An Alternate Method To Screw Cut Larger Pitches In The Centre Lathe .

I suffered under the tutelage of an old German machinist, and at the same time I was taking machine shop in high school. Klaus, always used the method you just presented, so I dared not do anything else in his shop. My High school teacher always had us set the compound at 29 1/2 degrees. Neither man ever explained just why that threading was done the way it was. Both methods worked just fine for me, and I was never questioned by any one in the companies I worked for. ( I think I was the only kid who was trusted to cut threads on valuable work pieces) At University, the machine shop teacher noticed me using your described method, and muttered something about a " Bad European influence" that I never understood. But again, I always got to thread the more important projects we built for the school. It was only a few years ago, after watching lots of different people cutting threads, on YouTube, that I did notice the difference in compound settings, And sure enough European, and Common Wealth machinist used your compound set at 90 degrees. Previously I had only cut multi lead threads, by using the compound set as you have shown. I liked that method, as I could always fudge a bit and always got a perfect fit, something that was not always easy to obtain. I used to think I was a pretty great machinist, but after watching some of the folks on YouTube, I look like a rank armature, even after almost 60 years of working in machine shops, including mine!!! So, I'm an old dog, who can still learn new tricks!!! LOL!!! I have to laugh, seeing you working in shorts, and talking about 40 degree C heat. I'm in Central California, and freezing in 40 degree F cold!!! LOL!!! I never liked being cold, and when I was in the Air Force, I was always getting stationed in very cold places, Like Colorado, Idaho, and New Jersey. The older fellows never understood why I always volunteered for SEA duty ( South East Asia). I remember the Snake river in Idaho, freezing solid in the winter of 1972. It was minus 60 degrees F at night, and warmed to minus 40 degrees F, for a day time high. There was never that much snow, but it was blizzard conditions a lot of the time. When the wind stopped blowing, and the sun was out, you could get sun burned in below zero F. That beautiful blanket of snow reflected the sun at all kinds of different angles, and radiantly cooked what ever flesh was exposed. I enjoy your presentations, thanks again for all your efforts, they are appreciated!!! Tim

A good-to-know technique that I have never heard of. Thanks Max.

Supprised no-one on YouTube has shown this method, especially useful to hit numbers when you have dro on cross slide, but not on compound.

Ive seen Curtis over at CEE and wondered what he was doing. This explains it cheers Max

Another great example of Trigonometry in machining. Moving the compound half the distance of the infeed is in reality creating the same thing as a 30 degree angle cut with just the compound...BRILLIANT!

Absolutely lovely threads. And cut like a true Jedi Lathe master Machinist ! ☝️👍🏻

Thanks for the show Max 🍻

Not criticising your technique as I've wrestled with setting the 29-29.5 degree compound angle and my compound has heaps of backlash, so this technique is a gift. Not trying to be picky, given that you're using 20 thou DOC on each pass, if you go to 11 thou on the compound to every 20 thou on the cross slide you'd be hitting 28.8 degrees. Great video and HUGE thank you Subscribed.

This works great because it's doing basically exactly what you're doing when setting your compound to 29.5. The sine of 29.5 is ~.49, which is close enough to .50. Great vid as always!

My milltronics cnc lathe offers 4 ways to have the lathe cut the threads. one was the way you just mentioned. i didn't know why one would need to do this till you mentioned the heavier threads. now it makes perfect sense. thank you

Really like your videos, becoming one of my favorite channels to watch! I'm from the states and I too keep compound at 29 degrees all the time. However, I think I'll try setting mine up like your just to see how it works out.

Vary helpful, I like the shot of the part being cut and as well being able to see you working the magic on the hand wheels, thanks for showing everyone who has an internet connection the right way to make chips.

Another great bit of info as you never know when an machining operation will give trouble. Thanks again Max Cheers

Hi Max, I wish I'd watched this before my last project. I got away with straight in cutting 5tpi but there were indeed some 'dramas'. I perhaps listened to people who said "I only ever go straight in" but recent events have taught me that's not necessarily good advice. My default is now to go in with the top slide angled. Cheers Paul

Another high caliber job good one Max

Great video Max! I have really been enjoying your content, as I only found your channel recently. Angled infeed is more common on conversational or CNC equipment with full form threading inserts in my experience. It's great to see you emulate that on the manual lathe! G'day from Alberta, Canada - the land of API pipe threads and frozen faces. Cheers 🍻

Glad I decided to stop by today, I learned a new threading trick, Thanks

Thanks for the knowledge Max. It's always good to be aware of different ways to accomplish a desired result. Stay cool down under!😅

Interesting technique, one I haven't seen before. Thanks for sharing, Max.

Good tutorial Max. I remember David Wilks using that same set up, but with a different technique, to cut multi-start threads. I usually thread with the compound at 90 but just plunge in. For most pitches my lathe is rigid enough that I can do that. I'll keep your method in mind if I cut some large threads and have problems with vibration. We have a windchill of -40 C right now. No shorts for me. Ken