@ 16:17 you diagnosed my problem and I am so grateful. Thank you for all the instruction and being my UA-cam teacher almost 2 years now. Next week I'm excited to make threads again
I've never single-point threaded on a lathe without a quick change gearbox and a thread dial. Intuitively, I always understood that you never disengage the half nut and reverse the spindle direction, and install apprropriate change gears. But i've never done it. Also, I've never cut metric threads except on a lathe that was so configured. I enjoyed your discussion of thread wires and the markings on the thread dial. I can well understand why you made a thread dial to use on your lathe. It is a real time-saver. Merci beaucoup pour une discussion intéressante, comme d'habitude.
16:00 A lesson I learned the hard way haha. The first thread I ever cut on my lil Atlas 618 was a acme thread(for a new to me heavy ten). I didn't have a thread chasing dial at that time, so I was keeping the split nuts engaged and reversing the chuck by hand, then, when I was almost done, I had the bright idea of keeping the nuts engaged and reversing the tumbler. My 2 dogs wouldn't look at me for an entire day after that. Thank you so much for all of your videos!
thaks Marc, just bought (i am a novice) a lathe which might be over my head. it is huge (to Me) and not a table top but a 14/40 grizzly. I am mechanically inclined and retired.. Only way for me to learn is to watch videos concerning this content. I like your presentation an plan on watching all available from your home listing. thanks again for sharing your experience with a novice.
I have a Harrison M250. The lead screw has 4 TPI as its an imperial machine. I have 6 numbers on my thread dial. So, I can cut any thread odd or even on any number 1-6 unless it's a pitch of 4-1/2, 5-1/2, 7-1/2 or 9-1/2. Those 4 pitches are only 1,3, or5 on the dial according to the metal tag. I think that's pretty convenient. Thanks for sharing, you made me think. I appreciate that.
Thank you for taking the time to provide this well presented explanation. I have a question, perhaps a dumb one but one I run up against often. I make only metric threads on my lathe and it has an imperial lead screw. I manage these threads with the correct gear set and by keeling the half-nut engaged. I can't quite see why I couldn't use the same thread dial mark I started with and do the disengage/reengage shuffle? My lathe (a French built machine made for the North American market and sold as "South Bend Nordic") has a good reversal system with electric brakes making my process practical. Please keep your great content coming, your experience and knowledge is vast and your knack for getting it across is a gift. I'm 65 years old and always enjoy learning as well as playing around in my shop. Marc, you are awesome!
There is a way to thread on a lathe that has no thread dial. Works even if the lathe does not have a reversing switch, and if I understood the guy correctly, it works on lathes that are using conversion gearing (imperial cutting metric or metric cutting imperial). A bit more involved in setup and use, but it works. Timing marks on the head stock/chuck, and on the feed screw, and a starting position mark for the carriage on the bed. One of your Countrymen demonstrated this method, some time back, it shouldn't be hard to find his video I thought of a way for getting a correct thread depth on a part that I could not do a "test fit" on, and I don't have thread gauge wires ... I tried it once, it worked once. It I can repeat that, I'll try to put it out there for others to try.
Allo Marc; Joe Pi showed cutting threads while running in reverse, cutting on the 'far side's of the part...same benefits as you showed with LH threading, but RH thread...
Hey Marc. Not related to threading but I really enjoyed your Heat Treatment of Steels 1, Hardening, Tempering. Have you ever considered doing something similar but for stainless?
I’ve always wanted to know more about the size hole to start with for tapping. Some hard materials might use a larger hole than the charts or some larger diameters with fine thread need a larger hole and I don’t know how to choose.
Marc, can/will you make a video to answer Mark's question? I've always just guessed at hole sizes when I didn't have the correct drill and have gotten away with it, but I'd also like to hear your thoughts on doing this, along with the answer(s) to Mark's question.
Some rules of thumb: A 100% thread is only 5% stronger than a 75% thread but takes twice the power to tap. A standard grade bolt screwed into a part to a depth of the bolt's diameter will break before it strips out a 50% thread in mild steel. 100% threads are useful on very thin stock. For tough materials like stainless steel,etc. a 60% thread is fine and 50% would be satisfactory. I have a tap drill chart that goes down to 50% for tap drills, but I've had it for 40 years and I can't remember where it came from. You can probably find a formula on line for figuring it out and maybe a chart already done. If you can't find one, let me know and I'll make a copy of mine and send it to you. Cheers from NC/USA
I'm not a machinest however I enjoy all your videos due to your fantastic communication and demonstations. And your sense of humor!
@ 16:17 you diagnosed my problem and I am so grateful. Thank you for all the instruction and being my UA-cam teacher almost 2 years now. Next week I'm excited to make threads again
I've never single-point threaded on a lathe without a quick change gearbox and a thread dial. Intuitively, I always understood that you never disengage the half nut and reverse the spindle direction, and install apprropriate change gears. But i've never done it. Also, I've never cut metric threads except on a lathe that was so configured. I enjoyed your discussion of thread wires and the markings on the thread dial. I can well understand why you made a thread dial to use on your lathe. It is a real time-saver. Merci beaucoup pour une discussion intéressante, comme d'habitude.
Great video Marc! It's informative, really helpful especially for novice machinists like me.
Take care my friend
Dimitris
16:00 A lesson I learned the hard way haha.
The first thread I ever cut on my lil Atlas 618 was a acme thread(for a new to me heavy ten). I didn't have a thread chasing dial at that time, so I was keeping the split nuts engaged and reversing the chuck by hand, then, when I was almost done, I had the bright idea of keeping the nuts engaged and reversing the tumbler. My 2 dogs wouldn't look at me for an entire day after that.
Thank you so much for all of your videos!
thaks Marc, just bought (i am a novice) a lathe which might be over my head.
it is huge (to Me) and not a table top but a 14/40 grizzly. I am mechanically inclined and retired.. Only way for me to learn is to watch videos concerning this content. I like your presentation an plan on watching all available from your home listing. thanks again for sharing your experience with a novice.
Thanks for sharing!
I have a Harrison M250. The lead screw has 4 TPI as its an imperial machine. I have 6 numbers on my thread dial. So, I can cut any thread odd or even on any number 1-6 unless it's a pitch of 4-1/2, 5-1/2, 7-1/2 or 9-1/2. Those 4 pitches are only 1,3, or5 on the dial according to the metal tag. I think that's pretty convenient. Thanks for sharing, you made me think. I appreciate that.
Hi,
A very interesting video... thank you...
Take care
Paul,,
Very well explained. Thanks
thank you for the white board explanation ........ this will save me time. I've been wasting a lot of it lol
I'm so glad to see you are back, I have missed your videos. I have wondered how you were doing and if the cancer was giving you issues.
Thank you for taking the time to provide this well presented explanation. I have a question, perhaps a dumb one but one I run up against often. I make only metric threads on my lathe and it has an imperial lead screw. I manage these threads with the correct gear set and by keeling the half-nut engaged. I can't quite see why I couldn't use the same thread dial mark I started with and do the disengage/reengage shuffle? My lathe (a French built machine made for the North American market and sold as "South Bend Nordic") has a good reversal system with electric brakes making my process practical.
Please keep your great content coming, your experience and knowledge is vast and your knack for getting it across is a gift. I'm 65 years old and always enjoy learning as well as playing around in my shop. Marc, you are awesome!
Sometimes close is good enough.
👌🏼
Clausing colchester made a nice lathe!
As usual Marc, great video!!! Thankyou for being so clear!!! Regards
carlos
There is a way to thread on a lathe that has no thread dial. Works even if the lathe does not have a reversing switch, and if I understood the guy correctly, it works on lathes that are using conversion gearing (imperial cutting metric or metric cutting imperial). A bit more involved in setup and use, but it works. Timing marks on the head stock/chuck, and on the feed screw, and a starting position mark for the carriage on the bed. One of your Countrymen demonstrated this method, some time back, it shouldn't be hard to find his video
I thought of a way for getting a correct thread depth on a part that I could not do a "test fit" on, and I don't have thread gauge wires ... I tried it once, it worked once. It I can repeat that, I'll try to put it out there for others to try.
Thank you!
Allo Marc; Joe Pi showed cutting threads while running in reverse, cutting on the 'far side's of the part...same benefits as you showed with LH threading, but RH thread...
Hey Marc. Not related to threading but I really enjoyed your Heat Treatment of Steels 1, Hardening, Tempering. Have you ever considered doing something similar but for stainless?
I’ve always wanted to know more about the size hole to start with for tapping. Some hard materials might use a larger hole than the charts or some larger diameters with fine thread need a larger hole and I don’t know how to choose.
Marc, can/will you make a video to answer Mark's question? I've always just guessed at hole sizes when I didn't have the correct drill and have gotten away with it, but I'd also like to hear your thoughts on doing this, along with the answer(s) to Mark's question.
Some rules of thumb: A 100% thread is only 5% stronger than a 75% thread but takes twice the power to tap. A standard grade bolt screwed into a part to a depth of the bolt's diameter will break before it strips out a 50% thread in mild steel. 100% threads are useful on very thin stock. For tough materials like stainless steel,etc. a 60% thread is fine and 50% would be satisfactory.
I have a tap drill chart that goes down to 50% for tap drills, but I've had it for 40 years and I can't remember where it came from. You can probably find a formula on line for figuring it out and maybe a chart already done.
If you can't find one, let me know and I'll make a copy of mine and send it to you.
Cheers from NC/USA
Marc, were you at NRC in Ottawa? I know a couple of people in the light/illumination area, there...
Yes! I was at U66 for 9 years in the eighties! Great bunch of people, I had a great time and learnt so much.
Flanc (fr) = Flank (en)
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