Threading Help

[Billh50]

I usually just use the cross slide on my HF 7x with no problems. Of course the largest thread I have done is a 5/8-11 and I ended up chasing it with a die to get rid of the slight taper.

 

[brino]

Personally I find that using the cross-slide to feed for threading causes more chatter than using the compound.
At least it did on my earlier "lesser" lathe, and that trained me to use only the compound.
I believe it's due to the length of tool face presented to the work.
-brino

 

[T Bredehoft]

Cannon Powershot SX60

THAT IS AWESOME! I thought I 'd seen zoom. but it makes me realize why I couldn't hear the music.

 

[savarin]

It's not necessary to use the compound slide at an angle on such a small thread, just do it from the cross slide straight in.
I realize that this is heresy in the hobbyist world but have been doing it this way for the last 30 years without problem, however once you reach very large very coarse threads (say 2 1/2-4 and above) it may help on a wiggly machine.

Since I made a plinth for my AXA tool post and removed the compound I also thread at 90 degrees.With sharp bits and small feeds I haven't had a problem (so far)
The largest thread I've cut is a 39x4mm, that was a bit of a pain from the backlash in my cross slide.

 

[intjonmiller]

I can't add any threading advice, but I can share a great comic published just Friday on the subject of superzoom cameras: http://xkcd.com/1719/

He exaggerates, but not by much. As a photographer myself I must emphasize that those zooms are a tradeoff. Both the aperture and the sensor size are very small in order to accomplish such a feat in such a small package. As a result they are only usable in at least moderately bridge light. (The D500, by comparison, can shoot usable images in the dark, but a lens that could zoom as much as the superzooms, yet be usable , on that sensor, would need a mount similar to a gun turret on a Humvee.)

Years ago I was a Kodak rep for a Christmas sales season temporary gig for some extra money. The image quality of their consumer grade cameras was never very impressive, but there has never been an easier to use camera. I could hand one to any elderly couple, no matter how old, and have them taking photos using any features I mentioned, without showing them how or giving them a manual. As soon as I told them what it could do they could find the feature in under a minute.

I bought my wife a Panasonic LX-100 because it is the best combination of size and image quality I could find. It's unbelievably good. And unbelievably hard to use. As a professional photographer I can't figure out how to do half of what it can do when I want to. If Kodak had put as much emphasis in image quality as they did on usability they would have absolutely dominated instead of going under.

Anyway, thanks for the reminder of that largely forgotten memory, and good job on your first thread (that counts).

 

[eeler1]

First thread? Excellent! Do another.

 

[epanzella]

I replaced my compound with a solid block and used the compound to make a heavy duty milling attachment on my G4003G. That was 3 years ago & I've been threading with the xslide ever since with zero problems.

 

[Tony Wells]

I believe that this is one of those things that is absolutely correct in theory, and comes into play without doubt on the small, light lathes in the home shop. But even in the commercial world, CNC programming makes allowance for several approaches to cutting threads, and they include what is the equivalent to compound feeding into a thread on a manual machine. And over the years, I have worked with several programmers that used methods other than straight in threading. On the few programs I have written (years ago, just for some emergency training) I used alternating sides when threading.

Bottom line is that some machines can plunge straight in and turn out a perfectly good thread, and on those, using the compound is probably a waste of effort. It then becomes a personal preference. Then on the other hand, some machines will never be able to do that, so there is no choice but to use the compound method. Straight in is not an option. So on those machines, it's not a personal preference.

 

[mikey]

In my opinion, which axis you use to cut the thread has less to do with the quality of the thread and fit than all the other variables involved. I find that if the tool is sharp, is ground with adequate side relief and the 60 degree included angle is accurate then the thread form will also be accurate and it matters little if the compound or cross slide is used. How "pretty" the thread is has more to do with how depths of cut are staged and which lubricant we use than anything else. Fits have more to do with the size of the work before a cut is made and how deep we go before we check for fit.

This is a Class 3 M12-1.25 thread cut into the end of a leadscrew made of 1144 Stressproof steel. It was cut on a Sherline lathe, which uses the cross slide to feed in and the leadscrew is turned by hand. Other than cleaning the chips off it is just as it comes off the lathe. While my Emco Super 11 lathe will cut the same quality of thread using the compound and will do it faster, it won't necessarily do it better.



To the OP, threading accurately is kind of like boring. It seems simple enough until you begin to look at all the variables you need to take into account. It is only after you can control those variables that threading, like boring, becomes simple. Hang in there, it will come - like all skills, these things take time.

 

[Wreck™Wreck]

I believe that this is one of those things that is absolutely correct in theory, and comes into play without doubt on the small, light lathes in the home shop. But even in the commercial world, CNC programming makes allowance for several approaches to cutting threads, and they include what is the equivalent to compound feeding into a thread on a manual machine. And over the years, I have worked with several programmers that used methods other than straight in threading. On the few programs I have written (years ago, just for some emergency training) I used alternating sides when threading.

Correct, many CNC machines have an approach angle in the canned threading cycle and many newer ones will give the option of approaching from each side on alternating passes.
However such a small thread should require neither if you do not have the need to make 1000 parts per day or week, tooling changes slow down the process a good deal and the alternating approach angles uses both sides of the tool for the heavy work.