
@@billshiff2060 just complicate slightly, I was in conversation with an old timer who was taught to grind the tool to slightly less than the thread angle and go in with the compound at the full angle.
And as a bit of an historical note, many of the first thread cutting lathes didn't even have top slides.
For fine threads (greater than 16tpi) I seldom set the compound, and just feed in with the cross slide. At 16 tpi, and coarser, I almost always use the compound.
@@vandalsgarage Yeah, actually the first cut is the same either way and a very shallow thread is just a bit more.
@@WinkysWorkshop Thanks I am flattered. Actually there is a LOT more to know about threads and thread cutting. I teach a course at the company because virtually none of the machinists have a full grasp of it. That came about because we had a HUGE rejection of aircraft parts being returned with no reason given except they are out of spec. They couldn't figure out what was wrong with them and were not going to embarrass themselves by asking Airbus what was wrong with them. They were 25∕8 - 16 UNJ spec female threads and they couldn't find the problem when the president mentioned it to me. I said I have the entire ASME spec manuals for all UN threads in my pocket and am expert in UNJ. It was quickly determined that the bore was undersized for a UNJ. So we just rebored them all up to spec and they were accepted. So they asked me to prepare a course on thread cutting and inspecting for the staff since I had already delved deeper into the subject than I ever imagined I'd have to in order to write the software I wanted for myself. There are a LOT of surprises lurking in them thar threads I can tell you.
Here’s some math that has helped me when chasing threads with the compound. Suppose you’re cutting 16 pitch threads at 29 degrees? Double depth of a 16 pitch thread is .081, but since the compound is feeding on the hypotenuse of the angle the depth will be deeper. The constant of 29 degrees is 1.144. Therefore the reading on the compound dial will be .081 x 1.144 = .093. I hope this helps.
Interesting concept
I was surprised
Always good to do some experimenting. Ideal way to figure out what works best.
You're right. I never though a half tool would do the best
Mark since You Tube does not rank creativity I will give you my own ranking. I am ranking you as a "Master Creator". This is an excellent demonstration and narration of one method verses the other. I always like the way you think the process all the way through.(easier on the spindle bearings) Unlike me I just turn the camera on and what you see is what you get and non-edited. But mine is only for documentation purposes only. I love the detail of how the chips looked. Cross slide seams to tear the chip where the compound shears the chip. i always say "Anyone can make chips but knowing how the chip is made separates the men from the boys." thanks as always for bringing us along.
Wow... thanks a bunch! You made my day!
Excellent information winky, great video, keep'um coming.
Thanks!
Little threads, cross slide, big threads, compound. Works for me.
I can see that. I'm used to the compound plus I don't have to remember the number on my dial like you do when you feed with the cross slide.
Great little discussion Mark, I agree with you. The professional machinists at the steell mill typically cut very nice threads with the insert tool and the cross slide on heavy lathes, while at home I preferred the 29 degree solution for my lighter lathe. Enjoyed very much, cheers!
Sound about right, thanks
I have made thousands and thousands of feet of English, Metric, Acme and pipe threads. It does not matter the method as long as you have a sharp tool and cut threads to the proper depth.
To a point I agree. Both methods made usable threads. I do think that feeding with the cross slide is a bit more demanding on the lathe. Going straight in the two chips are meeting at the tip of the tool resulting in more friction.
I had a big fight with jo pie about that. He made 1 video claiming it DID cut on the right side and then made a different video claiming it DIDN'T cut on the right side. He got VERY nasty about being called out on it. Even made an insulting video just about our argument. Of course he banned me from commenting on it and I unsubscribed and never watched his channel since.
At 29 the tool
cuts slightly on the right side. At 30 it lightly scrapes but doesn’t cut.
What a small thing to argue about!
@@ellieprice363 He made a video saying it does cut and another saying it does not. He just didn't like it being pointed out and asking him to clarify. It is a fundamental principal and that is never a small thing, especially when it is misleading and being widely disseminated.
I'm surprised that Joe banned you from commenting because of this subject. I also posted comments to his videos about his erroneous claims regarding cross-slide v compound thread cutting without any issues. I detest censorship and the YT'ers who abuse it. I suspect that there may be more to your experience because I haven't see evidence of Joe doing this, unlike Abom and Blondihacks who aggressively sanitize their comments.
I commented on his video saying it cuts on both sides.
I like Joe but we don't always agree.
Agree, the video I saw was pointing out that the right side cuts at the tip. He had a sharp half tool and got a rough pattern on the right side. Technically it cuts at 30 degrees but only on the tip (the amount of the tool advance).
Thanks for the interesting demonstration which you covered very well. I like feeding with the compound with a very small positive rake on the tool. Go straight in on the last couple of spring passes for a perfect thread.
Interesting... I'll try that
@@WinkysWorkshop 1 degree top side rake.
@@ellieprice363Any top rake will NOT give a correct thread profile. Probably ok for home shop thread but not for professional Industry Standards.
@@daveticehurst4191Technically correct but since the tool is cutting primarily on the leading edge the thread profile will be exactly 60 degrees.
Hello Winky, I enjoyed your practical application of threading, another good video for us folks out there, thanks for sharing, cheers from me. 😃👍👍👍👍👍
Thanks Me!
I was taught to thread with the compound @ 29.5 degrees almost 60 years ago. I have tried to cut threads with just the cross slide and it wasn't pretty. It seems the Aussies (Kurtis of CEE and Max of Swab valley) thread using the cross slide to cut the thread depth. Max explained that he sets the compound parallel to the work piece. When he advances the cross slide X amount he then advances the compound X/2 amount. Then proceeds to cut the thread. The video showed good results! Maybe you could try this method out and give us the results. KOKO!
Unless I misunderstood that is the same as advancing the compound set at 30 degrees.
@@WinkysWorkshop Almost but not quite and yes the results are for all practical purposes the same . With the compound at 30 degrees the cross slide is basically used as an index, the cross slide returns to a "zero" setting at the start of each pass. Therefore is not used to increase the depth of cut. In theory this method only cuts with the leading edge of the cutter (don't say anything different or Joe Pie will have a cow). The compound determines depth of cut. in the method I described or tried to describe the compound contributes nothing to the depth of the cut. The depth of cut is accomplished by movements of the cross slide only. The Movement of the compound lessens the amount of force on the cutter by reducing the contact with the trailing edge of the cutter to approximately 1/2. Remember that on each pass if the cross slide is moved say 0.2 mm the compound is moved 0.1 mm. If you have time check out one the videos from Swan Valley Machine shop. Max Grant explains this method much better than I. Also he does a demonstration as well. If I can find the video I will send you the title. Sorry if I did not communicate better.
@@jamesreed6121 I think this is exactly the same, the only advantage is being able to measure the depth of cut while adding a little complexity and a number to remember (or forget).
Going to make a Acme compound replacement rod for my old lathe. After this video, considering changing how I planned to cut it. Need to make a 52t gear first. Know what I will be doing in the next few days. Thank you for showing 'how to'.
Acme are hard to cut. I think next time I cut them I will cut with a narrow grooving tool mounted at a slight angle and then go back with the acme form tool.
I found the noise in my South Band 10L. It all came from a loose set screw on my electric motor pulley. Once it was tightend, it now sounds like a sewing maching.
That's great, now that I have an oiler on my gears its much more quiet but the new mic also helps.
Rigidity will indeed be a big factor, as will material. I tend to feed with cross slide on my lathes, but they're quite a bit larger than yours. I think this is the first threading demo I've seen where the machinist took a deep initial cut and then decreased progressively as the thread formed. Most people do 0.005" or so all the way in. Big waste of time. Great demo well explained. Thanks.
According to Cat Stevens (Yusef Latif) "The first cut is the deepest (baby I know)". I start with .02-.03 the first couple of passes, then progressively reduce depth.
Yep... you can take a huge first cut.
Cat Stevens? Ha, you must be my age.
Advance the compound a little on each pass to relieve the pressure on the cutting tool.
👍👍
Thanks
thank you so much, have a wonderful Independence Day my Friend, Paul in Orlando
Thanks, you too!
Very interesting, I am generally happy if the thread is just fit for purpose and I don't have to redo it!!!
Thanks
I often cut threads with h.s.s. tool oil stoned ,the threads are always a good finish with goog chips. Many repetitive threads I used tips. Interesting content.
I agree, sharp HSS makes a huge difference. Do you feed with the compound?
@@WinkysWorkshop I have used both methods, predominantly the compound method. My lathe has very little backlash, I try to screw cut at the highest rpm I can with job at hand use a cutting compound sulphur based, the material type I find plays a big part, 4140 possibly be my favourite , I do fair amount of stainless as well. I enjoyed the topic regards Ian.
@@iandibley8032 Yeah, higher speed is better as long as you can control it. I've always felt like the sulfur oil was better. I may need to go back to it.
Great video Mark. Interesting to see the half tool cut so well, must give that a go myself sometime! I have done it both ways on my Myford S7 , compound and cross slide , the cross slide probably more from error than design , but usually the compound is my go to.
Always look forward to your content , keep up the good work!!
Thanks you very much!
BTW I suggest you add a "Super Thanks button"
hahaha... 😜 send money! I'm kidding, thank!
I always liked cross slide more althou we were taught both ways.Its simplier to get a correct depth of cut -you use marker on a blank and then do the skim pass to check thread pitch,0 the cross slide dial and then you feed to the wanted depth.If geometry of the blade is good (when you grind hss for example)you will get a great fit by just using the dials.With practice over years you dont need thread micrometers or pin gauges or anything like that.
Something that i was never able to get with compound method .
That makes sense. Never thought of that. Although , you could double the move on your compound and get the same results.
@@WinkysWorkshop There is one more reason i like cross slide method -old lathes have worn out bed ways.I am speaking about 2 shifts for 20 years wear.And they can cut taper in the thread ,just like when you work on round objects.Its not a problem with short threads but if you do a long one it can be noticable .What i used to do is to find where thread gets stuck and then i slightly bump the dial with my hand as lathe is cutting the thread-if you do a spring pass in this case begin of thread can get very sloppy with too much play .We are speaking about a 10th of a mm ,sometimes even less.
But as long as you know the flaws of the machine that you are working on you can still make accurate parts ,within the reasoning tolerances-it wont be fast as a new machine but parts can be made.AKA you cant expect micron precision from a 20 years old manual lathe that was working 16h a day for 5 days a week.
@@armageddontools I do okay on my lathe but its worn out. I didn't realize how much until I made a follow rest.
For the mainly small threads that I make, I do it as follows:
- 1st pass straight in with the cross slide, depth about 1/3 of the thread height (there is little material to remove).
- 2nd pass usually 0.2 mm deeper and the compound 0.1 mm forward.
- 3rd and subsequent passes usually 0.1 mm deeper and the compound 0.1 mm alternating back and forth
- last passes 0.05 mm feed and +/- 0.05 mm flank shift
- A few spring passes without cros slide feed and +/- 0.01 with the compound
Always nice smooth flanks and no hassle with compound angle adjustment. Lubricate well!
Hmmm... too complicate for me
It seems complicated, but it really isn't. Regardless of the depth of cut: Just go straight in every time, but a little left, a little right and so on with the compound. That's all.
@@Michel-Uphoff I'm not trying to be contrary but it would be easier to just feed with the compound. You method works for the same reason.
@@WinkysWorkshop I'm not the only one who finds this way of cutting a thread the most easy and successful. For example, Kurtis from CEE Australia also does it this way. czcams.com/video/3VjT4peTVww/video.htmlsi=wobRDL2BMZwcI16Y&t=750
Give it a try...
@@Michel-Uphoff I'm sure you're correct on that... I might give it a try
A good topic to start a fight in a Machinist bar. LOL
I also prefer using the compound. When I need to make threads for my wood lathe, 1 1/4in x 8 tpi, even with using the compound I have to take light cuts due to the amount of metal being removed.
As you said, the sharp "half" threading tool made some really nice looking threads. Well done.
Dave.
Yeah... I was very surprised. I might have to start using HSS more often.
I have a threading tool from Arthur R Warner Co from here in PA which uses HSS inserts. This works well. Easy to use for external threads, needs a large ID for internal threads.
Dave.
@@lv_woodturner3899 I'll bet it works great. I had one of their inserts without the holder and never tied it.
...so how do you know you are arguing with a lathe operating machinist if you're not in a Machinist bar...? They always start with "well, let's face it..."
@@AttilaAsztalos Haha
Something that hasn't been mentioned is the chip flow. When feeding with the carriage, it produces two chips which must compete for the same space. It was pretty obvious watching when feeding straight in.
Very true. I pinned a comment to the top. The guy that made the comment explained this well. Thanks!
I think that the reason that the half profile tool cut so well is that the cuttings cleared from the work piece far better.
I agree. Plus the tool was HSS.
@@WinkysWorkshop As an apprentice we did an experiment in college where we started with a square piece of HSS and tried to cut with it,. We then added side clearance, which improved the cut and finally we added top rake again improving the cut.
@@grahamc887 For sure it makes a big difference. I was also surprised how much honing the cutting edge also helped
From videos I've seen, the straight-in method works fine for fine, shallow threads. Maybe another experiment with 28tpi?
I agree. Thanks
There is another method that is equivalent to using the compound set at 29' Set the compound parallel to the lathe axis and feed the cut with the cross slide but feed the compound one half the cross slide depth of cut. This means the depth of the thread can easily be read from the cross slide but moving the compound one half the depth of cut is equivalent to setting the compound to almost 29'
Two others have said the same. Aside from the compound interfering with the tail stock this method has the advantage of being able to cut to depth.
This method is as common as the other two but did not feature in the video?
Perhaps a contributing factor in the difference of finish between cross-slide with insert and cross-slide with your very clever ½ threading HSS tool might be how carbide cuts your workpiece vs HSS? (assuming your ‘factory tool’ was a carbide insert?. Love your videos and your thinking!
Yes, good point and I agree. I think I mentioned this... (could be wrong)
I've tried both methods and now plunge straight in. I go from left to right at higher speeds and use plenty of cutting oil, HSS tool. 1440 lathe. Decent threads. I've got carbide inserts but they are never as sharp as my HSS. Especially on quite small threaded things the inserts seem to want to push too much before cutting.
I agree, HSS is much sharper
One advantage of cross slide is that it is more rigid than compound -some people get rid of their compounds and make solid blocks with tools posts.If you have chatter problems-especially on small weaker hobby lathes that affect the quality of your threads consider locking the compound and use small depth of cut with cross slide.
Big heavy duty rough cutting industrial lathes dont even have compound slides and they use block tool posts instead of quick change tool posts.If you have a chinese lathe that may be your source of problems ,cheap quick change tool post +low rigidity of compound slide = chatter and bad thread quality .
Sharp tool with proper geometry and right speed +smaller depth of cut and several passes can get the job done even on cheap chinese lathe.
I've seen this before. My compound gibs are set tight and yes this is a plus. I would never want to do away with the compound unless I used the lathe for a specific purpose.
Big difference between cutting gummy stock at slow speed with carbide insert, and cutting same gummy stock at same slow speed with a high speed tool bit! Carbide insert will produce much better chip and profile cutting faster than you showed.
As for which method is better ? I always like to keep it simple using Cross Slide instead of Compound, especially if thread pitch dia has to be within given tolerance measuring with wires or Thread Mike.
You can always take several finish "air passes" for full profile carbide insert finish with Cross Slide if required. And/or even at that point, micro adjust produced thread profile with your Compound if necessary on last pass.
I agree that much higher surface speed will do much better with carbide but it's also risky if you are cutting close to a chuck or shoulder. As far a methods for feeding goes feeding with the compound is much easier for me. Mostly because I forget what my cross slide was set at when I back out to return for the next pass. When feeding with the cross slide you just go back to zero and you don't have to remember a number. As for hitting a thread spec the compound makes this easy, every move is have what the cross slide would be. It's like a fine adjustment. Ultimately if going in straight was proven to be better I would do it but I'm finding exactly the opposite to be true. I just pinned a comment to the top which explains exactly why I think this is true.
Thanks! Using the Cross Slide is still just one feed handle you have to keep track of in and out. Whereas feeding with the compound, each pass is moving the tool ever closer towards a shoulder or small undercut if that's what your dealing with.
Might not mean much on a 1/2-13 thread, but when you get into some serious tooling cutting larger dia. fine threads it can matter, especially if there is a slight shoulder as for a bearing.
Also, what I meant be my use of the word "simple" is you wont need any chart determining actual infeed to get to finish pitch dia, as it is simple math cutting with Cross Feed.
Here's the deal. I've desperately wanted to learn making threads with a lathe but every channel I've watched began at a level for advanced machinists, meaning it served no purpose for me. Your video does a great job regarding the "thread-making" portion but it doesn't let me understand "setup" from the beginning. What I'm missing is ... once the stock is inserted, once the end is faced, once a bevel is applied ... do you set the compound at a "zero" location away from the stock then feed it with the worm drive, only to return the compound to the zero again with a slightly deeper cut ??? This would be very helpful for me and I assume many other people who would like to learn to cut threads.
I'll make you a video and post it Friday. Be sure and watch!!!
@@WinkysWorkshop Thank You very much ...
Lots of comments regarding tool profile and angle of attack but I'm not hearing about speed, depth of cut, cutting oil (high sulpher content) all of which i have found can make a profound difference in thread quality. In my type of machinig im more so than not shooting for class 3 A-B threads. I dont want a customer unscrewing a thread protector and see threads that look like a beaver chewed on them.
Yeah, need to keep those beavers out of the shop. This video was mostly about comparing two feed methods but yes, higher speed cuts smoother. Threading against a shoulder and my reflexes limit the speed however. I agree on the oil. I used to use the sulfur oil all the time. The difference isn't drastic in my opinion but I feel like it was better.
@@WinkysWorkshop thread away from the head stock. It reduces reflex worry and "pu cker" factor.
@@WinkysWorkshop thread away from the head stock. It reduces reflex worry and "pu cker" factor.
@@johnseptien3138 Screw on chuck provides an alternative pucker factor.
@@johnseptien3138 Screw on chuck
I use the compound set at 29 degrees for two reasons not mentioned. Cutting with the cross slide means you have to remember the depth of the last pass. I can't have any distractions of any kind while cutting threads using this method. Total concentration is required... at least for me.
Secondly, by bringing the cutting tool up close to the work and turning the cross slide handle to about the 10;30 position and setting zero, you can then bring the tool to the work using the compound slide and setting it to zero also. The advantage of doing this is that you can now run the work at 150/200 rpm and then snap the tool out of the work without having to bother making an under cut for the thread. Do it several times and you will see it is pretty easy to do... and you can impress your friends.
As an aside, look in your reference book and notice that the major diameter for a thread is not the nominal diameter of the material. So, with metric or imperial the very first thing you do is turn the work to the correct diameter. Failure to do this may explain why the mating thread goes from won't go to will go with a sloppy fit and undersized pitch diameter in one pass. Correctly cut, the flat crest of a 60 deg. metric or imperial thread is 1/8th the pitch. You can cut a class 1 thread to size by just looking at it.
Cheers from NC/USA
Yep... I just got finished explaining to somebody that feeding with the compound is easier because you don't have to remember numbers. As far as the major diameter on inch threads goes, the major diameter is close to the stated size. If you put a tip on the threads the will be full diameter. So cutting thread on a 1/2" rod until they are sharp yields very close to the correct depth. Of course filing the tips off is needed to obtain the correct profile. I guess its a mater of preference, taking it off before cutting would work well.... but for most application I have good results filing the thread tips.
@@WinkysWorkshop There is another reason the work should be turned to the diameter shown in your handbook. It ensures that the major diameter of the thread is concentric with the pitch diameter. Filing the crest of the thread won't necessarily correct this fault. This fault may not come into play unless you are cutting a class 3 thread perhaps. In any case, easily avoided errors or problems should be avoided as you usually have enough other problems to worry about.
Cheers
@@aceroadholder2185 I suppose you're right. If I was in a business and making things to spec I'd want it right. Most often I just was a thread to fit a nut and the two times I needed accurate threads I used wires.
Use full form inserts for the thread you need. Root and crest rads all sorted.
I appreciate the content. The root doesn't match a proper profile with the last tool you used. However, I run my threading tools inverted for most jobs and sometimes even use the compound in conjuction with the inverted tooling. I actually disagree with using the compound in a 30/29.5 degree setup, but I also do more precision, or smaller, threading than most folks I know and I normally use carbide tooling due to the materials I thread. I do, however, use the compound when 'finding' thread done by incompetent gunsmiths, in order to correct their profile.
> The root doesn't match a proper profile with the last tool you used.
You mean the tip radius is too large?
> I actually disagree with using the compound in a 30/29.5 degree setup, but I also do more precision.
For very small threads I could see why. It not needed but I can't see why it would effect precision.
I noticed the run-out changed during the processes! But I vote COMPOUND. Or single Point.
Yes it did... a high quality chuck! Thanks
Not a thing about this comment thread makes any sense.
@@EitriBrokkr If you look at the stock on his test pieces you will see there is run out on the parts. Then It goes away towards the end of each threading process. But you have to look CLOSE.
You are correct.
Thanks!
The guy I have see cut with the cross slide also use the compound set at 0 and advance it by a few thou. I have yet to try it but it works well for them.
Thats what I did... although larger moves at first
@@WinkysWorkshop It did not show on the video that you moved the compound forwards with each pass.
@@marley589 The first thread was compound and the second was cross slide. In hindsight I should have shown my hand tuning the dial. It would have added clarity. I was wanting to show the chips forming and didnt think about showing it.
@@WinkysWorkshop This comment strings original post by @aaronfritz7234 referred to the compound at zero and advancing it a few thou every pass. You had the compound at 29 degrees. So your comment " thats what I did " is incorrect.
@@marley589 Sure enough, I got confused. Sorry about that. You are correct, I have never tried this method. Without going back to find the comment I think I recall that his compound was set parallel to the stock (which is actually 90 degrees) and he moved the cross slide and then doubled the move at the compound. I assume in separate passes after each correction. It sounds like a good way to lose track of what moves have been made. I'll stick with the compound move only. Simple and effective.
Mark is dead right about the ridgidity of the lathe. It is the main factor. I don't cut many threads but when I do it's compound driven. 29° for 60° threads and 27° FOR 55° threads (whitworth), close enough. I get much nicer thread on my rubber lathe 😂.
Rubber lathe? Haha. Thanks
I hope you get the viewing hours you deserve!
I've found it difficult to create a video that holds people's attention! I'm just a boring old guy!
Thanks! So far this video is getting a lot of views but its a controversial subject. I think your subject mater is more complicated.
I did the same test many years ago cutting a 12x1.5 thread in 303 stainless using a 1,5 pitch full form insert, even under a microscope you couldn't tell which was which.
Wow... that's interesting. Were you using HSS or carbide?
@@WinkysWorkshop full form carbide inserts, not sure of the make but certainly nothing special. My lathe is semi industrial ie not overly large or powerful, being a Colchester Bantam or early 60s vintage.
@@chrisstephens6673 Probably much more industrial than my lathe. I'd say the reason was how ridged the lathe is. One overlooked aspect of small older lathes is the small spindle and thread mount. A 1.5" spindle with a thread mount chuck is a weakness. Mine is slightly larger but still weak (1.625"). The strength of a thread mount goes up exponentially with size so a 2" or 2.5" thread mount is drastically more solid. I did a video with my Logan. I put a 3 foot bar in the chuck and pushed down with about 20 lbs pressure and the chuck actually pulled away from the spindle register. I remade the back plate with steel and it helped but never the less, it was still an issue. The original chucks for these small lathes were very low profile. New chucks have a full 1.5" more overhang (sometimes more).
What was the spindle size on your lathe?
I always use the compound. Why? Because I use HSS for threading and if I feed straight in the tip of the tool always chips off halfway though! Might just be chinesium HSS though.
Putting a radius on the tip helps this a lot but never the less, the tip is ripping more than cutting when you go straight in. I prefer the compound.
@@WinkysWorkshop Can't disagree with any of that. You can only put so much radius on before it doesnt conform to the specs though.
@@ThePottingShedWorkshop Very true
Feeding in with the cross slide makes it easy to see the exact cut depth on the dial. To cut on the leading edge and almost exactly simulate a 29 degrees feed in. Advance the compound half the depth of cut per pass with the compound set at zero, parallel to the spindle.
The opening comment regarding whether a particular method is better depending on the power of the lathe is a little misleading. The idea of reducing tool load by feeding on the flank is to protect the tool. The delicate tool form will chip or break before the lathe stalls.
Interesting idea, that would work!
@@WinkysWorkshop it's a very common practice. Very few use any other method once they know it.
@@tates11 I see no advantage.
@@WinkysWorkshop 1. You don't need to move your compound slide, leave it set at zero for standard turning operations.
2. The thread depth is a direct reading on the cross slide dial. No calculations or setting required.
93% load on the leading edge 7% on the trailing edge. It is taught as standard practice in Europe and I believe Australia also and probably many other countries too.
@@tates11 I see the depth of cut advantage although I never do this and seem to get it right. Leaving the compound angle set at zero is not a plus. It gets in the way of the tail stock.
I am irritated YT did not notify me about your last several videos 😡
Sorry to hear that
lol hay mark.... how about trying to improve on the cutting tool for threading ?
why not give the half-tool a relief so it actually cuts instead of having the chips slam into a flat surface on the tip of the tool.... it has always bothered me that threading kind'a rubs the chips off instead of cutting them off and inserts only slightly improved upon this but the area is so small you still get a flat area on the cutting edge... so why not just cut a relief behind the tip of say 5 degrees so the chip is actually cut ? may not work for hard metals
like stainless steel , or that may only work on soft metals, aluminum and copper,etc,etc.
but the reality is if it works on mild steel we all would be far better off using a half tool with a relief ! because when I thread i hardly ever get good clean threads so I have to run the corner of the file in the thread groves to clean then up.
a half tool might well cure that for me ! thanks Winky !
Yes yes yes... You are thinking like me! Ha. The half tool was ground with both back and left side relief which is better than most carbide inserts! I've always wondered why all these inserts on the market have all sorts of wild patterns and reliefs and the threading insert only has a back relief! More half tools on the way - Ha
Yes the half threading tool would cut much better with about 10 degrees top side rake. I prefer to call it “top side rake” instead of “back rake” since you definitely don’t want the tool tilted backwards.
@@ellieprice363 I think my side rake was a bit less, maybe 4 or 5 degree but I also ground some back rake hoping to make the tip cut the right side a little better. I'd say it probably was not needed.
@@ellieprice363 I cut the top rake square to the leading edge, I do advance the tool to cut on the leading edge though.
Me not knowing ANYTHING about cutting threads, doesn't it make a difference with the type and sharpness of the particular tool you are using?
Yes it does. A high speed steel (HSS) tool is sharper and will generally cut cleaner threads with less tool pressure than carbide.
@ellieprice363 along with the rigidity and size of lathe. So, pretty much EVERYTHING effects the quality of the work done on a work piece.
Yes and good point. For the two feed methods I used the same tool but that last test with the half tool was very sharp HSS. This is one reason it was a smoother thread.
Yep... you're right, thanks
I'm sure you've had this question asked before, but what in your lathe sounds like there are loose bearings rattling around?
Straight cut gears. Fairly typical for old south bends.
@@WinkysWorkshop Thanks.
@@rogeronslow1498 You're welcome.
The best part about doing it with the compound is you don’t have to remember each time how deep to cut, the cross slide just simply goes back to zero. You’re a liar if you’ve accidentally put too much of a cut on and see this big chip curling up.
And by the way you know you can do less than 29 degrees right? Can be anywhere from there to zero.
This is true, but I prefer 29
The intro was perfect, the visual aid was spot on, you should have stopped while you were ahead.
Carbide vs HSS with completely different geometries. Feeding 5 thou on a thread like that and wondering why the surface finish is terrible?
I don't know whats worse, this video or some of the completely clueless goofballs in the comment section.
Why do people have to be rude, describing a comment as a "goofball", just because they achieve the result they desire by a different technique?
There are may ways of achieving desired results, just because some use a different regularly used technique should nor require a rude response.
Wow! Why don’t you produce a threading video and lay your wonderful expertise on us?
@@ellieprice363 This logic makes no sense. How about people not post moronically stupid nonsense and water down the knowledge base? Videos like this only make society dumber. There are already plenty of good quality video's on the topic... What is the benefit of another one, poorly done, full of bad/nonsensical information?
@@EitriBrokkrCalm down. I suspect you’ve never cut a thread in your life.
@@ellieprice363 are you going to add anything constructive to the conversation? Or are you going to keep resorting to ridiculously made-up ad hominems?
I was afraid you were about to step on the third rail for bringing this up. Other channels have expressed their opinions and then gotten lambasted from all sides. Strap on your thick skin and smile. 🥸👍👀✅
Bring it on! Haha, I don't care.